Advertisements
Feeds:
Posts
Comments

Posts Tagged ‘Sepsis’


Cheetah Medical Introduces New Algorithm for Fluid Management

Reporter: Lawrence J Mulligan, PhD

 

Cheetah Medical Advances the Science of Fluid Management

Cheetah Medical is the pioneer and leading global provider of 100% noninvasive hemodynamic monitoring technologies that are designed for use in critical care, OR and emergency department settings. The CHEETAH NICOM™ and STARLING™ SV technologies use a proprietary algorithm to calculate parameters related to the volume of blood and the functioning of patients’ circulatory systems. Medical professionals use this information to assess patients’ unique volume requirements, guide volume management decisions and maintain adequate organ perfusion. Cheetah Medical technologies are designed to enable more confident, informed therapy decisions that support clinical goals of improving patient outcomes and driving economic efficiencies.

NEWTON, Mass. –(BUSINESS WIRE)– Cheetah Medical announced today that its eighth abstract on fluid management will be presented at Society of Critical Care Medicine meeting in January. Building on previous work, this abstract demonstrates a strong association between large volume fluid administration in septic shock and increased risk of death in more than 23,000 patients.

Each year, millions of patients require hemodynamic monitoring to ensure optimal volume and perfusion management. While intravenous fluid is typical first-line therapy for many critical care situations, volume management has been a challenge for the healthcare community. It is often difficult for a clinician to know the right amount of fluid to administer to patients, and there are serious complications associated with both under and over resuscitation.

“Ever since we’ve been using intravenous fluid, clinicians have been asking, ‘What is the right amount?’” said Doug Hansell, MD and Cheetah’s Chief Physician Executive. “Today, with non-invasive Cheetah technology, we have new tools to answer this question, and we are learning that getting this question right is more important than ever.”

Cheetah Medical has been working with leading researchers using a large U.S. dataset to better understand the risks and benefits of fluid administration. During the past two years, researchers have now released eight clinical abstracts on the importance of fluid management.

  • FLUID ADMINISTRATION IN SEPSIS AND SEPTIC SHOCK – PATTERNS AND OUTCOMES: Sepsis and septic shock is a huge national priority, as it is the most expensive condition to treat, at $24 billion per year (AHRQ). This study identified a strong association between large fluid administration (more than five liters) and excess mortality in septic shock patients. As expected, sicker patients received more fluid. However, even after accounting for the severity of illness, these patients had an increased risk of dying. (Society of Critical Care Medicine Annual Conference, January 2017)
  • FLUID ADMINISTRATION IN OPEN AND LAPAROSCOPIC ABDOMINAL SURGERY: The study looked at the relationship between intraoperative fluid therapy and complications following abdominal surgery.Based on data from 18,633 patients, an increase in complications was found with day-of-surgery fluid use above five liters for open abdominal procedures. The study recommended individualized fluid therapy to reduce potentially negative effects from over/under resuscitation with intravenous fluids. (American Society of Anesthesiologists [ASA] 2016 Annual Meeting)
  • FLUID PRESCRIPTIONS IN HOSPITALIZED PATIENTS WITH RENAL FAILURE: The implication of volume resuscitation and potential complications among patients with acute kidney injuries (AKIs) has been widely debated. This study examined the relationship between fluid administration and outcomesamong 62,695 AKI patients. It found the potential for both under and over resuscitation in those who received treatments with vasopressors. A better understanding of individual fluid needs was seen for patients requiring pressor and mechanical ventilation support. (European Society of Intensive Care Medicine [ESICM] Annual Congress, 2016)
  • EFFECTS OF FLUIDS ADMINISTRATION IN PATIENTS WITH SEPTIC SHOCK WITH OR WITHOUT HEART FAILURE (HF): The study examined the relationship between indications of fluid overload in sepsis patients (with or without diastolic HF) and outcomes. For 29,098 patients, mortality was the highest among those who received the highest volumes of fluid. It also noted that patients with diagnosed diastolic HF received less fluids and exhibited a significantly lower mortality than predicted. These lower mortality rates could be a result of a more conservative fluid treatment strategy applied in patients known to be at risk for fluid overload. (American Thoracic Society [ATS] 2016 International Conference)
  • WIDE PRACTICE VARIABILITY IN FLUID RESUSCITATION OF CRITICALLY ILL PATIENTS WITH ARDS: The study looked at how variable fluid resuscitation testing and treatments impacted the outcomes of patients with acute respiratory distress syndrome (ARDS). An analysis of 1,052 patients highlighted a highly variable fluid resuscitation. The findings suggest a widespread variability in provider decision-making regarding fluid resuscitation, which may be detrimental to quality and costs, lowering the overall value of care. (American Thoracic Society [ATS] 2016 International Conference)
  • POTENTIAL HARM ASSOCIATED WITH SEVERITY-ADJUSTED TREATMENT VARIABILITY IN FLUID RESUSCITATION OF CRITICALLY ILL SEPTIC PATIENTS: The study set out to determine treatment variability for patients with severe sepsis and how it may impact mortality. Retrospectively analyzing 77,032 patients, a high degree of treatment variability was found for fluid resuscitation, with a range of 250 ml to more than 7L of fluid administered. For patients who received less fluid, there was no increased risk of mortality. In those who received the most fluid, there was a strong association with worse hospital mortality. (American Thoracic Society [ATS] 2016 International Conference)
  • ASSOCIATION OF FLUIDS AND OUTCOMES IN EMERGENCY DEPARTMENT PATIENTS HOSPITALIZED WITH COMMUNITY-ACQUIRED PNEUMONIA (CAP): Analyzing 192,806 CAP patients, the study looked at the correlation between fluid-volume overload, hospital mortality and ventilator-free days (VFDs). A significant association was found between the amount of fluid administered on day one, increased mortality and decreased VFDs. The study may have also identified a subset of CAP patients who could benefit from a more restrictive fluid strategy. (36thInternational Symposium on Intensive Care and Emergency Medicine)
  • FLUID ADMINISTRATION IN COMMUNITY-ACQUIRED SEPSISEXAMINATION OF A LARGE ADMINISTRATIVE DATABASE: The study looked at variation in fluid administration practices and compliance with “Surviving Sepsis” guidelines, which recommend a minimum initial fluid administration of 30cc/kg in sepsis-induced tissue hypoperfusion patients. It found that a substantial proportion of patients (47.4 %) with community-acquired sepsis received less than the recommended guidelines within the first 24 hours. (Society of Critical Care Medicine Annual Conference, 2016)

“We are very proud to have supported this work – we are advancing the science of fluid management and helping to improve our understanding of how better fluid management may improve patient outcomes,” said Chris Hutchison, CEO of Cheetah Medical.

 

SOURCE

https://www.cheetah-medical.com/cheetah-medical-advances-science-fluid-management/

 

Other related articles published in this Open Access On-line Scientific Journal includes the following:

Advertisements

Read Full Post »


Rapid diagnosis of septicemia

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Rapid Diagnosis of Infection in the Critically Ill, a Multicenter Study of Molecular Detection in Bloodstream Infections, Pneumonia, and Sterile Site Infections

Jean-Louis Vincent,  David Brealey, Nicolas Libert, Nour Elhouda Abidi, Michael O’Dwyer, Kai Zacharowski, Malgorzata Mikaszewska-Sokolewicz, et al.
Crit Care Med. 2015;43(11):2283-2291.     http://www.medscape.com/viewarticle/853105

Objective: Early identification of causative microorganism(s) in patients with severe infection is crucial to optimize antimicrobial use and patient survival. However, current culture-based pathogen identification is slow and unreliable such that broad-spectrum antibiotics are often used to insure coverage of all potential organisms, carrying risks of overtreatment, toxicity, and selection of multidrug-resistant bacteria. We compared the results obtained using a novel, culture-independent polymerase chain reaction/electrospray ionization-mass spectrometry technology with those obtained by standard microbiological testing and evaluated the potential clinical implications of this technique.

Design: Observational study.

Setting: Nine ICUs in six European countries.

Patients: Patients admitted between October 2013 and June 2014 with suspected or proven bloodstream infection, pneumonia, or sterile fluid and tissue infection were considered for inclusion.

Interventions: None.

Measurements and Main Results: We tested 616 bloodstream infection, 185 pneumonia, and 110 sterile fluid and tissue specimens from 529 patients. From the 616 bloodstream infection samples, polymerase chain reaction/electrospray ionization-mass spectrometry identified a pathogen in 228 cases (37%) and culture in just 68 (11%). Culture was positive and polymerase chain reaction/electrospray ionization-mass spectrometry negative in 13 cases, and both were negative in 384 cases, giving polymerase chain reaction/electrospray ionization-mass spectrometry a sensitivity of 81%, specificity of 69%, and negative predictive value of 97% at 6 hours from sample acquisition. The distribution of organisms was similar with both techniques. Similar observations were made for pneumonia and sterile fluid and tissue specimens. Independent clinical analysis of results suggested that polymerase chain reaction/electrospray ionization-mass spectrometry technology could potentially have resulted in altered treatment in up to 57% of patients.

Conclusions: Polymerase chain reaction/electrospray ionization-mass spectrometry provides rapid pathogen identification in critically ill patients. The ability to rule out infection within 6 hours has potential clinical and economic benefits.

Introduction

The availability of rapid and reliable infectious disease diagnostics that can provide results directly from patient specimens represents a major unmet need in managing critically ill patients. Current sepsis guidelines recommend initiation of IV antibiotic therapy as early as possible, ideally within the first hour,[1] as any delay in effective antimicrobial therapy may result in decreased survival.[2] Effective therapy requires that the identity of causative pathogens and their resistance patterns are known. However, the current standard-of-care, which depends on blood culture-based initial diagnosis, often takes at least 48–72 hours to provide a result. Furthermore, cultures often remain negative even when bacterial or fungal infections are strongly suspected,[3] in part, related to concurrent antibiotic treatment.[4]

Molecular diagnostic techniques that do not depend on growth of organisms in culture may offer a distinct advantage over current methods. Most of the recently described molecular methods, however, rely on culture amplification as a precursor to diagnosis.[5–8] Although these techniques may accelerate diagnosis for positive cultures, they do not address the significant proportion of false-negative cultures observed in patients with sepsis. In addition, many of these methods also use targeted pathogen detection with limited pathogen coverage such that negative results are often not highly predictive.

Polymerase chain reaction followed by electrospray ionization-mass spectrometry (PCR/ESI-MS) can detect more than 800 bloodstream infection (BSI)-relevant pathogens in a single assay and in approximately 6 hours.[9–13] It can also identify three classes of antibiotic resistance markers associated with resistance to methicillin (mecA), vancomycin (vanA/vanB), and carbapenems (KPC). Using this technique, we recently demonstrated 83% sensitivity and 94% specificity compared with culture for direct detection of pathogens in whole-blood specimens from patients with suspected BSIs.[13]

Here, we describe findings from the multicenter observational Rapid Diagnosis of Infections in the Critically Ill (RADICAL) study. The primary objective was to compare results obtained using the novel culture-independent PCR/ESI-MS technology with those obtained from standard microbiological testing as a measure of clinical performance. Secondarily, to broadly address the clinical value of PCR/ESI-MS detections, a panel of independent clinical adjudicators was used to identify changes in patient management that may have occurred had the results from the PCR/ESI-MS technology been available for clinical use and assumed to be correct.

Patient Inclusion and Exclusion Criteria

Patients were considered for inclusion if they had 1) suspected or proven severe infection or sepsis and or 2) suspected or proven healthcare-associated pneumonia (HAP/HCAP), ventilator-associated pneumonia (VAP), or severe community-acquired pneumonia (sCAP). Because pneumonia is the most common precipitating cause of sepsis, there may be an overlap between these two populations, but patients were included in one of the two groups, not both. Pneumonia (HAP/HCAP, VAP, and sCAP) was diagnosed in patients with an endotracheal tube in situ and a new infiltrate on chest radiograph plus temperature more than 38°C or less than 35°C, increased sputum production, increased or decreased WBC count (> 12 or < 4 cells/mL3), or a clinical suspicion of pneumonia, and the treating clinician expected the patient to still be intubated the next day.

The following exclusion criteria were used: the treating clinician expected the patient to be discharged from the ICU on the day of evaluation or the following day, the treatment intent was palliative, the clinician was not committed to aggressive treatment, or death was deemed imminent and inevitable. Patients who had previously been included, but were readmitted to the ICU during the same hospitalization, were not included a second time.

 

Data Analysis

Results obtained with the PCR/ESI-MS technology for each specimen were compared with those obtained using conventional microbiology methods for the same sample. If multiple specimens were taken from a patient per standard-of-care protocols, each was independently analyzed in this study. Agreement and concordance were assessed using a McNemar test[16] and Cohen κ.[17] All percentages and CIs for proportions were calculated using the exact method and are rounded to the nearest percentage. Direct comparison of positive and negative results was conducted with organism identification for each method (conventional microbiology vs PCR/ESI-MS) for each specimen type. Coagulase-negative staphylococcus and other common skin contaminants were annotated as “potential contaminants” for both methods and excluded from the overall analysis, as previously described.[13]

Discrepant results between the PCR/ESI-MS and culture cannot be directly confirmed by an independent method, as previously described.[13] Two approaches were used to resolve discrepancies. In a subset of patients, multiple samples were collected per standard-of-care. This included two independent fresh venipunctures (left arm vs right arm) or one venipuncture plus one sample collected from an indwelling line. Paired analysis of PCR/ESI-MS testing results between these independently collected samples was conducted to indicate the likelihood of true infection. In addition, independent clinical adjudication (described below) was performed using all the clinical data collected as part of the study, including standard-of-care microbiology results and PCR/ESI-MS results.

 

Results

Of 543 patients enrolled in the study, 14 did not have matching PCR/ESI-MS or standard-of-care microbiology results and were excluded from the final analysis. Table 1 shows the patient demographics, reflecting a typically heterogeneous ICU population: one third of the patients were admitted from the emergency department; 75% were exposed to one or more antibiotics prior to study enrolment. Overall mortality was 29%, with cardiac arrest, septic shock, multiple organ failure, and acute respiratory distress syndrome accounting for ~62% of deaths.

BSI Analysis

A total of 616 direct whole-blood specimens from the 529 patients were tested to assess the accuracy of organism identification. PCR/ESI-MS results from analysis of blood using the bacteria, antibiotic resistance, and Candida BSI assay were compared with results from standard clinical microbiology cultures. As shown in Table 2, there were 228 PCR/ESI-MS positive specimens (36.5%) for at least one pathogen compared with 68 positive specimens by culture (10.9%). The total number of positive tests for each method was statistically different (McNemar test statistic = 137.6; df = 1; p < 0.0001). There were 55 samples that were positive for the same organism with both techniques (Table 2), yielding an overall concordance of identification (calculated sensitivity) of 81% (95% CI, 70–89%) and a κ value of 0.25 (95% CI, 0.18–0.31). In 13 instances, culture identified an organism that was either negative by PCR/ESI-MS (6/13) or the identity of the organism reported by PCR/ESI-MS did not match the organism identified by microbiology testing (7/13) (Table S1, Supplemental Digital Content 1,http://links.lww.com/CCM/B418). In contrast, PCR/ESI-MS reported a BSI-relevant organism in 173 additional specimens that were culture negative, resulting in a calculated assay specificity of 69% (Table S2, Supplemental Digital Content 1, http://links.lww.com/CCM/B418). Finally, there were 384 concordant negative specimens, yielding a negative predictive value (NPV) of ~97% (95% CI, 94–98%).

The frequencies of organisms detected from BSI specimens are shown in Figure 1. The distributions of the top 10 species detected by microbiology and those detected by PCR/ESI-MS were similar. The largest single discrepancy between the two methods by sheer volume of detections was in the identification of Escherichia coli. Although culture and PCR/ESI-MS techniques both reported E. coli as the most abundant species, PCR/ESI-MS detection was 4-fold higher (89 vs 21). Other organisms in which blood culture performed less well included the enterococcus species, Enterococcus faecalis (1 vs 10) and Enterococcus faecium (2 vs 25), Candida albicans (2 vs 13), and Staphylococcus aureus (14 vs 31). In contrast, Pseudomonas aeruginosa detection was comparable between the two methods (6 vs 8). Additional analysis of the PCR/ESI-MS results showed that the levels (genome equivalent/mL) of organisms reported in the majority of these PCR/ESI-MS positive, but culture-negative, cases were similar to cases in which culture matched PCR/ESI-MS detections (data not shown).

Figure 1.

http://img.medscape.com/article/853/105/853105-fig1.jpg

Bacteria and Candida detected in the Rapid Diagnosis of Infections in the Critically Ill (RADICAL) study. Distribution of organisms reported by polymerase chain reaction/electrospray ionization-mass spectrometry (PCR/ESI-MS) (blue bar) and culture (red bar) observed in the RADICAL study are shown, sorted by decreasing order of PCR/ESI-MS reported organisms. Both methods showed similar distribution for the top eight reportable organisms that were seen >5 times by PCR/ESI-MS, with some minor reshuffling of the order. PCR/ESI-MS showed a longer tail of reportable organisms that were infrequent (≤5 times). Normal skin flora are shown below the line were not included in further analysis by either method.

 

Nonbloodstream Infections

Heterogeneous samples from patients with suspected pneumonia or sterile site infections were also obtained in several cases. Overall, there were 185 LRT samples (88 BAL, 96 ETA, and 1 other) and 110 SF&T samples (36 intraperitoneal fluid, 14 pleural fluid, 11 CSF, 13 tissue, and 36 other fluid types). Results from the analysis of these specimens are shown in Table 3. LRT and SF&T specimens often had multiple detections reported by both methods in several samples. Only the primary detections by either method were included in the analysis. The overall sensitivities for concordance between standard-of-care and PCR/ESI-MS were 84% (95% CI, 74–91%) and 85% (95% CI, 72–93%), respectively. As for the bloodstream infection data, the McNemar test for both the LRT and the SF&T sample data showed that the total number of samples considered positive was significantly different for culture versus PCR/ESI-MS (McNemar test statistic = 20.9 for LRT and 15.2 for SF&T; p < 0.0001 in both cases). Also similar to the bloodstream infection data, there was more agreement in the contingency table comparing culture to PCR/ESI-MS than would be expected by chance (LRT κ = 0.35; 95% confidence limits, 0.23, 0.47 and SF&T κ = 0.27; 95% confidence limits, 0.11, 0.43). For LRT specimens, there was no statistically significant difference in sensitivity (p = 0.677) or specificity (p = 0.444) when testing the hypothesis that the BAL proportion – the ETA proportion was equal to zero.

In 151 patients, two or more specimen types (BSI plus LRT and/or SF&T) were obtained and analyzed. In 86 of these 151 cases (57%), the same organisms were reported by PCR/ESI-MS in all samples tested from an individual patient (data not shown). In comparison, culture concordance between the sample types was seen in only 19 cases (12%), driven largely by no detection reported in the BSI culture results.

Resistance Markers

There were no identified cases of Klebsiella-associated carbapenemase. There was a single report of vancomycin-resistant Enterococci, which was matched across the two methods. There were 23 reports of mecA+ staphylococcus organisms (seven in BSI samples, 13 in LRT samples, and three in SF&T samples), with the following agreement between PCR/ESI-MS and culture: for BSI samples, results were concordant in four cases, and PCR/ESI-MS was positive and culture negative in three; for LRT samples, results were concordant in three cases, PCR/ESI-MS was positive with culture negative in nine, and PCR/ESI-MS was negative with culture positive in one; and the three cases in the SF&T samples were concordant across PCR/ESI-MS and culture.

 

 

Discussion

The important findings of the RADICAL study are that PCR/ESI-MS detected BSI pathogens with high overall sensitivity and NPV; PCR/ESI-MS was three times more likely to identify an organism than standard culture; and, if available, PCR/ESI-MS results may have altered the treatment regimen in as many as 57% of patients.

Sepsis affects a large proportion of the critically ill population. Despite improvements in recent years, morbidity and mortality rates remain high.[18] The importance of initiating treatment as soon as possible has been highlighted and shown to be associated with improved outcomes,[2] yet this finding needs to be balanced against the direct risks and stewardship issues arising from overzealous or inappropriate antibiotic use.

Rapid diagnosis of severe infection or sepsis is thus crucial not only to optimize a patient’s chances of survival but also to encourage responsible antibiotic use. However, diagnosing infection accurately in critically ill patients is challenging. Characteristic clinical and laboratory signs of severe infection, such as tachycardia, fever, and altered WBC count, are nonspecific and are often present in other acute conditions. Biomarkers, such as C-reactive protein and procalcitonin, are also nonspecific and are of more value in ruling out infection than in making a definite diagnosis.[19] Microbiological culture results are negative in many patients with sepsis, largely because prior antimicrobial therapy affects ex vivo growth in culture medium.[1] Certain microorganisms are also particularly difficult to culture, requiring specific growth media or a particular environment. As culture results often require several days to become available, patients with suspected severe infection are, therefore, often started on empiric broad-spectrum antibiotics to increase the likelihood that a pathogenic organism will be adequately covered. This approach, although valid in terms of preventing delays in starting treatment with currently available diagnostic techniques, has several negative aspects, including the potential for toxicity with multiple antibiotics, the high-associated costs, and the effects of antibiotic pressure on the development of antimicrobial resistance.[20]

Availability of a technique that could provide more rapid pathogen identification directly from patient samples could, therefore, represent a marked improvement in terms of enabling more rapid diagnosis and earlier initiation of appropriate antimicrobial therapy, with associated beneficial effects on outcomes, antimicrobial resistance, costs, and toxicity. Various methods have been suggested for this purpose, including single pathogen assays, which are of limited use in patients with suspected sepsis in whom multiple organisms may be involved; selected-pathogen assays, which use specific molecular targets to identify some 20–35 species;[21–23] and broad-range pathogen assays, which use universal or conserved targets to identify many hundreds of species, but for which earlier versions lacked sensitivity due to the small volumes of blood extracted for analysis.[24,25]

 

Importantly, in 41% of cases, the panel of independent experts would have recommended a change in management, including initiation of therapy, altered antimicrobial spectrum, and/or change in duration of therapy, based on the PCR/ESI-MS results. This percentage increased to 57 when PCR/ESI-MS tests were positive.

Second, the greater detection rate of E. coli, S. aureus, E. faecium, C. albicans, and Klebsiella pneumoniae by PCR/ESI-MS compared with routine culture was unanticipated, and the explanation is unclear. Prior to study inclusion, most patients were exposed to combinations of two or more antibiotics active against Gram-positive and Gram-negative organisms and were often receiving one or more antifungals in addition. As stated above, the bacterium/fungus may have been largely cleared with preexisting antibiotics, hence the negative culture results, but remaining DNA remnants in the circulation may have been sufficient to give a positive PCR/ESI-MS. The sensitivity of the technique increases the risk of identifying contaminants and commensals; however, the pathogens most frequently detected in the study are those associated with infection. Accepting the validity of these data, the PCR/ESI-MS test could be of importance to help target antimicrobial therapy in patients who have already started antimicrobials and have negative cultures (salvage microbiology).[29] Further, ideally interventional, studies are warranted to confirm and further explore these findings.

Read Full Post »


Acute Lung Injury

Writer and Curator: Larry H. Bernstein, MD, FCAP 

 

 

Introduction

Acute lung injury is a serious phenomenon only recognized as having significant relevance to allogeneic blood transfusion in the last 15 years.  It is not limited to transfusion events, and is also related to SIRS and sepsis.  It is simulated in experimental models by lipoprotein, such as endotoxin.  It occurs in the pretransfused surgical patient, or in the medical patient as well.  Why it was not recognized earlier is a matter of conjecture.  The significant reduction in immune modulated blood type incompatibility reactions in Western countries is a factor.  The other factor is that the lipoprotein antigenic fractions involved are associated with component transfusions other than stored red cells. The following discussion will elaborate on what is increasingly recognized as a relevant issue in medicine today.
Transfusion Related Reaction

In medicinetransfusion related acute lung injury (TRALI) is a serious blood transfusion complication characterized by the acute onset of non-cardiogenic pulmonary edema following transfusion of blood products.[1]

Although the incidence of TRALI has decreased with modified transfusion practices, it is still the leading cause of transfusion-related fatalities in the United States from fiscal year 2008 through fiscal year 2012.

Transfusion Related Acute Lung Injury

TRALI-Hyaline_membranes_-_very_high_mag

TRALI-Hyaline_membranes_-_very_high_mag

Micrograph of diffuse alveolar damage, the histologic correlate of TRALI. H&E stain. Very high magnification micrograph of hyaline membranes, as seen in diffuse alveolar damage (DAD), the histologic correlate of acute respiratory distress syndrome (ARDS), transfusion related acute lung injury (TRALI), acute interstitial pneumonia (AIP).
http://upload.wikimedia.org/wikipedia/commons/thumb/c/c8/Hyaline_membranes_-_very_high_mag.jpg/1024px-Hyaline_membranes_-_very_high_mag.jpg

TRALI is defined as an acute lung injury that is temporally related to a blood transfusion; specifically, it occurs within the first six hours following a transfusion.[3]

It is typically associated with plasma components such as platelets and Fresh Frozen Plasma, though cases have been reported with packed red blood cells since there is some residual plasma in the packed cells. The blood component transfused is not part of the case definition. Transfusion-related acute lung injury (TRALI) is an uncommon syndrome that is due to the presence of leukocyte antibodies in transfused plasma. TRALI is believed to occur in approximately one in every 5000 transfusions. Leukoagglutination and pooling of granulocytes in the recipient’s lungs may occur, with release of the contents of leukocyte granules, and resulting injury to cellular membranes, endothelial surfaces, and potentially to lung parenchyma. In most cases leukoagglutination results in mild dyspnea and pulmonary infiltrates within about 6 hours of transfusion, and spontaneously resolves;

Occasionally more severe lung injury occurs as a result of this phenomenon and Acute Respiratory Distress Syndrome (ARDS) results. Leukocyte filters may prevent TRALI for those patients whose lung injury is due to leukoagglutination of the donor white blood cells, but because most TRALI is due to donor antibodies to leukocytes, filters are not helpful in TRALI prevention. Transfused plasma (from any component source) may also contain antibodies that cross-react with platelets in the recipient, producing usually mild forms of posttransfusion purpura or platelet aggregation after transfusion.

Another nonspecific form of immunologic transfusion complication is mild to moderate immunosuppression consequent to transfusion. This effect of transfusion is not completely understood, but appears to be more common with cellular transfusion and may result in both desirable and undesirable effects. Mild immunosuppression may benefit organ transplant recipients and patients with autoimmune diseases; however, neonates and other already immunosuppressed hosts may be more vulnerable to infection, and cancer patients may possibly have worse outcomes postoperatively.

http://en.wikipedia.org/wiki/Transfusion-related_acute_lung_injury

 

 

Perioperative transfusion-related acute lung injury: The Canadian Blood Services experience

Asim Alam, Mary Huang, Qi-Long Yi, Yulia Lin, Barbara Hannach
Transfusion and Apheresis Science 50 (2014) 392–398
http://dx.doi.org/10.1016/j.transci.2014.04.008

Purpose: Transfusion-related acute lung injury (TRALI) is a devastating transfusion-associated adverse event. There is a paucity of data on the incidence and characteristics of TRALI cases that occur perioperatively. We classified suspected perioperative TRALI cases reported to Canadian Blood Services between 2001 and 2012, and compared them to non-perioperative cases to elucidate factors that may be associated with an increased risk of developing TRALI in the perioperative setting. Methods: All suspected TRALI cases reported to Canadian Blood Services (CBS) since 2001 were reviewed by two experts or, from 2006 to 2012, the CBS TRALI Medical Review Group (TMRG). These cases were classified based on the Canadian Consensus Conference (CCC) definitions and detailed in a database. Two additional reviewers further categorized them as occurring within 72 h from the onset of surgery (perioperative) or not in that period (non-perioperative). Various demographic and characteristic variables of each case were collected and compared between groups. Results: Between 2001 and 2012, a total of 469 suspected TRALI cases were reported to Canadian Blood Services; 303 were determined to be within the TRALI diagnosis spectrum. Of those, 112 (38%) were identified as occurring during the perioperative period. Patients who underwent cardiac surgery requiring cardiopulmonary bypass (25.0%), general surgery (18.0%) and orthopedics patients (12.5%) represented the three largest surgical groups. Perioperative TRALI cases comprised more men (53.6% vs. 41.4%, p = 0.04) than non-perioperative patients. Perioperative TRALI patients more often required supplemental O2 (14.3% vs. 3.1%, p = 0.0003), mechanical ventilation (18.8% vs. 3.1%), or were in the ICU (14.3% vs. 3.7%, p = 0.0043) prior to the onset of TRALI compared to non-perioperative TRALI patients. The surgical patients were transfused on average more components than non-perioperative patients (6.0 [SD = 8.3] vs. 3.6 [5.2] products per patient, p = 0.0002). Perioperative TRALI patients were transfused more plasma (152 vs. 105, p = 0.013) and cryoprecipitate (51 vs. 23, p < 0.01) than non-perioperative TRALI patients. There was no difference between donor antibody test results between the groups. Conclusion: CBS data has provided insight into the nature of TRALI cases that occur perioperatively; this  group represents a large proportion of TRALI cases.

 

Transfusion-related acute lung injury: a clinical review

Alexander P J Vlaar, Nicole P Juffermans
Lancet 2013; 382: 984–94
http://dx.doi.org/10.1016/S0140-6736(12)62197-7

Three decades ago, transfusion-related acute lung injury (TRALI) was considered a rare complication of transfusion medicine. Nowadays, the US Food and Drug Administration acknowledge the syndrome as the leading cause of transfusion-related mortality. Understanding of the pathogenesis of TRALI has resulted in the design of preventive strategies from a blood-bank perspective. A major breakthrough in efforts to reduce the incidence of TRALI has been to exclude female donors of products with high plasma volume, resulting in a decrease of roughly two-thirds in incidence. However, this strategy has not completely eradicated the complication. In the past few years, research has identified patient-related risk factors for the onset of TRALI, which have empowered physicians to take an individualized approach to patients who need transfusion.

Development of an international consensus definition has aided TRALI research, yielding a higher incidence in specific patient populations than previously acknowledged Patients suffering from a clinical disorder such as sepsis are increasingly recognized as being at risk for development of TRALI. Thereby, from a diagnosis by exclusion, TRALI has become the leading cause of transfusion-related mortality. However, the syndrome is still under diagnosed and under-reported in some countries.

Although blood transfusion can be life-saving, it can also be a life-threatening intervention. Physicians use blood transfusion on a daily basis. Increased awareness of the risks of this procedure is needed, because management of patient-tailored transfusion could reduce the risk of TRALI. Such an individualized approach is now possible as insight into TRALI risk factors evolves. Furthermore, proper reporting of TRALI could prevent recurrence.

Absence of an international definition for TRALI previously contributed to underdiagnosis. As such, a consensus panel, and the US National Heart, Lung and Blood Institute Working Group in 2004, formulated a case definition of TRALI based on clinical and radiological parameters. The definition is derived from the widely used definition of acute lung injury (panel 1). Suspected TRALI is defined as fulfilment of the definition of acute lung injury within 6 h of transfusion in the absence of another risk factor (panel 1).

Although this definition seems to be straightforward, the characteristics of TRALI are indistinguishable from acute lung injury due to other causes, such as sepsis or lung contusion. Therefore, this definition would rule out the possibility of diagnosing TRALI in a patient with an underlying risk factor for acute lung injury who has also received a transfusion. To identify such cases, the term possible TRALI was developed.

Although the TRALI definition is an international consensus definition, surveillance systems in some countries, including the USA, France and the Netherlands, use an alternative in which imputability is scored. Imputability aims to identify the likelihood that transfusion is the causal factor. Imputability scores mostly imply that other causes of acute lung injury can be ruled out, so that diagnosis of TRALI is by exclusion. However, observational and animal studies suggest that risk factors for TRALI include other disorders, such as sepsis. Therefore, an imputability definition would result in underdiagnosis of TRALI. The consensus definition accommodates the uncertainty of the association of acute lung injury to the transfusion in possible TRALI. The conventional definition of TRALI uses a timeframe of 6 h in which acute lung injury needs to develop after a blood transfusion. In critically ill patients, transfusion increases the risk (odds ratio 2·13, 95% CI 1·75–2·52) for development of acute lung injury 6–72 h after transfusion.  However, whether the pathogenesis of delayed TRALI is similar to that of TRALI is unclear.

A two-hit hypothesis has been proposed for TRALI. The first hit is underlying patient factors, resulting in adherence of primed neutrophils to the pulmonary endothelium. The second hit is caused by mediators in the blood transfusion that activate the endothelial cells and pulmonary neutrophils, resulting in capillary leakage and subsequent pulmonary edema. The second hit can be antibody-mediated or non-antibody-mediated.

Panel 1: Definition of transfusion-related acute lung injury (TRALI)

Suspected TRALI

  • Acute onset within 6 h of blood transfusion
    • PaO2/FIO2<300 mm Hg, or worsening of P to F ratio
    • Bilateral infi ltrative changes on chest radiograph
    • No sign of hydrostatic pulmonary oedema (pulmonary arterial occlusion
    pressure ≤18 mm Hg or central venous pressure ≤15 mm Hg)
    • No other risk factor for acute lung injury

Possible TRALI
Same as for suspected TRALI, but another risk factor present for acute lung injury

Delayed TRALI
Same as for (possible) TRALI and onset within 6–72 h of blood transfusion

Pathophysiology of two-hit mediated transfusion-related acute lung injury (TRALI).  The pre-phase of the syndrome consists of a fi rst hit, which is mainly systemic. This first hit is the underlying disorder of the patient (eg, sepsis or pneumonia) causing neutrophil attraction to the capillary of the lung. Neutrophils are attracted to the lung by release of cytokines and chemokines from upregulated lung endothelium. Loose binding by L-selectin takes place. Firm adhesion is mediated by E-selectin and platelet-derived P-selectin and intracellular adhesion molecules (ICAM-1). In the acute phase of the syndrome, a second hit caused by mediators in the blood transfusion takes place. This hit results in activation of inflammation and coagulation in the pulmonary compartment. Neutrophils adhere to the injured capillary endothelium and marginate through the interstitium into the air space, which is filled with protein-rich edema fluid. In the air space, cytokines interleukin-1, -6, and -8, (IL-1, IL-6, and IL-8, respectively) are secreted, which act locally to stimulate chemotaxis and activate neutrophils resulting in formation of the elastase-α1-antitrypsin (EA) complex. Neutrophils can release oxidants, proteases, and other proinflammatory molecules, such as platelet-activating factor (PAF), and form neutrophil extracellular traps (NETs). Furthermore, activation of the coagulation system happens, shown by an increase in thrombin-antithrombin complexes (TATc), as does a decrease in activity of the fibrinolysis system, shown by a reduction in plasminogen activator activity. The influx of protein-rich edema fluid into the alveolus leads to the inactivation of surfactant, which contributes to the clinical picture of acute respiratory distress in the onset of TRALI. PAI-1 = plasminogen activator inhibitor-1.

Antibody-mediated TRALI is caused by passive transfusion of HLA or human neutrophil antigen (HNA) and corresponding antibodies from the donor directed against antigens of the recipient. Neutrophil activation occurs directly by binding of the antibody to the neutrophil surface (HNA antibodies) or indirectly, mainly by binding to the endothelial cells with activation of the neutrophil (HLA class I antibodies) or to monocytes with subsequent activation of the neutrophil (HLA class II antibodies). The antibody titer and the volume of antibody containing plasma both increase the risk for onset of TRALI. Although the role of donor HLA and HNA antibodies from transfused blood is widely accepted, not all TRALI cases are antibody mediated. In many patients, antibodies cannot be detected. Furthermore, many blood products containing antibodies do not lead to TRALI. This finding has led to development of an alternative hypothesis for the onset of TRALI, termed non-antibody-mediated TRALI.

Non-antibody-mediated TRALI is caused by accumulation of proinflammatory mediators during storage of blood products, and possibly by ageing of the erythrocytes and platelets themselves. Although most preclinical studies have noted a positive correlation between storage time of cell-containing blood products and TRALI, the mechanism is controversial. Two mechanisms have been suggested, including either plasma or the aged cells. In a small-case study and animal experiments, accumulation of bioactive lipids and soluble CD40 ligand (sCD40L) in the plasma layer of cell-containing blood products has been associated with TRALI. Bioactive lipids are thought to cause neutrophil activation through the G-protein coupled receptor on the neutrophil.

The two-hit model suggests that patients in a poor clinical state are at risk for development of TRALI. However, cases have been described of antibody-mediated TRALI developing in fairly healthy recipients. To explain this discrepancy, a threshold model has been suggested in which a threshold must be overcome to induce a TRALI reaction. The threshold is dependent both on the predisposition of the patient (first hit) and the quantity of antibodies in the transfusion (second hit). A large quantity of antibody that matches the recipient’s antigen can cause severe TRALI in a recipient with no predisposition.

Threshold model of antibody-mediated transfusion-related acute lung injury (TRALI). A specific threshold must be overcome to induce a TRALI reaction. To overcome a threshold, several factors act together: the activation status of the pulmonary neutrophils at the time of transfusion, the strength of the neutrophil-priming activity of transfused mediators (A), and the clinical status of the patient (B).

Panel 2: Clinical characteristics of transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO)

TRALI
• Dyspnea
• Fever
• Usually hypotension
• Hypoxia
• Leukopenia
• Thrombocytopenia
• Pulmonary edema on chest x-ray
• Normal left ventricular function*
• Normal pulmonary artery occlusion pressure

TACO
• Dyspnea
• Usually hypertension
• Hypoxia
• Pulmonary edema on chest radiographs
• Normal or decreased left ventricular function
• Increased pulmonary artery occlusion pressure
• Raised brain natriuretic peptide

Restrictive transfusion policy

The most effective prevention is a restrictive transfusion strategy. In a randomised clinical trial in critically ill patients, a restrictive transfusion policy for red blood cells was associated with a decrease in incidence of acute lung injury compared with a liberal strategy (7·7% vs 11·4%), suggesting that some of these patients might have had TRALI. The restrictive threshold was well tolerated and has greatly helped in guidance of red blood cell transfusion in the intensive-care unit.

Patient-tailored transfusion policy

Transfusion cannot be avoided altogether. A multivariate analysis in patients in intensive care showed that patient related risk factors contributed more to the onset of TRALI than did transfusion-related risk factors, suggesting that development of a TRALI reaction is dependent more on host factors then on factors in the blood product. Therefore, a patient-tailored approach aimed at reducing TRALI risk factors could be effective to alleviate the risk of TRALI.

Despite limitations of diagnostic tests, TRALI incidence seems to be high in at-risk patient populations. Therefore, TRALI is an underestimated health-care problem. Preventive measures, such as mainly male donor strategies, have been successful in reducing risk of TRALI. Identification of risk factors further improves the risk–benefit assessment of a blood transfusion. Efforts to further decrease the risk of TRALI needs increased awareness of this syndrome among physicians.

 

Transfusion-related acute lung injury: Current understanding and preventive strategies

A.P.J. Vlaar
Transfusion Clinique et Biologique 19 (2012) 117–124
http://dx.doi.org/10.1016/j.tracli.2012.03.001

Transfusion-related acute lung injury (TRALI) is the most serious complication of transfusion medicine. TRALI is defined as the onset of acute hypoxia within 6 hours of a blood transfusion in the absence of hydrostatic pulmonary edema. The past decades have resulted in a better understanding of the pathogenesis of this potentially life-threating syndrome. The present notion is that the onset of TRALI follows a threshold model in which both patient and transfusion factors are essential. The transfusion factors can be divided into immune and non-immune mediated TRALI. Immune-mediated TRALI is caused by the passive transfer of human neutrophil antibodies (HNA) or human leukocyte antibodies (HLA) present in the blood product reacting with a matching antigen in the recipient. Non-immune mediated TRALI is caused by the transfusion of stored cell-containing blood products. Although the mechanisms behind immune-mediated TRALI are reasonably well understood, this is not the case for non-immune mediated TRALI. The increased understanding of pathways involved in the onset of immune-mediated TRALI has led to the design of preventive strategies. Preventive strategies are aimed at reducing the risk to exposure of HLA and HNA to the recipient of the transfusion. These strategies include exclusion of “at risk” donors and pooling of high plasma volume products and have shown to reduce the TRALI incidence effectively.

Studies show that, in at risk patient populations, up to 8% of transfused patients may develop TRALI. Since the syndrome TRALI has been recognized, evidence on the pathogenesis of TRALI has been accumulating. The present notion is that the onset of TRALI follows a threshold model in which both patient and transfusion factors are essential in the development of TRALI. The transfusion factors can be divided into immune and non-immune mediated TRALI. Immune-mediated TRALI is caused by the passive transfer of human neutrophil antibodies (HNA) or human leukocyte antibodies (HLA) present in the blood product, reacting with a matching antigen in the recipient. Non-immune mediated TRALI is caused by the transfusion of stored cell-containing blood products. In recent years, many countries have successfully implemented preventive strategies resulting in a decrease of the incidence of TRALI.

Definition of transfusion-related acute lung injury (TRALI).

  • Acute onset within 6 hours after a blood transfusion
  • PaO2/FiO2 < 300 mmHg
  • Bilateral infiltrative changes on the chest X-ray
  • No sign of hydrostatic pulmonary edema (PAOP < 18 mmHg or CVP < 15 mmHg)
  • No other risk factor for acute lung injury present

Possible TRALI

  • Other risk factor for acute lung injury present

PAOP: pulmonary arterial occlusion pressure; CVP: central venous pressure

The first landmark report creating the basis for the understanding of the pathogenesis of TRALI was published by Popovsky et al. in 1983. They provided evidence on the association between the presence of leucocyte antibodies in the donor serum and onset of acute lung injury in the recipient of the transfusion. It was also recognized that multiparous blood donors whose plasma contained these antibodies represented a potential transfusion hazard. It was this research group that was the first to identify TRALI as a distinct clinical entity. Subsequently, many other authors reported on the association between the presence of HLA or HNA antibodies in donor blood and the onset of TRALI in the recipient.

Although the role of transfused blood donor HLA and HNA antibodies was widely accepted to be involved in the onset of TRALI, not all cases could be explained by this theory. A significant part of reported TRALI cases have no detectable antibodies. Also, many antibody-containing blood products fail to produce TRALI.

The alternative hypothesis proposed by the group of Silliman posed that TRALI is a “two hit” event. The “first hit” is the underlying condition of the patient, resulting in priming of the pulmonary neutrophil. The “second hit” is the transfusion of a blood product causing activation of the neutrophils in the pulmonary compartment, causing pulmonary edema finally resulting in TRALI. The transfusion factors causing the “second hit” are divided in two groups; immune and non-immune mediated TRALI.

The “second hit” is the transfusion itself and is either immune or non-immune mediated TRALI. The mechanisms behind immune-mediated TRALI are widely accepted and proven in both pre-clinical and clinical studies.  The mechanisms involved in non-immune mediated TRALI are less clear.

The role of stored cell-containing blood products in the onset of non-immune TRALI has extensively been studied in preclinical and clinical studies. Although most of the pre-clinical studies find a positive correlation between the transfusion of stored cell-containing blood products in the presence of a “first hit” and the onset of TRALI, the mechanism behind the onset is controversial.

TRALI management consists mainly of preventing future adverse reactions and providing proper incidence estimates. All suspected TRALI cases should be reported to the blood bank for immunologic work-up as it is impossible to distinguish immune-mediated TRALI from non-immune mediated TRALI at bedside. Immunologic work-up includes testing of incompatibility by cross-matching donor plasma against recipient’s leucocytes. A donor with antibodies which are incompatible with the patient is excluded from further donation of blood for transfusion products. Furthermore, it is important to stress that the absence of a positive serologic work-up does not exclude the diagnosis of TRALI. TRALI is a clinical diagnosis and the immunologic work-up can be supportive but is not part of the diagnosis of TRALI. the two-event hypothesis and threshold hypothesis do not exclude the role of antibodies in the occurrence of TRALI in the presence of an inflammatory condition. Thus any patient fulfilling the TRALI definition (including possible TRALI) should be reported to the blood bank for an immunologic work-up of the recipient and the implicated donors on the presence of HLA and HNA antibodies.

Prevention of immune-mediated TRALI is achieved by exclusion of donors proven to have HLA or HNA antibodies in their plasma present or donors “at risk” to have these antibodies present.

