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Posts Tagged ‘Coronary artery disease’


Progenitor Cell Transplant for MI and Cardiogenesis  (Part 1

Author and Curator: Larry H. Bernstein, MD, FCAP
and
Curator: Aviva Lev-Ari, PhD, RN
This article is Part I of a review of three perspectives on stem cell transplantation onto a substantial size of infarcted myocardium to generate cardiogenesis in tissue that is composed of both repair fibroblasts and cardiomyocytes, after essentially nontransmural myocardial infarct.

Progenitor Cell Transplant for MI and Cardiogenesis (Part 1)

Larry H. Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2013/10/28/progenitor-cell-transplant-for-mi-and-cardiogenesis/

Source of Stem Cells to Ameliorate Damage Myocardium (Part 2)

Larry H. Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2013-10-29/larryhbern/Source_of_Stem_Cells_to_Ameliorate_ Damaged_Myocardium/

An Acellular 3-Dimensional Collagen Scaffold Induces Neo-angiogenesis
 (Part 3)

Larry H. Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2013-10-29/larryhbern/An_Acellular_3-Dimensional_Collagen_Scaffold _Induces_Neo-angiogenesis/

The same approach is considered for stroke in one of these studies.  These are issues that need to be considered
  1. Adult stem cells
  2. Umbilical cord tissue sourced cells
  3. Sheets of stem cells
  4. Available arterial supply at the margins
  5. Infarct diameter
  6. Depth of ischemic necrosis
  7. Distribution of stroke pressure
  8. Stroke volume
  9. Mean Arterial Pressure (MAP)
  10. Location of infarct
  11. Ratio of myocytes to fibrocytes
  12. Coexisting heart disease and, or
  13. Comorbidities predisposing to cardiovascular disease, hypertension
  14. Inflammatory reaction against the graft

Transplantation of cardiac progenitor cell sheet onto infarcted heart promotes cardiogenesis and improves function

L Zakharova1, D Mastroeni1, N Mutlu1, M Molina1, S Goldman2,3, E Diethrich4, and MA Gaballa1*
1Center for Cardiovascular Research, Banner Sun Health Research Institute, Sun City, AZ; 2Cardiology Section, Southern Arizona VA Health Care System, and 3Department of Internal Medicine, The University of Arizona, Tucson, AZ; and 4Arizona Heart Institute, Phoenix, AZ
Cardiovascular Research (2010) 87, 40–49   http://dx.doi.org/10.1093/cvr/cvq027

Abstract

Aims

Cell-based therapy for myocardial infarction (MI) holds great promise; however, the ideal cell type and delivery system have not been established. Obstacles in the field are the massive cell death after direct injection and the small percentage of surviving cells differentiating into cardiomyocytes. To overcome these challenges we designed a novel study to deliver cardiac progenitor cells as a cell sheet.

Methods and results

Cell sheets composed of rat or human cardiac progenitor cells (cardiospheres), and cardiac stromal cells were transplanted onto the infarcted myocardium after coronary artery ligation in rats. Three weeks later, transplanted cells survived, proliferated, and differentiated into cardiomyocytes (14.6 ± 4.7%). Cell sheet transplantation suppressed cardiac wall thinning and increased capillary density (194 ± 20 vs. 97 ± 24 per mm2, P < 0.05) compared with the untreated MI. Cell migration from the sheet was observed along the necrotic trails within the infarcted area. The migrated cells were located in the vicinity of stromal-derived factor (SDF-1) released from the injured myocardium, and about 20% of these cells expressed CXCR4, suggesting that the SDF-1/CXCR4 axis plays, at least, a role in cell migration. Transplantation of cell sheets resulted in a preservation of cardiac contractile function after MI, as was shown by a greater ejection fraction and lower left ventricular end diastolic pressure compared with untreated MI.

Conclusion

The scaffold-free cardiosphere-derived cell sheet approach seeks to efficiently deliver cells and increase cell survival.These transplanted cells effectively rescue myocardium function after infarction by promoting not only neovascular-ization but also inducing a significant level of cardiomyogenesis
Keywords  Myocardial infarction • Cardiac progenitor cells • Cardiospheres • Cardiac regeneration • Contractility

Introduction

Despite advances in cardiac treatment after myocardial infarction (MI), congestive heart failure remains the number one killer world-wide. MI results in an irreversible loss of functional cardiomyocytes followed by scar tissue formation. To date, heart transplant remains the gold standard for treatment of end-stage heart failure, a procedure which will always be limited by the availability of a donor heart. Hence, developing a new form of therapy is vital.
A number of adult non-cardiac progenitor cells have been tested for myocardial regeneration, including skeletal myoblasts,1 bone-marrow2, and endothelial progenitor cells.3,4 In addition, several cardiac resident stem cell populations have been characterized based on the expression of stem cell marker proteins.5–8 Among these, the c-Kit+ population has been reported to promote myocardial repair.5,9 Recently, an ex vivo method to expand cardiac-derived progenitor cells from human myocardial biopsies and murine hearts was developed.10 Using this approach, undifferentiated cells (or cardiospheres) grow as self-adherent clusters from postnatal atrium or ventricular biopsy specimens.11
To date, the most common technique for cell delivery is direct injection into the infarcted myocardium.12 This approach is inefficient because more than 90% of the delivered cells die by apoptosis and only a small number of the survived cells differentiated into cardiomyocytes.13 An alternative approach to cell delivery is a biodegradable scaffold-based engineered tissue.14,15 This approach has the clear advantage in creating tissue patches of different shapes and sizes and in creating a beating heart by decellularization technology.16 Advances are being made to overcome the issue of small patch thickness and to minimize possible toxicity of the degraded substances from the scaffold.15 Recently, scaffold-free cell sheets were created from fibroblasts, mesenchymal cells, or neonatal myocytes.17,18 Transplantation of these sheets resulted in a limited improvement in cardiac function due to induced neovascularization and angiogenesis through secretion of angiogenic factors.17–19 However, few of those progenitor cells have differentiated into cardiomyocytes.17 The need to improve cardiac contractile function suggests focusing on cells with higher potential to differentiate to cardiomyocytes with an improved delivery method.
In the present study, we report a cell-based therapeutic strategy that surpasses limitation inherent in previously used methodologies. We have created a scaffold-free sheet composed of cardiac progenitor cells (cardiospheres) incorporated into a layer of cardiac stromal cells. The progenitor cells survived when transplanted as a cell sheet onto the infarcted area, improved cardiac contractile functions, and supported recovery of damaged myocardium by promoting not only vascularization but also a significant level of cardiomyogenesis. We also showed that cells from a sheet can be recruited to the site of injury driven, at least partially, by the stromal-derived factor (SDF-1) gradient.

Methods

Detailed methods are provided in the Supplementary Methods

Animals

Three-month-old Sprague Dawley male rats were used. Rats were randomly placed into four groups:
(1) sham-operated rats, n = 12;
(2) MI, n = 12;
(3) MI treated with rat sheet, n = 10; and
(4) MI treated with human sheet, n = 10.