  1. Exclusion of HLA or HNA positive donors
  2. Exclusion of donors “at risk” of being HLA or HNA positive
    Female donors – more specifically, multiparous donors
  3. Testing donors for HLA or HNA antibodies
  4. Multiple plasma pooling
    solvent/detergent plasma is produced from multiple donations, leading to an at least 500-fold dilution of a single plasma unit;
    neither HNA nor HLA antibodies are detectable in solvent/detergent fresh frozen plasma.
  5. To prevent non-immune mediated TRALI, the use of fresh blood only has been suggested

Strategies to prevent the onset of TRALI include the exclusion of female plasma donors and the pooling of plasma products. These strategies have already been implemented in some countries resulting in a reduction of the incidence of TRALI.
Transfusion-related immunomodulation (TRIM): An update

Eleftherios C. Vamvakas, Morris A. Blajchman
Blood Reviews (2007) 21, 327–348
http://dx.doi.org:/10.1016/j.blre.2007.07.003

Allogeneic blood transfusion (ABT)-related immunomodulation (TRIM) encompasses the laboratory immune aberrations that occur after ABT and their established or purported clinical effects. TRIM is a real biologic phenomenon resulting in at least one established beneficial clinical effect in humans, but the existence of deleterious clinical TRIM effects has not yet been confirmed. Initially, TRIM encompassed effects attributable to ABT by immunomodulatory mechanisms (e.g., cancer recurrence, postoperative infection, or virus activation). More recently, TRIM has also included effects attributable to ABT by pro-inflammatory mechanisms (e.g., multiple-organ failure or mortality). TRIM effects may be mediated by: (1) allogeneic mononuclear cells; (2) white-blood-cell (WBC)-derived soluble mediators; and/or (3) soluble HLA peptides circulating in allogeneic plasma. This review categorizes the available randomized controlled trials based on the inference(s) that they permit about possible mediator(s) of TRIM, and examines the strength of the evidence available for relying on WBC reduction or autologous transfusion to prevent TRIM effects.

Allogeneic blood transfusion (ABT) may either cause alloimmunization or induce tolerance in recipients. ABTs introduce a multitude of foreign antigens into the recipient, including HLA-DR antigens found on the donor’s dendritic antigen presenting cells (APCs). The presence or absence of recipient HLA-DR antigens on the donor’s white blood cells (WBCs) plays a decisive role as to whether alloimmunization or immune suppression will ensue following ABT. In general, allogeneic transfusions sharing at least one HLA-DR antigen with the recipient induce tolerance, while fully HLA-DR-mismatched transfusions lead to alloimmunization.

In addition to the degree of HLA-DR compatibility between donor and recipient, the immunogenicity of cellular or soluble HLA antigens associated with transfused blood components depends on the viability of the donor dendritic APCs and the presence of co-stimulatory signals for the presentation of the donor antigens to the recipient’s T cells. Nonviable APCs and/or the absence of the requisite co-stimulatory signals result in T-cell unreponsiveness.  Thus, when a multitude of antigens is introduced into the host by an ABT, the host response to some of these antigens is often decreased, and immune tolerance ensues. ABT has been shown to cause decreased helper T-cell count, decreased helper/suppressor T-lymphocyte ratio, decreased lymphocyte response to mitogens, decreased natural killer (NK) cell function, reduction in delayed-type hypersensitivity, defective antigen presentation, suppression of lymphocyte blastogenesis, decreased cytokine (IL-2, interferon-c) production, decreased monocyte/macrophage phagocytic function, and increased production of antiidiotypic and anticlonotypic antibodies.

All these laboratory immune aberrations that indicate immune suppression and occur in transfused patients could potentially be associated with clinically-manifest ABT effects. Thus a variety of beneficial or deleterious clinical effects, potentially attributable to ABT-related immunosuppression, have been described over the last 30 years. The constellation of all such ABT-associated laboratory and clinical findings is known as ABT-related immunomodulation (TRIM). Initially, TRIM encompassed effects attributable to ABT by means of immunologic mechanisms only; however more recently, the term has been used more broadly, to encompass additional effects that could be related to ABT by means of ‘‘proinflammatory’’ rather than ‘‘immunomodulatory’’ mechanisms.

Over 30 years ago, it was reported that pre-transplant ABTs could improve renal-allograft survival in patients who had undergone renal transplantation.  This beneficial immunosuppressive effect of ABT has been confirmed by animal data, observational clinical studies, and clinical experience worldwide, although it has not been proven in randomized controlled trials (RCTs). Before the advent of the AIDS pandemic, it had become standard policy in many renal units to deliberately expose patients on transplant waiting lists to one or more red blood cell (RBC) transfusions.

All the available data considered together indicate that TRIM is most likely a real biologic phenomenon, which results in at least one established beneficial clinical effect in humans, although the available evidence has not yet confirmed  the existence and/or magnitude of the deleterious clinical TRIM effects. In fact, the debate over the existence of such deleterious clinical TRIM effects has been long and sometimes acrimonious.

Many studies tended to indicate that patients receiving perioperative transfusion (compared with those not needing transfusion) almost always had a higher risk of developing postoperative bacterial infection. The studies also indicated that patients receiving ABT differed from those not receiving a transfusion in several prognostic factors that predisposed to adverse clinical outcomes.

The specific constituent(s) of allogeneic blood that mediate(s) either or both the immunomodulatory and the pro-inflammatory effect(s) of ABT remain
(s) unknown, and the published literature suggests that these TRIM effects
may be mediated by: (1) allogeneic mononuclear cells; (2) soluble biologic response modifiers released in a time dependent manner from WBC granules or membranes into the supernatant fluid of RBC or platelet concentrates
during storage; and/or  (3) soluble HLA class I peptides that circulate in allogeneic plasma. If each of these mediators do cause TRIM effects, ABT effects mediated by allogeneic mononuclear cells would be expected to be preventable by WBC reduction (performed either before or after storage of cellular blood components), as well as by autologous transfusion. The ABT effects mediated by soluble HLA peptides circulating in allogeneic plasma would be expected to be preventable only by autologous transfusion.

BENEFICIAL TRIM EFFECTS

  1. Enhanced survival of renal allografts
  2. Reduced recurrence rate of Crohn’s disease

DELETERIOUS

  1. Increased recurrence rate of resected malignancies
  2. Increased incidence of postoperative bacterial infections
  3. Activation of endogenous CMV or HIV infection
  4. Increased short-term (up to 3-month) mortality

Possible mechanisms and mediators of TRIM effects

Although the mechanisms of TRIM have been debated extensively, the exact mechanism(s) of this phenomenon has yet to be elucidated. A number of putative mechanisms have been postulated. The three major mechanisms accounting for much of the experimental data include:

  • clonal deletion,
  • induction of anergy, and
  • immune suppression.

Conceptually, clonal deletion refers to the inactivation and removal of alloreactive lymphocytes that would, for example, cause the rejection of an allograft; anergy implies immunologic nonresponsiveness; and immune suppression suggests that the responding cell is being inhibited of doing so by a cellular mechanism or by a cytokine. Antiidiotypic antibodies, which are predominantly of the VH6 gene family, have also been demonstrated in the sera of ABT recipients and in patients with long-term functioning renal allografts.

To date, no RCT has enrolled patients with sarcomas—tumors whose growth is stimulated by TGF-β—or patients with tumors for which the immune response plays a major role. (These would include skin tumors—such as melanomas, keratoacanthomas, squamous and basal-cell carcinomas—and certain virus-induced tumors—notably Kaposi’s sarcoma and certain lymphomas.) Instead, the 3 available RCTs of ABT and cancer recurrence enrolled patients with colorectal cancer—a tumor that is not sufficiently antigenic to render an impairment of host immunity capable of facilitating tumor growth, and a tumor whose cells have not been shown to be stimulated by TGF-β.

Fig not shown. Randomized controlled trials (RCTs) investigating the association of WBC-containing allogeneic blood transfusion (ABT) with cancer recurrence. For each RCT, the figure shows the odds ratio (OR) of cancer recurrence in recipients of non-WBC-reduced allogeneic versus autologous or WBC-reduced allogeneic RBCs, as calculated from an intention-to-treat analysis. A deleterious effect of ABT (and thus a benefit from autologous transfusion or WBC reduction) exists when the OR is greater than 1 as well as statistically significant. (In the figure, each OR is surrounded by its 95% confidence interval [CI]; if the 95% CI of the OR includes the null value of 1, the TRIM effect is not statistically significant [p > 0.05]).

Fig not shown. Randomized controlled trials (RCTs) investigating the association of WBC-containing allogeneic blood transfusions with postoperative infection (n = 17). For each RCT, the figure shows the odds ratio (OR) of postoperative infection in recipients of non-WBC reduced allogeneic versus autologous or WBC-reduced allogeneic RBCs, as calculated from an intention-to-treat analysis. A deleterious effect of ABT (and thus a benefit from autologous transfusion or WBC reduction) exists when the OR is greater than 1 as well as statistically significant. (In the figure, each OR is surrounded by its 95% confidence interval [CI]; if the 95% CI of the OR includes the null value of 1, the TRIM effect is not statistically significant [p > 0.05]).

The totality of the evidence from RCTs does not demonstrate a TRIM effect manifest across all clinical settings and transfused RBC products. Instead, WBC-containing ABT is associated with an increased risk of short-term (up to 3-month post transfusion) mortality from all causes combined specifically in cardiac surgery. The additional deleterious TRIM effect detected by the latest meta-analysis (i.e., the effect on postoperative infection prevented by poststorage filtration) contradicts current theories about the pathogenesis of TRIM, because it is not accompanied by a similar or larger effect prevented by prestorage filtration.

Thus, only in cardiac surgery (Fig. 5 – not shown) are the findings of RCTs pertaining to a deleterious TRIM effect consistent. Even in this setting, however, the reasons for the excess deaths attributed to WBC containing ABT remain elusive. The initial hypothesis suggested that WBC-containing ABT may predispose to MOF which, in turn, may predispose to mortality. However, hitherto, no cardiac-surgery RCT has demonstrated an association between WBC-containing ABT and MOF, and no other cause of death specifically attributed to WBC-containing ABT has been proposed.

The TRIM effect seen in cardiac surgery deserves further study to pinpoint the cause(s) of the excess deaths, but-now that the majority of transfusions in Western Europe and North America are WBC reduced- the undertaking of further RCTs comparing recipients of non-WBC-reduced versus WBC reduced allogeneic RBCs in cardiac surgery is unlikely. For countries that have not yet converted to universal WBC reduction, whether to opt for WBC reduction of all cellular blood components transfused in cardiac surgery-in the absence of information on the specific cause(s) of death ascribed to WBC-containing ABT-is a policy decision that will have to be made based on the hitherto available data.

 

Regulation of alveolar fluid clearance and ENaC expression in lung by exogenous angiotensin II

Jia Denga, Dao-xin Wanga, Wang Deng, Chang-yi Li, Jin Tong, Hilary Ma
Respiratory Physiology & Neurobiology 181 (2012) 53– 61
http://dx.doi.org:/10.1016/j.resp.2011.11.009

Angiotensin II (Ang II) has been demonstrated as a pro-inflammatory effect in acute lung injury, but studies of the effect of Ang II on the formation of pulmonary edema and alveolar filling remains unclear. Therefore, in this study the regulation of alveolar fluid clearance (AFC) and the expression of epithelial sodium channel (ENaC) by exogenous Ang II was verified. SD rats were anesthetized and were given Ang II with increasing doses (1, 10 and 100 [1]g/kg per min) via osmotic minipumps, whereas control rats received only saline vehicle. AT1 receptor antagonist ZD7155 (10 mg/kg) and inhibitor of cAMP degeneration rolipram (1 mg/kg) were injected intraperitoneally 30 min before administration of Ang II. The lungs were isolated for measurement of alveolar fluid clearance. The mRNA and protein expression of ENaC were detected by RT-PCR and Western blot. Exposure to higher doses of Ang II reduced AFC in a dose-dependent manner and resulted in a non-coordinate regulation of α-ENaC vs the regulation of β- and ϒ-ENaC, however Ang II type 1 (AT1) receptor antagonist ZD7155 prevented the Ang II-induced inhibition of fluid clearance and dysregulation of ENaC expression. In addition, exposure to inhibitor of cAMP degradation rolipram blunted the Ang II-induced inhibition of fluid clearance. These results indicate that through activation of AT1 receptor, exogenous Ang II promotes pulmonary edema and alveolar filling by inhibition of alveolar fluid clearance via downregulation of cAMP level and dysregulation of ENaC expression.

Effects of angiotensin II (Ang II) receptor antagonists and rolipram  on AFC

Effects of angiotensin II (Ang II) receptor antagonists and rolipram on AFC

Effects of angiotensin II (Ang II) receptor antagonists and rolipram on rat alveolar fluid clearance (AFC). Then AFC was measured 1 h after fluid instillation (4 mL/kg). Amiloride (100 [1]M), Ang II (10−7 M), ZD7155 (10−6 M), and rolipram (10−5 M) were added to the instillate as indicated (n = 10 per group). Mean values ± SEM. p < 0.01 vs control. p < 0.01 vs Ang II + ZD7155.
p < 0.05 vs amiloride. p < 0.05 vs Ang II.

Effects of angiotensin II (Ang II) on cyclic adenosine monophosphate (cAMP)

Effects of angiotensin II (Ang II) on cyclic adenosine monophosphate (cAMP)

Effects of angiotensin II (Ang II) on cyclic adenosine monophosphate (cAMP) concentration in lung. Rats were given saline or Ang II (1, 10 and 100 µg/kg per min) for 6 h, and cAMP in lung was determined by RIA (n = 30 per group). Mean values ± SEM. p < 0.01 vs control. p < 0.05 vs 10 µg/kg Ang II.

Histological examination of lung

Histological examination of lung

Histological examination of lung. Rats were given saline or Ang II (10 µg/kg per min) by osmotic minipump for 6 h. ZD7155 (10 mg/kg) was injected intraperitoneally 30 min before administration of Ang II. Shown are representative lung specimens obtained from the control (A), Ang II (B) and Ang II + ZD7155 (C) groups. All photographs are at 100× magnification. Interstitial edema and inflammatory cell infiltration were seen in Ang II group, but reduced in Ang II + ZD7155 group.
The present results demonstrate that Ang II infusion is associated with pulmonary edema and alveolar filling. Three important findings were observed:

(1) high doses of Ang II led to reduction of alveolar fluid clearance, and this effect was blunted by an AT1 receptor antagonist.
(2) Ang II infusion increased the abundance of α-ENaC, whereas decreased the abundance ofβ and ϒ-ENaC, and these effects were reversed in response to an AT1 receptor antagonist.
(3) Ang II infusion decreased cAMP concentration in lung tissue, and an inhibitor of cAMP degradation prevented inhibition of alveolar fluid clearance by Ang II, but had no effect on the dysregulation of ENaC.

Our data indicate that Ang II results in pulmonary edema by inhibition of alveolar fluid clearance via down-regulation of cellular cAMP level and dysregulation of the abundance of ENaC, whereas these effects are prevented by an AT1 receptor antagonist.

The renin-angiotensin system is a major regulator of body fluid and sodium balance, predominantly through the actions of its main effector Ang II. Several previous experimental studies demonstrated that plasma Ang II levels vary in both physiological and pathological conditions. In the kidney, Ang II added to the peritubular perfusion has a biphasic action with stimulation of sodium reabsorption at low doses (10−12–10−10M) and inhibition at high doses (10−7–10−6M) (Harris and Young, 1977). In vitro, Ang II also exerts a dose-dependent dual action on intestinal absorption (Levens, 1985). The evidence shows that the effect of Ang II on sodium and water absorption is dose-dependent. Our results showed that low intravenous doses of Ang II (<1 µg/kg per min) had no effect on alveolar fluid clearance which represents the sodium and water reabsorption in alveoli. However, with high intravenous doses, Ang II decreased alveolar fluid clearance. This finding suggests that the effect of Ang II on fluid absorption in lung is also dose-dependent.

 

Rat models of acute lung injury: Exhaled nitric oxide as a sensitive,noninvasive real-time biomarker of prognosis and efficacy of intervention

Fangfang Liu, Wenli Lib, Jürgen Pauluhn, Hubert Trübel, Chen Wang
Toxicology 310 (2013) 104– 114
http://dx.doi.org/10.1016/j.tox.2013.05.016

Exhaled nitric oxide (eNO) has received increased attention in clinical settings because this technique is easy to use with instant readout. However, despite the simplicity of eNO in humans, this endpoint has not frequently been used in experimental rat models of septic (endotoxemia) or irritant acute lung injury (ALI). The focus of this study is to adapt this method to rats for studying ALI-related lung disease and whether it can serve as instant, non-invasive biomarker of ALI to study lung toxicity and pharmacological efficacy. Measurements were made in a dynamic flow of sheath air containing the exhaled breath from spontaneously breathing, conscious rats placed into a head-out volume plethysmograph. The quantity of eNO in exhaled breath was adjusted (normalized) to the physiological variables (breathing frequency, concentration of exhaled carbon dioxide) mirroring pulmonary perfusion and ventilation. eNO was examined on the instillation/inhalation exposure day and first post-exposure day in Wistar rats intratracheally instilled with lipopolysaccharide (LPS) or single inhalation exposure to chlorine or phosgene gas. eNO was also examined in a Brown Norway rat asthma model using the asthmagen toluene diisocyanate (TDI). The diagnostic sensitivity of adjusted eNO was superior to the measurements not accounting forthe normalization of physiological variables. In all bioassays – whether septic, airway or alveolar irritant or allergic, the adjusted eNO was significantly increased when compared to the concurrent control. The maximum increase of the adjusted eNO occurred following exposure to the airway irritant chlorine. The specificity of adjustment was experimentally verified by decreased eNO following inhalation dosing ofthe non-selective nitric oxide synthase inhibitor amoni-guanidine. In summary, the diagnostic sensitivity of eNO can readily be applied to spontaneously breathing, conscious rats without any intervention or anesthesia. Measurements are definitely improved by accounting for the disease-related changes inexhaled CO2and breathing frequency. Accordingly, adjusted eNO appears to be a promising methodological improvement for utilizing eNO in inhalation toxicology and pharmacological disease models
with fewer animals.

 

Role of p38 MAP Kinase in the Development of Acute Lung Injury

J Arcaroli, Ho-Kee Yum, J Kupfner, JS Park, Kuang-Yao Yang, and E Abraham
Clinical Immunology 2001; 101(2):211–219
http://dx.doi.org:/10.1006/clim.2001.5108

Acute lung injury (ALI) is characterized by an intense pulmonary inflammatory response, in which neutrophils play a central role. The p38 mitogen-activated protein kinase pathway is involved in the regulation of stress-induced cellular functions and appears to be important in modulating neutrophil activation, particularly in response to endotoxin. Although p38 has potent effects on neutrophil functions under in vitro conditions, there is relatively little information concerning the role of p38 in affecting neutrophil driven inflammatory responses in vivo. To examine this issue, we treated mice with the p38 inhibitor SB203580 and then examined parameters of neutrophil activation and acute lung injury after hemorrhage or endotoxemia. Although p38 was activated in lung neutrophils after hemorrhage or endotoxemia, inhibition of p38 did not decrease neutrophil accumulation in the lungs or the development of lung edema under these conditions. Similarly, the increased production of proinflammatory cytokines and activation of NF-kB in lung neutrophils induced by hemorrhage or endotoxemia was not diminished by p38 inhibition. These results indicate that p38 does not have a central role
in the development of ALI after either hemorrhage or endotoxemia.

 

The coagulation system and pulmonary endothelial function in acute lung injury

James H. Finigan
Microvascular Research 77 (2009) 35–38
http://dx.doi.org:/10.1016/j.mvr.2008.09.002

Acute lung injury (ALI) is a disease marked by diffuse endothelial injury and increased capillary permeability. The coagulation system is a major participant in ALI and activation of coagulation is both a consequence and contributor to ongoing lung injury. Increased coagulation and depressed fibrinolysis result in diffuse alveolar fibrin deposition which serves to amplify pulmonary inflammation. In addition, existing evidence demonstrates a direct role for different components of coagulation on vascular endothelial barrier function. In particular, the pro-coagulant protein thrombin disrupts the endothelial actin cytoskeleton resulting in increased endothelial leak. In contrast, the anti-coagulant activated protein C (APC) confers a barrier protective actin configuration and enhances the vascular barrier in vitro and in vivo. However, recent studies suggest a complex landscape with receptor cross-talk, temporal heterogeneity and pro-coagulant/anticoagulant protein interactions. In this article, the major signaling pathways governing endothelial permeability in lung injury are reviewed with a particular focus on the role that endothelial proteins, such as thrombin and APC, which play on the vascular barrier function.

Acute lung injury (ALI) is a devastating illness with an annual incidence of approximately 200,000 and a mortality of 40%. Most commonly seen in the setting of sepsis, ALI is a complex inflammatory syndrome marked by increased vascular permeability resulting in tissue edema and organ dysfunction. The vascular endothelium is a key target and critical participant in the pathogenesis of sepsis-induced organ dysfunction and disruption of the endothelial barrier is central to the pathophysiology of both sepsis and ALI. Sepsis and acute lung injury (ALI) are syndromes marked by diffuse inflammation with a key feature being endothelial cell barrier disruption and increased vascular permeability resulting in widespread organ dysfunction. The endothelial cytoskeleton has been identified as a critical regulator of vascular barrier integrity with a current model of endothelial barrier regulation suggesting a balance between barrier-disrupting cellular contractile forces and barrier-protective cell–cell and cell–matrix forces. These competing forces exert their opposing effects via manipulation of the actin-based endothelial cytoskeleton and associated endothelial regulatory proteins. Endothelial cells generate tension via an actomyosin motor, and focally distributed changes in tension/relaxation can be accomplished by spatially-defined regulation of the phosphorylation of the regulatory 20 kDa myosin light chain (MLC) catalyzed by the Ca2+/calmodulin (CaM)-dependent enzyme myosin light chain kinase (MLCK).

Thrombin is the proto-typical coagulation protein with direct effects on the endothelial barrier via alterations in the cytoskeleton. In the coagulation cascade, thrombin converts fibrinogen to fibrin in the final step of thrombus formation and also activated platelets. In addition, this multifunctional protease is present at sites of vascular inflammation and induces barrier dysfunction. Through its receptor, protease-activated receptor-1 (PAR1), thrombin initiates a series of events which includes MLC phosphorylation, dramatic cytoskeletal reorganization and stress fiber formation, increased cellular contractility, paracellular gap formation, and enhanced fluid and protein transport. Similarly, thrombin exposure results in increased pulmonary edema in vivo, a finding which is also seen after treatment with a PAR1 activating peptide and attenuated in PAR1 knockout mice.

Disruptions in the coagulation system have long been recognized to be an integral part of inflammation, sepsis and ALI. In 1969, Saldeen demonstrated that thrombin infusion produced canine respiratory insufficiency which was linked pathologically to emboli in the pulmonary microcirculation, a condition he labeled the “Microembolism Syndrome” (Saldeen, 1979). Elemental to the pathophysiology of sepsis and ALI is a shift towards a pro-coagulant state. Bronchoalveolar (BAL) fluid from patients with ALI reflects this increase in procoagulant activity with elevated levels of fibrinopeptide A, factor VII and d-dimer. Concomitantly, there is a decrease in fibrinolytic activity, as shown by depressed BAL levels of urokinase and increased levels of the fibrinolysis inhibitors plasminogen activator inhibitor (PAI) and α2-antiplasmin.

Given that APC is a vascular endothelial protein which interacts with other coagulation proteins such as thrombin, it seems logical that it might have an effect on endothelial integrity. In cultured human pulmonary endothelial cells, while thrombin results in decreased electrical resistance, a reflection of increased permeability, pre- or post-exposure to physiologic concentrations of APC significantly attenuates this thrombin-induced drop in resistance. These APC-mediated alterations in barrier function are associated with MLC phosphorylation as well as activation of the endothelial protein Rac, and cytoskeletal re-arrangement in a barrier protective configuration all findings very reminiscent of the barrier protective signaling induced by the bioactive lipid, S1P. Interestingly, APC appears to activate sphingosine kinase and mediate its barrier protective effects through PI3 kinase and AKT-dependent ligation of the S1P receptor, S1P1. Moreover, the endothelial barrier-protective effects of APC have been observed in other tissues including brain and kidney. The barrier protection in these beds appears independent of any anti-coagulant effect of APC and is associated with decreased endothelial apoptosis.

Recently, the endothelial protein C receptor (EPCR) has been identified as a crucial participant in the protein C pathway. Structurally similar to the major histocompatibility class I/CD1 family of molecules, EPCR binds protein C, presenting it to the thrombin/TM complex, thereby increasing the activation of protein C by ∼20 fold. Importantly, APC can also bind EPCR, and while the bound form of APC loses its extra-cellular anti-coagulant activity, increasing evidence indicates that much, if not all, of APC intra-cellular signaling requires EPCR. APC-mediated increases in endothelial phosphor-MLC and activated Rac are all EPCR-dependent and APC-induced endothelial barrier protection requires ligation of EPCR.

Sepsis and ALI are significant causes of morbidity and mortality in the intensive care unit and are marked by zealous activation of the coagulation system. While this could conceivably confer certain benefits, such as enclosing and spatially controlling an infection, it is clear that this pro-coagulant environment participates in the pathophysiology of ALI, particularly via exacerbating endothelial damage and augmenting endothelial permeability. However, the biology of coagulation in ALI is incompletely understood and trials of new therapies specifically targeting coagulation in patients with ALI have been disappointing. Despite this, recent advances in the knowledge of the dynamic interplay between inflammation and coagulation in ALI as well as endothelial receptor-ligand binding and receptor cross talk have stimulated promising research and identified novel therapeutic targets for patients with ALI.

 

Phosphatidylserine-expressing cell by-products in transfusion: A pro-inflammatory or an anti-inflammatory effect?

  1. Saas, F. Angelot, L. Bardiaux, E. Seilles, F. Garnache-Ottou, S. Perruche
    Transfusion Clinique et Biologique 19 (2012) 90–97
    http://dx.doi.org/10.1016/j.tracli.2012.02.002

Labile blood products contain phosphatidylserine-expressing cell dusts, including apoptotic cells and microparticles. These cell by-products are produced during blood product process or storage and derived from the cells of interest that exert a therapeutic effect (red blood cells or platelets). Alternatively, phosphatidylserine-expressing cell dusts may also derived from contaminating cells, such as leukocytes, or may be already present in plasma, such as platelet-derived microparticles. These cell by-products present in labile blood products can be responsible for transfusion induced immunomodulation leading to either transfusion-related acute lung injury (TRALI) or increased occurrence of post-transfusion infections or cancer relapse. In this review, we report data from the literature and our laboratory dealing with interactions between antigen-presenting cells and phosphatidylserine-expressing cell dusts, including apoptotic leukocytes and blood cell-derived microparticles. Then, we discuss how these phosphatidylserine-expressing cell by-products may influence transfusion.

Potential consequences of phosphatidylserine-expressing cell by-products in transfusion

Potential consequences of phosphatidylserine-expressing cell by-products in transfusion

Potential consequences of phosphatidylserine-expressing cell by-products in transfusion. Interactions of phosphatidylserine-expressing cell dusts (apoptotic cells or microparticles) may lead to antigen-presenting cell activation or inhibition. Antigen-presenting cell activation may trigger inflammation and be involved in transfusion-related acute lung injury (TRALI), while antigen-presenting cell inhibition may exert transient immunosuppression or tolerance. Blood product process or storage may influence the generation of phosphatidylserine-expressing cell dusts. PtdSer: phosphatidylserine; APC: antigen-presenting cell.

Several publications report the presence of phosphatidylserine-expressing cell by-products in blood products. These cell by-products may be generated during the blood product process, such as filtration, or during storage (either cold storage for red blood cells or between 20–24 ◦C for platelets). Alternatively, they may be limited by filtration. Phosphatidylserine-expressing cell by-products can be apoptotic cells. Apoptotic cells have been found in different blood products: red blood cell units and platelet concentrates. These apoptotic cells correspond to dying cells of interest: red blood cells or platelets, both enucleated cells that can undergo apoptosis.

Immunomodulatory effects of apoptotic leukocytes

Immunomodulatory effects of apoptotic leukocytes

Immunomodulatory effects of apoptotic leukocytes. Early during the apoptotic program, phosphatidylserine-exposure occurs leading to apoptotic cell removal by macrophages or conventional dendritic cells. This uptake by antigen-presenting cells induces the production of anti-inflammatory factors and concomitantly inhibits the synthesis of inflammatory cytokines. These antigen-presenting cells are refractory to TLR activation. This leads to a transient immunosuppressive microenvironment. If antigen-presenting cells from this microenvironment migrate to secondary lymphoid organs, naive T cells are converted into inducible regulatory T cells. This leads to tolerance against apoptotic cell-derived antigens. M[1]: macrophage; cDC: conventional dendritic cells; PtdSer: phosphatidylserine; Treg: regulatory T cells; Th1: helper T cells; HGF: hepatocyte growth factor; IL-: interleukin; NO: nitrite oxide; PGE-2: prostaglandin-E2; TGF: transforming growth factor; TNF: tumor necrosis factor; TLR: Toll-like receptor.

Implication of phosphatidylserine in the inhibition of both inflammation and specific immune responses has been further demonstrated using  phosphatidylserine-expressing liposomes and is sustained by the following observations:

  • phosphatidylserine-dependent ingestion of apoptotic cells induces TGF-β secretion and resolution of lung inflammation;
  • inhibition of phosphatidylserine recognition through annexin-V enhances the immunogenicity of irradiated tumor cells in vivo;
  • masking of phosphatidylserine inhibits apoptotic cell engulfment and induces autoantibody production in mice.

Based on data from our group and Peter Henson’s group, some authors have speculated that apoptotic leukocytes present in blood products may be responsible for transfusion-related immunosuppression.

The first consequences of phosphatidylserine-expressing apoptotic cells in blood products may be a transient immunosuppression−responsible for an increase in infection rate and of cancer relapse−or tolerance induction− as observed after donor-specific transfusion − when Treg have been generated. However, apoptotic leukocytes become secondarily necrotic in the absence of phagocytes. This may certainly occur in blood product bags. Necrotic cells, through the release of damage-associated molecular patterns, may become immunogenic. The same process may occur for platelets. Necrotic platelets may represent the procoagulant form of platelets. Thus, hemostatic activation of platelets or their by-products may link thrombosis and inflammation to amplify lung microvascular damage during nonimmune TRALI.

What are the next steps to answer the question on the role of phosphatidylserine-expressing cell dusts in the modulation of immune responses after transfusion?

The next steps are to characterize or identify factors involved in the triggering of inflammation or its inhibition and produced during blood product storage or process. Several factors influence the immune responses against dying cells. We can speculate on some factors, including:

  • the number of phosphatidylserine-expressing cell byproducts contained per blood product, as the immunogenicity of apoptotic cells may be proportional to their number;
  • the occurrence of secondary necrosis and so the passive release of intracellular damage-associated molecular patterns that overpasses the inhibitory signals delivered by phosphatidylserine. One of these damage associated molecular patterns can be the heme released from stored red blood cells which signals via TLR4;
  • the size of cell by-products and especially microparticles, since these latter exert different functions according to their size. Moreover, antigen-presenting cells, such as plasmacytoid dendritic cells, respond only to lower size synthetic particles. This may explain the different responses observed between “amateur” phagocytes (plasmacytoid dendritic cells) versus professional phagocytes (conventional dendritic cells/macrophages) after incubation with microparticles. The size of cell by-products diminishes during plasma filtration, as assessed by dynamic light scattering from 101 to 464 nm in unfiltered fresh-frozen plasma versus 21 to 182 nm after 0.2 µm filtration process;
  • expression of the recently described phosphatidylserine receptors on different antigen-presenting cell subsets may also explain the different responses between plasmacytoid dendritic cells versus conventional dendritic cells/macrophages and may impact on the overall immune response.

 

Peroxisome proliferator-activated receptors and inflammation

Leonardo A. Moraes, Laura Piqueras, David Bishop-Bailey
Pharmacology & Therapeutics 110 (2006) 371 – 385
http://dx.doi.org:/10.1016/j.pharmthera.2005.08.007

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptors family. PPARs are a family of 3 ligand-activated transcription factors: PPARa (NR1C1), PPARh/y (NUC1; NR1C2), and PPARg (NR1C3). PPARα, -h/y, and -ϒ are encoded by different genes but show substantial amino acid similarity, especially within the DNA and ligand binding domains. All PPARs act as heterodimers with the 9-cis-retinoic acid receptors (retinoid X receptor; RXRs) and play important roles in the regulation of metabolic pathways, including those of lipid of biosynthesis and glucose metabolism, as well as in a variety of cell differentiation, proliferation, and apoptosis pathways. Recently, there has been a great deal of interest in the involvement of PPARs in inflammatory processes. PPAR ligands, in particular those of PPARα and PPARϒ, inhibit the activation of inflammatory gene expression and can negatively interfere with proinflammatory transcription factor signaling pathways in vascular and inflammatory cells. Furthermore, PPAR levels are differentially regulated in a variety of inflammatory disorders in man, where ligands appear to be promising new therapies.

Fig. not shown.  Structure and transcriptional activation of PPARs. (A) Generic schematic of the structure of the PPAR family of nuclear receptors. Indicated are the N–C terminal regions subdivided in to 4 domains: the A/B, N terminal domain [also called the activation function (AF)-1 domain]; C, the DNA binding domain; D, the F hinge_region; and E, the ligand binding domain (AF-2). (B) Generic scheme for the activation of a PPAR receptor as a transcription factor. PPAR activation leads to heterodimerization with RXR and an accumulation in the nucleus. Ligand activation of PPAR results in a change from a repressed binding protein complex which may contain histone deacetylases (HDAC), the nuclear receptor corepressor (NCo-R), and the silencing mediator of retinoid and thyroid signaling (SMRT) to an activation complex that may contain the histone acetylases, steroid receptor co-activator-1 (SRC-1), the PPAR binding protein (PBP), cAMP response element binding protein (CBP/p300), TATA box binding proteins, and RNA polymerase (RNA pol) III. The activated PPAR–RXR heterodimer complex binds to DNA sequences called PPAR response elements (PPRE) in target genes initiation their transcription.

Although the nature of true endogenous PPAR ligands are still not known (Bishop-Bailey & Wray, 2003), PPARs can be activated by a wide variety of F endogenous or pharmacological ligands. PPARα activators include a variety of endogenously present fatty acids, LTB4 and hydroxyeicosatetraenoic acids (HETEs), and clinically used drugs, such as the fibrates, a class of first-line drugs in the treatment of dyslipidemia. Similarly, PPARg can be activated by a number of ligands, including docosahexaenoic acid, linoleic acid, the anti-diabetic glitazones, used as insulin sensitizers, and a number of lipids, including oxidized LDL, azoyle-PAF, and eicosanoids, such as 5,8,11,14-eicosatetraynoic acid and the prostanoids PGA1, PGA2, PGD2, and its dehydration products of the PGJ series of cyclopentanones (e.g., 15 deoxy-D12,14-PGJ2). Dyslipidemia and insulin-dependent diabetes are commonly found existing together as part of the metabolic X syndrome.

Because PPARa and PPARg ligands independently are useful clinical drugs in the treatment of these respective disorders, synthetic dual PPARα/ϒ ligands have recently been developed and show a combined clinical efficacy. PPAR h/y activators include fatty acids and prostacyclin and synthetic compounds L-165,041, GW501516, compound F and L-783,483. Unlike PPARα or-ϒ, there are no PPAR h/y drugs in the clinic, although ligands are in phase II clinical trials for dyslipidemia (http://www.science.gsk.com/pipeline). Indeed, part of the challenge in determining the function of PPARh/y has been the identification and availability of new ligands with more potency and selectivity for use as pharmacological tools.

Fig. not shown. Mechanisms of the anti-inflammatory effects of PPARα. PPARα ligands inhibit the activities of NF-nB, AP-1, and T-bet within cells. In sites of local inflammation, tissue and endothelial cell activity is inhibited, and expressions of adhesion molecules (ICAM-1 and VCAM-1), pro-inflammatory cytokines (IL-1, -6, -8, -12, and TNFα), vasoactive mediators (inducible cyclo-oxygenase, inducible nitric oxide synthase, and endothelin-1; COX-2, iNOS, and ET-1), and proteases (MMP-9) are decreased. The inflammatory responses in leukocytes are also diminished. Monocyte/macrophage activity is decreased, and lipid metabolizing pathways increased, T- and B-lymphocyte proliferation and differentiation are inhibited, and T-lymphocyte and eosinophil chemotaxis reduced. Bold italic text indicates positive regulation by the PPAR, all other text indicates a negative regulation.

Fig. not shown. Mechanisms of the anti-inflammatory effects of PPAR h/y. PPAR h/y ligands inhibit the activities of NF-nB and release the suppressor BCL-6 from PPAR h/y. In sites of local inflammation, endothelial cell adhesion molecule (VCAM-1) and chemokine (MCP-1) are reduced. PPAR h/y and its endogenous ligand(s) are induced during the inflammatory response in keratinocytes, which then promotes cell survival (integrin-linked kinase—Akt pathway) and wound healing. The inflammatory responses in monocyte/ macrophages are modulated. In the absence of ligand, PPAR h/y sequesters BCL-6 and induces MCP-1, MCP-3, and IL-1h. When PPAR h/y ligand is given, BCL-6 is released and MCP-1, -3, and IL-1h levels are reduced. Bold italic text indicates positive regulation by the PPAR, all other text indicates a negative regulation.

Fig. not shown. Mechanisms of the anti-inflammatory effects of PPARg. PPARg ligands can inhibit the activities of NF-nB, AP-1, STAT-1, N-FAT, Erg-1, Jun, and GATA-3 within cells. In sites of local inflammation, tissue and endothelial cell activity is inhibited, and expression of adhesion molecules (ICAM-1), proinflammatory cytokines (IL-8, -12, and TNFα), chemokines (MCP-1, MCP-3, IP-10, Mig, and I-TAC), vasoactive mediators (inducible nitric oxide synthase and endothelin-1; iNOS and ET-1), and proteases (MMP-9) are decreased. The inflammatory responses in leukocytes are also diminished. Monocyte/ macrophage activity is decreased, T- and B-lymphocyte proliferation and differentiation are inhibited, and T-lymphocyte and eosinophil chemotaxis reduced. Platelet activity is inhibited and dendritic cell production of IL-12, and expression of CCL3, CCL5, and CD80 is reduced, so pro-inflammatory TH1 lymphocytes maturation is inhibited. Bold italic text indicates positive regulation by the PPAR, all other text indicates a negative regulation.

The PPARs are one of the most intensely studied members of the nuclear receptor gene family, and since their initial discovery just over decade ago, the PPARs have attracted an increasing amount of experimental and clinical research by investigators from different scientific areas. PPARs through their central roles in regulating energy homeostasis regulate physiological function in many cell types, tissues, and organ systems. Many disease states from carcinogenesis to inflammation have been linked to abnormalities in the function of PPAR-regulated transcription factors. PPARs are expressed or regulate pathophysiology of diverse human disorders including atherosclerosis, inflammation, obesity, diabetes, and the immune response. PPARs have beneficial effects in many inflammatory conditions, where they regulate cytokine production, adhesion molecule expression, fibrinolysis cell proliferation, apoptosis, and differentiation. Further studies and development of novel PPAR ligands and their selective modulators may lead to novel therapeutic agents in the many conditions associated with inflammatory processes.

 

Regulators of endothelial and epithelial barrier integrity and function in acute lung injury

Rudolf Lucas, Alexander D. Verin, Stephen M. Black, John D. Catravas
Biochemical Pharmacology 77 (2009) 1763–1772
http://dx.doi.org:/10.1016/j.bcp.2009.01.014

Pulmonary permeability edema is a major complication of acute lung injury (ALI), severe pneumonia and ARDS. This pathology can be accompanied by

(1) a reduction of alveolar liquid clearance capacity, caused by an inhibition of the expression of crucial sodium transporters, such as the epithelial sodium channel (ENaC) and the Na+-K+-ATPase,
(2) an epithelial and endothelial hyperpermeability and
(3) a disruption of the epithelial and endothelial barriers, caused by increased apoptosis or necrosis.

Since, apart from ventilation strategies, no standard treatment exists for permeability edema, the following chapters will review a selection of novel approaches aiming to improve these parameters in the capillary endothelium and the alveolar epithelium.

Apoptosis is an essential physiological process for the selective elimination of cells. However, the dysregulation of apoptotic pathways is thought to play an important role in the pathogenesis of ALI. Both delayed neutrophil apoptosis and enhanced endothelial/epithelial cell apoptosis have been identified in ALI/ARDS. In the case of neutrophils, which contribute significantly to ALI/ ARDS, studies in both animals and ARDS patients suggest that apoptosis is inhibited during the early stages (<2 h) of inflammation.

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily, that includes receptors for steroid hormones, thyroid hormones, retinoic acid, and fat-soluble vitamins. Since their discovery in 1990, increasing data has been published on the role of PPARs in diverse processes, including lipid and glucose metabolism, diabetes and obesity, atherosclerosis, cellular proliferation and differentiation, neurological diseases, inflammation and immunity. PPARs have both gene-dependent and gene-independent effects. Gene-dependent functions involve the formation of heterodimers with the retinoid X-receptor. Activation by PPAR ligands results in the binding of the heterodimer to peroxisome proliferator response elements, located in the promoter regions of PPAR-regulated genes. Gene independent effects involve the direct binding of PPARs to transcription factors, such as NF-kB, which then alters their binding to DNA promoter elements. PPARs can also bind and sequester various cofactors for transcription factors, and thus further alter gene expression. Importantly, the precise effects of PPARs vary greatly between cell types. To date, three subtypes of PPAR have been identified: α, β, and ϒ. There is increasing data suggesting that PPAR signaling may play an important role in the pathobiology of systemic vascular disease. However, there is less data implicating PPAR signaling in diseases of the lung.

A role for PPARs in the control of inflammation was first evidenced for PPARα, where mice deficient in PPARα exhibited an increased duration of ear-swelling in response to the proinflammatory mediator, LTB4. More recently, a number of studies in mice and in humans have shown that PPAR agonists exhibit anti-inflammatory effects under a wide range of conditions. There are two main mechanisms by which PPARs exert their anti-inflammatory effect. The first involves complex formation, and the inhibition of transcription factors that positively regulate the transcription of pro-inflammatory genes. These include nuclear factor-kB (NF-kB), signal transducers and activators of transcription (STATs), nuclear factor of activated T cells (NF-AT), CAAT/enhancer binding protein (C/EBP) and activator protein 1 (AP-1). These transcription factors are the main mediators of the major proinflammatory cytokines, chemokines, and adhesion molecules involved in inflammation. The second PPAR-mediated anti-inflammatory pathway is mediated by the sequestration of rate limiting, but essential, co-activators or co-repressors.

Recent studies have shown that PPAR signaling can attenuate the airway inflammation induced by LPS in the mouse. It was shown that mice treated with the PPARα agonist, fenofibrate, had decreases in both inflammatory cell infiltration and inflammatory mediators. Conversely, PPARα -/- mice have been shown to have a greater number of neutrophils and macrophages, and increased levels of inflammatory mediators in bronchoalveolar lavage fluids (BALF). Other PPAR agonists, such as rosiglitazone or SB 21994 have also been shown to reduce LPS-mediated ALI in the mouse lung. PPARϒ signaling has also been shown to be protective in regulating pulmonary inflammation associated with fluorescein isothiocyanate (FITC)-induced lung injury, with the PPARϒ ligand pioglitazone decreasing neutrophil infiltration. Collectively, these data suggest that therapeutic agents that activate either or both PPARα and PPARϒ could be beneficial for the treatment of ALI.

Permeability edema is characterized by a reduced alveolar liquid clearance capacity, combined with an endothelial hyperpermeability. Various signaling pathways, such as those involving reactive oxygen species (ROS), Rho GTPases and tyrosine phosphorylation of junctional proteins, converge to regulate junctional permeability, either by affecting the stability of junctional proteins or by modulating their interactions. The regulation of junctional permeability is mainly mediated by dynamic interactions between the proteins of the adherens junctions and the actin cytoskeleton. Actin-mediated endothelial cell contraction is the result of myosin light chain (MLC) phosphorylation by MLC kinase (MLCK) in a Ca2+/calmodulin-dependent manner. RhoA additionally potentiates MLC phosphorylation, by inhibiting MLC phosphatase activity through its downstream effector Rho kinase (ROCK). As such, actin/myosin-driven contraction will generate a contractile force that pulls VE-cadherin inward. This contraction will force VE-cadherin to dissociate from its adjacent partner, as such producing interendothelial gaps.

Vascular endothelial cells can be regulated by nucleotides released from platelets. During vascular injury, broken cells are also the source of the extracellular nucleotides. Furthermore, endothelium may provide a local source of ATP within vascular beds. Primary cultures of human endothelial cells derived from multiple blood vessels release ATP constitutively and exclusively across the apical membrane under basal conditions. Hypotonic challenge or the calcium agonists (ionomycin and thapsigargin) stimulate ATP release in a reversible and regulated manner. Enhanced release of pharmacologically relevant amounts of ATP was observed in endothelial cells under such stimuli as shear stress, lipopolysaccharide (LPS), and ATP itself. Pearson and Gordon demonstrated that incubation of aortic endothelial and smooth muscle cells with thrombin resulted in the specific release of ATP, which was converted to ADP by vascular hydrolases. Yang et al. showed that endothelial cells isolated from guinea pig heart release nucleotides in response to bradykinin, acetylcholine, serotonin and ADP. Nucleotide action is mediated by cell surface purinoreceptors. Once released from endothelial cells, ATP may act in the blood vessel lumen at P2 receptors on nearby endothelium downstream from the site of release. ATP is also degraded rapidly and its metabolites have also been recognized as signaling molecules, which can initiate additional receptor-mediated functions. These include ADP and the final hydrolysis product adenosine.

Signal transduction pathways implicated in ATP-mediated endothelial barrier enhancement

Signal transduction pathways implicated in ATP-mediated endothelial barrier enhancement

Signal transduction pathways implicated in ATP-mediated endothelial barrier enhancement

During the course of ALI, the alveolar space, as well as the interstitium, are sites of intense inflammation, leading to the local production of pro-inflammatory cytokines, such as IL-1β, TGF-β and TNF. The latter pleiotropic cytokine is a 51 kDa homotrimeric protein, binding to two types of receptors, i.e. TNF-R1 and TNF-R2 and which is mainly produced by activated macrophages and T cells. Soluble TNF, as well as the soluble TNF receptors 1 and 2, are generated upon cleavage of membrane TNF or of the membrane associated receptors, respectively, by the enzyme TNF-α convertase (TACE). TNF-R1, but not TNF-R2, contains a death domain, which signals apoptosis upon the formation of the Death Inducing Signaling Complex (DISC). In spite of its lack of a death domain, TNF-R2 can nevertheless be implicated in apoptosis induction, since its activation causes degradation of TNF Receptor Associated Factor 2 (TRAF2), an inhibitor of the TNF-R1-induced DISC formation. Moreover, apoptosis induction of lung microvascular endothelial cells by TNF was shown to require activation of both TNF receptors. TNF-R2 was also shown to be important for ICAM-1 upregulation in endothelial cells in vitro and in vivo, an activity important in the sequestration of leukocytes in the microvessels. Moreover, lung microvascular endothelial cells isolated from ARDS patients express significantly higher levels of TNF-R2 and of ICAM-1 than cells isolated from patients who had undergone a lobectomy for lung carcinoma, used as controls. These findings therefore suggest that ICAM-1 and TNF-R2 may have a particular involvement in the pathogenesis of acute lung injury.

Dichotomous activity of TNF in alveolar liquid clearance and barrier protection

Dichotomous activity of TNF in alveolar liquid clearance and barrier protection

Dichotomous activity of TNF in alveolar liquid clearance and barrier protection during ALI. TNF, which is induced during ALI, causes a downregulation of ENaC expression in type II alveolar epithelial cells, upon activating TNF-R1. Moreover, TNF increases permeability, by means of interfering with tight junctions (TJ) in both alveolar epithelial (AEC) and capillary endothelial cells (MVEC). ROS, the generation of which is frequently increased during ALI, were also shown to downregulate ENaC and Na+-K+-ATPase expression and moreover also lead to decreased endothelial barrier integrity. The TIP peptide, mimicking the lectin-like domain of TNF, is able to increase sodium uptake in alveolar epithelial cells and to restore endothelial barrier integrity, as such providing a significant protection against the development of permeability edema (red lines: inhibition, green arrows: activation).

Proposed mechanism of action for the anti-inflammatory and barrier-protective actions of hsp90 inhibitors.

Proposed mechanism of action for the anti-inflammatory and barrier-protective actions of hsp90 inhibitors.

Proposed mechanism of action for the anti-inflammatory and barrier-protective actions of hsp90 inhibitors.

Permeability edema represents a life-threatening complication of acute lung injury, severe pneumonia and ARDS, characterized by a combined dysregulation of pulmonary epithelial and endothelial apoptosis, endothelial barrier integrity and alveolar liquid clearance capacity. As such, it is likely that several of these parameters have to be targeted in order to obtain a successful therapy. This review focuses on a selection of recently discovered substances and mechanisms that might improve ALI therapy. As such, we have discussed the inhibition of apoptosis and necrosis occurring during ALI, by means of the restoration of Zn2+ homeostasis. PPARα and ϒ agonists can represent therapeutically  promising molecules, since they inhibit transcription factors as well as essential co-activators involved in the activation of pro-inflammatory cytokines, chemokines and adhesion molecules, all of which are implicated in ALI. Apart from inducing a potent inhibition of inflammation upon interfering with NF-kB activation, hsp90 inhibitors were shown to prevent and restore endothelial barrier integrity. These agents are able to significantly improve survival and lung function during LPS-induced ALI. A restoration of endothelial barrier integrity during ALI can also be obtained upon increasing extracellular levels of ATP or adenosine, which activate the purinoreceptors P2Y and P1A2, respectively, leading to a decrease in myosin light chain phosphorylation and an increase in MLC phosphatase 1 activity. The pro-inflammatory cytokine TNF is involved in endothelial apoptosis and hyperpermeability, as well as in the reduction of alveolar liquid clearance, upon activating its receptors. However, apart from its receptor binding sites, TNF harbors a lectin-like domain, which can be mimicked by the TIP peptide. This peptide has been shown to increase alveolar liquid clearance and moreover induces endothelial barrier protection. As such, TNF can be considered as a moonlighting cytokine, combining both positive and negative activities for permeability edema generation within one molecule.

 

The protective effect of CDDO-Me on lipopolysaccharide-induced acute lung injury in mice

Tong Chen, Yi Moua, Jiani Tan, LinlinWei, Yixue Qiao, Tingting Wei, et al.
International Immunopharmacology 25 (2015) 55–64
http://dx.doi.org/10.1016/j.intimp.2015.01.011

ALI is a clinical syndrome characterized by a disruption of epithelial integrity, neutrophil accumulation, noncardiogenic pulmonary edema, severe hypoxemia and an intense pulmonary inflammatory response with a wide array of increasing severity of lung parenchymal injury. Previous studies have shown that lots of pathogenesis contribute to ALI, such as oxidant/antioxidant dysfunction, dysregulation of inflammatory/anti-inflammatory pathway, upregulation of chemokine production and adhesion molecules. However, to date there is no effective medicine to control ALI. Lipopolysaccharide (LPS) is a main component of the outer membrane of Gram negative bacteria. It has been reported to activate toll like receptors 4 (TLR4) and to stimulate the release of inflammatory mediators inducing ALI-like symptoms. Intratracheal administration of LPS has been used to construct animal models of ALI.

The biological importance of naturally occurring triterpenoids has long been recognized. Oleanolic acid, exhibiting modest biological activities, has been marketed in China as an oral drug for the treatment of liver disorders in humans. Among its derivatives, bardoxolonemethyl (2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid methylester) CDDO-Me, had completed a successful phase I clinical trial for the treatment of cancer and started a phase II trial for the treatment of patients with pulmonary arterial hypertension. For its broad spectrum antiproliferative and anti-tumorigenic activities, CDDO-Me has also been reported to possess a number of pharmacological activities such as antioxidant, anti-tumor and anti-inflammatory effects. However, the mechanisms by which CDDO-Me exerted its anti-inflammatory effects on macrophage were insufficiently elucidated. More importantly, there is no available report to evaluate its therapeutic effect on acute lung injury.

CDDO-Me, initiated in a phase II clinical trial, is a potential useful therapeutic agent for cancer and inflammatory dysfunctions, whereas the therapeutic efficacy of CDDO-Me on LPS-induced acute lung injury (ALI) has not been reported as yet. The purpose of the present study was to explore the protective effect of CDDO-Me on LPS-induced ALI in mice and to investigate its possible mechanism. BalB/c mice received CDDO-Me (0.5 mg/kg, 2 mg/kg) or dexamethasone (5 mg/kg) intraperitoneally 1 h before LPS stimulation and were sacrificed 6 h later. W/D ratio, lung MPO activity, number of total cells and neutrophils, pulmonary histopathology, IL-6, IL-1β, and TNF-α in the BALF were assessed. Furthermore, we estimated iNOS, IL-6, IL-1β, and TNF-α mRNA expression and NO production as well as the activation of the three main MAPKs, AkT, IκB-α and p65. Pretreatment with CDDO-Me significantly ameliorated W/D ratio, lung MPO activity, inflammatory cell infiltration, and inflammatory cytokine production in BALF from the in vivo study. Additionally, CDDO-Me had beneficial effects on the intervention for pathogenesis process at molecular, protein and transcriptional levels in vitro. These analytical results provided evidence that CDDO-Me could be a potential therapeutic candidate for treating LPS-induced ALI.

Effects of CDDO-Me on LPS-mediated lung changes

Effects of CDDO-Me on LPS-mediated lung histopathologic changes in lung tissues. (A) The lung section from the control mice; (B) the lung section from the mice administered with LPS (8 mg/kg); (C) the lung section from the mice administered with dexamethasone (5 mg/kg) and LPS (8 mg/kg); (D) the lung section from the mice administered with CDDO-Me (0.5mg/kg) and LPS (8mg/kg); (E) the lung section from the mice administered with CDDO-Me (2mg/kg) and LPS (8mg/kg); (hematoxylin and eosin staining, magnification 200×). Control group: the green arrow indicated alveolar wall, no hyperemia. All the other groups: The black arrow indicated the inflammatory cell infiltration; the green arrow indicated alveolar wall hyperemia.

 

The impact of cardiac dysfunction on acute respiratory distress syndrome and mortality in mechanically ventilated patients with severe sepsis and septic shock: An observational study

Brian M. Fuller, Nicholas M. Mohr, Thomas J. Graetz, et al.
Journal of Critical Care 30 (2015) 65–70
http://dx.doi.org/10.1016/j.jcrc.2014.07.027

Purpose: Acute respiratory distress syndrome (ARDS) is associated with significant mortality and morbidity in survivors. Treatment is only supportive, therefore elucidating modifiable factors that could prevent ARDS could have a profound impact on outcome. The impact that sepsis-associated cardiac dysfunction has on ARDS is not known. Materials and Methods: In this retrospective observational cohort study of mechanically ventilated patients with severe sepsis and septic shock, 122 patients were assessed for the impact of sepsis-associated cardiac dysfunction on incidence of ARDS (primary outcome) and mortality. Results: Sepsis-associated cardiac dysfunction occurred in 44 patients (36.1%). There was no association of sepsis-associated cardiac dysfunction with ARDS incidence (p= 0.59) or mortality, and no association with outcomes in patients that did progress to ARDS after admission. Multivariable logistic regression demonstrated that higher BMI was associated with progression to ARDS (adjusted OR 11.84, 95% CI 1.24 to 113.0, p= 0.02). Conclusions: Cardiac dysfunction in mechanically ventilated patients with sepsis did not impact ARDS incidence, clinical outcome in ARDS patients, or mortality. This contrasts against previous investigations demonstrating an influence of nonpulmonary organ dysfunction on outcome in ARDS. Given the frequency of ARDS as a sequela of sepsis, the impact of cardiac dysfunction on outcome should be further studied.

 

Suppression of NF-κβ pathway by crocetin contributes to attenuation of lipopolysaccharide-induced acute lung injury in mice

Ruhui Yang, Lina Yang, Xiangchun Shen, Wenyuan Cheng, et al.
European Journal of Pharmacology 674 (2012) 391–396
http://dx.doi.org:/10.1016/j.ejphar.2011.08.029

Crocetin, a carotenoid compound, has been shown to reduce expression of inflammation and inhibit the production of reactive oxygen species. In the present study, the effect of crocetin on acute lung injury induced by lipopolysaccharide (LPS) was investigated in vivo. In the mouse model, pretreatment with crocetin at dosages of 50 and 100 mg/kg reduced the LPS-induced lung edema and histological changes, increased LPS-impaired superoxide dismutase (SOD) activity, and decreased lung myeloperoxidase (MPO) activity. Furthermore, treatment with crocetin significantly attenuated LPS-induced mRNA and the protein expressions of interleukin-6 (IL-6), macrophage chemoattractant protein-1 (MCP-1), and tumour necrosis factor-α (TNF-α) in lung tissue. In addition, crocetin at different dosages reduced phospho-IκB expression and NF-κB activity in LPS-induced lung tissue alteration. These results indicate that crocetin can provide protection against LPS-induced acute lung injury in mice.

 

Sauchinone, a lignan from Saururus chinensis, attenuates neutrophil pro-inflammatory activity and acute lung injury

Hui-Jing Han, Mei Li, Jong-Keun Son, Chang-Seob Seo, et al.
International Immunopharmacology 17 (2013) 471–477
http://dx.doi.org/10.1016/j.intimp.2013.07.011

Previous studies have shown that sauchinone modulates the expression of inflammatory mediators through mitogen-activated protein kinase (MAPK) pathways in various cell types. However, little information exists about the effect of sauchinone on neutrophils, which play a crucial role in inflammatory process such as acute lung injury (ALI). We found that sauchinone decreased the phosphorylation of p38 MAPK in lipopolysaccharide (LPS)-stimulated murine bone marrow neutrophils, but not ERK1/2 and JNK. Exposure of LPS-stimulated neutrophils to sauchinone or SB203580, a p38 inhibitor, diminished production of tumor necrosis factor (TNF)-α and macrophage inflammatory protein (MIP)-2 compared to neutrophils cultured with LPS. Treatment with sauchinone decreased the level of phosphorylated ribosomal protein S6 (rpS6) in LPS-stimulated neutrophils. Systemic administration of sauchinone to mice led to reduced levels of phosphorylation of p38 and rpS6 in mice lungs given LPS, decreased TNF-α and MIP-2 production in bronchoalveolar lavage fluid, and also diminished the severity of LPS-induced lung injury, as determined by reduced neutrophil accumulation in the lungs, wet/dry weight ratio, and histological analysis. These results suggest that sauchinone diminishes LPS-induced neutrophil activation and ALI.

In the present study, the systemic administration of sauchinone decreased the phosphorylation of p38 MAPK and rpS6 in mice lungs subjected to LPS and diminished the severity of LPS-induced ALI. Neutrophils play an important role in acute inflammatory processes, such as ALI, which was demonstrated by various experimental models. Previous reports suggested that p38 MAPK inhibition of murine neutrophils could lead to the loss of chemotaxis toward MIP-2, as well as the loss of TNF-αandMIP-2 production in response to LPS, and also attenuated neutrophil accumulation in LPS-induced ALI models. Therefore, the beneficial effects of sauchinone on LPS-induced ALI are likely associated with decreases in the production of pro-inflammatory mediators by neutrophils, consistent with our in vitro experiments. However, we cannot exclude that the effects of sauchinone on reducing the release of TNF-α and MIP-2 in mice lungs subjected to LPS, with the resultant prevention of ALI, could be affected by various pulmonary cell populations, such as alveolar macrophages. Also, the inhibitory effects of sauchinone on NF-κB activation through various pulmonary cell populations (Supplemental Fig. S2), in addition to p38MAPK activity in mouse lungs given LPS, might enhance the anti-inflammatory action of sauchinone in mouse lungs subjected to LPS. In conclusion, we found that sauchinone significantly diminished the release of inflammatory mediators in isolated neutrophils and lungs subjected to LPS. The anti-inflammatory action of sauchinone was associated with the prevention of p38 MAPK and rpS6 activation. These findings suggest that sauchinone may be an appropriate pharmacological candidate for the treatment of ALI as well as other neutrophil driven acute inflammatory diseases.
Supplementary data to this article can be found online at
http://dx.doi.org/10.1016/j.intimp.2013.07.011

 

Protective effect of dexmedetomidine in a rat model of α-naphthylthiourea- induced acute lung injury

Volkan Hancı, Gamze Yurdakan, Serhan Yurtlu, et al.
J Surg Res 178 (2012):424-430
http://dx.doi.org:/10.1016/j.jss.2012.02.027

Background: We assessed the effects of dexmedetomidine in a rat model of a-naphthylthiourea (ANTU)einduced acute lung injury.  Methods: Forty Wistar Albino male rats weighing 200e240 g were divided into 5 groups (n = 8 each), including a control group. Thus, there were one ANTU group and three dexmedetomidine groups (10-, 50-, and 100-mg/kg treatment groups), plus a control group. The control group provided the normal base values. The rats in the ANTU group were given 10 mg/kg of ANTU intraperitoneally and the three treatment groups received 10, 50, or 100 mg/kg of dexmedetomidine intraperitoneally 30 min before ANTU application. The rat body weight (BW), pleural effusion (PE), and lung weight (LW) of each group were measured 4 h after ANTU administration. The histopathologic changes were evaluated using hematoxylin-eosin staining. Results: The mean PE, LW, LW/BW, and PE/BW measurements in the ANTU group were significantly greater than in the control groups and all dexmedeto-midine treatment groups (P < 0.05). There were also significant decreases in the mean PE, LW, LW/BW and PE/BW values in the dexmedetomidine 50-mg/kg group compared with those in the ANTU group (P < 0.01). The inflammation, hemorrhage, and edema scores in the ANTU group were significantly greater than those in the control or dexmedetomidine 50-mg/kg group (P < 0.01). Conclusion: Dexmedetomidine treatment has demonstrated  a potential benefit by preventing ANTU-induced acute lung injury in an experimental rat model. Dexmedetomidine could have a potential protective effect on acute lung injury in intensive care patients.

 

Protective effects of Isofraxidin against lipopolysaccharide-induced acute lung injury in mice

Xiaofeng Niu, YuWang, Weifeng Li, Qingli Mu, et al.
International Immunopharmacology 24 (2015) 432–439
http://dx.doi.org/10.1016/j.intimp.2014.12.041

Acute lung injury (ALI) is a life-threatening disease characterized by serious lung inflammation and increased capillary permeability, which presents a high mortality worldwide. Isofraxidin (IF), a Coumarin compound isolated from the natural medicinal plants such as Sarcandra glabra and Acanthopanax senticosus, has been reported to have definite anti-bacterial, anti-oxidant, and anti-inflammatory activities. However, the effects of IF against lipopoly-saccharide-induced ALI have not been clarified. The aim of the present study is to explore the protective effects and potential mechanism of IF against LPS-induced ALI in mice. In this study, We found that pretreatment with IF significantly lowered LPS-induced mortality and lung wet-to-dry weight (W/D) ratio and reduced the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) in serum and bronchoalveolar lavage fluid (BALF). We also found that total cells, neutrophils and macrophages in BALF,MPO activity in lung tissues were markedly decreased. Besides, IF obviously inhibited lung histopathological changes and cyclooxygenase-2 (COX-2) protein expression. These results suggest that IF has a protective effect against LPS induced ALI, and the protective effect of IF seems to result from the inhibition of COX-2 protein expression in the lung, which regulates the production of PGE2.

Ingestion of LPS stimulates vascular permeability, promotes inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) from blood into lung tissues and activates numerous inflammatory cells such as neutrophils and macrophages. In macrophages, LPS challenge induces the transcription of gene encoding pro-inflammatory protein, which leads to cytokine release and synthesis of enzymes, such as cyclo-oxygenase-2 (COX-2). COX-2 usually can’t be found in normal tissues, but widely induced by pro-inflammatory stimuli, such as cytokines, endotoxins, and growth factors. COX-2 plays a vital role in the regulation of inflammatory process by modulating the production of prostaglandin E2 (PGE2). PGE2, induced by cytokines and other initiator, is an inflammatory mediator which is produced in the regulation of COX-2. Previous researches demonstrated that inhibition of COX-2 produced a dramatically anti-inflammatory effect with little gastrointestinal toxicity. Therefore, inhibition of COX-2 protein expression has far-reaching significance in the treatment of ALI.

effects of IF on LPS-induced mortality in ALI mice

effects of IF on LPS-induced mortality in ALI mice

The effects of IF on LPS-induced mortality in ALI mice (n = 12/group). IF (5, 10, 15 mg/kg, i.p.) or DEX (5 mg/kg, i.p.) were given to mice 1 h prior to LPS challenge. The mortalities were observed at 0, 12, 24, 36, 48, 60, and 72 h. ###P = 0.001 when compared with the control group; *P = 0.05, **P = 0.01, and ***P = 0.001 when compared with the LPS group.

 

Protective effects of intranasal curcumin on paraquot induced acute lung injury (ALI) in mice

Namitosh Tyagi, Asha Kumaria, D. Dash, Rashmi Singh
Environment  Toxicol  & Pharmacol  38 (2014) 913–921
http://dx.doi.org/10.1016/j.etap.2014.10.003

Paraquot (PQ) is widely and commonly used as herbicide and has been reported to be hazardous as it causes lung injury. However, molecular mechanism underlying lung toxicity caused by PQ has not been elucidated. Curcumin, a known anti-inflammatory molecule derived from rhizomes of Curcuma longa has variety of pharmacological activities including free-radical scavenging properties but the protective effects of curcumin on PQ-induced acute lung injury (ALI) have not been studied. In this study, we aimed to study the effects of curcumin on ALI caused by PQ in male parke’s strain mice which were challenged acutely byPQ (50 mg/kg, i.p.) with or without curcumin an hour before (5 mg/kg, i.n.) PQ intoxication. Lung specimens and the bronchoalveolar lavage fluid (BALF) were isolated for pathological and biochemical analysis after 48 h of PQ exposure. Curcumin administration has significantly enhanced superoxide dismutase (SOD) and catalase activities. Lung wet/dry weight ratio, malondialdehyde (MDA) and lactate dehydrogenase (LDH) content, total cell number and myeloperoxidase (MPO) levels in BALF as well as neutrophil infiltration were attenuated by curcumin. Pathological studies also revealed that intranasal curcumin alleviate PQ-induced pulmonary damage and pro-inflammatory cytokine levels like tumor necrosis factor-α (TNF-α) and nitric oxide (NO). These results suggest that intranasal curcumin may directly target lungs and curcumin inhalers may prove to be effective in PQ-induced ALI treatment in near future.

 

Phillyrin attenuates LPS-induced pulmonary inflammation via suppression of MAPK and NF-κB activation in acute lung injury mice

Wei-ting Zhong, Yi-chun Wu, Xian-xing Xie, Xuan Zhou, et al.
Fitoterapia 90 (2013) 132–139
http://dx.doi.org/10.1016/j.fitote.2013.06.003

Phillyrin (Phil) is one of the main chemical constituents of Forsythia suspensa (Thunb.), which has shown to be an important traditional Chinese medicine. We tested the hypothesis that Phil modulates pulmonary inflammation in an ALI model induced by LPS. Male BALB/c mice were pretreated with or without Phil before respiratory administration with LPS, and pretreated with dexamethasone as a control. Cytokine release (TNF-α, IL-1β, and IL-6) and amounts of inflammatory cell in bronchoalveolar lavage fluid (BALF) were detected by ELISA and cell counting separately. Pathologic changes, including neutrophil infiltration, interstitial edema, hemorrhage, hyaline membrane formation, necrosis, and congestion during acute lung injury in mice were evaluated via pathological section with HE staining. To further investigate the mechanism of Phil anti-inflammatory effects, activation of MAPK and NF-κB pathways was tested by western blot assay. Phil pretreatment significantly attenuated LPS-induced pulmonary histopathologic changes, alveolar hemorrhage, and neutrophil infiltration. The lung wet-to-dry weight ratios, as the index of pulmonary edema, were markedly decreased by Phil retreatment. In addition, Phil decreased the production of the proinflammatory cytokines including (TNF-α, IL-1β, and IL-6) and the concentration of myeloperoxidase (MPO) in lung tissues. Phil pretreatment also significantly suppressed LPS-induced activation of MAPK and NF-κB pathways in lung tissues. Taken together, the results suggest that Phil may have a protective effect on LPS-induced ALI, and it potentially contributes to the suppression of the activation of MAPK and NF-κB pathways. Phil may be a new preventive agent of ALI in the clinical setting.

A mass of studies have been reported basically on alleviating LPS-induced acute lung injury in models. Phillyrin (Fig. 1), a lignin, is one of the main chemical constituents of Forsythia suspensa (Thunb.), which is an important traditional Chinese medicine (“Lianqiao” in Chinese), and has long been used for gonorrhea, erysipelas, inflammation, pyrexia and ulcer. Previous studies indicated that Phil significantly inhibited NO production in LPS-activated macrophage cells. But there is not much evidence showing the anti-inflammatory properties of phillyrin. In the present study, we sought to investigate the effects of phillyrin on LPS-induced pulmonary inflammation in mice.

Fig. not shown. A: Effects of Phil on histopathological changes in lung tissues in LPS-induced ALI mice. Mice were given an intragastric administration of Phil (10 and 20 mg/kg) or Dex (5 mg/kg) 1 h prior to an intranasal administration of LPS. Then mice were anesthetized and lung tissue samples were collected at 6 h after LPS challenge for histological evaluation. These representative histological changes of the lung were obtained from mice of different groups (hematoxylin and eosin staining, original magnification 200×, Scale bar: 50 μm). B: Effects of Phil on LPS-induced lung morphology. The slides were histopathologically evaluated using a semi-quantitative scoring method. Lung injury was graded from 0 (normal) to 4 (severe) in four categories: congestion, edema, interstitial inflammation and inflammatory cell infiltration. The total lung injury score was calculated by adding up the individual scores of each category. The values presented are the means ± S.E.M. (n = 4–6 in each group). ##P b 0.01 vs. the control group, **P b 0.01 vs. the LPS group. Cont: control group; LPS: LPS group; Phil + LPS: Phil + LPS group; Dex + LPS: Dex + LPS group.

In summary, the present study indicated that Phil has a protective effect on LPS-induced acute lung injury. Phil significantly attenuated histopathological changes initiated by LPS via reducing over inflammatory responses. We also demonstrated that MAPK and NF-κB signaling pathways are the important targets of Phil to perform its actions. Phil acts by preventing NF-κB translocation to the nucleus or inhibiting the activation of MAPKs directly or indirectly, which is to be investigated in further studies. All these results suggest that Phil may be a new therapeutic agent for the prevention of inflammation during acute lung injury.

 

 

 

 

Read Full Post »


Advanced Topics in Sepsis and the Cardiovascular System at its End Stage

Author: Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2013/08/18/advanced-topics-in-Sepsis-and-the-Cardiovascular-System-at-its-End-Stage/

This article was written in continuation to and it is addressing additional scientific matters to the content presented on this subject in the third Section titled

III. Incidence of Sepsis (circulation infection with serious consequences)

of the 7/23/2013 article on:

Cardiovascular Complications: Death from Reoperative Sternotomy after prior CABG, MVR, AVR, or Radiation; Complications of PCI; Sepsis from Cardiovascular Interventions

Justin D Pearlman, MD, PhD, FACC and Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2013/07/23/cardiovascular-complications-of-multiple-etiologies-repeat-sternotomy-post-cabg-or-avr-post-pci-pad-endoscopy-andor-resultant-of-systemic-sepsis/

The Cardiac Dysfunction Attributable to Sepsis, Hemodynamic Collapse, and the Search for Therapeutic Options

Sepsis and the Heart – Cardiovascular Involvement in General Medical Conditions
M.W. Merx, MD; C. Weber, MD
University Hospital (C.W.), RWTH Aachen University, Aachen, Germany.
Circulation.2007; 116: 793-802doi: 10.1161/​CIRCULATIONAHA.106.678359
http://circ.ahajournals.org/content/116/7/793.full

Sepsis is generally viewed as a disease aggravated by an inappropriate immune response encountered in the afflicted individual. As an important organ system frequently compromised by sepsis and always affected by septic shock, the cardiovascular system and its dysfunction during sepsis have been studied in clinical and basic research for more than 5 decades. Although a number of mediators and pathways have been shown to be associated with myocardial depression in sepsis, the precise cause remains unclear to date. There is currently no evidence supporting global ischemia as an underlying cause of myocardial dysfunction in sepsis.  A circulating myocardial depressant factor in septic shock has long been proposed, and potential candidates for a myocardial depressant factor include cytokines, prostanoids, and nitric oxide, among others.  Endothelial activation and induction of the coagulatory system also contribute to the pathophysiology in sepsis.

Prompt and adequate antibiotic therapy accompanied by surgical removal of the infectious focus, if indicated and feasible, is the mainstay and also the only strictly causal line of therapy. In the presence of severe sepsis and septic shock, supportive treatment in addition to causal therapy is mandatory.  We delineate some characteristics of septic myocardial dysfunction, to assess the most commonly cited and reported underlying mechanisms of cardiac dysfunction in sepsis, and to briefly outline current therapeutic strategies and possible future approaches.

Sepsis, defined by consensus conference as “the systemic inflammatory response syndrome (SIRS) that occurs during infection,” is generally viewed as a disease aggravated by the inappropriate immune response encountered in the affected individual.  Morbidity and mortality are high, resulting in sepsis and septic shock being the 10th most common cause of death in the United States.  The total national hospital cost invoked by severe sepsis in the United States was estimated at approximately $16.7 billion with 215 000 associated deaths annually. A study from Britain documented a 46% in-hospital mortality rate for patients presenting with severe sepsis on admission to the intensive care unit.

Current Criteria for Establishment of the Diagnosis of SIRS, Sepsis, and Septic Shock

The cardiovascular system is an important organ system frequently affected by sepsis and always affected by septic shock.  Waisbren was the first to describe cardiovascular .dysfunction due to sepsis in 1951.  He recognized a hyperdynamic state with full bounding pulses, flushing, fever, oliguria, and hypotension.  He also described a second, smaller patient group who presented clammy, pale, and hypotensive with low volume pulses and who appeared more severely ill. The latter group might well have been volume underresuscitated, and indeed, timely and adequate volume therapy has been demonstrated to be one of the most effective supportive measures in sepsis therapy.

Under conditions of adequate volume resuscitation, the profoundly reduced systemic vascular resistance typically encountered in sepsis leads to a concomitant elevation in cardiac index that obscures the myocardial dysfunction that also occurs. As early as the mid-1980s, significant reductions in both stroke volume and ejection fraction in septic patients were observed with normal total cardiac output. The presence of cardiovascular dysfunction in sepsis is associated with a significantly increased mortality rate of 70% to 90% compared with 20% in septic patients without cardiovascular impairment.

Characteristics of Myocardial Dysfunction in Sepsis

Using portable radionuclide cineangiography, Calvin et al. were the first to demonstrate myocardial dysfunction in adequately volume-resuscitated septic patients who had decreased ejection fraction and increased end-diastolic volume index. Adding pulmonary artery catheters to serial radionuclide cineangiography, Parker and colleagues extended these observations with the 2 major findings that

(1) survivors of septic shock were characterized by increased end-diastolic volume index and decreased ejection fraction, whereas nonsurvivors typically maintained normal cardiac volumes, and

(2) these acute changes in end-diastolic volume index and ejection fraction, although sustained for several days, were reversible.

More recently, echocardiographic studies have demonstrated impaired left ventricular systolic and diastolic function in septic patients. These human studies, in conjunction with experimental studies have clearly established decreased contractility and impaired myocardial compliance as major factors that cause myocardial dysfunction in sepsis. Similar functional alterations, as discussed above, have been observed for the right ventricle.

Myocardial dysfunction in sepsis has also been analyzed with respect to its prognostic value. Parker et al. reviewing septic patients on initial presentation and at 24 hours to determine prognostic indicators, found a heart rate of <106 bpm to be the only cardiac parameter on presentation that predicted a favorable outcome.  At 24 hours after presentation, a systemic vascular resistance index > 1529 dyne · s−1 · cm−5 · m−2, a heart rate < 95 bpm or a reduction in heart rate >18 bpm, and a cardiac index > 0.5 L · min−1 · m−2 suggested survival.  In a prospective study, Rhodes et al. demonstrated the feasibility of a dobutamine stress test for outcome stratification, with nonsurvivors being characterized by an attenuated inotropic response.

The well-established biomarkers in myocardial ischemia and heart failure, cardiac troponin I and T, as well as B-type natriuretic peptide, have also been evaluated with regard to sepsis-associated myocardial dysfunction. B-type natriuretic peptide studies have delivered conflicting results in septic patients, confounded by pre-existing heart failure early in the course. Several small studies have reported a relationship between elevated cardiac troponin T and I and left ventricular dysfunction in sepsis, as assessed by echocardiographic ejection fraction or pulmonary artery catheter–derived left ventricular stroke work index.  Cardiac troponin levels also correlated with the duration of hypotension and the intensity of vasopressor therapy. In addition, increased sepsis severity, measured by global scores such as the Simplified Acute Physiology Score II (SAPS II) or the Acute Physiology And Chronic Health Evaluation II score (APACHE II), was associated with increased cardiac troponin levels, as was poor short-term prognosis.

Despite the heterogeneity of study populations and type of troponin studied, the mentioned studies were unequivocal in concluding that elevated troponin levels in septic patients reflect higher disease severity, myocardial dysfunction, and worse prognosis. In a recent meta-analysis of 23 observational studies, Lim et al. found cardiac troponin levels to be increased in a large percentage of critically ill patients. Furthermore, in a subset of studies that permitted adjusted analysis and comprised 1706 patients, this troponin elevation was associated with an increased risk of death (odds ratio, 2.5; 95% CI, 1.9 to 3.4, P<0.001). Thus, it appears reasonable to recommend inclusion of cardiac troponins in the monitoring of patients with severe sepsis and septic shock to facilitate prognostic stratification and to increase alertness to the presence of cardiac dysfunction in individual patients.

Mechanisms Underlying Myocardial Dysfunction in Sepsis

Cardiac depression during sepsis is probably multifactorial. Nevertheless, it is important to identify individual contributing factors and mechanisms to generate worthwhile therapeutic targets. As a consequence, a vast array of mechanisms, pathways, and disruptions in cellular homeostasis have been examined in septic myocardium.

An early theory of myocardial depression in sepsis based on the hypothesis of global myocardial ischemia has no support. Septic patients have been shown to have high coronary blood flow and diminished coronary artery–coronary sinus oxygen difference.  Coronary sinus blood studies in patients with septic shock have demonstrated complex metabolic alterations in septic myocardium, including increased lactate extraction, decreased free fatty acid extraction, and decreased glucose uptake.  Several magnetic resonance studies in animal models of sepsis have demonstrated the presence of normal high-energy phosphate levels in the myocardium.  CAD-aggravating factors encountered in sepsis encompass generalized inflammation and the activated coagulatory system. The endothelium plays a prominent role in sepsis, but little is known of the impact of preexisting, CAD-associated endothelial dysfunction in this context. In a postmortem study of 21 fatal cases of septic shock, previously undiagnosed myocardial ischemia at least contributed to death in 7 of the 21 cases (all 21 patients were males, with a mean age of 60.4 years

Myocardial Depressant Substance

Parrillo et al. first proposed  a circulating myocardial depressant factor in septic shock  more than 50 years ago. They quantitatively linked the clinical degree of septic myocardial dysfunction with the effect that serum, taken from respective patients, had on rat cardiac myocytes, with clinical severity correlating well with the decrease in extent and velocity of myocyte shortening. These effects were not seen when serum from convalescent patients whose cardiac function had returned to normal was applied or when serum was obtained from other critically ill, nonseptic patients. These findings were extended when ultrafiltrates from patients with severe sepsis and simultaneously reduced left ventricular stroke work index (< 30 g · m−1 · m−2) displayed cardiotoxic effects and contained significantly increased concentrations of interleukin (IL)-1, IL-8, and C3a. Recently, Mink et al. demonstrated that lysozyme c, a bacteriolytic agent believed to originate mainly from disintegrating neutrophilic granulocytes and monocytes, mediates cardiodepressive effects during Escherichia coli sepsis and, importantly, that competitive inhibition of lysozyme c can prevent myocardial depression in the respective experimental sepsis model. Additional potential candidates for myocardial depressant substance include other cytokines, prostanoids, and nitric oxide (NO).

Cytokines

Infusion of lipopolysaccharide (LPS, an obligatory component of Gram-negative bacterial cell walls) into both animals and humans partially mimics the hemodynamic effects of septic shock. Only a minority of patients with septic shock have detectable LPS levels, and the prolonged time course of septic myocardial dysfunction make the role of LPS inconsistent with LPS representing the sole myocardial depressant substance. Tumor necrosis factor-α (TNF-α) is an important early mediator of endotoxin-induced shock. TNF-α is mainly derived from activated macrophages. Studies using monoclonal antibodies directed against TNF-α or soluble TNF-α receptors failed to improve survival in septic patients. IL-1 is synthesized by monocytes, macrophages, and neutrophils in response to TNF-α and plays a crucial role in the systemic immune response. IL-1 depresses cardiac contractility by stimulating NO synthase (NOS). Transcription of IL-1 is followed by delayed transcription of IL-1 receptor antagonist (IL-1-ra), which functions as an endogenous inhibitor of IL-1. Recombinant IL-1-ra was evaluated in phase III clinical trials, which showed a tendency toward improved survival and increased survival time in a retrospective analysis of the patient subgroup with the most severe sepsis; but this initially promising therapy failed to deliver a survival benefit. IL-6, another proinflammatory cytokine, has also been implicated in the pathogenesis of sepsis and is considered a more consistent predictor of sepsis than TNF-α because of its prolonged elevation in the circulation. Although cytokines may very well play a key role in the early decrease in contractility, they cannot explain the prolonged duration of myocardial dysfunction in sepsis, unless they result in the induction or release of additional factors that in turn alter myocardial function, such as prostanoids or NO.

Prostanoids

Prostanoids are produced by the cyclooxygenase enzyme from arachidonic acid (an omega-6 derivative). The expression of cyclooxygenase enzyme-2 is induced, among other stimuli, by LPS and cytokines (cyclooxygenase enzyme-1 is expressed constitutively). Elevated levels of prostanoids such as thromboxane and prostacyclin that alter coronary autoregulation, coronary endothelial function, and intracoronary leukocyte activation, have been demonstrated in septic patients. Early animal studies with cyclooxygenase inhibitors such as indomethacin yielded very promising results. Along with other positive results, these led to an important clinical study involving 455 septic patients who were randomized to receive intravenous ibuprofen or placebo, but that study did not demonstrate improved survival for the treatment arm. Similarly, a smaller study on the effects of lornoxicam failed to provide evidence for a survival benefit through cyclooxygenase inhibition in sepsis.

Endothelin-1

Endothelin-1 upregulation has been demonstrated within 6 hours of LPS-induced septic shock. Cardiac overexpression of ET-1 triggers an increase in inflammatory cytokines (among others, TNF-α, IL-1, and IL-6), interstitial inflammatory infiltration, and an inflammatory cardiomyopathy that results in heart failure and death. The involvement of ET-1 in septic myocardial dysfunction is supported by the observation that tezosentan, a dual endothelin-A and endothelin-B receptor antagonist, improved cardiac index, stroke volume index, and left ventricular stroke work index in endotoxemic shock. However, higher doses of tezosentan exhibited cardiotoxic effects and led to increased mortality. Although ET-1 has been demonstrated to be of pathophysiological importance in a wide array of cardiac diseases through autocrine, endocrine, or paracrine effects, its biosynthesis, receptor-mediated signaling, and functional consequences in septic myocardial dysfunction warrant further investigation to assess the therapeutic potential of ET-1 receptor antagonists.

Free Radicals and Antioxidants: an Overview

The presence of free radicals in biological materials was discovered about 50 years ago. Today, there is a large body of evidence indicating that patients in hospital intensive care units (ICUs) are exposed to excessive free radicals from drugs and other substances that alter cellular reduction -oxidation (redox) balance, and disrupt normal biological functions. However, low levels of free radicals are also vital for many cell signaling events and are essential for proper cell function.

Normal cellular metabolism involves the production of ROS, and in humans, superoxide (O2 -) is the most commonly produced free radical. Phagocytic cells such as macrophages and neutrophils are prominent sources of O2 -. During an inflammatory response, these cells generate free radicals that attack invading pathogens such as bacteria and, because of this, the production of O2- by activated phagocytic cells in response to inflammation is one of the most studied free radical producing systems.

Excess free radicals can result from a variety of conditions such as tissue damage and hypoxia (limiting oxygen levels), overexposure to environmental factors (tobacco smoke, ultraviolet radiation, and pollutants), a lack of antioxidants, or destruction of free radical scavengers. When the production of damaging free radicals exceeds the capacity of the body’s antioxidant defenses to detoxify them, a condition known as oxidative stress occurs.

The hydroxyl radical (.OH) is the most reactive of the free radical molecules. OH- damages cell membranes and lipoproteins by a process termed lipid peroxidation. In fact, lipid peroxidation can be defined as the process whereby free radicals “steal” electrons from the lipids in our cell membranes, resulting in cell damage and increased production of ROS.

Catalase and glutathione peroxidase both work to detoxify O2-reactive radicals by catalyzing the formation of H2O2 derived from O2 -. The liver, kidney, and red blood cells possess high levels of catalase, which helps to detoxify chemicals in the body. The water-soluble tripeptide-thiol glutathione also plays an important role in a variety of detoxification processes. Glutathione is found in millimolar concentrations in the cell cytosol and other aqueous phases, and readily interacts with free radicals, especially the hydroxyl radical, by donating a hydrogen atom.

Adhesion Molecules

Surface-expression upregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 has been demonstrated in murine coronary endothelium and cardiomyocytes after LPS and TNF-α stimulation. After cecal ligation and double puncture, myocardial intercellular adhesion molecule-1 expression increases in rats. Vascular cell adhesion molecule-1 blockade with antibodies has been shown to prevent myocardial dysfunction and decrease myocardial neutrophil accumulation, whereas both knockout and antibody blockade of intercellular adhesion molecule-1 ameliorate myocardial dysfunction in endotoxemia without affecting neutrophil accumulation. But neutrophil depletion does not protect against septic cardiomyopathy, which suggests that the cardiotoxic potential of neutrophils infiltrating the myocardium is of lesser importance in this context.

Cells and signaling pathways

It is believed that sepsis and therefore septic shock are due to the inappropriate increase in the innate immune response via circulating and tissue inflammatory cells, such as monocytes/macrophages and neutrophils. These cells normally exist in a nonactivated state but are rapidly activated in response to bacteria. Sepsis induces a dysfunction in immune cells that contributes to the development of injuries by producing mediators such as cytokines and ROS.

LPS of Gram-negative organisms induces macrophages to secrete cytokines, which in turn activate T, and B cells to upregulate the adaptive immune responses. Toll-like receptor 4 (TLR4) is the LPS receptor and its stimulation induces nuclear factor kB (NF-kB) activation. The activation of NF-kB involves phosphorylation and degradation of IkB, an inhibitor of NF-kB. The NF-kB/IkB system exerts transcriptional regulation on proinflammatory genes encoded for various adhesion molecules and cytokines. Activation of NF-kB leads to the induction of NF-kB binding elements in their promoter regions and also leads to the induction of NF-kB dependent effector genes, which produce modifications in blood flow, and aggregation of neutrophils, and platelets. This results in damaged endothelium and also coagulation abnormalities often seen in patients with sepsis and septic shock. Therefore, NF-kB is reported to be an O2 sensor in LPS-induced endotoxemia.

The sources of ROS during sepsis are:

  • the mitochondrial respiratory chain.
  • the metabolic cascade of arachidonic acid.
  • the protease-mediated enzyme xanthine oxidase.
  • granulocytes and other phagocytes activated by complement, bacteria, endotoxin, lysosomal enzymes, etc.
  • Other oxidases mainly NADPH oxidase.

Activated immune cells produce O2 – as a cytotoxic agent as part of the respiratory burst via the action of membrane-bound NADPH oxidase on O2.

The increase of ROS after LPS challenge has been demonstrated in different models of septic shock in peritoneal macrophages and lymphocytes. This disturbance in the balance between pro-oxidants (ROS) and antioxidants in favor of the former is characteristic of oxidative stress in immune cells in response to endotoxin. In this context,

a typical behavior of these cells under an oxidative stress situation implies changes in different immune functions such as an increase in adherence and phagocytosis and a decrease in chemotaxis.  Neutrophils play a crucial role in the primary immune defense against infectious agents,which includes phagocytosis and the production of ROS. In addition, endogenous antioxidant defenses exist in a number of locations, namely intracellularly, on the cell membrane and extracellularly. The immune system is highly reliant on accurate cell-cell communication for optimal function, and any damage to the signaling systems involved will result in an impaired immune responsiveness.

Oxidative stress and modulation on GSH/GSSG (GSSG=oxidized GSH) levels also up-regulate gene expression of several other antioxidant proteins, such as manganese SOD, glutathione peroxidase, thioredoxin (Trx) and metallothionein.

Nitric Oxide

The current understanding of sepsis is a cascade of events that involves the microcirculation unevenly because of a differential effect on the large and contiguous intestinal epithelium, secondary effects on cardiopulmonary blood flows and cardiac output. This leads to a substantial body of work on therapeutic targets, either aimed at total inhibition or selective inhibition of NO synthase, and the special role of iNOS.