Myocardial infarction

MI was created by the ligation of the left coronary artery.20 Animals were intubated and ventilated using a small animal ventilator (Harvard Apparatus). A left thoracotomy was performed via the third intercostal rib, and the left coronary artery was ligated. The extent of infarct was verified by measuring the area at risk: heart was perfused with PBS containing 4 mg/mL Evans Blue as previously described by our laboratory.20 The area at risk was estimated by recording the size of the under-perfused (pale-colored) area of myocardium (see Supplementary material online, Figure S1). Only animals with an area at risk >30% were used in the present study. Post-mortem infarct size was measured using triphenyl tetrazolium chloride staining as previously described by our laboratory.20

Isolation of cardiosphere-forming cells

Cardiospheres were generated as described10 from atrial tissues obtained from:
(1) human atrial resection samples obtained from patients (aged from 53 to 73 years old) undergoing cardiac bypass surgery at Arizonam Heart Hospital (Phoenix, AZ) in compliance with Institutional Review Board protocol (n = 10),
(2) 3-month-old SD rats (n = 10). Briefly, tissues were cut into 1–2 mm3 pieces and tissue fragments were cultured ‘as explants’ in a complete explants medium for 4 weeks (Supplementary Methods).
Cell sheet preparation, labelling, handling, and transplantation
Cardiosphere-forming cells (CFCs) combined with cardiac stromal cells were seeded on double-coated plates (poly-L-lysine and collagen type IV from human placenta) in cardiosphere growing medium (Supplementary Methods). The sheets created from the same cell donors were divided into two groups,
one for transplantation and the other for characterization by immunostaining and RT–PCR (Supplementary Methods).
Prior to transplantation, rat cell sheets were labelled with 2 mM 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine, DiI, for tracking transplanted cells in rat host myocardium (Molecular Probes, Eugene, OR). Sheets created using human cells were transplanted unlabelled. Sheets were gently peeled off the collagen-coated plate and folded twice to form four layers. The entire sheet with 200 ml of media was
  • gently aspirated into the pipette tip,
  • transferred to the supporting polycarbonate filter (Costar) and
  • spread off by adding media drops on the sheet (Figure 2A).
Polycarbonate filter was used as a flexible mechanical support for cell sheet to facilitate handling during the transplantation. Immediately after LAD occlusion, the cell sheet was transplanted onto the infarcted area, allowed to adhere to the ventricle for 5–7 min, and the filter was removed before closing the chest (Figure 2A).

Cardiac function

Three weeks after MI, closed-chest in vivo cardiac function was measured using a Millar pressure conductance catheter system (Millar Instruments, Houston, TX) (Supplementary Methods).

Cell sheet survival, engraftment, and cell migration

Rat host myocardium and cell sheet composition after transplantation were characterized by immunostaining (Supplementary Methods). Rat-originated cells were traced by DiI, while human-originated cells were identified by immunostaining with anti-human nuclei or human lamin antibodies.
  1. To assess sheet-originated cardiomyocytes within the host myocardium, the number of cells positive for both human nuclei and myosin heavy chain (MHC) (human sheet); or both DiI and MHC (rat sheet) were counted.
  2. To assess sheet-originated capillaries within the rat host myocardium, the number of cells positive for both human nuclei and von Willebrand factor (vWf) (human sheet); or both DiI and vWf (rat sheet) were counted. Cells were counted in five microscopic fields within cell sheet and area of infarct (n = 5). The number of cells expressing specific markers was normalized to the total number of cells determined by 40,6-diamidino-2-phenylindole staining of the nuclei DNA.
  3. To assess the survival of transplanted cells, sections were stained with Ki-67 antibody followed by fluorescent detection and caspase 3 primary antibodies followed by DAB detection (Supplementary Methods).
  4. To evaluate human sheet engraftment, sections were stained with human lamin antibody followed by fluorescent detection (Supplementary Methods).
  5. Rat host inflammatory response to the transplanted human cell sheet 21 days after transplantation was evaluated by counting tissue mononuclear phagocytes and neutrophils (Supplementary Methods).

Imaging

Images were captured using Olympus IX70 confocal microscope (Olympus Corp, Tokyo, Japan) equipped with argon and krypton lasers or Olympus IX-51 epifluorescence microscope using excitation/emission maximum filters: 490/520 nm, 570 /595 nm, and 355 /465 nm. Images were processed using DP2-BSW software (Olympus Corp).

Statistics

All data are represented as mean ± SE Significance (P < 0.05) was deter-mined using ANOVA (StatView).

Results

Generation of cardiospheres

Cardiospheres were generated from atrial tissue explants. After 7–14 days in culture, a layer of stromal cells arose from the attached explants (Supplementary material online, Figure S2a). CFCs, small phase-bright single cells, emerged from explants and bedded down on the stromal cell layer (Supplementary material online, Figure S2b).
  • After 4 weeks, single CFCs, as well as cardiospheres (spherical colonies generated from CFCs) were observed (Supplementary material online, Figure S2c).
Cellular characteristics of cardiospheres in vitro
Immunocytochemical analysis of dissociated cardiospheres revealed that
  • 30% of cells were c-Kitþ indicating that the CFCs maintain multi-potency. About
  • 22 and 28% of cells expressed a, b-MHC and cardiac troponin I, respectively.
These cells represent an immature cardiomyocyte population because they were smaller (10–15 pm in length vs. 60–80 pm for mature cardiomyocytes) and no organized structure of MHC was detected. Furthermore
  • 17% of the cells expressed a-smooth muscle actin (SMA) and
  • 6% were positive for vimentin,
    • both are mesenchymal cell markers (Supplementary material online, Figure S3a and b).
  • Less then 5% of cells were positive for endothelial cell marker; vWf.
Cell characteristics of human cardiospheres are similar to those from rat tissues (Supplementary material online, Figure S3c).
Cardiospheres were further characterized based on the expression of c-Kit antigen. RT–PCR analysis was performed on both c-Kitþ and c-Kit2 subsets isolated from re-suspended cardiospheres. KDR, kinase domain protein receptor, was recently identified as a marker for cardiovascular lineage progenitors in differentiating embryonic stem cells.21 Here, we found that
  • the c-Kitþ cells were also Nkx2.5 and GATA4-positive, but were low or negative for KDR (Supplementary material online, Figure S3d). In contrast,
  • c-Kit2 cells strongly expressed KDR and GATA4, but were negative for Nkx2.5.
  • Both c-Kitþ and c-Kit2 subsets did not express Isl1, a marker for multipotent secondary heart field progenitors.22
Characteristics of cell sheet prior to transplantation
The cell sheet is a layer of cardiac stromal cells in which the cardiospheres were incorporated at a frequency of 21 ± 0.5 spheres per 100,000 viable cells (Figure 1A). The average diameter of cardiospheres within a sheet was 0.13 ± 0.02 mm and their average area was 0.2 ± 0.06 mm2 (Figure 1A). After sheets were peeled off the plate, it exhibited a heterogeneous thickness ranging from 0.05– 0.1 mm (n 1/4 10), H&E staining (Figure1B) and Masson’s Trichrome staining (Figure 1C) of the sheet sections revealed tissue-like organized structures composed of muscle tissue intertwined with streaks of collagen with no necrotic core. Based on the immunostaining results, sheet compiled of several cell types including
  • SMAþ cardiac stromal cells (50%),
  • MHCþ cardiomyocytes (20%), and
  • vWfþ endothelial cells (10%) (Figure 1D and E).
  • 15% of the sheet-forming cells were c-Kitþ suggesting the cells multipotency (Figure 1E).
  • Cells within the sheet expressed gap-junction protein C43, an indicator of electromechanical coupling between cells (Figure 1D).
  • 40% of cells were positive for the proliferation marker Ki-67 suggesting an active cell cycle state (Figure 1D, middle panel).
Human sheet expressed genes
  1. known to be upregulated in undifferentiated cardiovascular progenitors such as c-Kit and KDR;
  2. cardiac transcription factors Nkx2.5 and GATA4; genes related to adhesion, cell homing, and
  3. migration such as ICAM (intercellular adhesion molecule), CXCR4 (receptor for SDF-1), and
  4. matrix metalloprotease 2 (MMP2).
No expression of Isl1 was detected in human sheet (Figure 1F).
sheet transplant on MI_Image_2
Figure 1 Cell sheet characteristics. (A) Fully formed cell sheet. Arrow indicates integrated cardiosphere. (B) H&E staining; pink colour (arrowhead) indicates cytosol and blue (arrows) indicates nuclear stain. Note that there is no necrotic core within the cell sheet. (C) Masson’s Trichrome staining of sheet section. Arrowhead indicates collagen deposition within the sheet. (D and E) Sheet sections were labelled with antibodies against following markers: (D) vWf (green), Ki-67 (green), C43 (green); (E) c-Kit (green), MHC (red), SMA (red) as indicated on top of each panel. Nuclei were labelled with blue fluorescence of 40,6-diamidino-2-phenylindole (DAPI). (F) Gene expression analysis of the cell sheet. Scale bars, 200 pm (A) or 50 pm (B–E).