NO is synthesized from L-arginine by different isoenzymes of (NOS), and is implicated in a wide range of disease processes, exerting both detrimental and beneficial effects at the cellular and vascular levels. To date, three main isoforms of NOS are known:

  • neuronal NOS (NOS-1 or nNOS),
  • inducible NOS (NOS-2 or iNOS), and
  • endothelial NOS (NOS-3 or eNOS).

NO has been shown to play a key role in the pathogenesis of septic shock

Hyperproduction of NO induces

  • excessive vasodilation,
  • changes in vascular permeability, and
  • inhibition of noradrenergic nerve transmission,
  • all characteristics of human septic shock.

The recogniton of NO production by activated macrophages as part of the inflammatory process was an important milestone for assesing both the biological production of NO and the phenomenon of induction of NOS activity. The observation has been extended to neutrophils, lymphocytes, and other cell types. The role of NO in the pathophysiology of endotoxic shock was advanced by Thiemermann and Vane, who observed that administration of the specific NOS inhibitor N-methyl-L-arginine (L-NMMA) decreased the severe hypotension produced by administration of LPS. Other groups simultaneously reported similar results indicating that endotoxin increases NO production and prompted the idea that pharmacological inhibition of NOS may be useful in the treatment of inflammation and septic shock. However, clinical trials using L-NMMA failed to show a beneficial effect in septic shock patient. The major limitation for the use of NOS inhibitors in clinical studies is the development of pulmonary hypertension as a side effect of NOS blockade, which can be alleviated by the use of inhaled NO.

However, several compounds which modulate NO synthesis have been patented in recent years, such as various inflammatory mediators that have been implicated in the induction and activation of iNOS, particularly IFNg, TNFa, IL-1b, and platelet-activating factor (PAF) alone or synergistically. In addition to the activation of iNOS, cytokines and endotoxin may increase NO release by increasing arginine availability through the opening of the specific y+ channels and the expression of the cationic amino acid transporter (CAT), or by increasing tetrahydrobiopterin levels, a key cofactor in NO synthesis. Several experimental studies have demonstrated a decrease in NOS activity resulting in an impairment in endothelial-dependent relaxation during endotoxemia and experimental sepsis, possibly as the result of a cytokine-or hypoxia-induced shortened half-life of NOS mRNA, or of altered calcium mobilization.

Advanced Topics in Sepsis and the Cardiovascular System –  Augmentation for the third Section titled:

III. Incidence of Sepsis (circulation infection with serious consequences)

of the 7/23/2013 article on: Cardiovascular Complications: Death from Reoperative Sternotomy after prior CABG, MVR, AVR, or Radiation; Complications of PCI; Sepsis from Cardiovascular Interventions

NO exerts in vitro toxic effects including nuclear damage, protein and membrane phospholipid alterations, and the inhibition of mitochondrial respiration in several cell types. Mitochondrial impairment could also be considered as an adaptive phenomenon, decreasing cellular metabolism when the energy supply is limited. The toxicity of NO itself may be enhanced by the formation of ONOO- from the reaction of NO with O-2. Therefore, the multiple organ failure syndrome (MOFS) that often accompanies severe sepsis may be related to the cellular effects of excess NO or ONOO-.

Involvement of Nitrogen Species

NO reacts rapidly with ferrous iron, and at physiological concentrations, NO also binds to soluble guanylate cyclase and to another hemoprotein, cytochrome c oxidase (Complex IV), the terminal enzyme of the mitochondrial respiratory chain. NO can therefore control cellular functions via the reversible inhibition of respiration. There are a number of reactive NO species, such as

N2O3 and
ONOO-
that can also alter critical cellular components.

During the first hours after injury, iNOS-mediated NO production is upregulated, producing a burst of NO that far exceeds basal levels. This overabundance of NO produces significant cellular injury via several mechanisms.

NO may directly promote overwhelming peripheral vasodilation, resulting in vascular decomposition;

NO may upregulate the transcription NF-kB initiating an inflammatory signaling pathway that, in turn, triggers numerous inflammatory cytokines.

NO also interacts with the O-2 to yield ONOO-, a highly reactive compound that exacerbates the injury produced by either O-2 alone or NO alone.

The ONOO- generation which occurs during fluid resuscitation in the injured subject produces cellular death by enhancing DNA single strand breakage, activates the nuclear enzyme polyADP ribose synthetase (PARS), leading to cellular energy depletion and cellular necrosis. The detrimental effects of ONOO- in shock and resuscitation have been attributed to oxidation of sulfhydryl groups, the nitration of tyrosine, tryptophane, and guanine, as well as inhibition of the membrane sodium-potassium adenosine triphosphatase. PARS activation depletes NAD and thus alters electron transport, ATP synthesis, and glycolysis; and leads to DNA fragmentation and cellular apoptosis.

The activation of monocytes, macrophages and endothelial cells by LPS results in the expression of iNOS, and consequently increases the transformation of L-arginine to NO, which can combine with O2- to form ONOO-, causing tissue injury during shock, inflammation and ischemia reperfusion. NO stimulates H2O2 and O-2 production by mitochondria, increasing leakage of electrons from the respiratory chain. H2O2, in turn, participates in the upregulation of iNOS expression via NFkB activation. ONOO- has been shown to stimulate H2O2 production by isolated mitochondria. On the other hand, NO can decrease ROS-produced damage that occurs at physiological levels of NO. The high reactivity of NO with radicals might be beneficial in vivo by scavenging peroxyl radicals and inhibiting peroxidation. ONOO- may also be a signal transmitter and can mediate vasorelaxation, similarly to NO.

In sepsis, NO may exert direct and indirect effects on cardiac function. Sustained generation of NO occurs in systemic inflammatory reactions, such as septic shock with involvement in circulatory failure. In fact, myocardial iNOS activity has been reported in response to endotoxin and cytokines and inversely correlated with myocardial performance. Low-to-moderate doses of iNOS inhibitors restore myocardial contractility in hearts exposed to proinflammatory cytokines, whereas at higher doses, the effects are reversed. This finding may indicate that small amounts of NO produced by iNOS may be necessary to maintain contractility and can be cardio-protective in experimental sepsis.

A list of effects of NO in sepsis is as follows:

  • Inhibition of nitric oxide synthesis causes myocardial ischemia in endotoxemic rats
  • Nitric oxide causes dysfunction of coronary autoregulation in endotoxemic rats
  • Prolonged inhibition of nitric oxide synthesis in severe septic shock

Effect of L-NAME, an inhibitor of nitric oxide synthesis, on cardiopulmonary function in human septic shock:  Pulmonary hypertension and reduced cardiac output during inhibition of nitric oxide synthesis in human septic shock

Effect of L-NAME, an inhibitor of nitric oxide synthesis, on plasma levels of IL-6, IL-8, TNF-a and nitrite/nitrate in human septic shock

Endothelin-1 and blood pressure after inhibition of nitric oxide synthesis in human septic shock

Distribution and metabolism of NO-nitro-L-arginine methyl ester in patients with septic shock

Pulmonary hypertension and reduced cardiac output can be major side effects of continuous NO synthase inhibition. Pulmonary vasoconstriction is undesirable because it may compromise pulmonary gas exchange and because it increases the workload on the right ventricle.

Blood pressure and systemic vascular resistance increased during infusion of the NO synthase inhibitor L-NAME, and the dosage of catecholamines was reduced. The vasoconstrictive response to L-NAME most likely was the result of blocking the NO system . In addition to the systemic effects of L-NAME, severe pulmonary vasoconstriction was observed with L-NAME.

S-Methylisothiourea sulfate (SMT) is at least 10- to 30-fold more potent as an inhibitor of inducible NOS (iNOS) in immuno-stimulated cultured macrophages (EC50, 6 ,AM) and vascular smooth muscle cells (EC50, 2 ,uM) than NG-methyl-L-arginine (MeArg) or any other NOS inhibitor yet known. The effect of SMT on iNOS activity can be reversed by excess L-arginine in a concentration-dependent manner.  SMT, a potent and selective inhibitor of iNOS, may have considerable value in the therapy of circulatory shock of various etiologies and other pathophysiological conditions associated with induction of iNOS. SMT, or other iNOS-selective inhibitors, are likely to have fewer side effects which are related to the inhibition of eNOS, such as excessive vasoconstriction and organ ischemia), increased platelet and neutrophil adhesion and accumulation, and microvascular leakage.

Administration of the iron (III) complex of diethylenetriamine pentaacetic acid (DTPA iron (III), prevented death in Corynebacterium parvum 1 LPS-treated mice. Using electrochemistry, the binding of NO to DTPA iron (II) is confirmed.  Treatment with DTPA iron (III) resulted in a significant decrease in mortality compared to the untreated controls. The efficacy of DTPA iron (III) increased when given to mice 2 h or more after infection. The best results were observed when DTPA iron (III) was given 5 h after infection.  The iron (III) complex of diethylenetriamine pentaacetic acid (DTPA iron [III]) protected mice and baboons from the lethal effects of an infusion with live LD 100 Escherichia coli. In mice, optimal results were obtained when DTPA iron (III) was administered two or more hours after infection.

PJ34, a novel, potent PARP-1 inhibitor was found to protect against LPS induced tissue damage. PARP inhibitors protected Langendorff-perfused hearts against ischemia-reperfusion induced damages by activating the PI3-kinase–Akt pathway. The importance of the PI3-kinase–Akt pathway in LPS induced inflammatory mechanisms has gained support, raising the question whether this pathway was involved in the effect of PJ34 on LPS-induced septic shock.
Activation of the PI3-kinase–Akt/protein kinase B cytoprotective pathway is likely to contribute to the protective effects of PARP inhibitors in shock and inflammation.

Asymmetrical dimethyl arginine (ADMA) is an endogenous non-selective inhibitor of nitric oxide synthase that may influence the severity of organ failure and the occurrence of shock secondary to an infectious insult. Levels may be genetically determined by a promoter polymorphism in a regulatory gene encoding dimethylarginine dimethylaminohydrolase II (DDAH II).

ADMA levels and Sequential Organ Failure Assessment scores were directly associated on day one (p = 0.0001) and day seven (p = 0.002). The degree of acidaemia and lactaemia was directly correlated with ADMA levels at both time points (p < 0.01). On day seven, IL-6 was directly correlated with ADMA levels (p = 0.006). The variant allele with G at position -449 in the DDAH II gene was associated with increased ADMA concentrations at both time points (p < 0.05).
https://pharmaceuticalintelligence.com/2012/10/20/nitric-oxide-and-sepsis-hemodynamic-collapse-and-the-search-for-therapeutic-options/  larryhbern

Sepsis, Multi-organ Dysfunction Syndrome, and Septic Shock: A Conundrum of Signaling Pathways Cascading Out of Control   larryhbern
https://pharmaceuticalintelligence.com/2012/10/13/sepsis-multi-organ-dysfunction-syndrome-and-septic-shock-a-conundrum-of-signaling-pathways-cascading-out-of-control/

During sepsis, the inflammation triggers widespread coagulation in the bloodstream. A severe form of acute lung injury features pulmonary inflammation and increased capillary leak, is associated with a high mortality rate, and accounts for 100,000 deaths annually in the United States, especially associated with  sepsis. Neutrophils are major effector cells at the frontier of innate immune responses, and they play a critical role in host defense against invading .microorganisms. The tissue injury appears to be related to proteases and toxic reactive oxygen radicals released from activated neutrophils. Excessive procoagulant activity is of pathophysiological significance in these disease settings. This is consistent with a pneumonia or lung injury preceding sepsis. Indeed, it is not surprising that abdominal, cardiac bypass, and post cardiac revascularization may also lead to events resembling sepsis and/or cardiovascular collapse.

The activation of the coagulation cascade is one of the earliest events initiated following tissue injury. The prime function of this complex and highly regulated proteolytic system is to generate insoluble, crosslinked fibrin strands, which bind and stabilize weak platelet hemostatic plugs, formed at sites of tissue injury. The tissue factor-dependent extrinsic pathway is the predominant mechanism by which the coagulation cascade is locally activated. The cellular effects mediated via activation of proteinase-activated receptors (PARs) may be of particular importance. In this regard, studies in PAR1 knockout mice have shown that this receptor plays a major role in orchestrating the interplay between coagulation, inflammation and lung fibrosis.  The systemic inflammatory response syndrome (SIRS) is the massive inflammatory reaction resulting from systemic mediator release that may lead to multiple organ dysfunction.

For signal transduction, 01TREM-1 couples to the ITAM-containing adapter DNAX activation protein of 12 kDa (23DAP12 ). MARV and EBOV activate TREM-1 on human neutrophils, resulting in 12DAP12 phosphorylation, TREM-1 shedding, mobilization of intracellular calcium, secretion of proinflammatory cytokines, and phenotypic changes. TREM-1 is the best-characterized member of a growing family of 12DAP12-associated receptors that regulate the function of myeloid cells in innate and adaptive responses. TREM-1 (triggering receptor expressed on myeloid cells), a recently discovered receptor of the immunoglobulin superfamily, activates neutrophils and monocytes/macrophages by signaling through the adapter protein 12DAP12.

Circulating and organ-specific cell populations are activated to produce proinflammatory mediators during sepsis. Neutrophils and PBMCs bear TLR2 and TLR4, as well as other receptors, such as protein —coupled receptor, that induce increased generation of cytokines and other immunoregulatory proteins, as well as enhance release of proinflammatory mediators, including reactive oxygen species.

The expression of cytokines such as TNF-α and IL-1β is increased in sepsis, and engagement of TNF-α with type I(p55) and type II(p75) TNF receptors or IL-1β with IL-1 receptors belonging to the TLR/IL-1 receptor family produces activation of kinases (including Src, p38, extracellular signal—regulated kinase, and phosphoinositide 3–kinase) and transcriptional factors (such as nuclear factor [NF]–κB) important for further up-regulation of inflammatory proteins.

Identification of patients with cellular phenotypes characterized by increased activation of NF-κB, Akt, and protein 38, as well as discrete patterns of gene activation, may permit identification of patients with sepsis who are likely to have a worse clinical outcome In support of the hypothesis, greater nuclear accumulation of NF-κB is accompanied by higher mortality and worse clinical course in patients with sepsis. Persistent activation of NF-κB was found in nonsurvivors, with surviving patients having lower nuclear concentrations of NF-κB at early time points in their septic course than did nonsurvivors as well as more rapid return of nuclear accumulation of NF-κB. A study of surgical patients without sepsis supports the hypothesis that neutrophil phenotypes defined by NF-κB activation patterns predict clinical outcome. In that clinical series of patients undergoing repair of aortic aneurysms, higher preoperative levels of NF-κB in peripheral neutrophils were associated with death and with the development of postoperative organ dysfunction.

Insulin alleviates degradation of skeletal muscle protein by inhibiting the ubiquitin-proteasome system in septic rats

Qiyi Chen, Ning Li, Weiming Zhu, Weiqin Li, Shaoqiu Tang, et al. Chen et al. Journal of Inflammation 2011, 8:13

http://www.journal-inflammation.com/content/8/1/13

Hypercatabolism is common under septic conditions. Skeletal muscle is the main target organ for hypercatabolism, and this phenomenon is a vital factor in the deterioration of recovery in septic patients. In skeletal muscle, activation of the ubiquitin-proteasome system plays an important role in hypercatabolism under septic status. Insulin is a vital anticatabolic hormone and previous evidence suggests that insulin administration inhibits various steps in the ubiquitin-proteasome system. However, whether insulin can alleviate the degradation of skeletal muscle protein by inhibiting the ubiquitin-proteasome system under septic condition is unclear. This paper confirmed that mRNA and protein levels of the ubiquitin-proteasome system were upregulated and molecular markers of skeletal muscle proteolysis (tyrosine and 3-methylhistidine) simultaneously increased in the skeletal muscle of septic rats. We concluded that the ubiquitin-proteasome system is important skeletal muscle hypercatabolism in septic rats. Infusion of insulin can reverse the detrimental metabolism of skeletal muscle by inhibiting the ubiquitin-proteasome system, and the effect is proportional to the insulin infusion dose.

The International Sepsis Forum’s frontiers in sepsis: high cardiac output should be maintained in severe sepsis

Jean-Louis Vincent
Erasme Hospital, University of Brussels, Brussels, Belgium
Critical Care 2003; 7:276-278 (DOI 10.1186/cc2349)

Despite a usually normal or high cardiac output, severe sepsis is associated with inadequate tissue oxygenation, leading to organ failure and death. Some authors have suggested that raising cardiac output and oxygen delivery to predetermined supranormal values may be associated with improved

survival. While this may be of benefit in certain patients, bringing all patients to similar, supranormal values, is simplistic. It is much preferable to titrate therapy according to the needs of each individual patient. A combination of variables should be used for this purpose, in addition to a careful clinical evaluation, including not only cardiac  output but also the mixed venous oxygen saturation and the blood lactate concentrations. The concept is to assess the adequacy of the cardiac output in patients with severe sepsis, enabling management strategies aimed at optimizing cardiac output to be tailored to the individual patient.

The State of US Health, 1990-2010:  Burden of Diseases, Injuries, and Risk Factors

JAMA Aug 14, 2013, Vol 310, No. 6
US Burden of Disease Collaborators

We used the systematic analysis of descriptive epidemiology of 291 diseases and injuries, 1160 sequelae of these diseases and injuries, and 67 risk factors or clusters of risk factors from 1990 to 2010 for 187 countries developed for the Global Burden of Disease 2010. Disability-adjusted life-years (DALYs) were estimated as the sum of YLDs and YLLs. Deaths and DALYs related to risk factors were based on systematic reviews and meta-analyses of exposure data and relative risks for risk-outcome pairs. Healthy life expectancy (HALE) was used to summarize overall population health, accounting for both length of life and levels of ill health experienced at different ages.  From 1990 to 2010, US life expectancy at birth and HALE increased, all-cause death rates at all ages decreased, and age-specific rates of years lived with disability remained stable. However, morbidity and chronic disability now account for nearly half of the US health burden, and improvements in population health in the United States have not kept pace with advances in population health in other wealthy nations. http://jama.jamanetwork.com/article.aspx?articleid=1710486HYPERLINK “http://jama.jamanetwork.com/article.aspx?articleid=1710486&goback=.gde_3267353_member_265629812#%21″&HYPERLINK “http://jama.jamanetwork.com/article.aspx?articleid=1710486&goback=.gde_3267353_member_265629812#%21″goback=%2Egde_3267353_member_265629812#%21

The Evolution of an Inflammatory Response.

Stephen F Lowry
Surgical Infections 09/2009; 10(5):419-25. · 1.80 Impact Factor

An understanding of patient-specific variation and adaptability could direct individualized biologic and management interventions for severe injury and infection. Despite more detailed appreciation of the molecular mechanisms of danger and pathogen recognition and response biology, we have much to learn about the complexity of severe injury and infection. There is a great need to extend our investigation of these mechanisms to experimental and stress-modified clinical scenarios.

Frailty and Heart Disease.

Stephan von Haehling, Stefan D Anker, Wolfram Doehner, John E Morley, Bruno Vellas
Department of Cardiology, Campus Virchow-Klinikum, Berlin, Germany.
Int j cardiol (impact factor: 7.08). 08/2013; DOI:10.1016/j.ijcard.2013.07.068

Frailty is emerging as a syndrome of pre-disability that can identify persons at risk for negative outcomes. Its presence places the individual at risk for rapid deterioration when a major event such as myocardial infarction or hospitalization occurs. In patients with cardiovascular disease, frailty is about three times more prevalent than among elderly persons without.

Pro-atrial natriuretic peptide is a prognostic marker in sepsis, similar to the APACHE II score: an observational study

Nils G Morgenthaler1, Joachim Struck1, Mirjam Christ-Crain2, Andreas Bergmann1 and Beat Müller2

1Research Department, BRAHMS AG, Biotechnology Center, Hennigsdorf/Berlin, Germany

2Department of Internal Medicine, University Hospital, Basel, Switzerland
Critical Care 2005, 9:R37-R45 (DOI 10.1186/cc3015)

This article is online at: http://ccforum.com/content/9/1/R37

Additional biomarkers in sepsis are needed to tackle the challenges of determining prognosis and optimizing selection of high-risk patients for application of therapy. In the present study, conducted in a cohort of medical intensive care unit patients, our aim was to compare the prognostic

value of mid-regional pro-atrial natriuretic peptide (ANP) levels with those of other biomarkers and physiological scores.  Blood samples obtained in a prospective observational study conducted in 101 consecutive critically ill patients admitted to the intensive care unit were analyzed. The prognostic value of pro-ANP levels was compared with that of the Acute Physiology and Chronic Health Evaluation (APACHE) II score and with those of various biomarkers (i.e. C-reactive protein, IL-6 and procalcitonin). Mid-regional pro-ANP was detected in EDTA plasma from all patients using a new sandwich immunoassay.  The median pro-ANP value in the survivors was 194 pmol/l (range 20–2000 pmol/l), which was significantly lower than in the nonsurvivors (median 853.0 pmol/l, range 100–2000 pmol/l; P < 0.001). On the day of admission, pro-ANP levels, but not levels of other biomarkers, were significantly higher in surviving than in nonsurviving sepsis patients (P = 0.001). In a receiver operating characteristic curve analysis for the survival of patients with sepsis, the area under the curve (AUC) for pro-ANP was 0.88, which was significantly greater than the AUCs for procalcitonin and C-reactive protein, and similar to the AUC for the APACHE II score.

Bench-to-Bedside Review: Significance and Interpretation of Elevated Troponin in Septic Patients

Raphael Favory1,2 and Remi Neviere1
1Physiology Department, School of Medicine, EA2689 University of Lille, France

2Medical Intensive Care Unit, Universitary Hospital of Lille, France

Critical Care 2006, 10:224 (doi:10.1186/cc4991)  http://ccforum.com/content/10/4/224

Because no bedside method is currently available to evaluate myocardial contractility independent of loading conditions, a biological marker that could detect myocardial dysfunction in the early stage of severe sepsis would be a helpful tool in the management of septic patients. Clinical and experimental studies have reported that plasma cardiac troponin levels are increased in

sepsis and could indicate myocardial dysfunction and poor outcome. The high prevalence of elevated levels of cardiac troponins in sepsis raises the question of what mechanism results in their release into the circulation.
(Note: This study is prior to the hs-troponins)
The presence of microvascular failure and regional wall motion abnormalities, which are frequently observed in positive-troponin patients, also suggest ventricular wall strain and cardiac cell necrosis. Altogether, the available studies

support the contention that cardiac troponin release is a valuable marker of myocardial injury in patients with septic shock.

Myocardial Protection in Sepsis

Simon Shakar and Brian D Lowes
University of Colorado Denver, Aurora, CO 80045, USA
Critical Care 2008, 12:177 (doi:10.1186/cc6978)  http://ccforum.com/content/12/5/177

Sepsis with myocardial dysfunction is seen commonly. Beta-blockers have been used successfully to treat chronic heart failure based on the premise that chronically elevated adrenergic drive is detrimental to the myocardium. However, recent reports on the acute use of beta-blockers in situations with potential hemodynamic compromise have shown the risks associated with this approach.

Myocardial injury and depression are common during sepsis and are likely multi-factorial in etiology. The adrenergic nervous system is activated in sepsis and pharmacological doses of agonists are commonly utilized during goal directed therapy to support oxygen delivery and maintain perfusion pressure. There is a large body of evidence suggesting that excessive adrenergic levels can cause myocardial damage.

Recent large prospective trials would mandate caution when using beta-blockers in acute settings of hemodynamic compromise. The COMMIT trial in acute myocardial infarction showed that metoprolol’s benefit in reducing reinfarction and arrhythmia (10 per 1,000) was offset by an increase in cardiogenic shock (11 per 1,000). This was most prominent in the first day of therapy in elderly patients with tachycardia and low blood pressure, a population reminiscent

of the one discussed in the current series. The POISE trial showed that metoprolol, started 2 to 4 hours before surgery in high risk cardiac patients, led to increased rates of death and stroke. The rates of myocardial infarction were

reduced. Hypotension was very instrumental in causing the adverse events. Interestingly, sepsis and infection were also clearly more common on metoprolol.

Myocardial depression with beta-blockers could explain the need to escalate therapy with vasoactive drugs in the current series. Gore and colleagues showed that esmolol acutely reduced cardiac output by 20% in septic patients. There was also a reduction in blood pressure and oxygen delivery. Kukin

and colleagues studied low dose beta-blockers in chronic heart failure patients. They found that even 6.25 mg of metoprolol, given orally, acutely decreased cardiac output, stroke volume and stroke work index. After 3 months and uptitration to 50 mg bid, the administration of the drug continued to cause a decrease in cardiac output and stroke work index.

Bench-to-Bedside Review: Beta-Adrenergic Modulation in Sepsis

Etienne de Montmollin, Jerome Aboab, Arnaud Mansart and Djillali Annane
Service de Réanimation Polyvalente de l’hôpital Raymond Poincaré,  Garches, France
Critical Care 2009, 13:230 (doi:10.1186/cc8026  http://ccforum.com/content/13/5/230
Sepsis, despite recent therapeutic progress, still carries unacceptably high mortality rates. The adrenergic system, a key modulator of organ function and cardiovascular homeostasis, could be an interesting new therapeutic target for septic shock. beta-adrenergic regulation of the immune function in sepsis is complex and is time dependent. However, beta-2 activation as well as beta-1 blockade seems to downregulate proinflammatory response by modulating the

cytokine production profile. beta-1 blockade improves cardiovascular homeostasis in septic animals, by lowering myocardial oxygen consumption without altering organ perfusion, and perhaps by restoring normal cardiovascular variability. Beta-Blockers could also be of interest in the systemic catabolic response to sepsis, as they oppose epinephrine which is known to promote hyperglycemia, lipid and protein catabolism. Beta-1 blockade may reduce platelet aggregation and normalize the depressed fibrinolytic status induced by adrenergic stimulation. Therefore, beta-2 blockade as well as beta-2 activation improves sepsis-induced immune, cardiovascular and coagulation

dysfunctions. Beta-2 blocking, however, seems beneficial in the metabolic field. Enough evidence has been accumulated in the literature to propose beta-2 adrenergic modulation, beta-1 blockade and beta-2 activation in particular, as new promising therapeutic targets for septic dyshomeostasis, modulating favorably immune, cardiovascular, metabolic and coagulation systems.

Brain Natriuretic Peptide for Prediction of Mortality in Patients with Sepsis: a Systematic Review and Meta-Analysis

Fei Wang1†, Youping Wu1†, Lu Tang2,3†, Weimin Zhu1, Feng Chen1, et al.
Critical Care 2012, 16:R74    http://ccforum.com/content/16/3/R74

The prognostic role of brain natriuretic peptide (BNP) or N-terminal pro-B-type natriuretic peptide (NT-proBNP) in septic patients remains controversial. The purpose of this systematic review and meta-analysis was to investigate the value of elevated BNP or NT-proBNP in predicting mortality in septic patients.
PubMed, Embase and the Cochrane Central Register of Controlled Trials were searched (up to February 18, 2011). Studies were included if they had prospectively collected data on all-cause mortality in adult septic patients with either plasma BNP or NT-proBNP measurement. 12 studies with a total of 1,865 patients were included.
Elevated natriuretic peptides were significantly associated with increased risk of mortality (odds ratio (OR) 8.65, 95% confidence interval (CI) 4.94 to 15.13, P < 0.00001). The association was consistent for BNP (OR 10.44, 95% CI 4.99 to 21.58, P < 0.00001) and NT-proBNP (OR 6.62, 95% CI 2.68 to 16.34, P < 0.0001). The pooled sensitivity, specificity, positive likelihood ratio, and negative

likelihood ratio were 79% (95% CI 75 to 83), 60% (95% CI 57 to 62), 2.27 (95% CI 1.83 to 2.81) and 0.32 (95% CI 0.22 to 0.46), respectively.

Genetic Variation in Vitamin D Biosynthesis is associated with Increased Risk of Heart Failure

Genetic variation in CYP27B1 is associated with congestive heart failure in patients with hypertension.
RA Wilke, RU Simpson, BN Mukesh, SV Bhupathi, et al.
Pharmacogenomics 2009; 10(11): 1789-1797. http://dx.doi.org/10.2217/pgs.09.101

Genetic variation in vitamin D-dependent signaling is associated with congestive heart failure in human subjects with hypertension. Functional polymorphisms were selected from five candidate genes:

CYP27B1, CYP24A1, VDR, REN and ACE.

Using the Marshfield Clinic Personalized Medicine Research Project,
205 subjects with hypertension and congestive heart failure,
206 subjects with hypertension alone and
206 controls (frequency matched by age and gender) were genotyped.

In the context of hypertension, a SNP in CYP27B1 was associated with congestive heart failure (odds ratio: 2.14 for subjects homozygous for the C allele; 95% CI: 1.05–4.39).

Novel Mechanism for Disease Etiology for the Cardiac Phenotype: Modulation of Nuclear and Cytoskeletal Actin Polymerization.
Lamin A/C and emerin regulate MKL1–SRF activity by modulating actin dynamics

Chin Yee Ho, Diana E. Jaalouk, Maria K. Vartiainen & Jan Lammerding
Nature (2013) doi:10.1038/nature12105  http://www.nature.com/nature/journal/vaop/ncurrent/full/nature121

Laminopathies, caused by mutations in the LMNA gene encoding the nuclear envelope proteins lamins A and C, represent a diverse group of diseases that include Emery–Dreifuss muscular dystrophy (EDMD), dilated cardiomyopathy (DCM), limb-girdle muscular dystrophy, and Hutchison–Gilford progeria syndrome1. Most LMNA mutations affect skeletal and cardiac muscle by mechanisms that remain incompletely understood. Loss of structural function and altered interaction of mutant lamins with (tissue-specific) transcription factors have been proposed to explain the tissue-specific phenotypes.

Altered nucleo-cytoplasmic shuttling of MKL1 was caused by altered actin dynamics in Lmna−/− and Lmna N195K/N195K mutant cells. Ectopic expression of the nuclear envelope protein emerin, which is mislocalized in Lmna mutant cells and also linked to EDMD and DCM, restored MKL1 nuclear translocation and rescued actin dynamics in mutant cells.

These findings present a novel mechanism that could provide insight into the disease aetiology for the cardiac phenotype in many laminopathies, whereby lamin A/C and emerin regulate gene expression through modulation of nuclear and cytoskeletal actin polymerization.

Heart Disease and Stroke Statistics—2011 Update

A Report From the American Heart Association
American Heart Association Statistics Committee and Stroke Statistics Subcommittee
Circulation. 2011;123:e18-e209DOI: 10.1161/CIR.0b013e3182009701


● On the basis of 2007 mortality rate data, more than 2200 Americans die of CVD each day, an average of 1 death every 39 seconds. More than 150 000 Americans killed by CVD (I00 –I99) in 2007 were  65 years of age. In 2007,

nearly 33% of deaths due to CVD occurred before the age of 75 years, which is well before the average life expectancy of 77.9 years.

● Coronary heart disease caused  1 of every 6 deaths in the United States in 2007. Coronary heart disease mortality in 2007 was 406 351. Each year, an estimated 785 000 Americans will have a new coronary attack, and  470 000 will have a recurrent attack. It is estimated that an additional 195 000 silent first myocardial infarctions occur each year. Approximately every 25 seconds, an American will have a coronary event, and approximately every minute, someone will die of one.

Prevalence and Control of Traditional Risk Factors Remains an Issue for Many Americans

● Data from the National Health and Nutrition Examination Survey (NHANES) 2005–2008 indicate that 33.5% of US adults 20 years of age have hypertension (Table 7-1). This amounts to an estimated 76 400 000 US adults with hypertension. The prevalence of hypertension is nearly equal between men and women. African American adults have among the highest rates of hypertension in the world, at 44%. Among hypertensive adults, ~ 80% are aware of their condition, 71% are using antihypertensive medication, and only 48% of those aware that they have hypertension have their condition controlled.

● Despite 4 decades of progress, in 2008, among Americans ­­>18 years of age, 23.1% of men and 18.3% of women continued to be cigarette smokers. In 2009, 19.5% of students in grades 9 through 12 reported current tobacco use. The percentage of the nonsmoking population with detectable serum cotinine (indicating exposure to secondhand smoke) was 46.4% in 1999 to 2004, with declines occurring, and was highest for those 4 to 11 years of age (60.5%) and those 12 to 19 years of age (55.4%).

● An estimated 33 600 000 adults > 20 years of age have total serum cholesterol levels > 240 mg/dL, with a prevalence of 15.0% (Table 13-1).

● In 2008, an estimated 18 300 000 Americans had diagnosed diabetes mellitus, representing 8.0% of the adult population. An additional 7 100 000 had undiagnosed diabetes mellitus, and 36.8% had prediabetes, with abnormal

fasting glucose levels. African Americans, Mexican Americans, Hispanic/Latino individuals, and other ethnic minorities bear a strikingly disproportionate burden of diabetes mellitus in the United States (Table 16-1).

Commentary on Other Related Articles on this topic published on this Open Access Online Scientific Journal:

Automated Inferential Diagnosis of SIRS, sepsis, septic shock
https://pharmaceuticalintelligence.com/2012/08/01/automated-inferential-diagnosis-of-sirs-sepsis-septic-shock/  larryhbern

The role of biomarkers in the diagnosis of sepsis and patient management
https://pharmaceuticalintelligence.com/2012/07/28/the-role-of-biomarkers-in-the-diagnosis-of-sepsis-and-patient-management/   larryhbern

The SIRS reaction involves hormonally driven changes in liver glycogen reserves, triggering of  lipolysis, lean body proteolysis, and reprioritization of hepatic protein synthesis. The SIRS reaction unabated leads to a recurring cycle with hemodynamic collapse from septic shock, indistinguishable from cardiogenic shock, and death.
Alternative Designs for the Human Artificial Heart: Patients in Heart Failure –  Outcomes of Transplant (donor)/Implantation (artificial) and Monitoring Technologies for the Transplant/Implant Patient in the Community
https://pharmaceuticalintelligence.com/2013/08/05/alternative-designs-for-the-human-artificial-heart-the-patients-in-heart-failure-outcomes-of-transplant-donorimplantation-artificial-and-monitoring-technologies-for-the-transplantimplant-pat/

LH Bernstein, J Pearlman, A Lev-Ari

Postoperative Results

No injury (2324) Injury (231) P
PRCs 4.5 7.2 6.5 8.9 0.046
ICU stay (h) 102.3 228.6 146.3 346.9 < 0.001
Reoperation 127 5.5% 21 9.1% 0.024
sepsis 86 3.7% 16 6.9% 0.017
stroke 56 2.4% 11 4.8% 0.033
Prolonged
ventilation
505 21.7% 97 42.0% <0.001
Pneumonia 123 5.3% 25 10.8% <0.001
ARDS 32 1.4% 8 3.5% 0.015
Postop RenalFailure 237 10.2% 51 22.1% <0.001
MODS 45 1.9% 13 5.6% <0.001
Hosp Death 151 6.5% 43 18.6 <0.001

Confined Indolamine 2, 3 dioxygenase (IDO) Controls the Hemostasis of Immune Responses for Good and Bad
https://pharmaceuticalintelligence.com/2013/07/31/confined-indolamine-2-3-dehydrogenase-controls-the-hemostasis-of-immune-responses-for-good-and-bad/ Demet Sag

The immune response mechanism is the holy grail of the human defense system for health.   IDO, indolamine 2, 3-dioxygenase, is a key gene for homeostasis of immune responses and producing an enzyme catabolizing the first rate-limiting step in tryptophan degradation metabolism. The hemostasis of immune system is complicated.  IDO belongs to globin gene family to carry oxygen and heme.

The main function and genesis of IDO comes from the immune responses during host-microbial invasion and choice between tolerance and immunogenicity. In addition IDO has a role in vascular tone as well.  In human there are three kinds of IDOs, which are IDO1, IDO2, and TDO, with distinguished mechanisms and expression profiles. , IDO mechanism includes three distinguished pathways: enzymatic acts through IFNgamma, non-enzymatic acts through TGFbeta-IFNalpha/IFNbeta and moonlighting acts through AhR/Kyn.

IDO is a key homeostatic regulator and confined in immune system mechanism for the balance between tolerance and immunity.  This gene encodes indoleamine 2, 3-dioxygenase (IDO) – a heme enzyme (EC=1.13.11.52) that catalyzes the first rate-limiting step in tryptophan catabolism to N-formyl-kynurenine and acts on multiple tryptophan substrates including D-tryptophan, L-tryptophan, 5-hydroxy-tryptophan, tryptamine, and serotonin (1; 2; 3; 4).

Expression of IDO is common in antigen presenting cells (APCs), monocytes (MO), macrophages (MQs), DCs, T-cells, and some B-cells. IDO presentation in APCs is related to its role in the hierarchy and level of DC expression, but includes MOs in three DC cell subsets, CD14+CD25+, CD14++CD25+ and CD14+CD25++.

There are three types of IDO, pro-IDO like, IDO1, and IDO2.  In addition, another enzyme called TDO, tryptophan 2, 3, dehydrogenase solely degrades L-Trp by a rate-limiting mechanism in liver and brain.

The IDO1 mechanism is the target for immunotherapy applications. The initial discovery of IDO in human physiology is protection of pregnancy since lack of IDO results in premature recurrent abortion.   The initial rate-limiting step of tryptophan metabolism is catalyzed by either IDO or tryptophan 2, 3-dioxygenase (TDO), but the two are regulated with different mechanisms due to a His55 in TDO and a Ser167b in IDO.

IDO binds to only immune response cells, and TDO relates to NAD biosynthesis and is expressed solely in liver and brain.  It has been shown that knowledge on NADH/NAD, Kyn/Trp or Trp/Kyn ratios as well as Th1/Th2, CD4/CD8 or Th17/Th_reg are equally important for assessing the metabolic state.

DCs are the orchestrator of the immune response  with list of functions in uptake, processing, and presentation of antigens; activation of effector cells, such as T-cells and NK-cells; and secretion of cytokines and other immune-modulating molecules to direct the immune response.

Systemic inflammation (pneumonia, sepsis, malaria) creates hypotension and IDO expression has the effect of decreased vascular tone.  Moreover, inflammation activates the endothelial coagulation activation system causing coagulopathies on patients.  This reaction is namely endothelial cell activation of IDO by IFNgamma inducing Trp to Kyn conversion. Inflammation induces IDO expression in endothelial cells producing Kyn causing decrease of trp, arterial relaxation, and hypotension.

IDO for Commitment of a Life Time: The Origins and Mechanisms of IDO, indolamine 2, 3-dioxygenase
https://pharmaceuticalintelligence.com/2013/08/04/ido-for-commitment-of-a-life-time-the-origins-and-mechanisms-of-ido-indolamine-2-3-dioxygenase/

IDO, indolamine 2, 3-dioxygenase, is a key gene for homeostasis of immune responses and producing an enzyme catabolizing the first rate-limiting step in tryptophan degradation metabolism.

The mechanism of microbial response and origination of IDO is based on duplication of microbial IDO .  During microbial responses, Toll-like receptors (TLRs) play a role to differentiate and determine the microbial structures as a ligand to initiate production of cytokines and pro-inflammatory agents to activate specific T helper cells. Uniqueness of TLR comes from four major characteristics of each individual TLR by ligand specificity, signal transduction pathways, expression profiles and cellular localization . Thus, TLRs are important part of the immune response signaling mechanism to initiate and design adoptive responses from innate (naïve) immune system to defend the host.

The modification of IDO+ monocytes manage towards a specific subset of T cell activation with specific TLRs are significantly important.  The type of cell with correct TLR and stimuli improves or decreases the effectiveness of stimuli. .

3D Cardiovascular Theater – Hybrid Cath Lab/OR Suite, Hybrid Surgery, Complications Post PCI and Repeat Sternotomy/  A Lev-Ari
https://pharmaceuticalintelligence.com/2013/07/19/3d-cardiovascular-theater-hybrid-cath-labor-suite-hybrid-surgery-complications-post-pci-and-repeat-sternotomy/

Treatment options for LV failure, temporary circulatory support, IABP, impella recover.
https://pharmaceuticalintelligence.com/2013/07/17/treatment-options-for-left-ventricular-failure-temporary-circulatory-support-intra-aortic-balloon-pump-iabp-impella-recover-ldlp-5-0-and-2-5-pump-catheters-non-surgical-vs-bridge-therapy/  larryhbern

Clinical Indications for Use of Inhaled Nitric Oxide (iNO) in the Adult Patient Market: Clinical Outcomes after Use, Therapy Demand and Cost of Care/ A Lev-Ari
https://pharmaceuticalintelligence.com/2013/06/03/clinical-indications-for-use-of-inhaled-nitric-oxide-ino-in-the-adult-patient-market-clinical-outcomes-after-use-therapy-demand-and-cost-of-care/

Inhaled nitric oxide is a selective pulmonary vasodilator that improves ventilation–perfusion matching at low doses in patients with acute respiratory failure, potentially improving oxygenation and lowering pulmonary vascular resistance.

Treatment Goals for Inhaled Nitric Oxide

  • Improved oxygenation
  • Decreased pulmonary vascular resistance
  • Decreased pulmonary edema
  • Reduction or prevention of inflammation
  • Protection against infection

Dose-Response for Respiratory Failure in the Adult Patient – a response is defined as a 20 percent increase in oxygenation.
Dose-Response for Pulmonary Hypertension in the Adult Patient – a 30 percent decrease in pulmonary vascular resistance during the inhalation of nitric oxide (10 ppm for 10 minutes) has been used to identify an association with vascular responsiveness to agents that can be helpful in the long term.

Diagnosis of Cardiovascular Disease, Treatment and Prevention: Current & Predicted Cost of Care and the Promise of Individualized Medicine Using Clinical Decision Support Systems
https://pharmaceuticalintelligence.com/2013/05/15/diagnosis-of-cardiovascular-disease-treatment-and-prevention-current-predicted-cost-of-care-and-the-promise-of-individualized-medicine-using-clinical-decision-support-systems-2/  JPearlman, LH Bernstein, A lev-Ari

among older Americans, more are hospitalized for HF than for any other medical condition.

Prevalence estimates for HF were determined from 1999–2008 National Health and Nutrition Examination Survey (NHANES) and US Census Bureau projected population counts for years 2012 to 2030. HF is a clinical syndrome that results from a variety of cardiac disorders.

In the Western world the top 3 causes of HF are:

  • coronary artery disease
  • valvular disease
  • hypertension

Stages C and D represent the symptomatic phases of HF, with stage C manageable and stage D failing medical management, resulting in marked symptoms at rest or with minimal activity despite optimal medical therapy.

Classic demographic risk factors for the development of HF include:

  • older age,
  • male gender,
  • ethnicity, and
  • low socioeconomic status.
  • comorbid disease states contribute to the development of HF
  • Ischemic heart disease
  • Hypertension

Diabetes mellitus, insulin resistance, and obesity are also linked to HF development,
with diabetes mellitus increasing the risk of HF by +2-fold in men and up to 5-fold in women.
Smoking remains the single largest preventable cause of disease and premature death in the United States.

Hypertension caused by Arterial Stiffening is Ineffectively Treated by Diuretics and Vasodilatation Antihypertensives
Dr Reuven Zimlichman (Tel Aviv University, Israel)
http://www.theheart.org/article/1502067.do
the definitions of hypertension, as well as the risk-factor tables used to guide treatment, are no longer appropriate for a growing number of patients. New ambulatory blood-pressure-monitoring devices also measure arterial elasticity. “Unquestionably, these will improve our ability to diagnose both the status of the arteries and the changes of the arteries with time as a result of our treatment. So if we treat the patient and we see no improvement in arterial elasticity, something is not working—either the patient is not taking the medication, or our choice of medication is not appropriate, or the dose is insufficient, etc.”

Hypertension and Vascular Compliance: 2013 Thought Frontier – An Arterial Elasticity Focus
https://pharmaceuticalintelligence.com/2013/05/11/arterial-elasticity-in-quest-for-a-drug-stabilizer-isolated-systolic-hypertension-caused-by-arterial-stiffening-ineffectively-treated-by-vasodilatation-antihypertensives/   J Pearlman & A Lev-Ari

Conceptual development of the subject is presented in the following nine parts:
1.            Physiology of Circulation and Role of Arterial Elasticity
2.            Isolated Systolic Hypertension caused by Arterial Stiffening may be inadequately treated by Diuretics or Vasodilatation Antihypertensive Medications
3.            Physiology of Circulation and Compensatory Mechanism of Arterial Elasticity
4.            Vascular Compliance – The Potential for Novel Therapies Novel Mechanism for Disease Etiology: Modulation of Nuclear and Cytoskeletal Actin Polymerization. Genetic Therapy targeting Vascular Conductivity, Regenerative Medicine for Vasculature Protection
5.            In addition to curtailing high pressures, stabilizing BP variability is a potential target for management of hypertension
6.            Mathematical Modeling: Arterial stiffening explains much of primary hypertension
7.            Classification of Blood Pressure and Hypertensive Treatment Best Practice of Care in US
8.            Genetic Risk for High Blood Pressure
9.            Is it Hypertension or Physical Inactivity: Cardiovascular Risk and Mortality – New results in 3/2013.