Cell sheet survival and proliferation

Two approaches were used to track transplanted cells in the host myocardium.
  • rat cell sheets were labelled with red fluorescent dye, DiI, prior to the transplantation.
  • the sheet created from human cells (human sheet) were identified in rat host myocardium by immunostaining with human nuclei antibodies.
DiI-labelling together with trichrome staining showed engraftment of the cardiosphere-derived cell sheet to the infarcted myocardium (Figure 2B–D). In vivo sheets grew into a stratum with heterogeneous thickness ranging from 0.1–0.5 mm over native tissue. The percentage of Ki-67þ cells within the sheet was 37.5 ± 6.5 (Figure 2F) whereas host tissue was mostly negative (except for the vasculature).
To assess the viability of transplanted cells, the heart sections were stained with the apoptosis marker, caspase 3. A low level of caspase 3 was detected within the sheet, suggesting that the majority of transplanted cells survived after transplantation (Figure 2G).
sheet transplant on MI_Image_3
Figure 2 Transplantation and growth of cell sheet after transplantation.
(A) Sheet transplantation onto infarcted heart. Detached cell sheet on six-well plate (left); cell sheet folded on filter (middle); and transplanted onto left ventricle (right). Scale bar 2 mm. DiI-labelled cell sheets grafted above MI area at day 3
(B) and day 21
(C) after transplantation.
(D) LV section of untreated MI rat at day 21 showing no significant red fluorescence background.
Bottom row (B–D) demonstrates the enlargement of box-selected area of corresponding top panels.
(E) Similar sections stained with Masson’s Trichrome. Section of rat (F) or human (G) sheet treated rat at day 21 after MI.
(F) Section was stained with antibody against Ki-67 (green). Cell sheet was pre-labelled with DiI (red). Nuclei stained with blue fluorescence of DAPI.
(G) Section was double stained with human nuclei (blue) and caspase 3 (brown, arrows) antibodies and counterstained with eosin.
Asterisks (**) indicate cell sheet area. Scale bars 200 mm (B–D, top row), 100 mm (B–D, bottom row, and E) or 50 mm (F, G).
Identification of inflammatory response
Twenty-one days after transplantation of human cell sheet, inflammatory response of rat host was examined. Transplantation of human sheet on infarcted rats reduced the number of mononuclear phagocytes (ED1-like positive cells) compared with untreated MI control (Supplementary material online, Figure S4a–e and l). In addition, the number of neutrophils was similar in both control untreated MI and sheet-treated sections (Supplementary material online, Figure S4f–k and m). These data suggest that at 21 days post transplantation, human cell sheet was not associated with significant infiltration of host immune cells.

Cell sheet engraftment and migration

Development of new vasculature was determined in cardiac tissue sections by co-localization of DiI labelling and vWf staining (Figure 3C). Three weeks after transplantation, the capillary density of ischaemic myocardium in the sheet-treated group significantly increased compared with MI animals (194 ± 20 vs. 97 ± 24 per mm2, P < 0.05, Figure 3A and B). The capillaries originated from the sheet ranged in diameter from 10 to 40 jim (n 1/4 30). A gradient in capillary density was observed with higher density in the sheet area which was decreased towards underlying infarcted myocardium. Mature blood vessels were identified within the sheet area and in the underlying myocardium in close proximity to the sheet evident by vWf and SMA double staining (Figure 3D).
sheet transplant on MI_Image_4
Figure 3 Neovascularization of infarcted wall. (A) Frozen tissue sections stained with vWf antibody (green). LV section of control (sham), infarcted (MI), and MI treated with cell sheet (sheet) rats. Scale bar, 100 jim. (B) Capillary density decreased in the MI compared with sham (*P < 0.05) and improved after cell sheet treatment (#P < 0.05). (C) Neovascularization within cell sheet area was recognized by co-localization of DiI- (red) and vWf (green) staining. Scale bar 100 jim. (D) Mature blood vessels (arrows) were identified by co-localization of SMA (red) and vWf (green) staining. Scale bar 50 jim.
Furthermore, 3 weeks after transplantation, a large number of labelled human nuclei positive or DiI-labelled cells were detected deep within the infarcted area indicating cell migration from the epicardial surface to the infarct (Figure 4A, B, and D). Minor or no migration was detected when the cell sheet was transplanted onto non-infarcted myocardium, sham control (Figure 4C). To evaluate engraftment of sheet-originated cells, sections were labelled with anti-human nuclear lamin antibody. Quantification of engraftment was performed using two approaches: fluorescence intensity and cell counting. Fluorescence intensity of the signal was analysed and compared for different areas of myocardium (Figure 4E–J). Since the transplanted sheets are created by human cells and are stained with human nuclear lamin-labelled with green fluorescence, the signal intensity of the sheet is set to 100% (100% of cells are lamin-positive). Myocardial area with no or limited number of labelled cells had the lowest level of fluorescence signal (13%, or 3.2 ± 1.4% of total number of cells), while
  1. the area where the cell migrated from the sheet to the infarcted myocardium had higher signal intensity (47%, or 11.9 ± 1.7% of total number of cells), indicating a higher number of sheet-originated cells are engrafted in the infarcted area.) (Figure 4K and L).
  2. Migrated cells were positive for KDR (Supplementary material online, Figure S5).
sheet transplant on MI_Image_5
Figure 4 Engraftment quantification of cells migrated from the sheet into the infarcted area of MI. Animals were treated with rat (A) or human (B–F) sheets. Cardiomyocytes were labelled with MHC antibody (A, green or B, red). Rat sheet-originated cells were identified with DiI-labelling, red (A). Arrows indicate the track of migrating cells. Human sheet-originated cells were identified by immunostaining with human nuclei antibody followed by secondary antibodies conjugated with either Alexa 488 (B, E and F, green) or AP (C, D, blue). No migration was detected when the cell sheet was transplanted onto non-infarcted myocardium (C). Heart sections were counterstained with eosin, pink (C–D). Higher magnification of area selected in the box is presented (D, right). Immunofluorescence of sheet (green) grafted to the myocardium surface (E) or cells migrated to the infarction area (F). Fluorescence profiles acrossthe cell sheet itself(G, box 1), area underlying cell sheet (I, box 2) and infarction areawith migrated cells (F, box 3). Mean fluorescence intensityofthe grafted human (K) cells was determined by outlining the region of interest (ROI) and subtracting the background fluorescence for the same region. Fluorescence intensity was normalized to the area of ROI (ii 1/4 6). (L) Percent engraftment was defined as number of lamin-positive cells divided by total number of cells per ROI. ‘M’, myocardium,’S’ sheet, ‘I’ infarction. Scale bars 100 mm (A–C, D, left, E and F), or 50 mm (D, right).
To elucidate a possible mechanism of cell migration, sections were stained to detect SDF1 and its unique receptor CXCR4. The migration patterns of cells from the sheet coincided with SDF-1 expression. Within 3 days after MI, SDF-1 was expressed in the injured myocardium (Figure 5A). At 3 weeks after MI and sheet transplantation, SDF-1 was co-localized with the migrated labelled cells (Figure 5B). PCR analysis revealed CXCR4 expression in cell sheet before transplantation (Figure 1F). However, after transplantation only a fraction of migrated cells expressed CXCR4 (Figure 5C).
sheet transplant on MI_Image_6
Figure 5 Migration of sheet-originated cells into the infarcted area. Confocal images of MI animals treated with sheets from rats (A and B) or human (C). SDF1 (green) was detected at border zone of the infarct at day 3 (A) and day 21 (B). Rat sheet-originated cells were identified with DiI-labelling (red). Note co-localization of DiI-positive sheet-originated cells with SDF1 at 21 days after MI (B). Human cells were identified by immunostaining with human nuclei antibody, red, (C). Note human cells that migrated to the area of infarct express CXCR4 (green) (C). Scale bar, 200 mm (A, B) or 50 mm (C). ‘M’, myocardium, ‘S’ sheet, ‘I’ infarct.

3.7 Cardiac regeneration

The differentiation of migrating cells into cardiomyocytes was evident by the co-localization of MHC staining with either human nuclei (Figure 6A) or DiI (Figure 6B and C). In contrast to the immature cardiomyocyte-like cells within the pre-transplanted cell sheet, the migrated and newly differentiated cells within the myocardium were about 30–50 mm in size and co-expressed C43 (see Supplementary material online, Figure S6). Cardiomyogenesis within the infarcted myocardium was observed in the sheets created from either rat or human cells.
sheet transplant on MI_Image_6
Figure 6 Cardiac regeneration. Sections of MI animals treated with human (A) or rat (B, C) sheets. Human sheet was identified by immunostaining with human nuclei antibody (green). Section was double-stained with MHC (red) antibody. Newly formed cardiomyocytes was identified by co-localization of human nuclei and MHC (yellow, arrow). (B) Rat sheet-originated cells were identified by DiI labelling (red). Section was double-stained with MHC (green) antibody. Newly formed cardiomyocytes were detected by co-localization of DiI with MHC (yellow, arrows). (C) Higher magnification of area selected in the boxes (B). Scale bars 200 mm (B), or 20 mm (A, C). ‘M’, myocardium, ‘S’ sheet, ‘I’ infarct.

Cell sheet improved cardiac contractile function and retarded LV remodelling after MI

Closed-chest in vivo cardiac function was derived from left ventricle (LV) pressure–volume loops (PV loops), which were measured using a solid-state Millar conductance catheter system. MI resulted in a characteristic decline in LV systolic parameters and an increase in diastolic parameters (Table 1). Cell sheet treatment improved both systolic and diastolic parameters (Table 1). Specifically, load-dependent parameters of systolic function: ejection fraction (EF), dP/dTmax, and cardiac index (CI) were decreased in MI rats and increased towards sham control with the cell sheet treatment (Table 1). Diastolic function parameters, dP/dTmin, relaxation constant (Tau), EDV, and EDP were increased in the MI rats and returned towards sham control parameters after sheet treatment (Table 1). However, load-independent systolic function, Emax, was decreased after MI. Treatment with human sheet improved Emax, while treatment with rat sheet had no effect (Table 1). Treatment with either rat or human sheets retarded LV remodelling; as such that it increased the ratio of anteriolateral wall thickness/LV inner diameter (t/Di) and wall thickness/LV outer diameter (t/Do) (see Supplementary material online, Table S3). However, human sheets appear to further improve LV remodelling compared with rat sheets as indicated by increased ratio of wall thickness to ventricular diameter and decreased both EDV and EDP (Table 1 and see Supplementary material online, Table S3).
Table 1 Hemodynamic parameters
Table 1. hemodynamic parameters