Elastance in a cyclic pressure system of systole-diastole (contraction-dilation) presents impedance as a pulsatile load on the heart. Chronic exposure to elevated vascular impedance leads to impairment of lusiotropy (diastolic failure, stiff heart) and inotropy (systolic failure, weak heart).

Stiff or “lead pipe” blood vessels drop pressure precipitously to dangerously low levels in response to diuretics.
Stiff walls due to fibrosis or scar tissue have limited ability to dilate

Physiology of Circulation and Compensatory Mechanism of Arterial Elasticity

Arguably, HMG-CoA reductase inhibitors,  statin therapy is a second example of a medication that helps protect vascular elasticity, both by its lipid effects and its anti-inflammatory effects.

https://pharmaceuticalintelligence.com/2012/11/28/special-considerations-in-blood-lipoproteins-viscosity-assessment-and-treatment/

https://pharmaceuticalintelligence.com/2012/11/28/what-is-the-role-of-plasma-viscosity-in-hemostasis-and-vascular-disease-risk/

While among other reasons for Hypertension increasing prevalence with aging, arterial stiffening is one.

Yet, stiffer vessels are more efficient at transmitting pressure to distal targets. With aging, muscle mass diminishes markedly and the contribution to circulation from skeletal muscle tissue compressions combined with competent venous valves fades.

https://pharmaceuticalintelligence.com/2012/08/27/endothelial-dysfunction-diminished-availability-of-cepcs-increasing-cvd-risk-for-macrovascular-disease-therapeutic-potential-of-cepcs/

https://pharmaceuticalintelligence.com/2012/10/19/clinical-trials-results-for-endothelin-system-pathophysiological-role-in-chronic-heart-failure-acute-coronary-syndromes-and-mi-marker-of-disease-severity-or-genetic-determination/

https://pharmaceuticalintelligence.com/2012/11/13/peroxisome-proliferator-activated-receptor-ppar-gamma-receptors-activation-pparγ-transrepression-for-angiogenesis-in-cardiovascular-disease-and-pparγ-transactivation-for-treatment-of-dia/

With aging heart contractility diminishes. These issues can cause under perfusion of tissues, inadequate nutrient blood delivery (ischemia), lactic acidosis, tissue dysfunction and multi-organ failure. Hardened arteries may compensate. Thus, pharmacotherapy to increase Arterial Elasticity may be counter-indicated for patients with mild to progressive CHF.

https://pharmaceuticalintelligence.com/2013/05/05/bioengineering-of-vascular-and-tissue-models/

https://pharmaceuticalintelligence.com/2012/10/20/nitric-oxide-and-sepsis-hemodynamic-collapse-and-the-search-for-therapeutic-options/

https://pharmaceuticalintelligence.com/2012/10/17/chronic-heart-failure-personalized-medicine-two-gene-test-predicts-response-to-beta-blocker-bucindolol/

https://pharmaceuticalintelligence.com/2013/04/28/genetics-of-conduction-disease-atrioventricular-av-conduction-disease-block-gene-mutations-transcription-excitability-and-energy-homeostasis/

https://pharmaceuticalintelligence.com/2013/04/14/mitochondrial-metabolism-and-cardiac-function/

https://pharmaceuticalintelligence.com/2012/10/28/mitochondrial-damage-and-repair-under-oxidative-stress/

The hypothesis that we should focus on cellular therapies to increase vascular compliance may decrease the circulation efficiency and result in worsening of cardiac right ventricular morphology and development of Dilated cardiomyopathy and hypertrophic cardiomyopathy (muscle thickening and diastolic failure), an undesirable outcome resulting from an attempt to treat the hypertension.

https://pharmaceuticalintelligence.com/2012/10/01/ngs-cardiovascular-diagnostics-long-qt-genes-sequenced-a-potential-replacement-for-molecular-pathology/

https://pharmaceuticalintelligence.com/2012/08/29/positioning-a-therapeutic-concept-for-endogenous-augmentation-of-cepcs-therapeutic-indications-for-macrovascular-disease-coronary-cerebrovascular-and-peripheral/

https://pharmaceuticalintelligence.com/2012/08/28/cardiovascular-outcomes-function-of-circulating-endothelial-progenitor-cells-cepcs-exploring-pharmaco-therapy-targeted-at-endogenous-augmentation-of-cepcs/

https://pharmaceuticalintelligence.com/2013/02/28/the-heart-vasculature-protection-a-concept-based-pharmacological-therapy-including-thymosin/

Mitochondrial Dysfunction and Cardiac Disorders   larryhbern
https://pharmaceuticalintelligence.com/2013/04/14/mitochondrial-dysfunction-and-cardiac-disorders/

Mitochondria and Cardiovascular Disease: A Tribute to Richard Bing, Larry H Bernstein, MD, FACP https://pharmaceuticalintelligence.com/2013/04/14/chapter-5-mitochondria-and-cardiovascular-disease/

Mitochondrial Metabolism and Cardiac Function, Larry H Bernstein, MD, FACP https://pharmaceuticalintelligence.com/2013/04/14/mitochondrial-metabolism-and-cardiac-function/

Reversal of Cardiac mitochondrial dysfunction, Larry H Bernstein, MD, FACP https://pharmaceuticalintelligence.com/2013/04/14/reversal-of-cardiac-mitochondrial-dysfunction/

Read Full Post »


Cardiovascular Complications: Death from Reoperative Sternotomy after prior CABG, MVR, AVR, or Radiation; Complications of PCI; Sepsis from Cardiovascular Interventions

Author, Introduction and Summary: Justin D Pearlman, MD, PhD, FACC

and

Article Curator: Aviva Lev-Ari, PhD, RN

The Curator recommends the e-Reader to read the following book on Surgical Complications:

Complications
“Essential Reading For Anyone Involved In Medicine”–Amazon.com –  2002

Cardiovascular Complications:

I. Reoperative Sternotomy after prior CABG, MVR, AVR, or radiation therapy

IIa. PCI, and

IIb. PAD Endovascular Interventions: Carotid Artery Endarterectomy

III. Incidence of Sepsis (circulation infection with serious consequences)

UPDATED 11/2/2013

As minimally interventional techniques improve, patients are offered a choice of invasive surgical remedies or less invasive procedures (video assisted, robotic, or percutaneous). The decision should not rest on the size of the scar or even the up front risk and discomfort, but rather should weigh all aspects of the risks and benefits. In addition to the risks and benefits for the current problem, one should also consider why the problem occurred and its likelihood of recurrence. Open chest surgery has a clear disadvantage when it comes to recurrences, as the scars from first surgery interfere with second surgery. Opening the chest (sternotomy) for a second or third time poses elevated risks analyzed herein. This article reviews data from major centers addressing the risks from repeat sternotomy and from minimally invasive cardiovascular surgeries. Any invasion of the body elevates risk of infection, which can lead to sepsis and possible death, so that risk is also addressed.

I. Risk of Injury During Repeat Sternotomy for CABG or Aortic Valve Replacement, Open Heart Surgery

II. Complications After Percutaneous Coronary intervention (PCI) and endovascular surgery for Peripheral Artery Disease (PAD)

  • (a) Post PCIand 
  • (b) PAD Endovascular Interventions: Carotid Artery Endarterectomy

III. Cardiac Failure During Systemic Sepsis

This article addresses specific reports of complications but does not cover numerous other complications that may occur, such as lung collapse, cardiogenic shock, blood loss, local infection, emboli, thrombus, stroke.

I. Risk of Injury During Open Heart Surgery after prior Coronary Artery Bypass Grafting (CABG), Aortic Valve Replacement, Mitral Valve Replacement, or Radiation Therapy 

Conclusions of a Study conducted @Mayo Clinic on Reoperative (Repeat) Sternotomy (opening of the chest through the sternum):

Chan B. Park, MD,a,b Rakesh M. Suri, MD,a Harold M. Burkhart, MD,a Kevin L. Greason, MD,a

Joseph A. Dearani, MD,a Hartzell V. Schaff, MD,a and Thoralf M. Sundt III, MDa

Identifying patients at particular risk of injury during repeat sternotomy: Analysis of 2555 cardiac reoperations

Authors Affiliations: From the Division of Cardiovascular Surgery,

a Mayo Clinic, Rochester, Minn; and the Department of Thoracic and Cardiovascular Surgery,

b St. Paul’s Hospital, The Catholic University of Korea, Seoul, Korea.

Disclosures: None.

Read at the 90th Annual Meeting of The American Association for Thoracic Surgery, Toronto, Ontario, Canada, May 1–5, 2010. Received for publication April 6, 2010; revisions received July 19, 2010; accepted for publication July 30, 2010.

doi:10.1016/j.jtcvs.2010.07.086

Particular attention to protective strategies should be considered during reoperative sternotomy among patients with multiple previous sternotomies, previous mediastinal radiotherapy, and those with patent internal thoracic artery grafts. (J Thorac Cardiovasc Surg 2010;140:1028-35)

Of the 2555 patients,

  • 1537 (60%) had undergone previous coronary artery bypass grafting,
  • 700 (27%) previous mitral valve surgery, and
  • 643 (25%) previous aortic valve replacement (AVR).
  • 61 (2%) had prior mediastinal radiotherapy, and
  • 424 (17%) had more than one previous sternotomy.

 Injury Analysis – 9% events in 231 Patient in the study

In 231 patients, 267 injuries (9.0%) occurred.

Injury occurred

  • during sternotomy in 87 patients (33%) and
  • during prepump dissection in 135 (51%).

Hospital mortality rate was

6.5% among those without injury and

18.5% among those with injury (P < .001);

25% when injury occurred during sternal division

Injuries were more common

1. after previous coronary artery bypass grafting

  • 11% with previous coronary artery bypass grafting vs
  • 7% without, (P = .0012)

but not

  • previous aortic valve surgery,
  • previous mitral valve surgery, or
  • previous aorta surgery.

2.  Injury was also more common when the current operation was aortic valve replacement (AVR)

  • 10% with AVR vs
  • 8% without, (P = .04) or

3.  aorta surgery

  • 14% vs
  • 8% (P = .004).

Predicted injury by multivariate analysis –

Injury was an independent risk factor of hospital death (odds ratio, 2.6).

4.   previous radiotherapy (odds ratio, 4.9)

5.  a greater number of previous sternotomies (odds ratio 1.7), and

6.  a patent internal thoracic artery (odds ratio, 1.8)

J Thorac Cardiovasc Surg. 2010 Nov;140(5):1028-35. doi: 10.1016/j.jtcvs.2010.07.086.

Identifying patients at particular risk of injury during repeat sternotomy: analysis of 2555 cardiac reoperations.

Source

Division of Cardiovascular Surgery, Mayo Clinic, Rochester, MN 55905, USA.

Abstract

OBJECTIVES:

A variety of protective strategies during repeat sternotomy been proposed; however, it remains unclear for which patients they are warranted.

METHODS:

We identified adults undergoing repeat median sternotomy for routine cardiac surgery at our institution between January 1, 1996, and December 31, 2007. The operative notes and perioperative outcomes were reviewed.

RESULTS:

Of the 2555 patients, 1537 (60%) had undergone previous coronary artery bypass grafting, 700 (27%) previous mitral valve surgery, and 643 (25%) previous aortic valve replacement (AVR). Sixty-one patients (2%) had prior mediastinal radiotherapy, and 424 (17%) had more than one previous sternotomy. In 231 patients, 267 injuries (9.0%) occurred. Injury occurred during sternotomy in 87 patients (33%) and during prepump dissection in 135 (51%). The hospital mortality rate was 6.5% among those without injury and 18.5% among those with injury (P < .001); when injury occurred during sternal division, the mortality rate was 25%. Injuries were more common after previous coronary artery bypass grafting (11% with previous coronary artery bypass grafting vs 7% without, P = .0012) but not previous AVR, mitral valve surgery, or aortic surgery. Injury was also more common when the current operation was AVR (10% with AVR vs 8% without, P = .04) or aortic surgery (14% vs 8%, P = .004). On multivariate analysis, previous radiotherapy (odds ratio, 4.9), a greater number of previous sternotomies (odds ratio 1.7), and a patent internal thoracic artery (odds ratio, 1.8) predicted injury. Injury was an independent risk factor of hospital death (odds ratio, 2.6).

CONCLUSIONS:

Particular attention to protective strategies should be considered during reoperative sternotomy among patients with multiple previous sternotomies, previous mediastinal radiotherapy, and those with patent internal thoracic artery grafts.

Copyright © 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Comment in

TABLE 2. Hospital mortality according to Timing of Injury

Timing Mortality rate with injury P value

  • Re-entry 19/76 (25.0%) <.001
  • Prepump 20/121 (16.5%) <.001
  • Cardiopulmonary bypass (CPB)  3/14 (21.4%) .05
  • Aortic CrossClamp (ACC 1/11) (9.1%) .85
  • Closing 5/17 (29.4%) <.001

TABLE 1. Preoperative patient characteristics

Characteristic No injury (n 1/4 2324) Injury (n 1/4 231) P value

Age (y) 66.9  12.4 67.7  11.5 .509

Men 1583 (68.1%) 167 (72.3%) .192

Diabetes mellitus 499 (21.5%) 61 (26.4%) .084

Hypertension 1536 (66.2%) 158 (68.4%) .490

Hypercholesterolemia 1656 (71.4%) 171 (74.0%) .395

Myocardial infarction 633 (27.3%) 68 (29.4%) .480

Congestive heart failure 758 (32.6%) 89 (38.5%) .069

NYHA .064

I-II 492 (21.2%) 37 (16.0%)

III-IV 1830 (78.8%) 184 (84.0%)

Previous operation No injury (n 1/4 2324) Injury (n 1/4 231) P value

CABG 1375 (59.2%) 162 (70.1%) .001

Aortic valve surgery 586 (25.2%) 57 (24.7%) .857

Mitral valve surgery 645 (27.8%) 55 (23.8%) .200

Tricuspid valve surgery 64 (2.8%) 9 (3.9%) .320

Aorta surgery 167 (7.2%) 20 (8.7%) .413

Current operation No injury (n 1/4 2324) Injury (n 1/4 231) P value

CABG 897 (38.6%) 104 (45.0%) .056

Aortic valve surgery 1020 (43.9%) 118 (51.1%) .036

Mitral valve surgery 821 (35.3%) 80 (34.6%) .833

Tricuspid valve surgery 414 (17.8%) 52 (22.5%) .078

Aortic surgery 232 (10.0%) 37 (16.0%) .004

DISCUSSION

The results of the present study have confirmed the significant risk of cardiovascular injury during reoperative cardiac surgery. The death rate from such injury can be 10-30%, particularly  when occurring during division of the sternum. These risks are greatest among patients with multiple previous sternotomies or prior chest radiotherapy.

Current PROTOCOL at Virginia University, now suggested to be considered for adoption @Mayo Clinic:

The Mayo Clinic’s Authors write: Our findings are more consistent with those reported by Roselli and colleagues.2 The explanation of these institutional differences is unclear, although a number of practice differences are likely present between these institutions in terms of both patient substrate and surgical practice. Compared with the series from the University of Virginia, the Mayo series we have reported represents a greater percentage of total cases performed at the institution (13.5% vs 7.8%), with a somewhat greater percentage of those reoperations being for CABG (41% vs 60%). In the Mayo series, a lower percentage were first-time repeat sternotomies (83% vs 90%) and a greater percentage were the fourth time or more (2.7% vs 1.1%).

The incidence of previous radiotherapy in the University of Virginia series was not reported.

It is also unclear to what degree the differences in surgical practice, including the role of the assistant surgeons in performing the repeat sternotomy, could account for these differences. In the present retrospective study, we were unable to demonstrate an effect of experience or expertise in either the occurrence of injury or the outcome. However, it is clear to all practicing surgeons that, when injury occurs, the judgment and expertise of the operating surgeon is critical to expeditious institution of CPB or other ‘‘rescue’’ maneuvers.

Perhaps of more practical value and broad applicability, however, is the standardized approach to repeat sternotomy advocated by the group at the University of Virginia, including routine preoperative CT scanning if the procedure is the third or fourth sternotomy and insertion of a femoral arterial line by which emergent percutaneous arterial inflow cannulation can be accomplished, if necessary. In their series, emergent institution of CPB using the femoral route was instituted in 1.8% of reoperative patients, constituting 19% of the patients with injury. Most notably, in their series, no deaths occurred among these patients. Serious consideration should be given to adopting such protocols.

Our high mortality rate associated with SVG injury during sternotomy, however, supports the  recommendation by others to carefully assess the course of bypass grafts by preoperative angiography. Routine preoperative CT imaging of all patients with more than one previous sternotomy has been advocated by Morishita and colleagues,3 with a demonstrable reduction in operative complications. Roselli and colleagues2 identified a lack of preparative imaging as the most common ‘‘lapse’’ in the preventive strategy among patients with injury. Our data suggest that CT scanning might be particularly helpful in the subset of patients with multiple previous sternotomies or radiotherapy and would support the institution of a policy of routine scanning for these patients.

FIGURE 1. Hospital mortality according to emergent cardiopulmonary bypass (CPB) in The Journal of Thoracic and Cardiovascular Surgery c November 2010, pp. 1032

TABLE 5. Postoperative results

No injury (n 1/4 2324) —  Injury (n 1/4 231) — P value

Postoperative transfusion (U)

PRCs 4.5  7.2 6.5  8.9 .046

ICU stay (h) 102.3  228.6 146.3 +/- 346.9 <.001

Reoperation for bleeding 127 (5.5%) 21 (9.1%) .024

Sepsis 86 (3.7%) 16 (6.9%) .017

Stroke 56 (2.4%) 11 (4.8%) .033

Prolonged ventilation 505 (21.7%) 97 (42.0%) <.001

Pneumonia 123 (5.3%) 25 (10.8%) <.001

ARDS 32 (1.4%) 8 (3.5%) .015

Postoperative renal failure 237 (10.2%) 51 (22.1%) <.001

Multisystem failure 45 (1.9%) 13 (5.6%) <.001

Perioperative MI 9 (0.4%) 2 (0.9%) .289

Hospital death 151 (6.5%) 43 (18.6%) <.001

Abbreviations:

IABP, intra-aortic balloon pump; ICU, intensive care unit; ARDS, acute respiratory

distress syndrome; MI, myocardial infarction.

SOURCE
The Journal of Thoracic and Cardiovascular Surgery c November 2010, pp. 1032

Independent predictors for injury during repeat median sternotomy

The structures injured and the timing of injury in our study were similar to those reported by Roselli and colleagues.2  Bypass grafts were the most commonly injured and, perhaps in contrast to expectations, most injuries occurred during dissection, not during sternal division. Unlike their study, however, we found injury during sternal division to carry a greater mortality risk. We observed a remarkably high mortality rate associated with injury to the right ventricle, as did Roselli and colleagues.2  This may be particularly true in the presence of pulmonary hypertension, when attempts to repair the injury are hampered by inadequate access, progressive tearing of the ventricle secondary to traction injury, and what can be a relatively thin and friable free wall. The incidence of injury to the Internal thoracic artery (ITA) in our series (4.9%) was comparable to the 4.4%–5.3% reported by other investigators.11-14 Because the ITA was damaged more often during prepump dissection (20.7%) than during re-entry (11.5%), these data support the trend to avoid dissecting and isolating the ITA during AVR after previous CABG.12,13

FOUR CONCLUSIONS

1. On the basis of these data, we would advocate preoperative axial CT imaging to define the proximity of cardiovascular structures to the sternum of patients who have undergone more than one previous sternotomy and those who have undergone radiotherapy because these patients statistically have the greatest risk of injury.

2. We would also advocate considering percutaneous or open access of the femoral vessels, if not the institution of CPB, before sternotomy in these same patients, as well as those with significant pulmonary hypertension.

3. Because injury is common during prepump dissection, we support a philosophy of leaving patent ITA grafts undisturbed by attempts to gain control during AVR after previous CABG.

4. Finally, given the mortality rate associated with graft injury, patients with previous CABG should be considered for graft angiography or high-resolution CT.

Summary 

This is a very important study  on the Outcomes and the Complications involved in Cardiac Surgery @Mayo Clinic.

Study’s Objectives: A variety of protective strategies during repeat sternotomy been proposed; however, it remains unclear for which patients they are warranted.

Authors @Mayo Clinic reported:

We were unable to definitively assess the effect of any specific protective strategies on the incidence of injury. Because we do not have standardized or uniform prospective institutional policies in this regard, it was not possible to account for the confounding factor of the clinician’s judgment in the decision to use these strategies in particularly highrisk patients.

Our high mortality rate associated with saphenous vein graft (SVG) injury during sternotomy, however, supports the  recommendation by others to carefully assess the course of bypass grafts by preoperative angiography. Routine preoperative CT imaging of all patients with more than one previous sternotomy has been advocated by Morishita and colleagues,3 with a demonstrable reduction in operative complications.

The reader is advised to review another article Co-Curated by us on the following related study by Mayo Clinic researches, This article examines 10-year to 15-year survivals from arterial bypass grafts using arterial vs saphenous venous grafts.

CABG Survival in Multivessel Disease Patients: Comparison of Arterial Bypass Grafts vs Saphenous Venous Grafts

The conclusions in this article are:

In patients undergoing isolated coronary artery bypass graft surgery with LIMA to left anterior descending artery,

  • arterial grafting of the non-left anterior descending vessels conferred a survival advantage at 15 years compared with Saphenous Venous grafting (SVG).

It is still unproven whether these results apply to higher-risk subgroups of patients.

Related study

Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents,

REFERENCES

1. Sabik JF III, Blackstone EH, Houghtaling PL,Walts PA, LytleBW. Is reoperation

still a risk factor in coronary artery bypass surgery? Ann Thorac Surg. 2005;80:

1719-27.

2. Roselli EE, Pettersson GB, Blackstone EH, Brizzio ME, Houghtaling PL,

Lauck R, et al. Adverse events during reoperative cardiac surgery: Frequency,

characterization, and rescue. J Thorac Cardiovasc Surg. 2008;135:316-23.

3. Morishita K, Kawaharada N, Fukada J, Yamada A, Masaru T, Kuwaki K, et al.

Three or more median sternotomies for patients with valve disease: Role of computed

tomography. Ann Thorac Surg. 2003;75:1476-81.

4. Luciani N, Anselmi A, De Geest R, Martinelli L, Perisano M, Possati G. Extracorporeal

circulation by peripheral cannulation before redo sternotomy: Indications

and results. J Thorac Cardiovasc Surg. 2008;136:572-7.

5. Potter DD, Sundt TM III, Zehr KJ, Dearani JA, Daly RC, Mullany CJ, et al. Risk

of repeat mitral valve replacement for failed mitral valve prostheses. Ann Thorac

Surg. 2004;78:67-72.

6. Potter DD, Sundt TM III, Zehr KJ, Dearani JA, Daly RC, Mullany CJ, et al. Operative

risk of reoperative aortic valve replacement. J Thorac Cardiovasc Surg.

2005;129:94-103.

7. Sundt TM III, Murphy SF, Barzilai B, Schuessler RB, Mendeloff EN,

Huddleston CB, et al. Previous coronary artery bypass grafting is not a risk factor

for aortic valve replacement. Ann Thorac Surg. 1997;64:651-7.

8. Ellman PI, Smith RL, Girotti ME, Thompson PW, Peeler BB, Kern JA, et al. Cardiac

injury during resternotomy does not affect perioperative mortality. JAm Coll

Surg. 2008;206:993-9.

9. Chang ASY, Smedira NG, Chang CL, Benavides MM, Myhre U, Feng J, et al.

Cardiac surgery after mediastinal radiation: Extent of exposure influences outcome.

J Thorac Cardiovasc Surg. 2007;133:404-13.

10. Schmuziger M, Christenson JT, Maurice J, Mosimann E, Simonet F, Velebit V.

Reoperative myocardial revascularization: An analysis of 458 reoperations and

2645 single operations. Cardiovasc Surg. 1994;2:623-9.

11. Gillinov AM, Casselman FP, Lytle BW, Blackstone EH, Parsons EM, Loop FD,

et al. Injury to a patent left internal thoracic artery graft at coronary reoperation.

Ann Thorac Surg. 1999;67:382-6.

12. Byrne JG, Karavas AN, Filsoufi F, Mihaljevic T, Aklog L, Adams DH, et al. Aortic

valve surgery after previous coronary artery bypass grafting with functioning

internal mammary artery grafts. Ann Thorac Surg. 2002;73:779-84.

13. Smith RL, Ellman PI, Thompson PW, Girotti ME, Mettler BA, Ailawadi G, et al.

Do you need to clamp a patent left internal thoracic artery—Left anterior descending

graft in reoperative cardiac surgery? Ann Thorac Surg. 2009;87:742-7.

14. Coltharp WH, Decker MD, Lea JWIV, Petracek MR, Glassford DM,

Thormas CS, et al. Internal mammary artery graft at reoperation: Risks, benefits,

and methods of preservation. Ann Thorac Surg. 1991;52:225-9.

15. O’Brien MF, Harrocks S, Clarke A, Garlick B, Barnett AG. How to do safe sternal

reentry and the risk factors of redo cardiac surgery: A 21-year review with

zero major cardiac injury. J Cardiac Surg. 2002;17:4-13.

16. Klein G. Naturalistic decision making. Human Factors. 2008;50:456-60.

II. Complications After Percutaneous Coronary intervention (PCI) and endovascular surgery for Peripheral Artery Disease (PAD)

(a) after prior PCI, and

(b) after prior PAD Endovascular Interventions: Carotid Artery Endarterectomy

II(a)  PCI  After Prior PCI – Major occurring Complications include the following:

 

  • Hematoma (a firm collection of blood greater than 2 cm around or in the proximity of the access site).
  • Pseudoaneurysm / dissection,
  • A-V fistula and ischemic leg were also considered along with
  • Retroperitoneal bleed. Retroperitoneal bleeding was defined by any amount of bleeding in the retroperitoneum diagnosed by computer tomography.
  • Inflammation of the Lower extremity on the side of the access site to the femoral artery

UPDATED 11/2/2013

VIEW VIDEO

Impact of Intra-procedural Stent Thrombosis during Percutaneous Coronary Intervention: Insights from the CHAMPION PHOENIX Trial ONLINE FIRST

Philippe Généreux, MD1; Gregg W. Stone, MD1; Robert A. Harrington, MD4; C. Michael Gibson, MD5; Ph. Gabriel Steg, MD6; Sorin J. Brener, MD10; Dominick J. Angiolillo, MD, PhD11; Matthew J. Price, MD12; Jayne Prats, PhD13; Laura LaSalle, MPH2; Tiepu Liu, MD, PhD12; Meredith Todd, B.Sc12; Simona Skerjanec, Pharm.D12; Christian W. Hamm, MD14; Kenneth W. Mahaffey, MD4; Harvey D. White, DSc15; Deepak L. Bhatt, MD, MPH16
J Am Coll Cardiol. 2013;():. doi:10.1016/j.jacc.2013.10.022

Abstract

Objective  We sought to evaluate the clinical impact of intra-procedural stent thrombosis (IPST), a relatively new endpoint.

Background  In the prospective, double-blind, active-controlled CHAMPION PHOENIX trial, cangrelor significantly reduced periprocedural and 30-day ischemic events in patients undergoing percutaneous coronary intervention (PCI), including IPST.

Methods  An independent core laboratory blinded to treatment assignment performed a frame-by-frame angiographic analysis in 10,939 patients for the development of IPST, defined as new or worsening thrombus related to stent deployment anytime during the procedure. Adverse events were adjudicated by an independent, blinded clinical events committee.

Results  IPST developed in 89 patients (0.8%), including 35/5470 (0.6%) and 54/5469 (1.0%) in the cangrelor and clopidogrel arms, respectively (OR [95%CI] = 0.65 [0.42,0.99], p=0.04). Compared to patients without IPST, IPST was associated with a marked increase in composite ischemia (death, myocardial infarction [MI], ischemia-driven revascularization, or new onset out-of-lab stent thrombosis [ARC]) at 48 hours and at 30 days (29.2% vs. 4.5% and 31.5% vs. 5.7%, P<0.0001 for both). After controlling for potential confounders, IPST remained a strong predictor of all adverse ischemic events at both time points.

Conclusion  In the large-scale CHAMPION PHOENIX trial, the occurrence of IPST was strongly predictive of subsequent adverse cardiovascular events. The potent intravenous ADP antagonist cangrelor substantially reduced IPST, contributing to its beneficial effects at 48 hours and 30 days.

Clinical trial info  CHAMPION PHOENIX; NCT01156571

Bleeding and Vascular Complications at the Femoral Access Site Following Percutaneous Coronary Intervention (PCI): An Evaluation of Hemostasis Strategies

Author(s):

Dale R. Tavris, MD, MPH1, Yongfei Wang, MS2, Samantha Jacobs, BS1, Beverly Gallauresi, MPH, RN1, Jeptha Curtis, MD2, John Messenger, MD3, Frederic S. Resnic, MD, MSc4, Susan Fitzgerald, MS, RN5

Authors Affiliation

From the 1US Food and Drug Administration (FDA), Silver Spring, Maryland, 2Yale University, New Haven, Connecticut, 3University of Colorado, Boulder, Colorado, 4Brigham and Women’s Hospital, Boston, Massachusetts, and 5the American College of Cardiology, Bethesda, Maryland.

Abstract: Background. Previous research found at least one vascular closure device (VCD) to be associated with excess vascular complications, compared to manual compression (MC) controls, following cardiac catheterization. Since that time, several more VCDs have been approved by the Food and Drug Administration (FDA). This research evaluates the safety profiles of current frequently used VCDs and other hemostasis strategies. Methods. Of 1089 sites that submitted data to the CathPCI Registry from 2005 through the second quarter of 2009, a total of 1,819,611 percutaneous coronary intervention (PCI) procedures performed via femoral access site were analyzed. Assessed outcomes included bleeding, femoral artery occlusion, embolization, artery dissection, pseudoaneurysm, and arteriovenous fistula. Seven types of hemostasis strategy were evaluated for rate of “any bleeding or vascular complication” compared to MC controls, using hierarchical multiple logistic regression analysis, controlling for demographic factors, type of hemostasis, several indices of co-morbidity, and other potential confounding variables. Rates for different types of hemostasis strategy were plotted over time, using linear regression analysis.Results. Four of the VCDs and hemostasis patches demonstrated significantly lower bleeding or vascular complication rates than MC controls: Angio-Seal (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.65-0.70); Perclose (OR, 0.54; CI, 0.51-0.57); StarClose (OR, 0.77; CI, 0.72-0.82); Boomerang Closure Wire (OR, 0.63; CI, 0.53-0.75); and hemostasis patches (OR, 0.70; CI, 0.67-0.74). All types of hemostasis strategy, including MC, exhibited reduced complication rates over time. All trends were statistically significant except one. Conclusions. This large, nationally representative observational study demonstrated better safety profiles for most of the frequently used VCDs, compared to MC controls.

J INVASIVE CARDIOL 2012;24(7):328-334

Key words: hemostasis patch, mechanical compression, vascular closure device

Problems and Complications of the Transradial Approach for Coronary Interventions: A Review

The Journal of invasive Cardiology

Elizabeth Bazemore, BS and J. Tift Mann, III, MD

The benefits of the transradial approach have clearly been documented in numerous studies in the past ten years.1–9 Access site bleeding complication rates are lower and early ambulation results in a significant reduction in patient morbidity and a lower total procedure cost.3,4 Both patients undergoing the procedure and staff caring for these patients overwhelmingly prefer the transradial approach.10
As a result of these benefits, there has been an increase in the use of the radial artery for interventional procedures worldwide in the past several years. This experience has led to an understanding of the problems and complications that can result from the transradial approach. The purpose of the present manuscript is to review these issues.
Radial artery occlusion. Although this complication is a major concern, the consequences of radial artery occlusion are usually benign. The dual blood supply to the hand is an extremely protective mechanism (Figure 1). Hand ischemia with necrosis has occurred following prolonged cannulation of the radial artery for hemodynamic monitoring in critically ill patients; however, this complication has not been reported thus far after transradial coronary procedures.
The absence of ischemic complications is largely the result of the original recommendation by Kiemeneij that the transradial procedure be performed only in patients with a documented patent ulnar artery and palmar arch.1 This has traditionally been evaluated using the Allen’s test, but ultrasound, Doppler, and plethysmography prior to the procedure are more accurate methods.11
Plethysmography is probably the simplest and most effective method. A pulse oximetry test is performed with the probe placed on the patient’s thumb (Figure 2). The persistence of waveform and high oximetry readings after digital occlusion of the radial artery is very strong evidence that the patient will have sufficient collateral flow to prevent hand ischemia if the radial artery should become occluded as a result of the procedure. Barbeau has demonstrated the reappearance of the waveform and a high oximetry reading two minutes after initial negative results.11 This delayed recruitment of collaterals may be an additional explanation for the absence of hand ischemia with radial occlusion.
Several variables influence the incidence of radial artery occlusion. Adequate anticoagulation is extremely important. This is usually not an issue in patients undergoing interventional procedures, but the incidence of radial occlusion was as high as 30% in patients receiving only 1,000 units of heparin during diagnostic catheterization.12 The incidence of radial occlusion is reduced significantly by administering at least 5,000 units of heparin during the procedure.12,13 Due to this risk of radial occlusion, we tend to reserve the use of the radial artery for interventional procedures and “look-see” diagnostic catheterization. Elective diagnostic catheterizations are performed transradially only when there is an increased risk of femoral complications.
Catheter size has been shown to be an important predictor of post-procedure radial artery occlusion. Saito has studied the ratio of the radial artery internal diameter to the external diameter of the arterial sheath.14 The incidence of occlusion was 4% in patients with a ratio of greater than 1, as compared to 13% in those with a ratio of less than 1. Radial procedures have traditionally been performed using 6 Fr catheters, and most patients have an internal radial artery diameter larger than the 2.52 mm external 6 Fr sheath diameter.14 The incidence of radial occlusion following 6 Fr procedures is less than 5%, but the rate increases with larger sheath sizes.4,13 Virtually all interventional procedures can now be performed through large-bore, 6 Fr guide catheters, and larger-sized catheters are rarely necessary. For straightforward procedures, 5 Fr guide catheters may be utilized and are particularly useful in smaller women.
When the radial artery is utilized for hemodynamic monitoring in critically ill patients, the incidence of radial occlusion is significantly higher in patients with cannulation times greater than 24 hours, as compared to those under 20 hours.15 Since catheters are virtually always removed at the conclusion of a catheterization or interventional procedure, the time of cannulation may not be a factor. However, prolonged post-procedure compression times, particularly with high pressure using a mechanical device, may be a factor. We use sufficient pressure only to achieve hemostasis and try to remove the device as quickly as possible. Even in patients with intensive anticoagulation, it is rarely necessary to maintain mechanical compression for longer than one to two hours. A compression dressing using non-occlusive pressures can then be applied.
In summary, post-procedure radial occlusion occurs only in a small percentage of patients and is virtually always asymptomatic because of the dual blood supply to the hand. Patients with generalized vascular disease, diabetes mellitus, and those undergoing repeat procedures are more susceptible. The incidence can be minimized with appropriate anticoagulation, proper sheath selection, and avoiding prolonged high-pressure compression following the procedure.
Non-occlusive radial artery injury. Recent studies have demonstrated that permanent radial artery injury without occlusion may occur following transradial intervention in some patients. Mean radial artery internal diameter as measured by ultrasound was smaller in patients undergoing repeat transradial interventional procedures as compared to the initial procedure.16 This smaller diameter was not present on the day following the procedure, but developed during a mean follow up of 4.5 months. Wakeyama et al. demonstrated with intravascular ultrasound that this progressive narrowing is due to intimal hyperplasia, presumably induced by trauma from the cannulation sheath or catheter.17 The studies in our laboratory show that this hyperplasia is usually segmental rather than diffuse and is not present in all patients with a previous transradial procedure (Figure 3). The incidence of subsequent intimal hyperplasia in patients undergoing radial procedures is yet to be determined.
The ramifications of this injury are important not only in patients undergoing repeat interventional procedures, but also in patients in whom the radial artery may be used as a conduit for coronary artery bypass surgery. At our center, this is not an issue as most procedures are performed from the right radial artery and surgeons use the left radial artery for bypass graft purposes. At present, it would seem prudent not to use a radial artery that previously has been used for a catheterization as a bypass graft.
Radial artery spasm. Much of the morbidity of the transradial procedure is related to vasospasm induced by the introduction of a sheath or catheter into the radial artery. The vessel has a prominent medial layer that is largely dominated by alpha-1 adenoreceptor function.18 Thus, increased levels of circulating catecholamines are a cause of radial artery spasm. Local anesthesia and adequate sedation to control anxiety during catheter insertion are important preventative measures.
It has been demonstrated in isolated radial artery ring segments that nitroglycerin and verapamil are effective agents in preventing arterial spasm.19 Indeed, a vasodilator cocktail consisting of 3–6 mg of verapamil injected intra-arterially prior to sheath insertion is extremely effective in preventing radial artery spasm. The effect of the drug is immediate and significant arterial dilatation can be seen within minutes of its administration (Figure 4).
Intra-arterial verapamil and nitroglycerin have virtually eliminated vasospasm as a cause of significant morbidity of the procedure. It is now possible to perform transradial procedures using short sheaths and arm discomfort generally occurs only in patients with very small or tortuous radial arteries, particularly if guide catheter manipulation is excessive.
Spasm distal to the access site may be a cause of access failure. Occasionally, guide wire or guide catheter induced focal spasm may occur in a tortuous segment. Angiographic visualization of these areas is important as they generally respond to repeat verapamil administration and can be traversed with an angled hydrophilic coated guide wire. A soft-tipped coronary guide wire may also be used to cross these areas (Figure 5).
Sheath-induced spasm is also minimized by the use of sheaths with hydrophilic coating. Kiemeneij has documented that both patient discomfort and the force required to remove a sheath as measured by an automatic pull-back device was significantly less with hydrophilic coated sheaths as opposed to non-coated sheaths.20
Local access bleeding. The most important benefit of transradial procedures is the elimination of access site bleeding complications.1–4 The radial artery puncture site is located over bone and can easily be compressed with minimal pressure. Thus, bleeding from the radial access site can virtually always be prevented. Although manual pressure from an experienced operator is the ideal method to obtain hemostasis, several compression devices have been developed in an attempt to maximize operator and staff efficiency. Local hematomas may occur as a result of improper device application or device failure. It is important to emphasize that compression of the radial artery both proximally and distally to the puncture site must be performed because of retrograde flow from the palmar arch collaterals.
Forearm hematoma. Bleeding may occur from a site in the radial artery remote from the access site. The most common cause is perforation of a small side branch by the guide wire in patients receiving a platelet glycoprotein IIb/IIIa inhibitor (Figure 6). Avulsion of a small radial recurrent artery arising from a radial loop is another important cause of this syndrome.21,22 Hydrophilic guidewires preferentially select this small arterial remnant in patients with a radial loop and forceful advancement of the guide catheter can result in avulsion of the vessel. Radial artery perforation has been described in 1% of patients although in our experience the incidence is substantially lower. A low threshold to perform a radial artery arteriogram when any resistance to guide wire or catheter insertion is encountered will help prevent this complication.
Recognition of this bleeding remote from the access site is important as hemostatic pressure must be applied to an area other than the access site. Hemostasis is usually easily accomplished by the application of an Ace bandage to the forearm. A blood pressure sphygmomanometer may also be utilized. The latter is inflated to systolic pressure and then gradually released over a period of one to two hours. Sealing of a perforation with a long sheath is also an option, but this is rarely necessary.22
Compartment syndrome is the most dreaded complication of radial artery hemorrhage. A large hematoma causes hand ischemia due to pressure-induced occlusion of both the radial and ulnar arteries. Fasciotomy with hematoma evacuation must be performed as an emergency procedure to prevent chronic ischemic injury. This complication is rare, occurring only once in our early experience; it should always be preventable.

Access failure. Failure to cannulate the radial artery using a 20 gauge needle and a 0.025 mm straight Terumo guide wire occurs in less than 5% of patients with an experienced operator. The importance of adequate patient sedation and local anesthesia in the prevention of radial artery spasm has previously been emphasized. In addition, meticulous attention to detail is important as the probability of failure increases as the number of unsuccessful attempts to puncture the artery increases. It should be emphasized that the puncture site is proximal to the styloid process of the radius bone. The radial artery distally usually bifurcates and becomes less superficial and attempting to puncture the vessel too distally is a common cause of access failure (Figure 7).
The radial loop is the most common congenital anomaly of the radial artery and may be a cause of access failure. It occurs in 1–2% of patients and may be unilateral or bilateral.21 Wide loops can occasionally be traversed with hydrophilic guidewires and 5 Fr catheters without excessive patient discomfort.23 However, in most cases, it is preferable to consider an alternative access site.
Radial arteries that are smaller than 2 mm in diameter are difficult to access. These are generally seen in smaller women and patients with previous radial procedures. The use of a 5 Fr guide in this situation may be an option. However, complex or difficult procedures cannot be performed through a 5 Fr guide catheter.
Miscellaneous complications. Pseudoaneurysm formation may rarely occur at the radial artery access site. This is usually easily managed with thrombin injection and/or mechanical compression. However, surgery may be required. Radial artery avulsion due to intense spasm has been described but this complication should virtually never occur using contemporary techniques. Sterile abscesses rarely occur with the use of hydrophilic coated sheaths.24
Conclusion. The radial artery is an excellent access site for coronary interventions. Although technically more challenging with a definite learning curve, there are significant advantages to this approach. Complications are infrequent and many are preventable with careful technique.

 http://www.invasivecardiology.com/article/3821

J Invasive Cardiol. 2010 Apr;22(4):175-8.

Vascular complications after percutaneous coronary intervention following hemostasis with the Mynx vascular closure device versus the AngioSeal vascular closure device.

Source

Department Cardiology, New York Medical College, Macy Pavilion, Valhalla, NY 10595, USA.

Abstract

We investigated the prevalence of vascular complications after PCI following hemostasis in 190 patients (67% men and 33% women, mean age 64 years) treated with the AngioSeal vascular closure device (St. Jude Medical, Austin, Texas) versus 238 patients (67% men and 33% women, mean age 64 years) treated with the Mynx vascular closure device (AccessClosure, Mountain View, California).

RESULTS:

Death, myocardial infarction or stroke occurred in none of the 190 patients (0%) treated with the AngioSeal versus none of 238 patients (0%) treated with the Mynx. Major vascular complications occurred in 4 of 190 patients (2.1%) treated with the AngioSeal versus 5 of 238 patients (2.1%) treated with the Mynx (p not significant). Major vascular complications in patients treated with the AngioSeal included removal of a malfunctioning device (1.1%), hemorrhage requiring intervention (0.5%) and hemorrhage with a loss of > 3g Hgb (0.5%). The major vascular complications in patients treated with the Mynx included retroperitoneal bleeding requiring surgical intervention (0.8%), pseudoaneurysm with surgical repair (0.8%) and hemorrhage with a loss of > 3g Hgb (0.4%). These complications were not significantly different between the two vascular closure devices (p = 0.77). Minor complications included hematoma > 5 cm (0.5%, n = 1) within the AngioSeal group, as well as procedure failure requiring > 30 minutes of manual compression after device deployment, which occurred in 7 out of 190 patients (3.7%) treated with the AngioSeal versus 22 of 238 patients with the Mynx (9.2%) (p = 0.033).

CONCLUSIONS:

Major vascular complications after PCI following hemostasis with vascular closure devices occurred in 2.1% of 190 patients treated with the AngioSeal vascular closure device versus 2.1% of 238 patients treated with the Mynx vascular closure device (p not significant). The Mynx vascular closure device appears to have a higher rate of device failure.

Comment in

http://www.ncbi.nlm.nih.gov/pubmed/20351388

Z Kardiol. 2005 Jun;94(6):392-8.

Incications and complications of invasive diagnostic procedures and percutaneous coronary interventions in the year 2003. Results of the quality control registry of the Arbeitsgemeinschaft Leitende Kardiologische Krankenhausarzte (ALKK).

Source

Herzzentrum Ludwigshafen, Bremserstrasse 79, 67063 Ludwigshafen, Germany. Uwe.Zeymer@t-online.de

Abstract

BACKGROUND:

The ALKK registry contains about 20% of the invasive and interventional cardiological procedures performed in Germany.