Discussion

The majority of the cardiac progenitor cells delivered using our scaffold-free cell sheet survived after transplantation onto the infarcted heart. A significant percentage of transplanted cells migrated from the cell sheet to the site of infarction and differentiated into car-diomyocytes and vasculature leading to improving cardiac contractile function and retarding LV remodelling. Thus, delivery of cardiac progenitor cells together with cardiac mesenchymal cells in a form of scaffold-free cell sheet is an effective approach for cardiac regeneration after MI.
Consistent with previous studies,5,11 here we showed that cardio-spheres are composed of multipotent precursors, which have the capacity to differentiate to cardiomyocytes and other cardiac cell types. When we fractioned cardiospheres based on c-Kit expression, we identified two subsets: Kitþ /KDR2/low/Nkx2.5þ and Kit2/KDRþ/ Nkx2.52(Supplementary material online, Figure S3d), which are likely reflecting cardiac and vascular progenitors.20
In the present study, delivery of cardiac progenitor cells as a cell sheet facilitates cell survival after transplantation. Necrotic cores, commonly observed in tissue engineered patches,23,24 are absent in cardiosphere sheets prior to transplantation (Figure 1B and C). Poor cell survival is caused by multiple processes such as: ischemia from the lack of vasculature and anoikis due to cell detachment from sub-strate.25 A possible mechanism of cell survival within the sheet is the induction of neo-vessels soon after transplantation due to the presence of endothelial cells within the sheet before transplantation (Figure 10). The cell sheet continued to grow in vivo (Figure 2B and C), suppressed cardiac wall thinning, and prevented LV remodelling at 21 days after transplantation (see Supplementary material online, Table S3). This maybe due to the induction of neovascularization (Figure 3), which may prevents ischemia-induced cell death (Figure 2G). Another likely mechanism of cell survival is that the cells within the scaffold-free sheet maintained cell-to-cell adhesion16 as shown by ICAM expression (Figure 1F). The cells also exhibit C43-positive junctions (Figure 10, see Supplementary material online, Figure S6), which may facilitate electromechanical coupling between the transplanted cells and the native myocardium.
We observed cell migration from the sheet to the infarcted myocardium (Figure 4A and B, E and F), which may be facilitated by the strong expression of MMP2 in the cell sheet (Figure 1F). Although, the mechanism of cardiac progenitor cell migration remains unclear, previous observations showed that SDF-1 is upregulated after MI and plays a role in bone-marrow and cardiac stem cell migration.26,27 Our data suggest that SDF-1-CXCR4 axis plays, at least in part, a role in cardiac progenitor cell migration from cell sheet to the infarcted myocardium. This conclusion is based on the following observations: (1) cell sheet expresses CXCR4 prior to transplantation (Figure 1F), (2) migrated cells are located in the vicinity of SDF-1 release (Figure 5A and B), and (3) about 20% of migrated cells expressed CXCR4. Note, not all the migrated cells expressed CXCR4 suggesting other mechanisms are involved in cell migration (Figure 5C).
Here we report that implanting cardiosphere-generated cell sheet onto infarcted myocardium not only improved vascularization but also promoted cardiogenesis within the infarcted area (Figure 6). A larger number of newly formed cardiomyocytes were found deep within the infarct compared with the cell sheet periphery. Notably the transplantation of the cell sheet resulted in a significant improvement of the cardiac contractile function after MI, as was shown by an increase of EF and decrease of LV end diastolic pressure (Table 1).
The beneficial effect of cell sheet is, in part, due to the presence of a large number of activated cardiac mesenchymal stromal cells (myofibroblasts) within the sheet. Myofibroblasts are known to provide a mechanical support for grafted cells, facilitating contraction28 and to induce neovascularization through the release of cytokines.17 In addition, mesenchymal cells are uniquely immunotolerant. In xenograft models unmatched mesenchymal cells transplanted to the heart of immunocompetent rats were shown to suppress host immune response29 presumably due to inhibition of T-cell activation.30 Consistently with previous study from our laboratory,31 here, we demonstrated host tolerance to the cell sheet 21 days after MI. Finally, phase II and III clinical trials are currently undergoing in which allogeneic MSCs are used to treat MI in patients (Osiris Therapeutic, Inc.).
In summary, our results show that cardiac progenitor cells can be delivered as a cell sheet, composed of a layer of cardiac stromal cells impregnated with cardiospheres. After transplantation, cells from the cell sheet migrated to the infarct, partially driven by SDF-1 gradient, and differentiated into cardiomyocytes and vasculature. Transplantation of cell sheet was associated with prevention of LV remodelling, reconstitution of cardiac mass, reversal of wall thinning, and significant improvement in cardiac contractile function after MI. Our data also suggest that strategies, which utilize undigested cells, intact cell–cell interactions, and combined cell types such as our scaffold-free cell sheet should be considered in designing effective cell therapy.

References

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Cardiovascular Genetics: Functional Characterization and Clinical Applications  @ 2013 Annual Conference of American Society of Human Genetics in Boston, 10/22-26, 2013

Reporter: Aviva Lev- Ari, PhD, RN

Sessions and Events 

The 63rd Annual Conference of American Society of Human Genetics in Boston, 10/22-26, 2013

http://www.ashg.org/cgi-bin/2013/ashg13SOE.pl 

PLATFORM ABSTRACTS

http://www.ashg.org/2013meeting/pdf/46025_Platform_bookmark%20for%20Web%20Final%20from%20AGS.pdf

We express a special interest in Session 58

Friday, October 25, 2013 Boston Convention Center 

2:00 PM–4:15 PM

Concurrent Platform (abstract-driven) Session E (54-62)

SESSION 58 – Cardiovascular Genetics: Functional Characterization and Clinical Applications

Room 205, Level 2, Convention Center

Moderators: Dan E. Arking, Johns Hopkins Univ. Sch. of Med.
Myriam Fornage, Univ. of Texas Hlth Sci. Ctr. at Houston

Human Syndromic Atrioventricular Septal Defect

367/2:00 A homozygous mutation in Smoothened, a member of the Sonic hedgehog (SHH)-GLI pathway is involved in human syndromic atrioventricular septal defect. W. S. Kerstjens-Frederikse, Y. Sribudiani, M. E. Baardman, L. M. A. Van Unen, R. Brouwer, M. van den Hout, C. Kockx, W. Van IJcken, A. J. Van Essen, P. A. Van Der Zwaag, G. J. Du Marchie Sarvaas, R. M. F. Berger, F. W. Verheijen, R. M. W. Hofstra.

A homozygous mutation in Smoothened, a member of the Sonic Hedgehog (SHH)-GLI pathway is involved in human syndromic atrioventricular septal defect.

W.S. Kerstjens-Frederikse1, Y. Sribudiani2, M.E. Baardman1, L.M.A. Van Unen2, R. Brouwer2, M. van den Hout2, C. Kockx2, W. Van IJcken2, A.J. Van Essen1, P.A. Van Der Zwaag1, G.J. Du Marchie

Sarvaas3, R.M.F. Berger3, F.W. Verheijen2, R.M.W. Hofstra2.

1) Dept Gen, Univ of Groningen, Univ Med Ctr Groningen, Netherlands;

2) Dept Gen, Erasmus Med Ctr, Rotterdam, Netherlands; 3) Dept Ped Cardiol, Univ of Groningen, Univ Med Ctr Groningen, Netherlands.

Introduction: Atrioventricular septal defect (AVSD) is a common congenital heart disease with a high impact on personal health. It is often accompanied by other congenital anomalies and in many of these syndromic AVSDs, defects in the sonic hedgehog (SHH)-GLI signalling pathway have been detected. SMO codes for the transmembrane protein smoothened (SMO), which is active in cells with a primary cilium and is located on the ciliary membrane. SMO is a key protein in the SHH-GLI signaling cascade.

Methods: Two probands, a twin boy and girl, presented with an AVSD, large fontanel, postaxial polydactyly and skin syndactyly of the second and third toes of both feet. The boy also had hypospadias. The parents were consanguineous and they had one healthy older child. Karyotyping was normal and Smith-Lemli-Opitz syndrome (SLOS) was excluded. Exome sequencing was performed and candidate variants were validated by Sanger sequencing.