METHODS:

In 2003 a total of 82,282 consecutive diagnostic invasive and 30,689 interventional procedures from 75 hospitals were centrally collected and analyzed.

RESULTS:

The main indication for an invasive diagnostic procedure was coronary artery disease in 92.5% of cases, myocardial disease in 1.6%, impaired left ventricular function in 4.0%, valve disease in 4% and other indications in 1.9%. An acute coronary syndrome was present in 25% of the patients. The rate of severe complications in patients with a lone diagnostic invasive procedure was low (<0.5%). The indication for percutaneous coronary intervention (n=30,689) was stable angina in 44.1%, ST elevation myocardial infarction in 22.3%, non ST elevation myocardial infarction in 14.8%, unstable angina in 10.0%, silent ischemia in 2.2%, prognostic in 5.2% of patients. The majority of interventions were performed directly after the diagnostic procedure (n=23,887=78.6%). The intervention was successful in 94.6% of cases. Stent implantation was performed in 77.2%, with 1 stent in 88.4%, two stents in 7.6% and 3 or more stents in 3.3%. A drug-eluting stent was implanted in 3.6% of the cases. The complication rate after PCI was influenced by the indication for the intervention. The in-hospital mortality in patients with cardiogenic shock was 33%, while in patients with stable angina, silent ischemia and prognostic indication only 0.2% died.

CONCLUSION:

There is an increase of invasive diagnostic and interventional procedures in patients with acute coronary syndromes, with 47% of PCIs performed in these patient. PCIs were performed in 75% of the cases directly after the diagnostic procedure. The rate of stent implantation seems to have reached a plateau at around 80%, while drug-eluting stents were implanted only in a minority of cases. The complication rate is mainly dependent on the clinical presentation of the patients and the indication for PCI.

http://www.ncbi.nlm.nih.gov/pubmed/15940439

Coronary arterial complications after percutaneous coronary intervention in Behçet’s disease

Authors: Kinoshita T, Fujimoto S, Ishikawa Y, Yuzawa H, Fukunaga S, Toda M, Wagatsuma K, Akasaka Y, Ishii T, Ikeda T

Published Date February 2013 Volume 2013:4 Pages 9 – 12

DOI: http://dx.doi.org/10.2147/RRCC.S41240,

Published: 05 February 2013
Toshio Kinoshita,1 Shinichiro Fujimoto,Yukio Ishikawa,2 Hitomi Yuzawa,1 Shunji Fukunaga,1Mikihito Toda,3 Kenji Wagatsuma,3 Yoshikiyo Akasaka,2 Toshiharu Ishii,2 Takanori Ikeda1
1Department of Cardiovascular Medicine, 2Department of Pathology, 3Division of Interventional Cardiology, Toho University Faculty of Medicine, Ohta City, Tokyo, Japan

Abstract: Behçet’s disease is a multisystemic vascular inflammatory disease, but concurrent cardiac diseases, such as acute myocardial infarction, are rare. Several complications may arise after coronary intervention for coronary lesions that interfere with treatment, and the incidence of coronary arterial complications due to invasive therapy remains unclear. Further, the long-term outcomes in patients with Behçet’s disease after stenting for acute myocardial infarction have not been described. The present report describes a 35-year-old Japanese man with Behçet’s disease who developed acute myocardial infarction. A coronary aneurysm developed at the stenting site of the left anterior descending coronary artery, along with stenosis in the left anterior descending segment proximal to the site. Although invasive therapy was considered, medication including immunosuppressants was selected because of the high risk of vascular complications after invasive therapy. The coronary artery disease has remained asymptomatic for the 4 years since the patient started medication. This case underscores the importance of considering the incidence of coronary arterial complications and of conservative treatment when possible.

Keywords: Behçet’s disease, myocardial infarction, coronary arterial complications, percutaneous coronary intervention, immunosuppressants

http://www.dovepress.com/coronary-arterial-complications-after-percutaneous-coronary-interventi-peer-reviewed-article-RRCC-recommendation1

REFERENCES

  1. Marso SP, Amin AP, House JA, et al; on behalf of the National Cardiovascular Data Registry. Association between use of bleeding avoidance strategies and risk of periprocedural bleeding among patients undergoing percutaneous coronary intervention. JAMA. 2010;303(21):2156-2164.
  2. Heart Disease and Stroke Statistics — 2011 Update. American Heart Association, 2011.
  3. Tavris DR, Gallauresi BA, Dey S, Brindis R, Mitchel K. Risk of local adverse events by gender following cardiac catheterization. Pharmacoepidemiol Drug Saf. 2007;16(2):125-131.
  4. United States Food and Drug Administration (US FDA). Manufacturer and user facility device experience; MAUDE Database, 2001: Accessed atwww.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/TextResults.cfm
  5. Tavris DR, Dey S, Gallauresi B, et al. Risk of local adverse events following cardiac catheterization by hemostasis device use — phase II. J Invasive Cardiol. 2005;17(12):644-650.
  6. An initiative of the American College of Cardiology Foundation, the NCDR, National Cardiovascular Data Registry, is a comprehensive, outcomes-based suite of registries focused on quality improvement. www.ncdr.com. 
  7. Applegate RJ, Sacrinty MT, Kutcher MA, et al. Propensity score analysis of vascular complications after diagnostic cardiac catheterization and percutaneous coronary intervention 1998-2003. Catheter Cardiovasc Interv. 2006;67(4):556-562.
  8. Applegate RJ, Sacrinty M, Kutcher MA, et al. Vascular complications with newer generations of Angio-Seal vascular closure devices. J Interv Cardiol. 2006;19(1):67-74.
  9. Applegate RJ, Sacrinty MT, Kutcher MA, et al. Propensity score analysis of vascular complications after diagnostic cardiac catheterization and percutaneous coronary intervention using thrombin hemostatic patch-facilitated manual compression. J Invasive Cardiol. 2007;19(4):164-170.
  10. Sulzbach-Hoke LM, Ratcliffe SJ, Kimmel SE, et al. Predictors of complications following sheath removal with percutaneous coronary intervention. J Cardiovasc Nurs. 2010;25(3):E1-E8.
  11. Legrand V, Doneux P, Martinez C, et al. Femoral access management: comparison between two different vascular closure devices after percutaneous coronary intervention. Acta Cardiol. 2005;60(5):482-488.
  12. Hermiller JB, Simonton C, Hinohara T, et al. The StarClose Vascular Closure System: interventional results from the CLIP study. Catheter Cardiovasc Interv. 2006;68(5):677-683.
  13. Martin JL, Pratsos A, Magargee E, et al. A randomized trial comparing compression, Perclose Proglide and Angio-Seal VIP for arterial closure following percutaneous coronary intervention: the CAP trial. Catheter Cardiovasc Interv. 2008;71(1):1-5.
  14. Deuling JH, Vermeulen RP, Anthonio RA, et al. Closure of the femoral artery after cardiac catheterization: a comparison of Angio-Seal, StarClose, and manual compression. Catheter Cardiovasc Interv. 2008;71(4):518-523.
  1. Wong SC, Bachinsky W, Cambier P, et al; ECLIPSE Trial Investigators. A randomized comparison of a novel bioabsorbable vascular closure device versus manual compression in the achievement of hemostasis after percutaneous femoral procedures: the ECLIPSE (Ensure’s Vascular Closure Device Speeds Hemostasis Trial). JACC Cardiovasc Interv. 2009;2(8):785-793.
  2. Arora N, Matheny ME, Sepke C, Resnic FS. A propensity analysis of the risk of vascular complications after cardiac catheterization procedures with the use of vascular closure devices. Am Heart J. 2007;153(4):606-611.
  3. Castillo-Sang M, Tsang AW, Almaroof B, et al. Femoral artery complications after cardiac catheterization: a study of patient profile. Ann Vasc Surg. 2010;24(3):328-335.
  4. Sanborn TA, Ebrahimi R, Manoukian SV, et al. Impact of femoral vascular closure devices and antithrombotic therapy on access site bleeding in acute coronary syndromes: the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial. Circ Cardiovasc Interv. 2010;3(1):57-62.
  5. Iqtidar AF, Li D, Mather J, McKay RG. Propensity matched analysis of bleeding and vascular complications associated with vascular closure devices vs standard manual compression following percutaneous coronary intervention. Conn Med. 2011;75(1):5-10.
  6. Marso SP, Amin AP, House JA, et al; National Cardiovascular Data Registry. Association between use of bleeding avoidance strategies and risk of periprocedural bleeding among patients undergoing percutaneous coronary intervention. JAMA. 2010;303(21):2156-2164.
  7. Ahmed B, Piper WD, Malenka D, et al. Significantly improved vascular complications among women undergoing percutaneous coronary intervention: a report from the Northern New England Percutaneous Coronary Intervention Registry. Circ Cardiovasc Interv. 2009;2(5):423-429.
  8. Trimarchi S, Smith DE, Share D, et al; BMC2 Registry. Retroperitoneal hematoma after percutaneous coronary intervention: prevalence, risk factors, management, outcomes, and predictors of mortality: a report from the BMC2 (Blue Cross Blue Shield of Michigan Cardiovascular Consortium) registry. JACC Cardiovasc Interv. 2010;3(8):845-850.
  9. Vaitkus PT. A meta-analysis of percutaneous vascular closure devices after diagnostic catheterization and percutaneous coronary intervention. J Invasive Cardiol. 2004;16(5):243-246.
  10. Koreny M, Riedmuller E, Nikfardjam M, et al. Arterial puncture closing devices compared with standard manual compression after cardiac catheterization — systematic review and meta-analysis. JAMA. 2004;291(3):350-357.
  11. Nikolsky E, Mehran R, Halkin A, et al. Vascular complications associated with arteriotomy closure devices in patients undergoing percutaneous coronary procedures: a meta-analysis. J Am Coll Cardiol. 2004;44(6):1200-1209.
  12. Biancari F, D’Andrea V, Di Marco C, et al. Meta-analysis of randomized trials on the efficacy of vascular closure devices after diagnostic angiography and angioplasty. Am Heart J. 2010;159(4):518-531.
  13. Tavris DR, Dey S, Gallauresi B, et al. Risk of local adverse events following cardiac catheterization by hemostasis device use — phase II. J Invasive Cardiol. 2005;17(12): 644-650.

Frequency and Costs of Ischemic and Bleeding Complications After Percutaneous Coronary Interventions: Rationale for New Antithrombotic Therapy

Journal of Invasive Cardiology

http://www.invasivecardiology.com/article/2489

Author(s):

Mauro Moscucci, MD

Recent advances in catheter technology and antithrombotic therapy have led to a continuous improvement in outcomes of percutaneous coronary intervention (PCI). These improved outcomes have been associated with broadening of the indications for PCI, with an exponential growth in number of procedures performed, but they have also been paralleled by incremental procedure costs. The estimated costs of PCI currently range from $8,000–$13,000.1 With over 800,000 cases performed each year in the United States (US) alone, this represents over $10 billion annually for the US Healthcare System.2 Roughly half of these costs are incurred by the Center for Medicare and Medicaid Services (CMS, formerly known as the Health Care Financing Administration).3 Total costs of PCI include disposable equipment used during the procedure (balloons, catheters, stents, etc.), cardiac catheterization laboratory overhead and depreciation, nursing and pharmacy costs, laboratory costs and physician services. In addition, factors that have been found to be associated with increased PCI costs include the use of special devices such as atherectomy or vascular closure devices, the use of multiple stents, the use of platelet glycoprotein (GP) IIb/IIIa inhibitors, and the presence of certain patient demographic characteristics including advanced age, gender and other comorbidities.1,4,5 Finally, complications related to the procedure have been identified in several studies as the single most significant contributor to increased costs of PC.5–7

Methods to reduce the cost of PCI include re-use of balloon catheters,8 percutaneous revascularization performed at the same time as diagnostic catheterization,9 reduced anticoagulation, the use of new devices or pharmacological interventions to reduce restenosis and complications, and the use of competitive bidding for cardiac cath lab supplies.10 For example, the evolution of anticoagulation therapy in stented patients from a regime of post-procedural heparin and warfarin to one of thienopyridines and aspirin,11 and the subsequent reduction of length of stay from 4 days in 1995 to 2 days in 2000, have helped keep total procedure costs down.12 In addition, a reduction in complication rates appears to be a key target for cost reduction efforts. In support of this statement, in the economic assessment of the Evaluation of 7E3 for the Prevention of Ischemic Complications (EPIC) trial in high-risk patients, Mark et al. identified bleeding complications, urgent and non-urgent coronary artery bypass graft surgery (CABG), and urgent and non-urgent percutaneous transluminal coronary angioplasty (PTCA) as important correlates of incremental costs.7 Unfortunately, standard aggressive antithrombotic therapy aimed toward a reduction of ischemic complications is often associated with an increase in bleeding complications. In the analysis of the EPIC trial, the benefits of abciximab in decreasing procedure costs through a reduction of ischemic complications were offset by drug acquisition costs and by an increase in bleeding complications.7 Thus, with ischemic complications becoming more rare as a result of improvement in PCI technology and more aggressive antithrombotic therapy, bleeding has become a rather common and costly complication of PCI, with a blood transfusion estimated to add up to $8,000 to the cost of care for the PCI patient.13

Based on these premises, it appears that the next challenge in the care of PCI patients will be to determine how to continue to prevent ischemic complications without increasing the risk of bleeding. This paper examines the frequency of PCI complications in both recent clinical trials and actual practice, discusses the costs of complications, and explores improvements in patient management and particularly changes in anticoagulation therapy that might impact total costs of PCI.

Complication rates in clinical trials

Ischemic complications in clinical trials. Despite advances in PCI technology and adjunctive pharmacotherapy, data from clinical trials indicate that ischemic complications still occur in 5–15% of patients.14–19 Typically, clinical trials define ischemic complications as a combination of death, myocardial infarction (MI; both Q-wave and non-Q wave) and either urgent or any target vessel revascularization (TVR). Different definitions of MI or revascularization can make comparisons across trials difficult. However, comparisons may still be possible through the application of strict meta-analysis methodology. A recent meta-analysis combined data from 6 double-blind PCI trials conducted predominantly in North America between 1993 and 1998.20 A total of 16,546 patients were enrolled in these trials (Table 1). Protocols and case report forms for trials included in the analysis were compared to ensure reasonable consistency of study methods, patient management, data reporting and data structure. Integration of the databases from the trials enabled a direct comparison of key event rates at 7 days, using standard classifications and criteria for severity. The meta-analysis showed that the use of high-dose heparin (175 U/kg) was associated with significantly less frequent clinical ischemic events (8.1%) than lower doses of heparin (100 U/kg; 10.3%). In this same meta-analysis, event rates in patients treated with low-dose heparin (70 U/kg) plus a GP IIb/IIIa inhibitor was 6.5%.20 Although not included in this meta-analysis, it is worth noting that the incidence of death, MI and revascularization in the ESPRIT trial was 9.3% in patients treated with low-dose heparin alone (60 U/kg).21

Bleeding complications in clinical trials. In clinical trials of antiplatelet and anti-thrombotic therapy in PCI, bleeding complications are generally defined using either thrombolysis in myocardial infarction (TIMI)22 or global utilization of streptokinase or tPA outcomes (GUSTO)23 criteria (Table 2). Rates of major bleeding in clinical trials using these criteria are generally less than 2% (Table 3).14–19,21,24,25 However, these restrictive definitions may not capture all clinically significant bleeding. For example, neither the TIMI nor the GUSTO major bleeding definition includes the need for a blood transfusion as part of the criteria. Thus, a broader measure of bleeding using a combination of both major and minor bleeding defined by TIMI or GUSTO criteria appears more likely to be representative of bleeding rates in clinical practice.

In the meta-analysis of contemporary PCI trials, TIMI criteria were used to classify hemorrhagic events, permitting direct comparisons between trials. In the high-dose heparin group, the combination of TIMI major and minor bleeding occurred in 10.5% of patients compared with a rate of 10.7% in the low-dose heparin group, while the bleeding rate was 14.3% in patients receiving a combination of GP IIb/IIIa inhibitors and low-dose heparin.

As shown in Table 3, when both TIMI major and minor bleeding are combined in contemporary PCI trials, bleeding complications average 4–14%, depending on patient characteristics and the drug regime used. In addition, when transfusions are included in the definition, the frequency of bleeding complications increases substantially. For example, in NICE-3, bleeding complications were 10.5% when transfusions were included in the criteria, but only 2% of the patients experienced TIMI major bleeding.26

Notably, the only adjunctive anti-thrombotic agent shown to reduce both ischemic and bleeding complications in PCI is bivalirudin. In the Bivalirudin Angioplasty Trial,27 the risk of bleeding was decreased 62% in the bivalirudin group compared with high-dose heparin. The combined rate of TIMI major and TIMI minor bleeding in bivalirudin patients (n = 2,161) was found to be 4.3% in the meta-analysis of contemporary PCI trials with a corresponding ischemic event rate of 6.6%.20

Complications in practice

Ischemic complications in practice. Rates of ischemic complications in clinical practice are difficult to determine. Although several investigators have published data from multicenter databases, these data tend to be 3–5 years old by the time manuscripts are in print. Since trends in the published literature do show continued reduction in PCI complications over time, the frequency of complications noted in these publications may overestimate the actual rate of complications in clinical practice today. In addition, rates of complications can vary widely across institutions due to differences in practice patterns, definitions, operator skills and resource utilization. For example, in the Society for Cardiac Angiography and Interventions (SCA&I) registry, stent use among laboratories varied from 29–95%.28 Others have found lower complication rates in patients whose procedure was performed by a high-volume operator or in a high-volume institution.29 We identified 6 published reports of PCI complications in clinical practice reporting a variety of ischemic outcomes.1,28–31

Saucedo et al. prospectively collected data on 900 patients undergoing successful elective stent placement in native coronary arteries between January 1994 and December 1995.30 The purpose of this study was to evaluate the incidence and long-term clinical consequences of patients with creatine kinase (CK) myocardial isoenzyme band (CK-MB) elevations after stenting. By design, all patients in this observational study had a successful procedure defined as an increase of > 20% in luminal diameter with final percent diameter stenosis of < 50%, without the occurrence of any major complications (death, Q-wave MI and CABG). Nevertheless, 26.4% of patients had CK-MB elevations 1–5 times the upper limit of normal (ULN) and 8.5% had CK-MB elevations > 5 times ULN. In total, 3.9% of patients required a repeat diagnostic catheterization for recurrent ischemia and 1.2% required urgent target vessel revascularization. In this study, patients requiring the use of GP IIb/IIIa inhibitors were excluded.

The Northern New England group (NNE) collected data on 14,498 patients undergoing PCI between 1994 and 1996.29 In this study, outcomes included the in-hospital occurrence of death; emergency CABG (eCABG) or non-eCABG; or new MI (defined as chest pain, diaphoresis, dyspnea or hypotension associated with the development of new Q-waves or ST-T wave changes and a rise in CK to at least twice normal with a positive CK-MB). Overall, death occurred in 1.2% of patients, CABG in 2.6% (0.8% eCABG and 1.8% non-eCABG), and MI in 2%. Stents were used in 22% of patients enrolled in this registry.

In the National Cardiovascular Network database (NCN), Batchelor et al. reported complications of PCI in 109,708 patients who underwent PCI between 1994 and 1997.31 In this observational study, in-hospital mortality was defined as the occurrence of death after the procedure, MI was defined as the appearance of new Q-waves in 2 contiguous leads on a 12-lead electrocardiogram (ECG) for up to 30 days post-PCI, and repeat revascularization was defined as the need for CABG or additional PCI prior to discharge. In this study, death occurred in 1.3% of patients, Q-wave MI in 1.4% and repeat revascularization in 4.5%. Half of the patients underwent stenting in this study. Notably, this database did not record myocardial enzymes or the use of GP IIb/IIIa inhibitors.

Aronow and colleagues observed outcomes in a cohort of consecutive registry patients undergoing coronary stent placement between 1995 and 1997.32 A total of 373 patients underwent PCI during this time period, with death occurring in 9 patients (2.4%), CABG in 3 (0.8%) and MI in 19 (5.1%, including both QWMI and NQWMI). Repeat diagnostic catheterization was performed in 3.2% of patients and repeat PCI in 0.8%.

The SCA&I registry evaluated outcomes in 16,811 patients undergoing either balloon angioplasty (n = 6,121) or stenting (n = 10,690) between July 1996 and December 1998.28 In this observational analysis, 12.9% of patients received a GP IIb/IIIa inhibitor, 87% of patients enrolled in the database underwent PCI between 1997 and 1998, and 60% of the stent patients were enrolled in 1998. Outcomes reported included in-hospital death (occurring at any time during the hospitalization) and eCABG, defined as CABG occurring immediately after PCI. Death occurred in 0.4% of patients and eCABG in 0.5%.

Finally, Cohen and others recorded in-laboratory complications in 26,421 patients at 70 different centers undergoing PCI in 1998.1 In-laboratory complications were rare, with death occurring in 0.17%, cardiac arrest in 0.32%, stroke in 0.03%, ventricular fibrillation or tachycardia in 0.94%, abrupt closure in 0.71%, and eCABG in 0.53%. Overall, 72% of patients received stents and 20% received GP IIb/IIIa inhibitors.

In addition to published reports of PCI complications, data from unpublished sources can be used to determine outcomes in a more contemporary cohort of patients undergoing PCI.33 The MQ-Profile (MQ-Pro) Database [Cardinal Information Corporation (CIC), Marlborough, Massachusetts] is maintained by CIC, which sells and distributes software to US acute-care hospitals for the collection of detailed clinical and administrative data. Data from 5,373 PCI procedures performed between July 1, 1998 and June 30, 1999 were obtained from the database using International Classification of Diseases 9th Edition (ICD-9) procedure codes for PCI (36.01, 36.02, 36.05). Demographic, clinical and economic data were collected on each patient using a combination of database retrieval and chart review. In this analysis, death was defined as discharge disposition of “deceased”, MI as the presence of ECG changes consistent with MI (new Q-waves or ST-segment changes) or an increase in CK-MB of at least 2 times the testing facility’s ULN. CABG was identified by the presence of ICD-9 procedure code 36.1 and repeat PCI by either code 36.01, 36.02, or 36.05. Failed PCI was defined by the term “failed PTCA” in chart notes (for patients without a previous history of PCI) and recurrent ischemia documented by ECG changes. Death occurred in 2.0% of patients, MI in 3.1%, CABG in 1.3% and repeat PCI in 5.5%. Translated into a combined endpoint similar to those used in clinical trials, the rate of death/MI/revascularization was 11.9%.

Data from these published and unpublished observations of contemporary PCI practice indicate that while in-laboratory ischemic complications are exceedingly rare, in-hospital ischemic complications still occur in a substantial number of patients. Using an approximation of outcomes from these published and unpublished reports, mortality averages 1%, Q-wave MI occurs in 2% of patients, NQWMI in 6%, CABG in 2% and repeat PCI occurs in 3–5% of patients. It is important to underscore that although most deaths following PCI are due to underlying comorbidities (i.e., acute MI, cardiogenic shock, etc.) rather than to the procedure itself, few deaths still occur as a complication of the procedure.34,35 Extrapolated to the estimated PCI population of 800,000 cases per year, then 8,000 people will die and 64,000 will experience an MI. In addition, approximately 16,000 will require CABG and as many as 40,000 will need a repeat PCI before hospital discharge.

II(b) PAD Endovascular Interventions: Carotid Artery Endarterectomy

  • Original Contributions

Medical Complications Associated With Carotid Endarterectomy

Stroke.1999; 30: 1759-1763  doi: 10.1161/​01.STR.30.9.1759

  1. Maurizio Paciaroni, MD;
  2. Michael Eliasziw, PhD;
  3. L. Jaap Kappelle, MD;
  4. Jane W. Finan, BScN;
  5. Gary G. Ferguson, MD;
  6. Henry J. M. Barnett, MD;
  7. for the North American Symptomatic Carotid Endarterectomy Trial (NASCET) Collaborators

+Author Affiliations


  1. From the John P. Robarts Research Institute (M.P., M.E., L.J.K., J.W.F., H.J.M.B) and the Departments of Epidemiology and Biostatistics (M.E.) and Clinical Neurological Sciences (M.E., G.G.F., H.J.M.B.), University of Western Ontario, London, Ontario, Canada.
  1. Correspondence to Dr H.J.M. Barnett, John P. Robarts Research Institute, PO Box 5015, 100 Perth Dr, London, ON N6A 5K8, Canada. E-mail barnett@rri.on.ca

Abstract

Background and Purpose—Carotid endarterectomy (CE) has been shown to be beneficial in patients with symptomatic high-grade (70% to 99%) internal carotid artery stenosis. To achieve this benefit, complications must be kept to a minimum. Complications not associated with the procedure itself, but related to medical conditions, have received little attention.

Methods—Medical complications that occurred within 30 days after CE were recorded in 1415 patients with symptomatic stenosis (30% to 99%) of the internal carotid artery. They were compared with 1433 patients who received medical care alone. All patients were in the North American Symptomatic Carotid Endarterectomy Trial (NASCET).

Results—One hundred fifteen patients (8.1%) had 142 medical complications: 14 (1%) myocardial infarctions, 101 (7.1%) other cardiovascular disorders, 11 (0.8%) respiratory complications, 6 (0.4%) transient confusions, and 10 (0.7%) other complications. Of the 142 complications, 69.7% were of short duration, and only 26.8% prolonged hospitalization. Five patients died: 3 from myocardial infarction and 2 suddenly. Medically treated patients experienced similar complications with one third the frequency. Endarterectomy was ≈1.5 times more likely to trigger medical complications in patients with a history of myocardial infarction, angina, or hypertension (P<0.05).

Conclusions—Perioperative medical complications were observed in slightly fewer than 1 of every 10 patients who underwent CE. The majority of these complications completely resolved. Most complications were cardiovascular and occurred in patients with 1 or more cardiovascular risk factors. In this selected population, the occurrence of perioperative myocardial infarction was uncommon.

Key Words:

The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Endarterectomy Trial showed unequivocal benefit of carotid endarterectomy (CE) in symptomatic patients with high-grade internal carotid artery (ICA) stenosis (70% to 99%).1 2 The parallel study dealing with symptomatic patients with moderate-grade stenosis (30% to 69%) showed benefits of CE only in a carefully selected group of patients.3 Currently, CE is the most common elective peripheral vascular procedure, which in 1997 was performed in ≈130 000 patients in the United States.4

Despite benefit in the long term, CE may cause complications either by the operation itself or by concomitant medical conditions. The challenge for the future is to reduce the perioperative risk as much as possible. The incidence and type of complications that are directly related to the surgical procedure have been the subject of many reports,5 6 7 8 910 whereas medical complications that are not directly caused by the procedure have received less attention. The aim of the present study is to describe the incidence and type of medical complications that occurred in patients randomized into NASCET and to determine their association with baseline risk factors.

Subjects and Methods

The methods of the NASCET have been described in detail elsewhere.1 11 Briefly, NASCET was a randomized clinical trial designed to compare the benefit of best medical therapy alone with best medical therapy plus CE in patients with recent transient or nondisabling neurological deficit caused by cerebral or retinal ischemia in the territory of the ICA. Among the exclusions were patients with recent history (6 months) of myocardial infarction, unstable angina pectoris, atrial fibrillation, recent congestive heart failure, and valvular heart disease. For inclusion, the ICA had to have a 30% to 99% stenosis as assessed by selective carotid angiography and to be technically suitable for CE. Baseline evaluations included a detailed medical history and complete physical and neurological examination.

Surgeons were invited to join NASCET if the center had a documented CE stroke and death rate of ≤6% in a minimum of 50 consecutive cases over a 2-year period. Surgery was completed at the earliest opportunity after randomization, and patients underwent a second complete physical and neurological examination 30 days after surgery. All medical and surgical complications that caused transient or permanent disability within the 30-day period were recorded.

Medical complications consisted of myocardial infarction (based on ECG and cardiac enzyme changes), arrhythmia (requiring antiarrhythmic medication), congestive heart failure, angina pectoris, hypertension (diastolic blood pressure >100 mm Hg requiring intravenous medication), hypotension (systolic pressure <90 mm Hg requiring administration of vasopressor agent), sudden death, respiratory problems (pneumonia, atelectasis, pulmonary edema, or exacerbation of chronic obstructive pulmonary disease), renal failure (doubling of preoperative urea and/or creatinine), depression, and confusion (requiring restraint). Complications were considered mild if they were transient and did not prolong hospital stay, moderate if they were transient but caused delay in hospital discharge, and severe if they were associated with permanent disability or death.

In the present study, patients were excluded from the analyses if they had serious complications that were directly attributable to the surgical procedure, such as those due to anesthesia, thrombosis at the operative site, wound hematomas requiring surgical intervention, or deficits from a vagus nerve injury interfering with swallowing. These surgical complications are described in detail elsewhere.12 For comparative purposes, a list of complications that occurred in the medically treated arm of NASCET was compiled for the 32-day period after randomization (ie, the 30-day period plus the average 2 days that lapsed from randomization to CE in the surgical arm). In both the surgical and medical arms, patients were censored at the time of a stroke, since the subsequent medical complications are commonly the result of the stroke.

Cox proportional hazards regression modeling was used to identify baseline factors that increased the risk of perioperative medical complications. Adjusted hazard rates and adjusted hazard ratios were used to summarize the results. The estimated hazard ratio (or relative hazard) is a measure of association that can be interpreted as a relative risk. Hazard ratios with corresponding probability value of <0.05 were considered statistically significant. Adjusted hazard rates were obtained from the regression model by using the mean value for a factor being adjusted.

The modeling strategy consisted of initially fitting a “full” model, which included all factors. A “final” model was determined by eliminating all factors that were not significantly predictive of the medical complications, using a backward selection approach. The “change-in-estimate” strategy was used to determine whether the remaining factors in the final model were independent risk factors. A factor was considered an independent risk factor if the change in hazard ratios between the full and final models was <10%.

Results

A total of 1436 eligible patients were randomized to the surgical arm and 1449 to the medical arm of the NASCET. In the surgical arm, 21 patients were not operated on for various reasons.12 In the medical arm 16 patients crossed over to surgical therapy within 30 days, leaving 1433 patients for analysis. CE was performed in 1415 patients (328 patients with severe stenosis and 1087 with moderate stenosis). Of the 1415, 59 (4.2%) patients had serious surgical complications that excluded them from further analyses, and 115 (8.1%) had medical complications (Table 1). Of the 142 complications, 69.7% were mild, 26.8% were moderate, and 3.5% were severe. Twenty patients had ≥2 complications. No patient had pulmonary embolus, renal failure, or depression requiring medication. Cardiovascular disorders were >4 times as common as all other conditions combined. All 5 severe complications were fatal and were caused by cardiovascular disorders: 3 patients had fatal myocardial infarction, and 2 patients died suddenly. Of the patients with fatal myocardial infarction, 2 patients had massive myocardial infarctions on the day of surgery. In the other patient, CE was prolonged (7 hours) because of intraoperative occlusion of the ICA. Twenty-four hours after CE, the patient had a myocardial infarction followed by cardiac arrest, leaving the patient in a vegetative state. The patient died 2 months later. Two patients died suddenly on days 3 and 6 after CE, and both had a history of previous myocardial infarction. All patients with fatal medical complications were male, and all had multiple cardiovascular risk factors.

http://stroke.ahajournals.org/content/30/9/1759.full

REFERENCES

  1. North American Symptomatic Carotid Endarterectomy Trial (NASCET). Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med. 1991;325:445–453.
  2. European Carotid Surgery Trialists’ Collaborative Group. MRC European Carotid Surgery Trial: interim results for symptomatic patients with severe (70–99%) or with mild (0–29%) carotid stenosis. Lancet. 1991;337:1235–1243.
  3. Barnett HJM, Taylor DW, Eliasziw M, Fox AJ, Ferguson GG, Haynes RB, Rankin RN, Clagett GP, Hachinski VC, Sackett DL, Thorpe KE, Meldrum HE, for the North American Symptomatic Carotid Endarterectomy Trial Collaborators. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. N Engl J Med. 1998;339:1415–1425.
  4. Kozak LJ, Owings MF. Ambulatory and inpatient procedures in the United States, 1995. National Center for Health Statistics. Vital Health Stat 13. 1998;135:1–116.
  5. Hertzer NR. Early complications of carotid endarterectomy: incidence, diagnosis, and management. In: Moore WS, ed. Surgery for Cerebrovascular Disease. Philadelphia, Pa: WB Saunders Co; 1996:625–649.
  6. Fode NC, Sundt TM, Robertson JT, Peerless SJ, Shields CB. Multicenter retrospective review of results and complications of carotid endarterectomy in 1981.Stroke. 1986;17:370–375.
  7. Goldstein LB, Moore WS, Robertson JT, Chaturvedi S. Complication rates for carotid endarterectomy: a call to action. Stroke. 1997;28:889–890.
  8. Young B, Moore WS, Robertson JT, Toole JF, Ernst CB, Cohen SN, Broderick JP, Dempsey RJ, Hosking JD. An analysis of perioperative surgical mortality and morbidity in the Asymptomatic Carotid Atherosclerosis Study. Stroke.1996;27:2216–2224.
  9. McCrory DC, Goldstein LB, Samsa GP, Oddone EZ, Landsman PB, Moore WS, Matchar DB. Predicting complications of carotid endarterectomy. Stroke.1993;24:1285–1291.
  10. Rothwell PM, Slattery J, Warlow CP. Clinical and angiographic predictors of stroke and death from carotid endarterectomy: systemic review. BMJ.1997;315:1571–1517.
  11. North American Symptomatic Carotid Endarterectomy Trial (NASCET) Steering Committee. North American Symptomatic Carotid Endarterectomy Trial: methods, patient characteristics, and progress. Stroke. 1991;22:711–720.
  12. Ferguson GG, Barnett HJM, Eliasziw M, Finan JW, Clagett GP, Barnes R, Barr H, Wallace C, for the North American Symptomatic Carotid Endarterectomy Trial (NASCET) Collaborators. North American Symptomatic Carotid Endarterectomy Trial (NASCET): surgical results in 1415 patients. Stroke. In press.
  13. Hertzer NR, Young JR, Beven EG, Graor RA, O’Hara PJ, Ruschaupt WF, deWolfe VG, Maljovec LC. Coronary angiography in 506 patients with extracranial cerebrovascular disease. Arch Intern Med. 1985;145:849–852.
  14. Mangano DT. Perioperative cardiac morbidity. Anesthesiology. 1990;72:153–184.
  15. Goldstein LB, McCrory DC, Landsman PB, Samsa GP, Auncukiewicz M, Oddone EZ, Matchar DB. Multicenter review of preoperative risk factors for carotid endarterectomy in patients with ipsilateral symptoms. Stroke. 1994;24:1116–1121.
  16. Musser DJ, Nicholas GG, Reed JF III. Death and adverse cardiac events after carotid endarterectomy. J Vasc Surg. 1994;19:615–622.
  17. Urbinati S, Di Pasquale G, Andreoli A, Lusa AM, Carini G, Grazi P, Labanti G, Passarelli P, Corbelli C, Pinelli G. Preoperative non-invasive coronary risk stratification in candidates for carotid endarterectomy. Stroke. 1994;25:2022–2027.
  18. Adams HP Jr, Brott TG, Crowell RM, Furlan AJ, Gomez CR, Grotta J, Helgason CM, Marler JR, Woolson RF, Zivin JA, Feinberg W, Mayberg M. Guidelines for the management of patients with acute ischemic stroke: a statement for healthcare professionals from a special writing group of the Stroke Council, American Heart Association. Stroke. 1994;25:1901–1914.
  19. Feinberg WM, Albers GW, Barnett HJ, Biller J, Caplan LR, Carter LP, Hart RG, Hobson RW II, Kronmal RA, Moore WS, Robertson JT, Adams HP, Mayberg M. Guidelines for the management of transient ischemic attacks: from the Ad Hoc Committee on Guidelines for the Management of Transient Ischemic Attacks of the Stroke Council of the American Heart Association. Circulation. 1994;89:2950–2965.
  20. Hankey GJ, Warlow CP. Cost-effective investigation of patients with suspected transient ischaemic attacks. J Neurol Neurosurg Psychiatry. 1992;55:171–176.
  21. Wong JH, Findlay JM, Suarez-Almazor ME. Regional performance of carotid endarterectomy: appropriateness, outcomes, and risk factors for complications.Stroke. 1997;28:891–898.
  22. Holton P, Wood JB. The effect of bilateral removal of the carotid bodies and denervation of the carotid sinuses in two human subjects. J Physiol (Lond).1965;181:365–378.
  23. Lilly MP, Brunner MJ, Wehberg KE, Rudolphi DM, Queral LA. Jugular venous vasopressin increases during carotid endarterectomy after cerebral reperfusion. J Vasc Surg. 1992;16:1–9.
  24. Smith BL. Hypertension following carotid endarterectomy: the role of cerebral renin production. J Vasc Surg. 1984;1:623–627.
  25. Eliasziw M, Spence JD, Barnett HJM. Carotid endarterectomy does not affect long-term blood pressure: observations from the NASCET. Cerebrovasc Dis.1998;8:20–24.
  26. Solomon RA, Loftus CM, Quest DO, Correll JW. Incidence and etiology if intracerebral hemorrhage following carotid endarterectomy. J Neurosurg.1986;64:29–34.
  27. Hafner DH, Smith RB, King OW, Perdue GD, Stewart MT, Rosenthal D, Jordan WD. Massive intracerebral hemorrhage following carotid endarterectomy. Arch Surg.1987;122:305–307.
  28. Piepgras DG, Morgan MK, Sundt TM, Yanagihara T, Mussman LM. Intracerebral hemorrhage after carotid endarterectomy. J Neurosurg. 1988;68:532–536.
  29. Jansen C, Sprengers AM, Moll FL, Vermeulen FE, Hamerlijnck RP, van Gijn J, Ackerstaff RG. Prediction of intracerebral hemorrhage after carotid endarterectomy by clinical criteria and intraoperative transcranial Doppler monitoring. Eur J Vasc Surg. 1994;8:303–308.
  30. Chambers BR, Smidt U, Koh O. Hyperperfusion post-endarterectomy.Cerebrovasc Dis. 1994;4:32–37.
  31. Penn AA, Schomer DF, Steinberg GK. Imaging studies of cerebral hyperperfusion after carotid endarterectomy: case report. J Neurosurg. 1995;83:133–137.
  32. Baptista MV, Maeder P, Dewarrat A, Bogousslavsky J. Conflicting images.Lancet. 1998;351:414.

Intraoperative use of dextran is associated with cardiac complications after carotid endarterectomy.

J Vasc Surg. 2013 Mar;57(3):635-41. doi: 10.1016/j.jvs.2012.09.017. Epub 2013 Jan 18.

Source

Section of Vascular and Endovascular Surgery, Boston University Medical Center, Boston, MA, USA. Alik.Farber@bmc.org

Abstract

OBJECTIVE:

Although dextran has been theorized to diminish the risk of stroke associated with carotid endarterectomy (CEA), variation exists in its use. We evaluated outcomes of dextran use in patients undergoing CEA to clarify its utility.

METHODS:

We studied all primary CEAs performed by 89 surgeons within the Vascular Study Group of New England database (2003-2010). Patients were stratified by intraoperative dextran use. Outcomes included perioperative death, stroke, myocardial infarction (MI), and congestive heart failure (CHF). Group and propensity score matching was performed for risk-adjusted comparisons, and multivariable logistic and gamma regressions were used to examine associations between dextran use and outcomes.

RESULTS:

There were 6641 CEAs performed, with dextran used in 334 procedures (5%). Dextran-treated and untreated patients were similar in age (70 years) and symptomatic status (25%). Clinical differences between the cohorts were eliminated by statistical adjustment. In crude, group-matched, and propensity-matched analyses, the stroke/death rate was similar for the two cohorts (1.2%). Dextran-treated patients were more likely to suffer postoperative MI (crude: 2.4% vs 1.0%; P = .03; group-matched: 2.4% vs 0.6%; P = .01; propensity-matched: 2.4% vs 0.5%; P = .003) and CHF (2.1% vs 0.6%; P = .01; 2.1% vs 0.5%; P = .01; 2.1% vs 0.2%; P < .001). In multivariable analysis of the crude sample, dextran was associated with a higher risk of postoperative MI (odds ratio, 3.52; 95% confidence interval, 1.62-7.64) and CHF (odds ratio, 5.71; 95% confidence interval, 2.35-13.89).

CONCLUSIONS:

Dextran use was not associated with lower perioperative stroke but was associated with higher rates of MI and CHF. Taken together, our findings suggest limited clinical utility for routine use of intraoperative dextran during CEA.

J Vasc Surg. 2008 Nov;48(5):1139-45. doi: 10.1016/j.jvs.2008.05.013. Epub 2008 Jun 30.

Factors associated with stroke or death after carotid endarterectomy in Northern New England.

Source

Section of Vascular Surgery Dartmouth-Hitchcock Medical Center, Lebanon, NH 03765, USA. philip.goodney@hitchcock.org

Abstract

OBJECTIVE:

This study investigated risk factors for stroke or death after carotid endarterectomy (CEA) among hospitals of varying type and size participating in a regional quality improvement effort.

METHODS:

We reviewed 2714 patients undergoing 3092 primary CEAs (excluding combined procedures or redo CEA) at 11 hospitals in Northern New England from January 2003 through December 2007. Hospitals varied in size (25 to 615 beds) and comprised community and teaching hospitals. Fifty surgeons reported results to the database. Trained research personnel prospectively collected >70 demographic and clinical variables for each patient. Multivariate logistic regression models were used to generate odds ratios (ORs) and prediction models for the 30-day postoperative stroke or death rate.

RESULTS:

Across 3092 CEAs, there were 38 minor strokes, 14 major strokes, and eight deaths (5 stroke-related) < or =30 days of the index procedure (30-day stroke or death rate, 1.8%). In multivariate analyses, emergency CEA (OR, 7.0; 95% confidence interval [CI], 1.8-26.9; P = .004), contralateral internal carotid artery occlusion (OR, 2.8; 95% CI, 1.3-6.2; P = .009), preoperative ipsilateral cortical stroke (OR, 2.4; 95% CI, 1.1-5.1; P = .02), congestive heart failure (OR, 1.6; 95% CI, 1.1-2.4, P = .03), and age >70 (OR, 1.3; 95% CI, 0.8-2.3; P = .315) were associated with postoperative stroke or death. Preoperative antiplatelet therapy was protective (OR, 0.4; 95% CI, 0.2-0.9; P = .02). Risk of stroke or death varied from <1% in patients with no risk factors to nearly 5% with patients with > or =3 risk factors. Our risk prediction model had excellent correlation with observed results (r = 0.96) and reasonable discriminative ability (area under receiver operating characteristic curve, 0.71). Risks varied from <1% in asymptomatic patients with no risk factors to nearly 4% in patients with contralateral internal carotid artery occlusion (OR, 3.2; 95% CI, 1.3-8.1; P = .01) and age >70 (OR, 2.9; 95% CI, 1.0-4.9, P = .05). Two hospitals performed significantly better than expected. These differences were not attributable to surgeon or hospital volume.

CONCLUSION:

Surgeons can “risk-stratify” preoperative patients by considering the variables (emergency procedure, contralateral internal carotid artery occlusion, preoperative ipsilateral cortical stroke, congestive heart failure, and age), reducing risk with antiplatelet agents, and informing patients more precisely about their risk of stroke or death after CEA. Risk prediction models can also be used to compare risk-adjusted outcomes between centers, identify best practices, and hopefully, improve overall results.

III. Cardiac Failure During Systemic Sepsis

CHANGES IN HEART FUNCTION DURING SEPSIS

The patient with sepsis has severely altered physiology in a number of ways, which can influence cardiac function. Firstly, there is a

  • Loss of intravascular volume due to excessive third space loss that results in a decrease in preload. Systemic vascular resistance is decreased which results in a fall in afterload. In addition,
  • end diastolic volumes often increase and
  • ejection fraction falls. However, many of these changes are overcome by an
  • increase in heart rate that may result in an increase in cardiac output. However, it should be remembered that even in the presence of high cardiac outputs it is usually always possible to demonstrate
  • ventricular dysfunction in patients with sepsis. Echocardiographic studies consistently confirm that there is decreased left ventricular systolic function in humans with sepsis.

In addition, there have been many studies in animals and a few in humans which have confirmed the presence of

  • diastolic dysfunction – particularly in those patients that go on to die from sepsis.

In the presence of adequate fluid resuscitation there is an increase in end diastolic volume and this is probably a normal response to a decrease in contractility. However, in the non-survivors of sepsis there is a normal or low end diastolic volume that is the result of a decrease in ventricular diastolic compliance. Thus, there is a decreased end diastolic volume at the same filling pressure.