Results: A novel homozygous missense mutation c.1725C>T (p.R575W) in SMO (7q32.3) was detected. Functional studies in fibroblasts of the patients showed normal expression of SMO protein but an abnormal localization of SMO, outside the cilia. Moreover we show severely reduced downstream GLI1 mRNA expression after stimulation with the SMO agonist purmorphamine. These results, together with the previously described association of SHH signalling defects with AVSD and SLOS, suggest that this SMO mutation is involved in syndromic AVSD in these patients.

Conclusion: We present the first reported smoothened mutation in humans, in two patients with an AVSD and a phenotype resembling Smith-Lemli-Opitz syndrome

Left Ventricular Noncompaction – Model in Zebrafish

368/2:15 Identification of PRDM16 as a disease gene for left ventricular non-compaction and the efficient generation of a personalized disease model in zebrafish. A.-K. Arndt, S. Schaefer, R. Siebert, S. A. Cook, H.-H. Kramer, S. Klaassen, C. A. MacRae.

 

Identification of PRDM16 as a disease gene for left ventricular noncompaction

and the efficient generation of a personalized disease

model in zebrafish. A.-K. Arndt1,2, S. Schaefer3, R. Siebert4, S.A. Cook5,

H.-H. Kramer2, S. Klaassen6, C.A. MacRae1. 

1) Cardiovascular Division, Brigham and Women’s Hospital, Boston, MA;

2) Department of Congenital Heart Disease and Pediatric Cardiology, University Hospital of Schleswig- Holstein, Kiel, Germany,;

3) Max-Delbruck-Center for Molecular Medicine, Berlin, Germany; 4) Institute of Human Genetics, University Hospital Schleswig Holstein, Kiel, Germany;

5) National Heart Centre, Singapore;

6) Department of Pediatric Cardiology, Charité, Berlin, Germany.

Using our own data and publically available array comparative genomic hybridization data, we identified the transcription factor PRDM16(PR domain containing 16) as a causal gene for the cardiomyopathy associated with monosomy 1p36, and confirmed its role in individuals with non-syndromic left ventricular noncompaction cardiomyopathy (LVNC) and dilated cardiomyopathy (DCM). In a cohort of 75 non-syndromic patients with LVNC we detected 3 sporadic mutations, including 1 truncation mutant, 1 frameshift null mutation, and a single missense mutant. In addition, in a series of cardiac biopsies from 131 individuals with DCM, we found 5 individuals with 4 previously unreported non-synonymous variants in the coding region of PRDM16. None of the PRDM16 mutations identified were observed in over 6500 controls.

PRDM16 has not previously been associated with cardiovascular disease. Modeling of PRDM16 haploinsufficiency and a human truncation mutant in zebrafish resulted in impaired cardiomyocyte proliferation with associated physiologic defects in cardiac contractility and cell-cell coupling.

Using a phenotype-driven screening approach in the fish, we have identified 5 compounds that are able to rescue the physiologic defects associated with mutant or haploinsufficient PRDM16. Notably, all of the compounds had the capacity to restore cardiomyocyte proliferation and to prevent apoptosis in the model. Wildtype zebrafish also demonstrated a significant increase in cardiomyocyte numbers after treatment with the compounds suggesting a pro-proliferative effect of the compounds. In addition, the compounds also rescued the contractile and electrical defects observed in these disease models. These findings underline the importance of personalized disease models for specific pathways, to accelerate the exploration of disease biology and the development of innovative therapeutic approaches.

Genetics of Cerebral Small Vessel Disease

369/2:30 Mutation and copy number variation of FOXC1 causes cerebral small vessel disease. C. R. French, S. Seshadri, A. L. Destefano, M. Fornage, D. J. Emery, M. Hofker, J. Fu, A. J. Waskiewicz, O. J. Lehmann.

Mutation and copy number variation of FOXC1 causes cerebral small vessel disease. C.R. French1, S. Seshadri2, A.L Destefano3, M. Fornage4, D.J. Emery5, M. Hofker6, J. Fu6, A.J. Waskiewicz7, O.J. Lehmann1, 8.

1) Ophthalmology, University of Alberta, Edmonton, AB, Canada;

2) Department of Neurology, Boston University, Boston, MA, U. S. A;

3) School of Public Health, Boston University, Boston, MA, U. S. A;

4) Institute of Molecular Medicine and School of Public Health, University of Texas Health Sciences

Center, Houston, TX, U.S.A;

5) Department of Radiology, University of Alberta, Edmonton, AB, Canada;

6) Department of Medical Genetics, University Medical Center Groningen, Groningen, The Netherlands;

7) Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada;

8) Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.

Cerebral small vessel disease (CSVD) represents a major risk factor for stroke and cognitive decline in the elderly. The ability to readily visualize its microangiopathic features by magnetic resonance imaging provides opportunities for using markers of CSVD to identify novel stroke associated pathways. Using targeted genome-wide association analysis we identified CSVD associated single nucleotide polymorphisms (SNPs) adjacent to the forkhead transcription factor FOXC1, and using eQTL analysis in two independent data sets, demonstrate that such SNP’s are associated with FOXC1 expression levels.

We further demonstrate, using magnetic resonance imaging, that patients with either FOXC1 mutation or copy number variation exhibit CSVD. These findings, present in patients as young as two years of age and observed with missense and nonsense mutations as well as FOXC1-encompassing segmental deletion and duplication, demonstrate FOXC1 dysfunction induces cerebral small vessel pathology. A causative role for FOXC1 in the development and maintenance of cerebral vasculature is supported by the cerebral hemorrhage generated by morpholino-induced suppression of FOXC1 orthologs in a zebrafish model system. Furthermore, in vivo imaging demonstrates profoundly impaired migration of neural crest cells and their subsequent association with nascent vasculature, a process required for the differentiation of perivascular mural cells. In addition, foxc1 inhibition reduces the expression of pdgfra, a gene critically required for vascular stability via its role in mural cell recruitment. Taken together, these data support a requirement for Foxc1 in stabilizing newly formed vasculature via recruitment of neural crest derived mural cells, and define a casual role for FOXC1 in cerebrovascular pathology.

Genetics & Brugada Syndrome

370/2:45 Genetic association of common variants with a rare cardiac disease, the Brugada syndrome, in a multi-centric study. C. Dina, J. Barc, Y. Mizusawa, C. A. Remme, J. B. Gourraud, F. Simonet, P. J. Schwartz, L. Crotti, P. Guicheney, A. Leenhardt, C. Antzelevitch, E. Schulze-Bahr, E. R. Behr, J. Tfelt-Hansen, S. Kaab, H. Watanabe, M. Horie, N. Makita, W. Shimizu, P. Froguel, B. Balkau, M. Gessler, D. Roden, V. M. Christoffels, H. Le Marec, A. A. Wilde, V. Probst, J. J. Schott, R. Redon, C. R. Bezzina.