During sepsis, a

  • decrease in contractility results in a shift to the right of the end-systolic pressure / volume curve and if this is not compensated for results in a
  • decrease in stroke volume and cardiac output.

When patients with sepsis are appropriately fluid resuscitated there is an

  • increase in end diastolic pressure that increases stroke volume. In addition, the
  • decrease in afterload will also increase stroke volume and will prevent a decrease in ejection fraction.

Alas, because there is a decrease in systolic contractility it would be expected that there would also be a decrease in diastolic stiffness which would allow cardiac output to be maintained despite the relatively low filling pressures. However, if this diastolic compliance change does not occur (as in the nonsurvivors of sepsis) then it is apparent  that the ability of the ventricle to generate a stroke volume is impaired at both ends of the curve.

The cause of the altered cardiac function in sepsis remains unknown although there are many theoretical explanations. Clearly, one of the most important mechanisms which can be readily corrected is hypovolaemia.

  • Myocardial oedema may contribute to a decrease in contractility.
  • Increased circulating catecholamines can result in a decrease in diastolic compliance, particularly important since these agents are often used to improve myocardial contractility.
  • Increased intrathoracic pressure caused by positive pressure ventilation can also result in decreased diastolic compliance. In addition, many of the
  • mediators of the inflammatory response, including products of activated endothelial cells and polymorphonuclear leucocytes (e.g. nitric oxide, tumour necrosis factor and interleukins 1 and 2) have all been postulated as negative inotropes and negative lusitropes.

Another, as yet, unidentified agent which is believed to be released from the splanchnic bed –

  • myocardial depressant factor – is postulated to play a role.

Treatments aimed at correcting the effects of these various inflammatory mediators may be eventually found but until these approaches have been proven to be beneficial the septic patient will continue to be managed according to the physiological principles outlined by Starling.

http://www.rcsed.ac.uk/RCSEDBackIssues/journal/vol46_1/4610005.htm

Sepsis and the Heart – Cardiovascular Involvement in General Medical Conditions

  1. M.W. Merx, MD;
  2. C. Weber, MD

+Author Affiliations


  1. From the Department of Medicine (M.W.M.), Division of Cardiology, Pulmonary Diseases and Vascular Medicine and the Institute of Molecular Cardiovascular Research (IMCAR) at the University Hospital (C.W.), RWTH Aachen University, Aachen, Germany.
  1. Correspondence to Marc W. Merx, MD, Medizinische Klinik I, Universitätsklinikum der RWTH Aachen, Pauwelstraße 30, 52057 Aachen, Germany (e-mailmmerx@ukaachen.de), or Christian Weber, MD, Institut für Kardiovaskuläre Molekularbiologie, Universitätsklinikum der RWTH Aachen, Pauwelstraße 30, 52057 Aachen, Germany (e-mail cweber@ukaachen.de).
Circulation.2007; 116: 793-802doi: 10.1161/​CIRCULATIONAHA.106.678359

Abstract

Sepsis is generally viewed as a disease aggravated by an inappropriate immune response encountered in the afflicted individual. As an important organ system frequently compromised by sepsis and always affected by septic shock, the cardiovascular system and its dysfunction during sepsis have been studied in clinical and basic research for more than 5 decades. Although a number of mediators and pathways have been shown to be associated with myocardial depression in sepsis, the precise cause remains unclear to date. There is currently no evidence supporting global ischemia as an underlying cause of myocardial dysfunction in sepsis; however, in septic patients with coexistent and possibly undiagnosed coronary artery disease, regional myocardial ischemia or infarction secondary to coronary artery disease may certainly occur.

A circulating myocardial depressant factor in septic shock has long been proposed, and potential candidates for a myocardial depressant factor include

  • cytokines,
  • prostanoids, and
  • nitric oxide, among others.
  • Endothelial activation and
  • induction of the coagulatory system also contribute to the pathophysiology in sepsis.

Prompt and adequate antibiotic therapy accompanied by surgical removal of the infectious focus, if indicated and feasible, is the mainstay and also the only strictly causal line of therapy. In the presence of severe sepsis and septic shock, supportive treatment in addition to causal therapy is mandatory. The purpose of this review is to delineate some characteristics of septic myocardial dysfunction, to assess the most commonly cited and reported underlying mechanisms of cardiac dysfunction in sepsis, and to briefly outline current therapeutic strategies and possible future approaches.

Key Words:

Sepsis, defined by consensus conference as “the systemic inflammatory response syndrome (SIRS) that occurs during infection,”1 is generally viewed as a disease aggravated by the inappropriate immune response encountered in the affected individual (for review, see Hotchkiss and Karl2 and Riedemann et al,3). The Table gives the current criteria for the establishment of the diagnosis of systemic inflammatory response syndrome, sepsis, and septic shock.1,4 Morbidity and mortality are high, resulting in sepsis and septic shock being the 10th most common cause of death in the United States.5 The incidence of sepsis and sepsis-related deaths appears to be increasing by 1.5% per year.6 In a recent study,6 the total national hospital cost invoked by severe sepsis in the United States was estimated at approximately $16.7 billion on the basis of an estimated severe sepsis rate of 751 000 cases per year with 215 000 associated deaths annually. A recent study from Britain documented a 46% in-hospital mortality rate for patients presenting with severe sepsis on admission to the intensive care unit.7

Current Criteria for Establishment of the Diagnosis of SIRS, Sepsis, and Septic Shock1,4

As an important organ system frequently affected by sepsis and always affected by septic shock, the cardiovascular system and its dysfunction during sepsis have been studied in clinical and basic research for more than 5 decades. In 1951, Waisbren was the first to describe cardiovascular dysfunction due to sepsis.8 He recognized a hyperdynamic state with full bounding pulses, flushing, fever, oliguria, and hypotension. In addition, he described a second, smaller patient group who presented clammy, pale, and hypotensive with low volume pulses and who appeared more severely ill. With hindsight, the latter group might well have been volume underresuscitated, and indeed, timely and adequate volume therapy has been demonstrated to be one of the most effective supportive measures in sepsis therapy.9

Under conditions of adequate volume resuscitation, the profoundly reduced systemic vascular resistance typically encountered in sepsis10 leads to a concomitant elevation in cardiac index that obscures the myocardial dysfunction that also occurs. However, as early as the mid-1980s, significant reductions in both stroke volume and ejection fraction in septic patients were observed despite normal total cardiac output.11 Importantly, the presence of cardiovascular dysfunction in sepsis is associated with a significantly increased mortality rate of 70% to 90% compared with 20% in septic patients without cardiovascular impairment.12 Thus, myocardial dysfunction in sepsis has been the focus of intense research activity. Although a number of mediators and pathways have been shown to be associated with myocardial depression in sepsis, the precise cause remains unclear.

The purpose of the present review is to delineate some characteristics of septic myocardial dysfunction, to assess the most commonly cited and reported underlying mechanisms of cardiac dysfunction in sepsis, and to briefly outline current therapeutic strategies and possible future approaches. This review is not intended to be all inclusive.

Characteristics of Myocardial Dysfunction in Sepsis

Using portable radionuclide cineangiography, Calvin et al13 were the first to demonstrate myocardial dysfunction in adequately volume-resuscitated septic patients with decreased ejection fraction and increased end-diastolic volume index. Adding pulmonary artery catheters to serial radionuclide cineangiography, Parker and colleagues11 extended these observations with the 2 major findings that (1) survivors of septic shock were characterized by increased end-diastolic volume index and decreased ejection fraction, whereas nonsurvivors typically maintained normal cardiac volumes, and (2) these acute changes in end-diastolic volume index and ejection fraction, although sustained for several days, were reversible. More recently, echocardiographic studies have demonstrated impaired left ventricular systolic and diastolic function in septic patients.14–16 These human studies, in conjunction with experimental studies ranging from the cellular level17 to isolated heart studies18,19 and to in vivo animal models,20–22 have clearly established decreased contractility and impaired myocardial compliance as major factors that cause myocardial dysfunction in sepsis.

Notwithstanding the functional and structural differences between the left and right ventricle, similar functional alterations, as discussed above, have been observed for the right ventricle, which suggests that right ventricular dysfunction in sepsis closely parallels left ventricular dysfunction.23–26 However, the relative contribution of the right ventricle to septic cardiomyopathy remains unknown.

Myocardial dysfunction in sepsis has also been analyzed with respect to its prognostic value. Parker et al,27 reviewing septic patients on initial presentation and at 24 hours to determine prognostic indicators, found a heart rate of <106 bpm to be the only cardiac parameter on presentation that predicted a favorable outcome. At 24 hours after presentation, a systemic vascular resistance index >1529 dyne · s−1 · cm−5 · m−2, a heart rate <95 bpm or a reduction in heart rate >18 bpm, and a cardiac index >0.5 L · min−1 · m−2 suggested survival.27 In a prospective study, Rhodes et al28 demonstrated the feasibility of a dobutamine stress test for outcome stratification, with nonsurvivors being characterized by an attenuated inotropic response. The well-established biomarkers in myocardial ischemia and heart failure, cardiac troponin I and T, as well as B-type natriuretic peptide, have also been evaluated with regard to sepsis-associated myocardial dysfunction. Although B-type natriuretic peptide studies have delivered conflicting results in septic patients (for review, see Maeder et al29), several small studies have reported a relationship between elevated cardiac troponin T and I and left ventricular dysfunction in sepsis, as assessed by echocardiographic ejection fraction30–33 or pulmonary artery catheter–derived left ventricular stroke work index.34 Cardiac troponin levels also correlated with the duration of hypotension35 and the intensity of vasopressor therapy.34In addition, increased sepsis severity, measured by global scores such as the Simplified Acute Physiology Score II (SAPS II) or the Acute Physiology And Chronic Health Evaluation II score (APACHE II), was associated with increased cardiac troponin levels,31,33 as was poor short-term prognosis.32,33,35,36 Despite the heterogeneity of study populations and type of troponin studied, the mentioned studies were univocal in concluding that elevated troponin levels in septic patients reflect higher disease severity, myocardial dysfunction, and worse prognosis. In a recent meta-analysis of 23 observational studies, Lim et al37 found cardiac troponin levels to be increased in a large percentage of critically ill patients. Furthermore, in a subset of studies that permitted adjusted analysis and comprised 1706 patients, this troponin elevation was associated with an increased risk of death (odds ratio, 2.5; 95% CI, 1.9 to 3.4, P<0.001)37; however, the underlying mechanisms clearly require further research.

Thus, it appears reasonable to recommend inclusion of cardiac troponins in the monitoring of patients with severe sepsis and septic shock to facilitate prognostic stratification and to increase alertness to the presence of cardiac dysfunction in individual patients. However, it remains to be shown whether risk stratification based on cardiac troponins can identify patients in whom aggressive therapeutic regimens might reap the greatest benefit and so translate into a survival benefit.

Mechanisms Underlying Myocardial Dysfunction in Sepsis

Cardiac depression during sepsis is probably multifactorial (Figure). Nevertheless, it is important to identify individual contributing factors and mechanisms to generate worthwhile therapeutic targets. As a consequence, a vast array of mechanisms, pathways, and disruptions in cellular homeostasis have been examined in septic myocardium.

Figure

View larger version:

Synopsis of potential underlying mechanisms in septic myocardial dysfunction. MDS indicates myocardial depressant substance.

Global Ischemia

An early theory of myocardial depression in sepsis was based on the hypothesis of global myocardial ischemia; however, septic patients have been shown to have high coronary blood flow and diminished coronary artery–coronary sinus oxygen difference.38 As in the peripheral circulation, these alterations can be attributed to disturbed flow autoregulation or disturbed oxygen utilization.39,40 Coronary sinus blood studies in patients with septic shock have also demonstrated complex metabolic alterations in septic myocardium, including increased lactate extraction, decreased free fatty acid extraction, and decreased glucose uptake.41 Furthermore, several magnetic resonance studies in animal models of sepsis have demonstrated the presence of normal high-energy phosphate levels in the myocardium.42,43 It has also been proposed that myocardial dysfunction in sepsis may reflect hibernating myocardium.44 To reach this conclusion, Levy et al44 studied a murine cecal ligation and double-puncture model and observed diminished cardiac performance, increased myocardial glucose uptake, and deposits of glycogen in a setting of preserved arterial oxygen tension and myocardial perfusion. Although all of the above-mentioned findings reflect important alterations in coronary flow and myocardial metabolism, mirroring effects observed in peripheral circulation during sepsis, there is no evidence supporting global ischemia as an underlying cause of myocardial dysfunction in sepsis. However, in septic patients with coexistent and possibly undiagnosed coronary artery disease (CAD), regional myocardial ischemia or infarction secondary to CAD may certainly occur. The manifestation of myocardial ischemia due to CAD might even be facilitated by the volatile hemodynamics in sepsis, as well as by the generalized microvascular dysfunction so frequently observed in sepsis.45 Additional CAD-aggravating factors encountered in sepsis encompass generalized inflammation and the activated coagulatory system. Furthermore, the endothelium plays a prominent role in sepsis (see below), but little is known of the impact of preexisting, CAD-associated endothelial dysfunction in this context. In a postmortem study of 21 fatal cases of septic shock, previously undiagnosed myocardial ischemia at least contributed to death in 7 of the 21 cases (all 21 patients were males, with a mean age of 60.4 years).46 It certainly appears prudent to remain wary of CAD complications while treating sepsis, especially in patients with identifiable risk factors and in view of the ever-increasing mean age of intensive care unit patients and including septic patients.

Myocardial Depressant Substance

A circulating myocardial depressant factor in septic shock was first proposed more than 50 years ago.47 Parrillo et al48 quantitatively linked the clinical degree of septic myocardial dysfunction with the effect the serum, taken from respective patients, had on rat cardiac myocytes, with clinical severity correlating well with the decrease in extent and velocity of myocyte shortening. These effects were not seen when serum from convalescent patients whose cardiac function had returned to normal was applied or when serum was obtained from other critically ill, nonseptic patients.48 In extension of these findings, ultrafiltrates from patients with severe sepsis and simultaneously reduced left ventricular stroke work index (<30 g · m−1 · m−2) displayed cardiotoxic effects and contained significantly increased concentrations of interleukin (IL)-1, IL-8, and C3a.49Recently, Mink et al50 demonstrated that lysozyme c, a bacteriolytic agent believed to originate mainly from disintegrating neutrophilic granulocytes and monocytes, mediates cardiodepressive effects during Escherichia coli sepsis and, importantly, that competitive inhibition of lysozyme c can prevent myocardial depression in the respective experimental sepsis model. Additional potential candidates for myocardial depressant substance include other cytokines, prostanoids, and nitric oxide (NO). Some of these will be discussed below.

Cytokines

Infusion of lipopolysaccharide (LPS, an obligatory component of Gram-negative bacterial cell walls) into both animals and humans51 partially mimics the hemodynamic effects of septic shock.51,52 However, only a minority of patients with septic shock have detectable LPS levels, and the prolonged time course of septic myocardial dysfunction and the chemical characteristics of LPS are not consistent with LPS representing the sole myocardial depressant substance.48,53 Tumor necrosis factor-α (TNF-α) is an important early mediator of endotoxin-induced shock.54 TNF-α is derived from activated macrophages, but recent studies have shown that TNF-α is also secreted by cardiac myocytes in response to sepsis.55 Although application of anti-TNF-α antibodies improved left ventricular function in patients with septic shock,56 subsequent studies using monoclonal antibodies directed against TNF-α or soluble TNF-α receptors failed to improve survival in septic patients.57–59 IL-1 is synthesized by monocytes, macrophages, and neutrophils in response to TNF-α and plays a crucial role in the systemic immune response. IL-1 depresses cardiac contractility by stimulating NO synthase (NOS).60 Transcription of IL-1 is followed by delayed transcription of IL-1 receptor antagonist (IL-1-ra), which functions as an endogenous inhibitor of IL-1. Recombinant IL-1-ra was evaluated in phase III clinical trials, which showed a tendency toward improved survival61 and increased survival time in a retrospective analysis of the patient subgroup with the most severe sepsis62; however, to date, this initially promising therapy has failed to deliver a statistically significant survival benefit. IL-6, another proinflammatory cytokine, has also been implicated in the pathogenesis of sepsis and is considered a more consistent predictor of sepsis than TNF-α because of its prolonged elevation in the circulation.63 Although cytokines may very well play a key role in the early decrease in contractility, they cannot explain the prolonged duration of myocardial dysfunction in sepsis, unless they result in the induction or release of additional factors that in turn alter myocardial function, such as prostanoids or NO.64,65

Prostanoids

Prostanoids are produced by the cyclooxygenase enzyme from arachidonic acid. The expression of cyclooxygenase enzyme-2 is induced, among other stimuli, by LPS and cytokines (cyclooxygenase enzyme-1 is expressed constitutively).66 Elevated levels of prostanoids such as thromboxane and prostacyclin, which have the potential to alter coronary autoregulation, coronary endothelial function, and intracoronary leukocyte activation, have been demonstrated in septic patients.67 Early animal studies with cyclooxygenase inhibitors such as indomethacin yielded very promising results.68,69Along with other positive results, these led to an important clinical study involving 455 septic patients who were randomized to receive intravenous ibuprofen or placebo.70Unfortunately, that study did not demonstrate improved survival for the treatment arm. Similarly, a more recent, smaller study on the effects of lornoxicam failed to provide evidence for a survival benefit through cyclooxygenase inhibition in sepsis.71 Animal studies aimed at elucidating possible benefits of isotype-selective cyclooxygenase inhibition have so far produced conflicting results.72,73

Endothelin-1

Endothelin-1 (ET-1; for an in-depth review of endothelin in sepsis, see Gupta et al74) upregulation has been demonstrated within 6 hours of LPS-induced septic shock.75Cardiac overexpression of ET-1 triggers an increase in inflammatory cytokines (among others, TNF-α, IL-1, and IL-6), interstitial inflammatory infiltration, and an inflammatory cardiomyopathy that results in heart failure and death.76 The involvement of ET-1 in septic myocardial dysfunction is supported by the observation that tezosentan, a dual endothelin-A and endothelin-B receptor antagonist, improved cardiac index, stroke volume index, and left ventricular stroke work index in endotoxemic shock.77 However, higher doses of tezosentan exhibited cardiotoxic effects and led to increased mortality.77Although ET-1 has been demonstrated to be of pathophysiological importance in a wide array of cardiac diseases through autocrine, endocrine, or paracrine effects, its biosynthesis, receptor-mediated signaling, and functional consequences in septic myocardial dysfunction warrant further investigation to assess the therapeutic potential of ET-1 receptor antagonists.

Nitric Oxide

NO exerts a plethora of biological effects in the cardiovascular system.78 It has been shown to modulate cardiac function under physiological and a multitude of pathophysiological conditions. In healthy volunteers, low-dose NO increases LV function, whereas inhibition of endogenous NO release by intravenous infusion of the NO synthase (NOS) inhibitor NG-monomethyl-L-arginine reduced the stroke volume index.79 Higher doses of NO have been shown to induce contractile dysfunction by depressing myocardial energy generation.80 The absence of the important NO scavenger myoglobin (Mb) in Mb knockout mice results in impaired cardiac function that is partially reversible by NOS inhibition.81 Endogenous NO contributes to hibernation in response to myocardial ischemia by reducing oxygen consumption and preserving calcium sensitivity and contractile function.82 NO also represents a potent modulator of myocardial ischemia/reperfusion injury. However, as in sepsis-related NO research, the reported effects of NO on ischemia/reperfusion injury are inconsistent owing to a multitude of confounding experimental factors.83

Sepsis leads to the expression of inducible NOS (iNOS) in the myocardium,84,85 followed by high-level NO production, which in turn importantly contributes to myocardial dysfunction, in part through the generation of cytotoxic peroxynitrite, a product of NO and superoxide (for an excellent review, see Pacher et al86). In iNOS-deficient mice, cardiac function is preserved after endotoxin challenge.87 Nonspecific NOS inhibition restores cardiac output and stroke volume after LPS injection.88 Strikingly, in septic patients, infusion of methylene blue, a nonspecific NOS inhibitor, improves mean arterial pressure, stroke volume, and left ventricular stroke work and decreases the requirement for inotropic support but, unfortunately, does not alter outcome.89 An interesting study comparing the inhibition of NO superoxide and peroxynitrite in cytokine-induced myocardial contractile failure found peroxynitrite to indeed be the most promising therapeutic target.90 It has also been proposed that the constitutively expressed mitochondrial isoform of NOS (mtNOS), the expression of which can be augmented by induction, controls rates of oxidative phosphorylation by inhibiting various steps of the respiratory chain.91 Although this hypothesis would provide a plausible explanation for the reduced coronary oxygen extraction observed during sepsis (see above), the effects of sepsis on expression of mtNOS and NO generation remain to be explored. Furthermore, the constitutively expressed endothelial NOS (eNOS), previously neglected in the context of sepsis, has been shown to be an important regulator of iNOS expression, resulting in a more stable hemodynamic status in eNOS-deficient mice after endotoxemia.92 Very recently, a functional NOS in red blood cells (rbcNOS) was identified that regulates deformability of erythrocyte membranes and inhibits activation of platelets.93 With both effect targets thus far demonstrated for rbcNOS lying at the core of microvascular dysfunction in sepsis, this discovery opens a whole new window to NO-related sepsis research. Given the existence of different NOS isoforms and their various modulating interactions, dose-dependent NO effects, and the precise balance of NO, superoxide, and thus peroxynitrite generated in subcellular compartments, further advances in our understanding of the complex NO biology and its derived reactive nitrogen species hold the promise of revealing new, more specific and effective therapeutic targets.

Adhesion Molecules

Surface-expression upregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 has been demonstrated in murine coronary endothelium and cardiomyocytes after LPS and TNF-α stimulation.94 After cecal ligation and double puncture, myocardial intercellular adhesion molecule-1 expression increases in rats.95Vascular cell adhesion molecule-1 blockade with antibodies has been shown to prevent myocardial dysfunction and decrease myocardial neutrophil accumulation,94,96 whereas both knockout and antibody blockade of intercellular adhesion molecule-1 ameliorate myocardial dysfunction in endotoxemia without affecting neutrophil accumulation.94 In addition, neutrophil depletion does not protect against septic cardiomyopathy, which suggests that the cardiotoxic potential of neutrophils infiltrating the myocardium is of lesser importance in this context.94 Other aspects of adhesion molecules are discussed in conjunction with possible statin effects below.

The e-Reader is advised to consider the following expansion on the subject matter carrying the discussion to additional related clinical issues:

Advanced Topics in Sepsis and the Cardiovascular System at its End Stage

Author: Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2013/08/18/advanced-topics-in-sepsis-and-the-cardiovascular-system-at-its-end-stage/

Therapeutic Approaches: The Present and the Future

A detailed discussion of therapeutic options in septic patients would clearly be beyond the scope of this review, and readers are kindly referred to the multiple excellent reviews published on the subject (eg, Hotchkiss and Karl,2 Annane et al,4 and Dellinger et al97). Although a number of preventive measures, such as prophylactic antibiotics, maintenance of normoglycemia, selective digestive tract decontamination, vaccines, and intravenous immunoglobulin, have shown benefit in distinct patient populations, preventive strategies with a broader aim remain elusive. Once sepsis is manifest (see the Table for criteria), prompt and adequate antibiotic therapy accompanied by surgical removal of the infectious focus, if indicated and feasible, is the mainstay and also the only strictly causal line of therapy. In the presence of severe sepsis and septic shock, supportive treatment in addition to causal therapy is mandatory. Supportive therapy encompasses early and goal-directed fluid resuscitation,9 vasopressor and inotropic therapy, red blood cell transfusion, mechanical ventilation, and renal support when indicated. It is very likely beneficial to monitor cardiac performance in these patients. A wide array of techniques are available for this purpose, ranging from echocardiography to pulmonary catheters, thermodilution techniques, and pulse pressure analysis.98 Because none of these techniques have demonstrated superiority, physicians should use the method with which they are most familiar. Whichever method is chosen, it should be applied frequently to tailor supportive therapy to the individual patient and to achieve the “gold standard” of early goal-directed therapy. In recent years, several attempts have been made to therapeutically address myocardial dysfunction in sepsis. Although the combination of norepinephrine as vasopressor and dobutamine as inotropic agent is probably the most frequently applied in septic shock, there is currently no evidence to recommend one catecholamine over the other.97 In human endotoxemia, epinephrine has been demonstrated to inhibit proinflammatory pathways and coagulation activation, as well as to augment antiinflammatory pathways,99,100 whereas no immunomodulatory or coagulant effects could be demonstrated for dobutamine in a similar setting.101 Isoproterenol has recently been applied successfully in a small group of patients with septic shock, no known history of CAD, and inappropriate mixed venous oxygen concentration despite correction of hypoxemia and anemia.102 In a cecal ligation and double-puncture model of sepsis, the β-blocker esmolol given continuously after sepsis induction improved myocardial oxygen utilization and attenuated myocardial dysfunction,103 which suggests that therapeutic strategies proven in ischemic heart failure might also hold promise in septic cardiomyopathy. However, the optimal mode of β-receptor stimulation (or indeed inhibition) to limit myocardial dysfunction remains a wide-open field for inspired investigation.

Given the generally accepted view of sepsis as a disease largely propelled by an inappropriate immune response, numerous basic research and clinical trials have been undertaken to curb the lethal toll of sepsis through modulation of this uncontrolled immune response.2,3 To date, activated protein C104 and low-dose hydrocortisone105 have emerged as the only inflammation-modulating substances that have been confirmed to be of benefit in patients with severe sepsis and septic shock. Over the past years, increasing evidence has accumulated that suggests that inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, or statins, have therapeutic benefits independent of cholesterol lowering, termed “pleiotropic” effects. These have added a wide scope of potential targets for statin therapy that range from decreasing renal function loss106 and lowering mortality in patients with diastolic heart failure107 to prevention and treatment of stroke,108 to name just a few. These pleiotropic effects include antiinflammatory and antioxidative properties, improvement of endothelial function, and increased NO bioavailability and thus might contribute to the benefit observed with statin therapy. Notably, these important immunomodulatory effects of statins have been demonstrated to be independent of lipid lowering109 and appear to be mediated via interference with the synthesis of mevalonate metabolites (nonsteroidal isoprenoid products). Blockade of the mevalonate pathway has been shown to suppress T-cell responses,110 reduce expression of class II major histocompatibility complexes on antigen presenting cells,109 and inhibit chemokine synthesis in peripheral blood mononuclear cells.111 Furthermore, CD11b integrin expression and CD11b-dependent adhesion of monocytes have been found to be attenuated by the initiation of statin treatment in hypercholesterolemic patients.112 In this context, Yoshida et al113 have reported that statins reduce the expression of both monocytic and endothelial adhesion molecules, eg, the integrin leukocyte function-associated antigen-1 (LFA-1), via an inhibition of Rho GTPases, in particular their membrane anchoring by geranylation. In addition, mechanisms for antiinflammatory actions of statins have been revealed that are not related to the isoprenoid metabolism. For instance, Weitz-Schmidt et al114 have identified that some statins act as direct antagonists of LFA-1 owing to their capacity to bind to the regulatory site in the LFA-1 i-domain. In addition to these multifaceted antiinflammatory effects, statins may interfere with activation of the coagulation cascade, as illustrated by the suppression of LPS-induced monocyte tissue factor in vitro.115 Beyond their immunomodulatory functions, statins have been shown to exert direct antichlamydial effects during pulmonary infection with Chlamydia pneumoniae in mice,116 and a recent report suggests the benefit of statins may also extend to viral pathogens.117

Given the strong impact of statins on inflammation, statins might represent a welcome enforcement in the battle against severe infectious diseases such as sepsis. Consequently, several investigators have evaluated the role of statins in the prevention and treatment of sepsis. In a retrospective analysis, Liappis et al118 demonstrated a reduced overall and attributable mortality in patients with bacteremia who were treated concomitantly with statins. Pretreatment with simvastatin has been shown to profoundly improve survival in a polymicrobial murine model of sepsis by preservation of cardiovascular function and inhibition of inflammatory alterations.19 Encouraged by these findings, the same model was used to successfully treat sepsis in a clinically feasible fashion, ie, treatment was initiated several hours after the onset of sepsis. With different statins (atorvastatin, pravastatin, and simvastatin) being effective, the therapeutic potential of statins in sepsis appears to be a class effect.22 Recently, Steiner et al119observed that pretreatment with simvastatin can suppress the inflammatory response induced by LPS in healthy human volunteers. Furthermore, in a prospective observational cohort study in patients with acute bacterial infections performed by Almog et al,120previous treatment with statins was associated with a considerably reduced rate of severe sepsis and intensive care unit admissions. A total of 361 patients were enrolled in that study, and 82 of these patients had been treated with statins for at least 4 weeks before their admission. Severe sepsis developed in 19% of patients in the no-statin group compared with only 2.4% in patients who were taking statins. The intensive care unit admission rates were 12.2% for the no-statin group and 3.7% for the statin group. Because of the number of patients enrolled, the study was not powered to detect differences in mortality, although the large effect on sepsis rate and intensive care unit admission were at least suggestive. As the most recent development in this field, Hackam et al121 have produced an impressive observational study by initial evaluation of 141 487 cardiovascular patients, which resulted in a well-paired and homogenous study cohort of 69 168 patients after propensity-based matching. Drawing from this solid base, Hackam and coauthors were able to support the conclusion that statin therapy is associated with a considerably decreased rate of sepsis (hazard ratio, 0.81; 95% CI, 0.72 to 0.90), severe sepsis (hazard ratio, 0.83; 95% CI, 0.70 to 0.97), and fatal sepsis (hazard ratio, 0.75; 95% CI, 0.61 to 0.93). This protective effect prevailed at both high and low statin doses and for several clinically important subpopulations, such as diabetic and heart failure patients.

As has been suggested previously,122 statins might provide cumulative benefit by reducing mortality from cardiovascular and infectious diseases such as sepsis. However, statins may have detrimental effects in distinct subsets of patients. Therefore, caution should prevail, and the use of statins in patients with sepsis must be accompanied by meticulous monitoring of unexpected side effects and well-designed randomized, controlled clinical trials.

Beyond an apparent rationale for randomized trials on statins in sepsis, it is notable that the results with other immunomodulatory approaches in sepsis have yielded rather limited success. For instance, use of the anti-TNF antibody F(ab′)2 fragment afelimomab led to a significant but rather modest reduction in risk of death and to improved organ-failure scores in patients with severe sepsis and elevated IL-6 levels.123 Moreover, a selective inhibitor of group IIA secretory phospholipase A2 failed to improve clinical outcome for patients with severe sepsis, with a negative trend most pronounced among patients with cardiovascular failure.124 Hence, because none of the available strategies proven to be effective in sepsis are designed specifically to target myocardial dysfunction, one might conclude that strategies that preferentially address cardiac morbidity in sepsis may be a promising area for investigation. For instance, lipoteichoic acid, a major virulence factor in Gram-positive sepsis, causes cardiac depression by activating myocardial TNF-α synthesis via CD14 and induces coronary vascular disturbances by activating thromboxane 2 synthesis. It thus contributes to cardiac depression and may therefore be a worthwhile and cardiac-specific target.125 The implications of intensified efforts in the search for successful novel approaches to the treatment of myocardial dysfunction in sepsis may be considerable with regard to improved patient care that results in reduced mortality. This is of major significance in view of the substantial economic consequences of increasing sepsis morbidity in an aging population.