Genetic association of common variants with a rare cardiac disease,

the Brugada Syndrome, in a multi-centric study. C. Dina1,2, J. Barc3, Y.

Mizusawa3, C.A. Remme3, J.B. Gourraud1,2, F. Simonet1, P.J. Schwartz4,

L. Crotti4, P. Guicheney5, A. Leenhardt6, C. Antzelevitch7, E. Schulze-Bahr8,

E.R. Behr9, J. Tfelt-Hansen10, S. Kaab11, H. Watanabe12, M. Horie13, N.

Makita14, W. Shimizu15, P. Froguel 16, B. Balkau17, M. Gessler18, D.

Roden19, V.M. Christoffels3, H. Le Marec1,2, A.A. Wilde3, V. Probst1,2, J.J.

Schott1,2, R. Redon1,2, C.R. Bezzina3.

1) Thorx Inst, INSERM UMR 1087, CNRS, Nantes, France;

2) CHU Nantes, l’institut du thorax, Nantes, France;

3) Heart Failure Research Center, Academic Medical Center, Amsterdam, Netherlands;

4) University of Pavia, Pavia, Italy;

5) InsermUMR956, UPMC, Paris, France;

6) Cardiology Unit, Hôpital Bichat, Assistance Publique- Hôpitaux de Paris, Nantes, France;

7) Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, NY, United States;

8) Department of Cardiovascular Medicine, University Hospital, Münster, Germany;

9) Cardiovascular Sciences Research Centre, St George’s University, London, United Kingdom;

10) Laboratory of Molecular Cardiology, University of Copenhagen, Copenhagen, Denmark;

11) 1Department of Medicine I, Ludwig-Maximilians University, Munich, Germany;

12) Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan;

13) Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan;

14) Department of Molecular Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan;

15) Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan;

16) CNRS UMR 8199, Pasteur Institute, Lille, France;

17) Inserm UMR 1018, Centre for research in Epidemiology and Population Health, Villejuif, France;

18) Theodor-Boveri-Institute, University of Wuerzburg, Wuerzburg, Germany;

19) Department of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, United States.

The Brugada Syndrome (BrS) is considered as a rare Mendelian disorder with autosomal dominant transmission. BrS is associated with an increased risk of sudden cardiac death and specific electrocardiographic features consisting of ST-segment elevation in the right precordial leads. Loss-of-function mutations in SCN5A, encoding the pore-forming subunit of the cardiac sodium channel (Nav1.5), are identified in ~20% of patients. However, studies in families harbouring mutations in SCN5A have demonstrated low disease penetrance and in some instances absence of the familial SCN5A mutation in some affected members. These observations suggest a more complex inheritance model. To identify common genetic factors modulating disease risk, we conducted a genome-wide association study on 312 individuals with BrS and 1115 ancestry-matched controls. Two genomic regions displayed significant association. Both associations were replicated on two independent case/control sets from Europe (598/855) and Japan (208/1016) and a third locus emerged, all three with extremely significant p-values (1.10-14 down to 1.10-68). To our knowledge, this is the first time that several common variants are associated with a rare disease, with very high effect (Osdds-ratio) ranging from 1.58 to 2.55. While two loci displaying association hits had already been shown to influence ECG parameters in the general population, the third one encompasses a transcription factor which had never been related to cardiac arrhythmia. We showed that this factor regulates Nav1.5 channel expression in hearts of homozygous knockout embryos and influence cardiac conduction velocity in adult heterozygous mice. At last, we found that the cumulative effect of the 3 loci on disease susceptibility was unexpectedly large, indicating that common genetic variation may have a strong impact on predisposition to rare disease.

Mutations, Vasculopathy with Fever and Early Onset Strokes

371/3:00 Loss-of-function mutations in CECR1, encoding adenosine deaminase 2, cause systemic vasculopathy with fever and early onset strokes. Q. Zhou, A. Zavialov, M. Boehm, J. Chae, M. Hershfield, R. Sood, S. Burgess, A. Zavialov, D. Chin, C. Toro, R. Lee, M. Quezado, A. Ombrello, D. Stone, I. Aksentijevich, D. Kastner.

Loss-of-Function Mutations in CECR1, Encoding Adenosine Deaminase

2,Cause Systemic Vasculopathy with Fever and Early Onset

Strokes. Q. Zhou1, A. Zavialov2, M. Boehm3, J. Chae1, M. Hershfield4, R.

Sood5, S. Burgess6, A. Zavialov2, D. Chin1, C. Toro7, R. Lee8, M. Quezado9,

A. Ombrello1, D. Stone1, I. Aksentijevich1, D. Kastner1.

1) Inflammatory Disease Section, NHGRI, Bethesda, USA;

2) Turku Centre for Biotechnology, University of Turku, Turku, Finland;

3) Laboratory of Cardiovascular Regenerative Medicine, NHLBI, Bethesda, USA;

4) Department of Medicine, Duke University Medical Center, Durham, USA;

5) Zebrafish Core, NHGRI, Bethesda, USA;

6) Developmental Genomics Section, NHGRI, Bethesda, USA;

7) NIH Undiagnosed Diseases Program, NIH, Bethesda, USA;

8) Translational Surgical Pathology Section, NCI, Bethesda, USA;

9) General Surgical Pathology Section, NCI, Bethesda, USA.

We recently observed 5 unrelated patients with fevers, systemic inflammation, livedo reticularis, vasculopathy, and early-onset recurrent ischemic strokes. We performed exome sequencing on affected patients and their unaffected parents. The 5 patients shared 3 missense mutations in CECR1, encoding adenosine deaminase 2 (ADA2), with the genotypes A109D/ Y453C, Y453C/G47A, G47A/H112Q, R169Q/Y453C, and R169Q/28kb genomic deletion encompassing the 5’UTR and first exon of CECR1.

All mutations are either novel or present at low frequency (<0.001) in several large databases, consistent with the recessive inheritance. The Y453C mutation was present in 2/13004 alleles in an NHLBI database. Both alleles are found in 2 affected siblings who suffered from late-onset ischemic stroke, indicating that heterozygous mutations in ADA2 might be associated with susceptibility to adult stroke. Computer modeling based on the crystal structure of the human ADA2 suggests that CECR1 mutations either disrupt protein stability or impair ADA2 enzyme activity. All patients had at least a 10-fold reduction in serum and plasma concentrations of ADA2, and reduced ADA2-specific adenosine deaminase activity. Western blots showed a decrease in protein expression in supernatants of cultured patients’ cells. ADA2 is homologous to ADA1, which is mutated in some patients with SCID.