REFERENCES

in Circulation.2007; 116: 793-802 doi: 10.1161/​CIRCULATIONAHA.106.678359

  1. Bone RC, Balk RA, Cerra FB, Dellinger RP, Fein AM, Knaus WA, Schein RMH, Sibbald WJ. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. Chest1992; 101: 1644–1655.
  2. Hotchkiss RS, Karl IE. The pathophysiology and treatment of sepsis. N Engl J Med2003; 348: 138–150.
  3. Riedemann NC, Guo R, Ward PA. Novel strategies for the treatment of sepsis.Nat Med2003; 9: 517–524.
  4. Annane D, Bellissant E, Cavaillon JM. Septic shock. Lancet2005; 365: 63–78.
  5. Martin GS, Mannino DM, Eaton S, Moss M. The epidemiology of sepsis in the United States from 1979 through 2000. N Engl J Med2003; 348: 1546–1554.
  6. Angus DC, Linde-Zwirble WT, Lidicker J, Clermont G, Carcillo J, Pinsky MR. Epidemiology of severe sepsis in the United States: analysis of incidence, outcome, and associated costs of care. Crit Care Med2001; 29: 1303–1310.
  7. Padkin A, Goldfrad C, Brady AR, Young D, Black N, Rowan K. Epidemiology of severe sepsis occurring in the first 24 hrs in intensive care units in England, Wales, and Northern Ireland. Crit Care Med2003; 31: 2332–2338.
  8. Waisbren BA. Bacteremia due to gram-negative bacilli other than the Salmonella: a clinical and therapeutic study. AMA Arch Intern Med1951; 88: 467–488.
  9. Rivers E, Nguyen B, Havstad S, Ressler J, Muzzin A, Knoblich B, Peterson E, Tomlanovich M; Early Goal-Directed Therapy Collaborative Group. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med.2001; 345: 1368–1377.
  10. Bone RC. Gram-negative sepsis: background, clinical features, and intervention.Chest1991; 100: 802–808.
  11. Parker MM, Shelhamer JH, Bacharach SL, Green MV, Natanson C, Frederick TM, Damske BA, Parrillo JE. Profound but reversible myocardial depression in patients with septic shock. Ann Intern Med1984; 100: 483–490.
  12. Parrillo JE, Parker MM, Natanson C, Suffredini AF, Danner RL, Cunnion RE, Ognibene FP. Septic shock in humans: advances in the understanding of pathogenesis, cardiovascular dysfunction, and therapy. Ann Intern Med1990; 113:227–242.
  13. Calvin JE, Driedger AA, Sibbald WJ. An assessment of myocardial function in human sepsis utilizing ECG gated cardiac scintigraphy. Chest1981; 80: 579–586.
  14. Jafri SM, Lavine S, Field BE, Bahorozian MT, Carlson RW. Left ventricular diastolic function in sepsis. Crit Care Med1990; 18: 709–714.
  15. Munt B, Jue J, Gin K, Fenwick J, Tweeddale M. Diastolic filling in human severe sepsis: an echocardiographic study. Crit Care Med1998; 26: 1829–1833.
  16. Poelaert J, Declerck C, Vogelaers D, Colardyn F, Visser CA. Left ventricular systolic and diastolic function in septic shock. Intensive Care Med1997; 23: 553–560.
  17. Ren J, Ren BH, Sharma AC. Sepsis-induced depressed contractile function of isolated ventricular myocytes is due to altered calcium transient properties. Shock.2002; 18: 285–288.
  18. McDonough KH, Smith T, Patel K, Quinn M. Myocardial dysfunction in the septic rat heart: role of nitric oxide. Shock1998; 10: 371–376.
  19. Merx MW, Liehn EA, Janssens U, Lütticken R, Schrader J, Hanrath P, Weber C. HMG-CoA reductase inhibitor simvastatin profoundly improves survival in a murine model of sepsis. Circulation2004; 109: 2560–2565.
  20. Natanson C, Fink MP, Ballantyne HK, Mac Vittie TJ, Conklin JJ, Parrillo JE. Gram-negative bacteremia produces both severe systolic and diastolic cardiac dysfunction in a canine model that simulates human septic shock. J Clin Invest.1986; 78: 259–270.
  21. Stahl TJ, Alden PB, Ring WS, Madoff RC, Cerra FB. Sepsis-induced diastolic dysfunction in chronic canine peritonitis. Am J Physiol Heart Circ Physiol1990;258: H625–H633.
  22. Merx MW, Liehn EA, Graf J, van de Sandt A, Schaltenbrand M, Schrader J, Hanrath P, Weber C. Statin treatment after onset of sepsis in a murine model improves survival. Circulation2005; 112: 117–124.
  23. Vincent JL, Thirion M, Brimioulle S, Lejeune P, Kahn RJ. Thermodilution measurement of right ventricular ejection fraction with a modified pulmonary artery catheter. Intensive Care Med1986; 12: 33–38.
  24. Dhainaut JF, Brunet F, Monsaillier JF, Villemant D, Devaux JY, Konno M, De Gournay JM, Armaganidis A, Iotti G, Huyghebaert MF. Bedside evaluation of right ventricular performance using a rapid computerized thermodilution method. Crit Care Med1987; 15: 148–152.
  25. Dhainaut JF, Lanore JJ, de Gournay JM, Huyghebaert MF, Brunet F, Villemant D, Monsallier JF. Right ventricular dysfunction in patients with septic shock.Intensive Care Med1988; 14: 488–491.
  26. Parker MM, McCarthy KE, Ognibene FP, Parrillo JE. Right ventricular dysfunction and dilatation, similar to left ventricular changes, characterize the cardiac depression of septic shock in humans. Chest1990; 97: 126–131.
  27. Parker MM, Shelhamer JH, Natanson C, Alling DW, Parrillo JE. Serial cardiovascular variables in survivors and nonsurvivors of human septic shock: heart rate as an early predictor of prognosis. Crit Care Med1987; 15: 923–929.
  28. Rhodes A, Lamb FJ, Malagon I, Newman PJ, Grounds RM, Bennett ED. A prospective study of the use of a dobutamine stress test to identify outcome in patients with sepsis, severe sepsis, or septic shock. Crit Care Med1999; 27: 2361–2366.
  29. Maeder M, Fehr T, Rickli H, Ammann P. Sepsis-associated myocardial dysfunction: diagnostic and prognostic impact of cardiac troponins and natriuretic peptides. Chest2006; 129: 1349–1366.
  30. Fernandes CJ, Akamine N, Knobel E. Cardiac troponin: a new serum marker of myocardial injury in sepsis. Intensive Care Med1999; 25: 1165–1168.
  31. ver Elst KM, Spapen HD, Nguyen DN, Garbar C, Huyghens LP, Gorus FK. Cardiac troponins I and T are biological markers of left ventricular dysfunction in septic shock. Clin Chem2000; 46: 650–657.
  32. Ammann P, Fehr T, Minder EI, Gunter C, Bertel O. Elevation of troponin I in sepsis and septic shock. Intensive Care Med2001; 27: 965–969.
  33. Mehta NJ, Khan IA, Gupta V, Jani K, Gowda RM, Smith PR. Cardiac troponin I predicts myocardial dysfunction and adverse outcome in septic shock. Int J Cardiol.2004; 95: 13–17.
  34. Turner A, Tsamitros M, Bellomo R. Myocardial cell injury in septic shock. Crit Care Med1999; 27: 1775–1780.
  35. Arlati S, Brenna S, Prencipe L, Marocchi A, Casella GP, Lanzani M, Gandini C. Myocardial necrosis in ICU patients with acute non-cardiac disease: a prospective study. Intensive Care Med2000; 26: 31–37.
  36. Spies C, Haude V, Fitzner R, Schroder K, Overbeck M, Runkel N, Schaffartzik W. Serum cardiac troponin T as a prognostic marker in early sepsis. Chest1998;113: 1055–1063.
  37. Lim W, Qushmag I, Devereaux PJ, Heels-Ansdell D, Lauzier F, Ismaila AS, Crowther MA, Cook DJ. Elevated cardiac troponin measurements in critically ill patients. Arch Intern Med2006; 166: 2446–2454.
  38. Cunnion RE, Schaer GL, Parker MM, Natanson C, Parrillo JE. The coronary circulation in human septic shock. Circulation1986; 73: 637–644.
  39. Herbertson MJ, Werner HA, Russell JA, Iversen K, Walley KR. Myocardial oxygen extraction ratio is decreased during endotoxemia in pigs. J Appl Physiol.1995; 79: 479–486.
  40. Powell RJ, Machiedo GW, Rush BF, Dikdan G. Oxygen free radicals: effect on red cell deformability in sepsis. Crit Care Med1991; 19: 732–735.
  41. Dhainaut JF, Huyghebaert MF, Monsallier JF, Lefevre G, Dall’Ava-Santucci J, Brunet F, Villemant D, Carli A, Raichvarg D. Coronary hemodynamics and myocardial metabolism of lactate, free fatty acids, glucose, and ketones in patients with septic shock. Circulation1987; 75: 533–541.
  42. Solomon MA, Correa R, Alexander HR, Koev LA, Cobb JP, Kim DK, Roberts WC, Quezado ZM, Scholz TD, Cunnion RE, Hoffman WD, Bacher J, Yatsiv I, Danner RL, Banks SM, Ferrans VJ, Balaban RS, Natanson C. Myocardial energy metabolism and morphology in a canine model of sepsis. Am J Physiol Heart Circ Physiol1994; 266: H757–H768.
  43. Van Lambalgen AA, van Kraats AA, Mulder MF, Teerlink T, van den Bos GC. High-energy phosphates in heart, liver, kidney, and skeletal muscle of endotoxemic rats. Am J Physiol Heart Circ Physiol1994; 266: H1581–H1587.
  44. Levy RJ, Piel DA, Acton PD, Zhou R, Ferrari VA, Karp JS, Deutschman CS. Evidence of myocardial hibernation in the septic heart. Crit Care Med2005; 33:2752–2756.
  45. Hinshaw LB. Sepsis/septic shock: participation of the microcirculation: an abbreviated review. Crit Care Med1996; 24: 1072–1078.
  46. Hoffmann R. Tissue Doppler echocardiography: already of clinical significance? Z Kardiol2002; 91: 677–684.
  47. Wiggers CJ. Myocardial depression in shock: a survey of cardiodynamic studies.Am Heart J1947; 33: 633–650.
  48. Parrillo JE, Burch C, Shelhamer JH, Parker MM, Natanson C, Schuette W. A circulating myocardial depressant substance in humans with septic shock: septic shock patients with a reduced ejection fraction have a circulating factor that depresses in vitro myocardial cell performance. J Clin Invest1985; 76: 1539–1553.
  49. Hoffmann JN, Werdan K, Hartl WH, Jochum M, Faist E, Inthorn D. Hemofiltrate from patients with severe sepsis and depressed left ventricular contractility contains cardiotoxic compounds. Shock1999; 13: 174–180.
  50. Mink SN, Jacobs H, Duke K, Bose D, Cheng ZQ, Light RB. N,N′,N″-triacetylglucosamine, an inhibitor of lysozyme, prevents myocardial depression in Escherichia coli sepsis in dogs. Crit Care Med2004; 32: 184–193.
  51. Suffredini AF, Fromm RE, Parker MM, Brenner M, Kovacs JA, Wesley RA, Parrillo JE. The cardiovascular response of normal humans to the administration of endotoxin. N Engl J Med1989; 321: 280–287.
  52. Danner RL, Elin RJ, Hosseini JM, Wesley RA, Reilly JM, Parrillo JE. Endotoxemia in human septic shock. Chest1991; 99: 169–175.
  53. Reilly JM, Cunnion RE, Burch-Whitman C, Parker MM, Shelhamer JH, Parrillo JE. A circulating myocardial depressant substance is associated with cardiac dysfunction and peripheral hypoperfusion (lactic acidemia) in patients with septic shock. Chest1989; 95: 1072–1080.
  54. Sharma AC, Motew SJ, Farias S, Alden KJ, Bosmann HB, Law WR, Ferguson JL. Sepsis alters myocardial and plasma concentrations of endothelin and nitric oxide in rats. J Mol Cell Cardiol1997; 29: 1469–1477.
  55. Horton JW, Maass D, White J, Sanders B. Nitric oxide modulation of TNF-alpha-induced cardiac contractile dysfunction is concentration dependent. Am J Physiol Heart Circ Physiol2000; 278: H1955–H1965.
  56. Vincent JL, Bakker J, Marecaux G, Schandene L, Kahn RJ, Dupont E. Administration of anti-TNF antibody improves left ventricular function in septic shock patients: results of a pilot study. Chest1992; 101: 810–815.
  57. Fisher CJ, Agosti JM, Opal SM, Lowry SF, Balk RA, Sadoff JC, Abraham E, Schein RM, Benjamin E; the Soluble TNF Receptor Sepsis Study Group. Treatment of septic shock with the tumor necrosis factor receptor:Fc fusion protein. N Engl J Med1996; 334: 1697–1702.
  58. Abraham E, Glauser MP, Butler T, Garbino J, Gelmont D, Laterre PF, Kudsk K, Bruining HA, Otto C, Tobin E, Zwingelstein C, Lesslauer W, Leighton A; Ro 45-2081 Study Group. p55 Tumor necrosis factor receptor fusion protein in the treatment of patients with severe sepsis and septic shock: a randomized controlled multicenter trial. JAMA1997; 277: 1531–1538.
  59. Abraham E, Anzueto A, Gutierrez G, Tessler S, San Pedro G, Wunderink R, Dal Nogare A, Nasraway S, Berman S, Cooney R, Levy H, Baughman R, Rumbak M, Light RB, Poole L, Allred R, Constant J, Pennington J, Porter S; NORASEPT II Study Group. Double-blind randomised controlled trial of monoclonal antibody to human tumour necrosis factor in treatment of septic shock. Lancet1998; 351: 929–933.
  60. Francis SE, Holden H, Holt CM, Duff GW. Interleukin-1 in myocardium and coronary arteries of patients with dilated cardiomyopathy. J Mol Cell Cardiol1998;30: 215–223.
  61. Opal SM, Fisher CJ Jr, Dhainaut JF, Vincent JL, Brase R, Lowry SF, Sadoff JC, Slotman GJ, Levy H, Balk RA, Shelly MP, Pribble JP, LaBrecque JF, Lookabaugh J, Donovan H, Dubin H, Baughman R, Norman J, DeMaria E, Matzel K, Abraham E, Seneff M; Interleukin-1 Receptor Antagonist Sepsis Investigator Group. Confirmatory interleukin-1 receptor antagonist trial in severe sepsis: a phase III, randomized, double-blind, placebo-controlled, multicenter trial. Crit Care Med1997; 25: 1115–1124.
  62. Fisher CJ Jr, Dhainaut JF, Opal SM, Pribble JP, Balk RA, Slotman GJ, Iberti TJ, Rackow EC, Shapiro MJ, Greenman RL; Phase III rhIL-1ra Sepsis Syndrome Study Group. Recombinant human interleukin 1 receptor antagonist in the treatment of patients with sepsis syndrome: results from a randomized, double-blind, placebo-controlled trial. JAMA1994; 271: 1836–1843.
  63. Damas P, Ledoux D, Nys M, Vrindts Y, De Groote D, Franchimont P, Lamy M. Cytokine serum level during severe sepsis in human IL-6 as a marker of severity.Ann Surg1992; 215: 356–362.
  64. Schulz R, Nava E, Moncada S. Induction and potential biological relevance of a Ca2+-independent nitric oxide synthase in the myocardium. Br J Pharmacol1992;105: 575–580.
  65. Finkel MS, Oddis CV, Jacob TD, Watkins SC, Hattler BG, Simmons RL. Negative inotropic effects of cytokines on the heart mediated by nitric oxide.Science1992; 257: 387–389.
  66. Liu SF, Newton R, Evans TW, Barnes PJ. Differential regulation of cyclo-oxygenase-1 and cyclo-oxygenase-2 gene expression by lipopolysaccharide treatment in vivo in the rat. Clin Sci (Lond)1996; 90: 301–306.
  67. Reines HD, Halushka PV, Cook JA, Wise WC, Rambo W. Plasma thromboxane concentrations are raised in patients dying with septic shock. Lancet1982; 2: 174–175.
  68. Fletcher JR, Ramwell PW. Modification, by aspirin and indomethacin, of the haemodynamic and prostaglandin releasing effects of E. coli endotoxin in the dog.Br J Pharmacol1977; 61: 175–181.
  69. Parratt JR, Sturgess RM. E. coli endotoxin shock in the cat; treatment with indomethacin. Br J Pharmacol1975; 53: 485–488.
  70. Bernard GR, Wheeler AP, Russel JA, Schein R, Summer WR, Steinberg KP, Fulkerson WJ, Wright PE, Christmann BW, Dupont WD, Higgins SB, Swindell BB; The Ibuprofen in Sepsis Study Group. The effects of ibuprofen on the physiology and survival of patients with sepsis. N Engl J Med1997; 336: 912–918.
  71. Memis D, Karamanlioglu B, Turan A, Koyuncu O, Pamukcu Z. Effects of lornoxicam on the physiology of severe sepsis. Crit Care2004; 8: R474–R482.
  72. Tunctan B, Altug S, Uludag O, Demirkay B, Abacioglu N. Effects of cyclooxygenase inhibitors on nitric oxide production and survival in a mice model of sepsis. Pharmacol Res2003; 48: 37–48.
  73. Reddy RC, Chen GH, Tateda K, Tsai WC, Phare SM, Mancuso P, Peters-Golden M, Standiford TJ. Selective inhibition of COX-2 improves early survival in murine endotoxemia but not in bacterial peritonitis. Am J Physiol Lung Cell Mol Physiol.2001; 281: L537–L543.
  74. Gupta A, Brahmbhatt S, Kapoor R, Loken L, Sharma AC. Chronic peritoneal sepsis: myocardial dysfunction, endothelin and signaling mechanisms. Front Biosci.2005; 10: 3183–3205.
  75. Shindo T, Kurihara H, Kurihara Y, Morita H, Yazaki Y. Upregulation of endothelin-1 and adrenomedullin gene expression in the mouse endotoxin shock model. J Cardiovasc Pharmacol1998; 31: S541–S544.
  76. Yang LL, Gros R, Kabir MG, Sadi A, Gotlieb AI, Husain M, Stewart DJ. Conditional cardiac overexpression of endothelin-1 induces inflammation and dilated cardiomyopathy in mice. Circulation2004; 109: 255–261.
  77. Konrad D, Oldner A, Rossi P, Wanecek M, Rudehill A, Weitzberg E. Differentiated and dose-related cardiovascular effects of a dual endothelin receptor antagonist in endotoxin shock. Crit Care Med2004; 32: 1192–1199.
  78. Schulz R, Rassaf T, Massion PB, Kelm M, Balligand JL. Recent advances in the understanding of the role of nitric oxide in cardiovascular homeostasis. Pharmacol Ther2005; 108: 225–256.
  79. Rassaf T, Poll LW, Brouzos P, Lauer T, Totzeck M, Kleinbongard P, Gharini P, Andersen K, Schulz R, Heusch G, Modder U, Kelm M. Positive effects of nitric oxide on left ventricular function in humans. Eur Heart J2006; 27: 1699–1705.
  80. Kelm M, Schafer S, Dahmann R, Dolu B, Perings S, Decking UK, Schrader J, Strauer BE. Nitric oxide induced contractile dysfunction is related to a reduction in myocardial energy generation. Cardiovasc Res1997; 36: 185–194.
  81. Merx MW, Godecke A, Flogel U, Schrader J. Oxygen supply and nitric oxide scavenging by myoglobin contribute to exercise endurance and cardiac function.FASEB J2005; 19: 1015–1017.
  82. Heusch G, Post H, Michel MC, Kelm M, Schulz R. Endogenous nitric oxide and myocardial adaptation to ischemia. Circ Res2000; 87: 146–152.
  83. Schulz R, Kelm M, Heusch G. Nitric oxide in myocardial ischemia/reperfusion injury. Cardiovasc Res2004; 61: 402–413.
  84. Preiser JC, Zhang H, Vray B, Hrabak A, Vincent JL. Time course of inducible nitric oxide synthase activity following endotoxin administration in dogs. Nitric Oxide2001; 5: 208–211.
  85. Khadour FH, Panas D, Ferdinandy P, Schulze C, Csont T, Lalu MM, Wildhirt SM, Schulz R. Enhanced NO and superoxide generation in dysfunctional hearts from endotoxemic rats. Am J Physiol Heart Circ Physiol2002; 283: H1108–H1115.
  86. Pacher P, Beckman JS, Liaudet L. Nitric oxide and peroxynitrite in health and disease. Physiol Rev2007; 87: 315–424.
  87. Ullrich R, Scherrer-Crosbie M, Bloch KD, Ichinose F, Nakajima H, Picard MH, Zapol WM, Quezado ZM. Congenital deficiency of nitric oxide synthase 2 protects against endotoxin-induced myocardial dysfunction in mice. Circulation2000; 102:1440–1446.
  88. Hwang TL, Yeh CC. Hemodynamic and hepatic microcirculational changes in endotoxemic rats treated with different NOS inhibitors. Hepatogastroenterology.2003; 50: 188–191.
  89. Kirov MY, Evgenov OV, Evgenov NV, Egorina EM, Sovershaev MA, Sveinbjornsson B, Nedashkovsky EV, Bjertanaes LJ. Infusion of methylene blue in human septic shock: a pilot, randomized, controlled study. Crit Care Med2001; 29:1860–1867.
  90. Ferdinandy P, Danial H, Ambrus I, Rothery RA, Schulz R. Peroxynitrite is a major contributor to cytokine-induced myocardial contractile failure. Circ Res2000;87: 241–247.
  91. Elfering SL, Sarkela TM, Giulivi C. Biochemistry of mitochondrial nitric-oxide synthase. J Biol Chem2002; 277: 38079–38086.
  92. Connelly L, Madhani M, Hobbs AJ. Resistance to endotoxic shock in endothelial nitric-oxide synthase (eNOS) knock-out mice: a pro-inflammatory role for eNOS-derived NO in vivo. J Biol Chem2005; 280: 10040–10046.
  93. Kleinbongard P, Schulz R, Rassaf T, Lauer T, Dejam A, Jax TW, Kumara I, Gharini P, Kabanova S, Ozuyaman B, Schnurch H-G, Gödecke A, Weber A-A, Robenek M, Robenek H, Bloch W, Rosen P, Kelm M. Red blood cells express a functional endothelial nitric oxide synthase. Blood2006; 107: 2943–2951.
  94. Raeburn CD, Calkins CM, Zimmerman MA, Song Y, Ao L, Banerjee A, Harken AH, Meng X. ICAM-1 and VCAM-1 mediate endotoxemic myocardial dysfunction independent of neutrophil accumulation. Am J Physiol Regul Integr Comp Physiol.2002; 283: R477–R486.
  95. Neviere R, Guery B, Mordon S, Zerimech F, Charre S, Wattel F, Chopin C. Inhaled NO reduces leukocyte-endothelial cell interactions and myocardial dysfunction in endotoxemic rats. Am J Physiol Heart Circ Physiol2000; 278:H1783–H1790.
  96. Raeburn CD, Calkins CM, Zimmerman MA, Song Y, Ao L, Banerjee A, Meng X, Harken AH. Vascular cell adhesion molecule-1 expression is obligatory for endotoxin-induced myocardial neutrophil accumulation and contractile dysfunction.Surgery2001; 130: 319–325.
  97. Dellinger RP, Carlet JM, Masur H, Gerlach H, Calandra T, Cohen J, Gea-Banacloche J, Keh D, Marshall JC, Parker MM, Ramsay G, Zimmerman JL, Vincent JL, Levy MM. Surviving sepsis campaign guidelines for management of severe sepsis and septic shock. Crit Care Med2004; 32: 858–873.
  98. Hollenberg SM, Ahrens TS, Annane D, Astiz ME, Chalfin DB, Dasta JF, Heard SO, Martin C, Napolitano LM, Susla GM, Totaro R, Vincent JL, Zanotti-Cavazzoni S. Practice parameters for hemodynamic support of sepsis in adult patients: 2004 update. Crit Care Med2004; 32: 1928–1948.
  99. van der Poll T, Coyle SM, Barbosa K, Braxton CC, Lowry SF. Epinephrine inhibits tumor necrosis factor-alpha and potentiates interleukin 10 production during human endotoxemia. J Clin Invest1996; 97: 713–719.
  100. van der Poll T, Levi M, Dentener M, Jansen PM, Coyle SM, Braxton CC, Buurman WA, Hack CE, ten Cate JW, Lowry SF. Epinephrine exerts anticoagulant effects during human endotoxemia. J Exp Med1997; 185: 1143–1148.
  101. Lemaire L, de Kruif M, Giebelen IA, Levi M, van der Poll T, Heesen M. Dobutamine does not influence inflammatory pathways during human endotoxemia.Crit Care Med2006; 34: 1365–1371.
  102. Leone M, Boyadjiev I, Boulos E, Antonini F, Visintini P, Albanese J, Martin C. A reappraisal of isoproterenol in goal-directed therapy of septic shock. Shock2006;26: 353–357.
  103. Suzuki T, Morisaki H, Serita R, Yamamoto M, Kotake Y, Ishizaka A, Takeda J. Infusion of the beta-adrenergic blocker esmolol attenuates myocardial dysfunction in septic rats. Crit Care Med2005; 33: 2294–2301.
  104. Bernard GR, Vincent JL, Laterre PF, LaRosa SP, Dhainaut JF, Lopez-Rodriguez A, Steingrub JS, Garber GE, Helterbrand JD, Ely EW, Fisher CJ Jr; Recombinant Human Protein C Worldwide Evaluation in Severe Sepsis (PROWESS) Study Group. Efficacy and safety of recombinant human activated protein C for severe sepsis. N Engl J Med2001; 344: 699–709.
  105. Annane D. Corticosteroids for septic shock. Crit Care Med2001; 29: S117–S120.
  106. Tonelli M, Isles C, Craven T, Tonkin A, Pfeffer MA, Shepherd J, Sacks FM, Furberg C, Cobbe SM, Simes J, West M, Packard C, Curhan GC. Effect of pravastatin on rate of kidney function loss in people with or at risk for coronary disease. Circulation2005; 112: 171–178.
  107. Fukuta H, Sane DC, Brucks S, Little WC. Statin therapy may be associated with lower mortality in patients with diastolic heart failure: a preliminary report.Circulation2005; 112: 357–363.
  108. Zhang L, Zhang ZG, Ding GL, Jiang Q, Liu X, Meng H, Hozeska A, Zhang C, Li L, Morris D, Zhang RL, Lu M, Chopp M. Multitargeted effects of statin-enhanced thrombolytic therapy for stroke with recombinant human tissue-type plasminogen activator in the rat. Circulation2005; 112: 3486–3494.
  109. Kwak B, Mulhaupt F, Myit S, Mach F. Statins as a newly recognized type of immunomodulator. Nat Med2000; 6: 1399–1402.
  110. Kurakata S, Kada M, Shimada Y, Komai T, Nomoto K. Effects of different inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, pravastatin sodium and simvastatin, on sterol synthesis and immunological functions in human lymphocytes in vitro. Immunopharmacology1996; 34: 51–61.
  111. Romano M, Diomede L, Sironi M, Massimiliano L, Sottocorno M, Polentarutti N, Guglielmotti A, Albani D, Bruno A, Fruscella P, Salmona M, Vecchi A, Pinza M, Mantovani A. Inhibition of monocyte chemotactic protein-1 synthesis by statins. Lab Invest2000; 80: 1095–1100.
  112. Weber C, Erl W, Weber KS, Weber PC. HMG-CoA reductase inhibitors decrease CD11b expression and CD11b-dependent adhesion of monocytes to endothelium and reduce increased adhesiveness of monocytes isolated from patients with hypercholesterolemia. J Am Coll Cardiol1997; 30: 1212–1217.
  113. Yoshida M, Sawada T, Ishii H, Gerszten RE, Rosenzweig A, Gimbrone MA Jr, Yasukochi Y, Numano F. HMG-CoA reductase inhibitor modulates monocyte-endothelial cell interaction under physiological flow conditions in vitro: involvement of Rho GTPase-dependent mechanism. Arterioscler Thromb Vasc Biol2001; 21:1165–1171.
  114. Weitz-Schmidt G, Welzenbach K, Brinkmann V, Kamata T, Kallen J, Bruns C, Cottens S, Takada Y, Hommel U. Statins selectively inhibit leukocyte function antigen-1 by binding to a novel regulatory integrin site. Nat Med2001; 7: 687–692.
  115. Colli S, Eligini S, Lalli M, Camera M, Paoletti R, Tremoli E. Vastatins inhibit tissue factor in cultured human macrophages: a novel mechanism of protection against atherothrombosis. Arterioscler Thromb Vasc Biol1997; 17: 265–272.
  116. Erkkila L, Jauhiainen M, Laitinen K, Haasio K, Tiirola T, Saikku P, Leinonen M. Effect of simvastatin, an established lipid-lowering drug, on pulmonary Chlamydia pneumoniae infection in mice. Antimicrob Agents Chemother2005; 49: 3959–3962.
  117. del Real G, Jimenez-Baranda S, Mira E, Lacalle RA, Lucas P, Gomez-Mouton C, Alegret M, Pena JM, Rodriguez-Zapata M, Alvarez-Mon M, Martinez A, Manes S. Statins inhibit HIV-1 infection by down-regulating Rho activity. J Exp Med2004;200: 541–547.
  118. Liappis AP, Kan VL, Rochester CG, Simon GL. The effect of statins on mortality in patients with bacteremia. Clin Infect Dis2001; 33: 1352–1357.
  119. Steiner S, Speidl WS, Pleiner J, Seidinger D, Zorn G, Kaun C, Wojta J, Huber K, Minar E, Wolzt M, Kopp CW. Simvastatin blunts endotoxin-induced tissue factor in vivo. Circulation2005; 111: 1841–1846.
  120. Almog Y, Shefer A, Novack V, Maimon N, Barski L, Eizinger M, Friger M, Zeller L, Danon A. Prior statin therapy is associated with a decreased rate of severe sepsis. Circulation2004; 110: 880–885.
  121. Hackam DG, Mamdani M, Li P, Redelmeier DA. Statins and sepsis in patients with cardiovascular disease: a population-based cohort analysis. Lancet2006; 367:413–418.
  122. Merx MW, Weber C. Statins: a preventive strike against sepsis in patients with cardiovascular disease? Lancet2006; 367: 372–373.
  123. Panacek EA, Marshall JC, Alberson TE, Johnson DH, Johnson S, MacArthur RD, Miller M, Barchuk WT, Fischkoff S, Kaul M, Teoh L, Van Meter L, Daum L, Lemeshow S, Hicklin G, Doig C. Efficacy and safety of the monoclonal anti-tumor necrosis factor antibody F(ab′)2 fragment afelimomab in patients with severe sepsis and elevated interleukin-6 levels. Crit Care Med2004; 32: 2173–2182.
  124. Zeiher BG, Steingrub J, Laterre PF, Dmitrienko A, Fukiishi Y, Abraham E; EZZI Study Group. LY315920NA/S-5920, a selective inhibitor of group IIA secretory phospholipase A2, fails to improve clinical outcome for patients with severe sepsis.Crit Care Med2005; 33: 1741–1748.
  125. Grandel U, Hopf M, Buerke M, Hattar K, Heep M, Fink L, Bohle RM, Morath S, Hartung T, Pullamsetti S, Schermuly RT, Seeger W, Grimminger F, Sibelius U. Mechanisms of cardiac depression caused by lipoteichoic acids from Staphylococcus aureus in isolated rat hearts. Circulation2005; 112: 691–698.
    SOURCE

Circulation.2007; 116: 793-802doi: 10.1161/​CIRCULATIONAHA.106.678359

Other articles on Sepsis published on this Open Access Online Scientific Journal, include the following:

Advanced Topics in Sepsis and the Cardiovascular System at its End Stage

Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2013/08/18/advanced-topics-in-sepsis-and-the-cardiovascular-system-at-its-end-stage/

Nitric Oxide and Sepsis, Hemodynamic Collapse, and the Search for Therapeutic Options

Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2012/10/20/nitric-oxide-and-sepsis-hemodynamic-collapse-and-the-search-for-therapeutic-options/

Sepsis, Multi-organ Dysfunction Syndrome, and Septic Shock: A Conundrum of Signaling Pathways Cascading Out of Control

Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2012/10/13/sepsis-multi-organ-dysfunction-syndrome-and-septic-shock-a-conundrum-of-signaling-pathways-cascading-out-of-control/

Automated Inferential Diagnosis of SIRS, sepsis, septic shock

Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2012/08/01/automated-inferential-diagnosis-of-sirs-sepsis-septic-shock/

The role of biomarkers in the diagnosis of sepsis and patient management

Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2012/07/28/the-role-of-biomarkers-in-the-diagnosis-of-sepsis-and-patient-management/

Bernstein, HL, Pearlman, JD and A. Lev-Ari  Alternative Designs for the Human Artificial Heart: The Patients in Heart Failure – Outcomes of Transplant (donor)/Implantation (artificial) and Monitoring Technologies for the Transplant/Implant Patient in the Community

https://pharmaceuticalintelligence.com/2013/08/05/alternative-designs-for-the-human-artificial-heart-the-patients-in-heart-failure-outcomes-of-transplant-donorimplantation-artificial-and-monitoring-technologies-for-the-transplantimplant-pat/

Pearlman, JD and A. Lev-Ari 7/22/2013 Cardiac Resynchronization Therapy (CRT) to Arrhythmias: Pacemaker/Implantable Cardioverter Defibrillator (ICD) Insertion

https://pharmaceuticalintelligence.com/2013/07/22/cardiac-resynchronization-therapy-crt-to-arrhythmias-pacemakerimplantable-cardioverter-defibrillator-icd-insertion/

Lev-Ari, A. 7/19/2013 3D Cardiovascular Theater – Hybrid Cath Lab/OR Suite, Hybrid Surgery, Complications Post PCI and Repeat Sternotomy

https://pharmaceuticalintelligence.com/2013/07/19/3d-cardiovascular-theater-hybrid-cath-labor-suite-hybrid-surgery-complications-post-pci-and-repeat-sternotomy/

Pearlman, JD and A. Lev-Ari 7/17/2013 Emerging Clinical Applications for Cardiac CT: Plaque Characterization, SPECT Functionality, Angiogram’s and Non-Invasive FFR

https://pharmaceuticalintelligence.com/2013/07/17/emerging-clinical-applications-for-cardiac-ct-plaque-characterization-spect-functionality-angiograms-and-non-invasive-ffr/

Lev-Ari, A. 7/14/2013 Vascular Surgery: International, Multispecialty Position Statement on Carotid Stenting, 2013 and Contributions of a Vascular Surgeon at Peak Career – Richard Paul Cambria, MD

https://pharmaceuticalintelligence.com/2013/07/14/vascular-surgery-position-statement-in-2013-and-contributions-of-a-vascular-surgeon-at-peak-career-richard-paul-cambria-md-chief-division-of-vascular-and-endovascular-surgery-co-director-thoracic/

Lev-Ari, A. 7/9/2013 Heart Transplant (HT) Indication for Heart Failure (HF): Procedure Outcomes and Research on HF, HT @ Two Nation’s Leading HF & HT Centers

https://pharmaceuticalintelligence.com/2013/07/09/research-programs-george-m-linda-h-kaufman-center-for-heart-failure-cleveland-clinic/

Lev-Ari, A. 7/8/2013 Becoming a Cardiothoracic Surgeon: An Emerging Profile in the Surgery Theater and through Scientific Publications 

https://pharmaceuticalintelligence.com/2013/07/08/becoming-a-cardiothoracic-surgeon-an-emerging-profile-in-the-surgery-theater-and-through-scientific-publications/

Pearlman, JD and A. Lev-Ari  7/4/2013 Fractional Flow Reserve (FFR) & Instantaneous wave-free ratio (iFR): An Evaluation of Catheterization Lab Tools (Software Validation) for Ischemic Assessment (Diagnostics) – Change in Paradigm: The RIGHT vessel not ALL vessels

https://pharmaceuticalintelligence.com/2013/07/04/fractional-flow-reserve-ffr-instantaneous-wave-free-rario-ifr-an-evaluation-of-catheterization-lab-tools-for-ischemic-assessment/

Lev-Ari, A. 7/1/22013 Endovascular Lower-extremity Revascularization Effectiveness: Vascular Surgeons (VSs), Interventional Cardiologists (ICs) and Interventional Radiologists (IRs)

https://pharmaceuticalintelligence.com/2013/07/01/endovascular-lower-extremity-revascularization-effectiveness-vascular-surgeons-vss-interventional-cardiologists-ics-and-interventional-radiologists-irs/

Lev-Ari, A. 6/10/2013 No Early Symptoms – An Aortic Aneurysm Before It Ruptures – Is There A Way To Know If I Have it?

https://pharmaceuticalintelligence.com/2013/06/10/no-early-symptoms-an-aortic-aneurysm-before-it-ruptures-is-there-a-way-to-know-if-i-have-it/

Lev-Ari, A. 6/9/2013 Congenital Heart Disease (CHD) at Birth and into Adulthood: The Role of Spontaneous Mutations

https://pharmaceuticalintelligence.com/2013/06/09/congenital-heart-disease-at-birth-and-into-adulthood-the-role-of-spontaneous-mutations-the-genes-and-the-pathways/

Lev-Ari, A. 6/3/2013 Clinical Indications for Use of Inhaled Nitric Oxide (iNO) in the Adult Patient Market: Clinical Outcomes after Use, Therapy Demand and Cost of Care

https://pharmaceuticalintelligence.com/2013/06/03/clinical-indications-for-use-of-inhaled-nitric-oxide-ino-in-the-adult-patient-market-clinical-outcomes-after-use-therapy-demand-and-cost-of-care/

Lev-Ari, A. 6/2/2013 Inhaled Nitric Oxide in Adults: Clinical Trials and Meta Analysis Studies – Recent Findings

https://pharmaceuticalintelligence.com/2013/06/02/inhaled-nitric-oxide-in-adults-with-acute-respiratory-distress-syndrome/

Pearlman, JD and A. Lev-Ari 5/24/2013 Imaging Biomarker for Arterial Stiffness: Pathways in Pharmacotherapy for Hypertension and Hypercholesterolemia Management

https://pharmaceuticalintelligence.com/2013/05/24/imaging-biomarker-for-arterial-stiffness-pathways-in-pharmacotherapy-for-hypertension-and-hypercholesterolemia-management/

Pearlman, JD and A. Lev-Ari 5/22/2013 Acute and Chronic Myocardial Infarction: Quantification of Myocardial Perfusion Viability – FDG-PET/MRI vs. MRI or PET alone

https://pharmaceuticalintelligence.com/2013/05/22/acute-and-chronic-myocardial-infarction-quantification-of-myocardial-viability-fdg-petmri-vs-mri-or-pet-alone/

Lev-Ari, A. 5/17/2013 Synthetic Biology: On Advanced Genome Interpretation for Gene Variants and Pathways: What is the Genetic Base of Atherosclerosis and Loss of Arterial Elasticity with Aging

https://pharmaceuticalintelligence.com/2013/05/17/synthetic-biology-on-advanced-genome-interpretation-for-gene-variants-and-pathways-what-is-the-genetic-base-of-atherosclerosis-and-loss-of-arterial-elasticity-with-aging/

Justin D Pearlman, HL Bernstein and A. Lev-Ari 5/15/2013 Diagnosis of Cardiovascular Disease, Treatment and Prevention: Current & Predicted Cost of Care and the Promise of Individualized Medicine Using Clinical Decision Support Systems

https://pharmaceuticalintelligence.com/2013/05/15/diagnosis-of-cardiovascular-disease-treatment-and-prevention-current-predicted-cost-of-care-and-the-promise-of-individualized-medicine-using-clinical-decision-support-systems-2/

Pearlman, JD and A. Lev-Ari 5/11/2013 Hypertension and Vascular Compliance: 2013 Thought Frontier – An Arterial Elasticity Focus

https://pharmaceuticalintelligence.com/2013/05/11/arterial-elasticity-in-quest-for-a-drug-stabilizer-isolated-systolic-hypertension-caused-by-arterial-stiffening-ineffectively-treated-by-vasodilatation-antihypertensives/

Pearlman, JD and A. Lev-Ari 5/7/2013 On Devices and On Algorithms: Arrhythmia after Cardiac Surgery Prediction and ECG Prediction of Paroxysmal Atrial Fibrillation Onset

https://pharmaceuticalintelligence.com/2013/05/07/on-devices-and-on-algorithms-arrhythmia-after-cardiac-surgery-prediction-and-ecg-prediction-of-paroxysmal-atrial-fibrillation-onset/

Pearlman, JD and A. Lev-Ari 5/4/2013 Cardiovascular Diseases: Decision Support Systems for Disease Management Decision Making

https://pharmaceuticalintelligence.com/2013/05/04/cardiovascular-diseases-decision-support-systems-for-disease-management-decision-making/

Lev-Ari, A. 5/3/2013 Gene, Meis1, Regulates the Heart’s Ability to Regenerate after Injuries.

https://pharmaceuticalintelligence.com/2013/05/03/gene-meis1-regulates-the-hearts-ability-to-regenerate-after-injuries/

Lev-Ari, A. 4/30/2013 Prostacyclin and Nitric Oxide: Adventures in Vascular Biology – A Tale of Two Mediators

https://pharmaceuticalintelligence.com/2013/04/30/prostacyclin-and-nitric-oxide-adventures-in-vascular-biology-a-tale-of-two-mediators/

Lev-Ari, A. 4/28/2013 Genetics of Conduction Disease: Atrioventricular (AV) Conduction Disease (block): Gene Mutations – Transcription, Excitability, and Energy Homeostasis

https://pharmaceuticalintelligence.com/2013/04/28/genetics-of-conduction-disease-atrioventricular-av-conduction-disease-block-gene-mutations-transcription-excitability-and-energy-homeostasis/

Lev-Ari, A. 4/25/2013 Economic Toll of Heart Failure in the US: Forecasting the Impact of Heart Failure in the United States – A Policy Statement From the American Heart Association

https://pharmaceuticalintelligence.com/2013/04/25/economic-toll-of-heart-failure-in-the-us-forecasting-the-impact-of-heart-failure-in-the-united-states-a-policy-statement-from-the-american-heart-association/

Lev-Ari, A. 4/24/2013 Harnessing New Players in Atherosclerosis to Treat Heart Disease

https://pharmaceuticalintelligence.com/2013/04/25/harnessing-new-players-in-atherosclerosis-to-treat-heart-disease/

Lev-Ari, A. 4/25/2013 Revascularization: PCI, Prior History of PCI vs CABG

https://pharmaceuticalintelligence.com/2013/04/25/revascularization-pci-prior-history-of-pci-vs-cabg/

Lev-Ari, A. 4/7/2013 Cholesteryl Ester Transfer Protein (CETP) Inhibitor: Potential of Anacetrapib to treat Atherosclerosis and CAD

https://pharmaceuticalintelligence.com/2013/04/07/cholesteryl-ester-transfer-protein-cetp-inhibitor-potential-of-anacetrapib-to-treat-atherosclerosis-and-cad/

Lev-Ari, A. 4/4/2013 Hypertriglyceridemia concurrent Hyperlipidemia: Vertical Density Gradient Ultracentrifugation a Better Test to Prevent Undertreatment of High-Risk Cardiac Patients

https://pharmaceuticalintelligence.com/2013/04/04/hypertriglyceridemia-concurrent-hyperlipidemia-vertical-density-gradient-ultracentrifugation-a-better-test-to-prevent-undertreatment-of-high-risk-cardiac-patients/

Lev-Ari, A. 4/3/2013 Fight against Atherosclerotic Cardiovascular Disease: A Biologics not a Small Molecule – Recombinant Human lecithin-cholesterol acyltransferase (rhLCAT) attracted AstraZeneca to acquire AlphaCore

https://pharmaceuticalintelligence.com/2013/04/03/fight-against-atherosclerotic-cardiovascular-disease-a-biologics-not-a-small-molecule-recombinant-human-lecithin-cholesterol-acyltransferase-rhlcat-attracted-astrazeneca-to-acquire-alphacore/

Lev-Ari, A. 3/31/2013 High-Density Lipoprotein (HDL): An Independent Predictor of Endothelial Function & Atherosclerosis, A Modulator, An Agonist, A Biomarker for Cardiovascular Risk

https://pharmaceuticalintelligence.com/2013/03/31/high-density-lipoprotein-hdl-an-independent-predictor-of-endothelial-function-artherosclerosis-a-modulator-an-agonist-a-biomarker-for-cardiovascular-risk/

Lev-Ari, A. 3/10/2013 Acute Chest Pain/ER Admission: Three Emerging Alternatives to Angiography and PCI

https://pharmaceuticalintelligence.com/2013/03/10/acute-chest-painer-admission-three-emerging-alternatives-to-angiography-and-pci/

Lev-Ari, A. and L H Bernstein 3/7/2013 Genomics & Genetics of Cardiovascular Disease Diagnoses: A Literature Survey of AHA’s Circulation Cardiovascular Genetics, 3/2010 – 3/2013

https://pharmaceuticalintelligence.com/2013/03/07/genomics-genetics-of-cardiovascular-disease-diagnoses-a-literature-survey-of-ahas-circulation-cardiovascular-genetics-32010-32013/

Lev-Ari, A. 2/28/2013 The Heart: Vasculature Protection – A Concept-based Pharmacological Therapy including THYMOSIN

https://pharmaceuticalintelligence.com/2013/02/28/the-heart-vasculature-protection-a-concept-based-pharmacological-therapy-including-thymosin/

Lev-Ari, A. 2/27/2013 Arteriogenesis and Cardiac Repair: Two Biomaterials – Injectable Thymosin beta4 and Myocardial Matrix Hydrogel

https://pharmaceuticalintelligence.com/2013/02/27/arteriogenesis-and-cardiac-repair-two-biomaterials-injectable-thymosin-beta4-and-myocardial-matrix-hydrogel/

Lev-Ari, A. 12/29/2012. Coronary artery disease in symptomatic patients referred for coronary angiography: Predicted by Serum Protein Profiles

https://pharmaceuticalintelligence.com/2012/12/29/coronary-artery-disease-in-symptomatic-patients-referred-for-coronary-angiography-predicted-by-serum-protein-profiles/

Bernstein, HL and Lev-Ari, A. 11/28/2012. Special Considerations in Blood Lipoproteins, Viscosity, Assessment and Treatment

https://pharmaceuticalintelligence.com/2012/11/28/special-considerations-in-blood-lipoproteins-viscosity-assessment-and-treatment/

Lev-Ari, A. 11/13/2012 Peroxisome proliferator-activated receptor (PPAR-gamma) Receptors Activation: PPARγ transrepression for Angiogenesis in Cardiovascular Disease and PPARγ transactivation for Treatment of Diabetes

https://pharmaceuticalintelligence.com/2012/11/13/peroxisome-proliferator-activated-receptor-ppar-gamma-receptors-activation-pparγ-transrepression-for-angiogenesis-in-cardiovascular-disease-and-pparγ-transactivation-for-treatment-of-dia/

Lev-Ari, A. 10/19/2012 Clinical Trials Results for Endothelin System: Pathophysiological role in Chronic Heart Failure, Acute Coronary Syndromes and MI – Marker of Disease Severity or Genetic Determination?

https://pharmaceuticalintelligence.com/2012/10/19/clinical-trials-results-for-endothelin-system-pathophysiological-role-in-chronic-heart-failure-acute-coronary-syndromes-and-mi-marker-of-disease-severity-or-genetic-determination/

Lev-Ari, A. 10/4/2012 Endothelin Receptors in Cardiovascular Diseases: The Role of eNOS Stimulation

https://pharmaceuticalintelligence.com/2012/10/04/endothelin-receptors-in-cardiovascular-diseases-the-role-of-enos-stimulation/

Lev-Ari, A. 10/4/2012 Inhibition of ET-1, ETA and ETA-ETB, Induction of NO production, stimulation of eNOS and Treatment Regime with PPAR-gamma agonists (TZD): cEPCs Endogenous Augmentation for Cardiovascular Risk Reduction – A Bibliography

https://pharmaceuticalintelligence.com/2012/10/04/inhibition-of-et-1-eta-and-eta-etb-induction-of-no-production-and-stimulation-of-enos-and-treatment-regime-with-ppar-gamma-agonists-tzd-cepcs-endogenous-augmentation-for-cardiovascular-risk-reduc/

Lev-Ari, A. 8/29/2012 Positioning a Therapeutic Concept for Endogenous Augmentation of cEPCs — Therapeutic Indications for Macrovascular Disease: Coronary, Cerebrovascular and Peripheral

https://pharmaceuticalintelligence.com/2012/08/29/positioning-a-therapeutic-concept-for-endogenous-augmentation-of-cepcs-therapeutic-indications-for-macrovascular-disease-coronary-cerebrovascular-and-peripheral/

Lev-Ari, A. 8/28/2012 Cardiovascular Outcomes: Function of circulating Endothelial Progenitor Cells (cEPCs): Exploring Pharmaco-therapy targeted at Endogenous Augmentation of cEPCs

https://pharmaceuticalintelligence.com/2012/08/28/cardiovascular-outcomes-function-of-circulating-endothelial-progenitor-cells-cepcs-exploring-pharmaco-therapy-targeted-at-endogenous-augmentation-of-cepcs/

Lev-Ari, A. 8/27/2012 Endothelial Dysfunction, Diminished Availability of cEPCs, Increasing CVD Risk for Macrovascular Disease – Therapeutic Potential of cEPCs

https://pharmaceuticalintelligence.com/2012/08/27/endothelial-dysfunction-diminished-availability-of-cepcs-increasing-cvd-risk-for-macrovascular-disease-therapeutic-potential-of-cepcs/

Lev-Ari, A. 8/24/2012 Vascular Medicine and Biology: CLASSIFICATION OF FAST ACTING THERAPY FOR PATIENTS AT HIGH RISK FOR MACROVASCULAR EVENTS Macrovascular Disease – Therapeutic Potential of cEPCs

https://pharmaceuticalintelligence.com/2012/08/24/vascular-medicine-and-biology-classification-of-fast-acting-therapy-for-patients-at-high-risk-for-macrovascular-events-macrovascular-disease-therapeutic-potential-of-cepcs/

Lev-Ari, A. 7/19/2012 Cardiovascular Disease (CVD) and the Role of agent alternatives in endothelial Nitric Oxide Synthase (eNOS) Activation and Nitric Oxide Production

https://pharmaceuticalintelligence.com/2012/07/19/cardiovascular-disease-cvd-and-the-role-of-agent-alternatives-in-endothelial-nitric-oxide-synthase-enos-activation-and-nitric-oxide-production/

Lev-Ari, A. 4/30/2012 Resident-cell-based Therapy in Human Ischaemic Heart Disease: Evolution in the PROMISE of Thymosin beta4 for Cardiac Repair

https://pharmaceuticalintelligence.com/2012/04/30/93/

Lev-Ari, A. 5/29/2012 Triple Antihypertensive Combination Therapy Significantly Lowers Blood Pressure in Hard-to-Treat Patients with Hypertension and Diabetes

https://pharmaceuticalintelligence.com/2012/05/29/445/

Lev-Ari, A. 7/2/2012 Macrovascular Disease – Therapeutic Potential of cEPCs: Reduction Methods for CV Risk

https://pharmaceuticalintelligence.com/2012/07/02/macrovascular-disease-therapeutic-potential-of-cepcs-reduction-methods-for-cv-risk/

 

Read Full Post »


Reporter: Aviva Lev-Ari, PhD, RN

Correspondence in NEJM

To the Editor:

Ranieri et al. (May 31 issue)1 report the results of yet another negative trial involving patients with septic shock. I cannot help but wonder whether these negative trials reflect a failure of the study design rather than the study drug. The Prospective Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis and Septic Shock (PROWESS-SHOCK) protocol required patients to begin treatment “within 24 hours after the first dose of a vasopressor.” Did the patients simply receive treatment after the opportunity to affect the sepsis cascade was missed? The authors provide data on the median time from the initiation of antibiotics to initial vasopressor therapy (2.5 hours), but they do not provide information regarding the time from diagnosis, from initiation of vasopressors, or from arrival in the emergency department until study-drug administration. It is hard to close the book on any therapy for critically ill patients until it is known whether it was administered during the time frame when the therapy would be most likely to show benefit. Common sense dictates that early interventions would be more helpful than later interventions.

Judd E. Hollander, M.D.
University of Pennsylvania, Philadelphia, PA
judd.hollander@uphs.upenn.edu

No potential conflict of interest relevant to this letter was reported.

1 References

1

Ranieri VM, Thompson BT, Barie PS, et al. Drotrecogin alfa (activated) in adults with septic shock. N Engl J Med 2012;366:2055-2064
Full Text | Web of Science | Medline

To the Editor:

Although disappointing, the results of the PROWESS-SHOCK study in which drotrecogin alfa (activated) (DrotAA) (recombinant human activated protein C) was used for severe sepsis are not surprising. Biologically active molecules such as DrotAA are likely to be effective in targeting specific pathophysiological disturbances in disease states such as severe meningococcal sepsis with disseminated intravascular coagulation or purpura fulminans as the dominant clinical feature.1That no biologically active substance has shown benefit in sepsis may have more to do with studies that involve heterogeneous groups of patients with diverse causes of sepsis rather than a single disease entity. Anecdotal reports of the use of activated protein C in severe meningococcal disease in children and adults2-4 provide support for the view that DrotAA could be therapeutically useful in this condition. Unfortunately, DrotAA was abruptly withdrawn from the market. This means that clinical trials of human recombinant activated protein C in life-threatening meningococcal infection can no longer be conducted.

Vineet Nayyar, F.R.A.C.P., F.C.I.C.M.
Thomas Solano, F.R.A.C.P., F.C.I.C.M.
Westmead Hospital, Westmead, NSW, Australia

No potential conflict of interest relevant to this letter was reported.

4 References

4 References

    1. 1

      Faust SN, Levin M, Harrison OB, et al. Dysfunction of endothelial protein C activation in severe meningococcal sepsis. N Engl J Med 2001;345:408-416
      Full Text | Web of Science | Medline

    1. 2

      Veldman A, Fischer D, Wong FY, et al. Human protein C concentrate in the treatment of purpura fulminans: a retrospective analysis of safety and outcome of 94 pediatric patients.Crit Care 2010;14:R156-R156
      CrossRef | Web of Science

    1. 3

      Thomas GL, Wigmore T, Clark P. Activated protein C for the treatment of fulminant meningococcal septicaemia. Anaesth Intensive Care 2004;32:284-287
      Web of Science

  1. 4

    Vincent J-L, Nadel S, Kutsogiannis DJ, et al. Drotrecogin alfa (activated) in patients with severe sepsis presenting with purpura fulminans, meningitis, or meningococcal disease: a retrospective analysis of patients enrolled in recent clinical studies. Crit Care 2005;9:R331-R343
    CrossRef | Web of Science

Author/Editor Response

We agree with Hollander’s implication that multiple reasons may explain why a study such as PROWESS-SHOCK did not show a benefit. However, PROWESS-SHOCK showed that DrotAA did not benefit patients who met the specific criteria for septic shock that were defined for enrollment in the trial.

It is difficult to define precisely when sepsis begins. We did record the time from the start of treatment with a vasopressor to the start of study-drug infusion1 and found no heterogeneity in the treatment effect on 28-day mortality (see Fig. S1 in the Supplementary Appendix, available with the full text of our article at NEJM.org) and 90-day mortality (Figure 2B of our article), according to quartiles of time of this interval. The mean (±SD) time from the start of a vasopressor to the start of DrotAA was 17.2±5.7 hours, which is similar to the interval from the first organ failure to the start of DrotAA reported in the PROWESS study (17.5±12.8 hours).2 The shortest interval was 4 hours. Thus, we found no evidence of a beneficial effect of DrotAA early during the course of septic shock.

Meningitis was listed as the cause of septic shock in only 24 of 1696 patients enrolled in PROWESS-SHOCK, and Neisseria meningitidis was cultured in samples obtained from only 7 patients. Thus, our study cannot address the question of the efficacy of DrotAA for that specific population. However, as Nayyar and Solano suggest, we did anticipate that if DrotAA was beneficial, the benefit would be greatest among patients presenting with a more coagulopathic phenotype. Thus, there were also predefined subgroups according to the protein C class and baseline Sequential Organ Failure Assessment score for coagulation. There was no heterogeneity in the treatment effect on 28-day mortality (Fig. S1 in the Supplementary Appendix of our article) and 90-day mortality (Figure 2B of our article) in these subgroups. Furthermore, the relatively small Resolution of Organ Failure in Pediatric Patients with Severe Sepsis trial included subgroups of children with septic coagulopathy and purpura fulminans and showed no treatment effect of DrotAA as compared with placebo.3 That all six remaining subgroups in PROWESS-SHOCK did not show a treatment effect should reassure clinicians who no longer have DrotAA available for the treatment of septic shock.

B. Taylor Thompson, M.D.
Massachusetts General Hospital, Boston, MA
tthompson1@partners.org

V. Marco Ranieri, M.D.
Università di Torino, Turin, Italy

for the PROWESS-SHOCK Steering Committee
3 REFERENCES

    1. 1

      PROWESS SHOCK Steering Committee, Thompson BT, Ranieri VM, et al. Statistical analysis plan of PROWESS SHOCK study. Intensive Care Med 2010;36:1972-1973
      CrossRef | Web of Science

    1. 2

      Bernard GR, Vincent J-L, Laterre P-F, et al. Efficacy and safety of recombinant human activated protein C for severe sepsis. N Engl J Med 2001;344:699-709
      Full Text | Web of Science | Medline

  1. 3

    Nadel S, Goldstein B, Williams MD, et al. Drotrecogin alfa (activated) in children with severe sepsis: a multicentre phase III randomised controlled trial. Lancet2007;369:836-843
    CrossRef | Web of Science | Medline

http://www.nejm.org/doi/full/10.1056/NEJMc1207701?query=TOC

SOURCE:

N Engl J Med 2012; 367:968-969  September 6, 2012

Read Full Post »

Older Posts »