In contrast to ADA1, ADA2 is expressed predominantly in myeloid cells and is a secreted protein, and its affinity for adenosine is much less than ADA1. Animal models suggest that ADA2 is the prototype for a family of growth factors (ADGFs).Although there is no mouse homolog of CECR1, there are 2 zebrafish homologs, Cecr1a and Cecr1b. Using morpholino technology to knock down the expression of the ADA2 homologs, we observed intracranial hemorrhages in approximately 50% of the zebrafish embryos harboring the knockdown construct, relative to 3% in controls. Immunohistochemical studies of endothelial cells from patients’ skin biopsies demonstrate a diffuse systemic vasculopathy characterized by impaired endothelial integrity, endothelial cellular activation, and a perivascular infiltrate of CD8 T-cells and CD163-positive macrophages. ADA2 is not expressed in the endothelial cells. Our data suggest that ADA2 may be necessary for vascular integrity in the developing zebrafish as an endothelial cell-extrinsic growth factor, and that the near absence of functional ADA2 in patients may lead to strokes by a similar mechanism.

Genetics of Atherosclerotic Plaque in Patients with Chronic Coronary Artery Disease

372/3:15 Genetic influence on LpPLA2 activity at baseline as evaluated in the exome chip-enriched GWAS study among ~13600 patients with chronic coronary artery disease in the STABILITY (STabilisation of Atherosclerotic plaque By Initiation of darapLadIb TherapY) trial. L. Warren, L. Li, D. Fraser, J. Aponte, A. Yeo, R. Davies, C. Macphee, L. Hegg, L. Tarka, C. Held, R. Stewart, L. Wallentin, H. White, M. Nelson, D. Waterworth.

Genetic influence on LpPLA2 activity at baseline as evaluated in the exome chip-enrichedGWASstudy among ~13600 patients with chronic coronary artery disease in the STABILITY (STabilisation of Atherosclerotic plaque By Initiation of darapLadIb TherapY) trial.

L. Warren1, L. Li1, D. Fraser1, J. Aponte1, A. Yeo2, R. Davies3, C. Macphee3, L. Hegg3,

L. Tarka3, C. Held4, R. Stewart5, L. Wallentin4, H. White5, M. Nelson1, D.

Waterworth3.

1) GlaxoSmithKline, Res Triangle Park, NC;

2) GlaxoSmithKline, Stevenage, UK;

3) GlaxoSmithKline, Upper Merion, Pennsylvania, USA;

4) Uppsala Clinical Research Center, Department of Medical Sciences, Uppsala University, Uppsala, Sweden;

5) 5Green Lane Cardiovascular Service, Auckland Cty Hospital, Auckland, New Zealand.

STABILITY is an ongoing phase III cardiovascular outcomes study that compares the effects of darapladib enteric coated (EC) tablets, 160 mg versus placebo, when added to the standard of care, on the incidence of major adverse cardiovascular events (MACE) in subjects with chronic coronary heart disease (CHD). Blood samples for determination of the LpPLA2 activity level in plasma and for extraction of DNA was obtained at randomization. To identify genetic variants that may predict response to darapladib, we genotyped ~900K common and low frequency coding variations using Illumina OmniExpress GWAS plus exome chip in advance of study completion. Among the 15828 Intent-to-Treat recruited subjects, 13674 (86%) provided informed consent for genetic analysis. Our pharmacogenetic (PGx) analysis group is comprised of subjects from 39 countries on five continents, including 10139 Whites of European heritage, 1682 Asians of East Asian or Japanese heritage, 414 Asians of Central/South Asian heritage, 268 Blacks, 1027 Hispanics and 144 others. Here we report association analysis of baseline levels of LpPLA2 to support future PGx analysis of drug response post trial completion. Among the 911375 variants genotyped, 213540 (23%) were rare (MAF < 0.5%).

Our analyses were focused on the drug target, LpPLA2 enzyme activity measured at baseline. GWAS analysis of LpPLA2 activity adjusting for age, gender and top 20 principle component scores identified 58 variants surpassing GWAS-significant threshold (5e-08).

Genome-wide stepwise regression analyses identified multiple independent associations from PLA2G7, CELSR2, APOB, KIF6, and APOE, reflecting the dependency of LpPLA2 on LDL-cholesterol levels. Most notably, several low frequency and rare coding variants in PLA2G7 were identified to be strongly associated with LpPLA2 activity. They are V279F (MAF=1.0%, P= 1.7e-108), a previously known association, and four novel associations due to I1317N (MAF=0.05%, P=4.9e-8), Q287X (MAF=0.05%, P=1.6e-7), T278M (MAF=0.02%, P=7.6e-5) and L389S (MAF=0.04%, P=4.3e-4).

All these variants had enzyme activity lowering effects and each appeared to be specific to certain ethnicity. Our comprehensive PGx analyses of baseline data has already provided great insight into common and rare coding genetic variants associated with drug target and related traits and this knowledge will be invaluable in facilitating future PGx investigation of darapladib response.

Genetics of influence IL-18 regulation in patients with Acute Coronary Syndrome

373/3:30 Genome-wide association study identifies common and rare genetic variants in caspase-1-related genes that influence IL-18 regulation in patients with acute coronary syndrome. A. Johansson, N. Eriksson, E. Hagström, C. Varenhorst, A. Åkerblom, M. Bertilsson, T. Axelsson, B. J. Barratt, R. C. Becker, A. Himmelmann, S. James, H. A. Katus, G. Steg, R. F. Storey, A. Syvänen, L. Wallentin, A. Siegbahn.

Genome-wide association study identifies common and rare genetic

variants in caspase-1-related genes that influence IL-18 regulation in

patients with Acute Coronary Syndrome. A. Johansson1, 2, N. Eriksson1,

E. Hagström1,3, C. Varenhorst1,3, A. Åkerblom1,3, M. Bertilsson1, T. Axelsson4,

B.J. Barratt5, R.C. Becker6, A. Himmelmann7, S. James1,3, H.A.

Katus8, G. Steg9, R.F. Storey10, A. Syvänen4, L. Wallentin1,3, A. Siegbahn1,11.

1) Uppsala Clinical Research Center, Uppsala University, Sweden;

2) Department of Immunoloy, Genetics and Pathology, Uppsala University, Sweden;

3) Department of Medical Sciences, Cardiology, Uppsala University, Sweden;

4) Department of Medical Sciences, Molecular Medicine, Science for Life Laboratory, Uppsala University, Sweden;

5) AstraZeneca R&D, Alderley Park, Cheshire, UK;

6) Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina, USA;

7) AstraZeneca Research and Development, Mölndal, Sweden;

8) Medizinishe Klinik, Universitätsklinikum Heidelberg, Heidelberg, Germany;

9) INSERM-Unité 698, Paris, France; Assistance Publique-Hôpitaux de Paris, Hôpital Bichat, Paris, France; Université Paris-Diderot, Sorbonne-Paris Cité, Paris, France;

10) Department of Cardiovascular Science, University of Sheffield, Sheffield, UK;

11) Department of Medical Sciences, Clinical Chemistry, Uppsala University, Sweden.

 

Interleukin 18 (IL-18) levels are increased in patients with acute coronary syndromes (ACS) and correlated with myocardial injury. We performed a genome-wide association study (GWAS) to identify genetic determinants of IL-18 levels in patients with ACS. In the PLATelet inhibition and patient Outcomes (PLATO) trial, enrolling a broad selection of ACS patients, baseline plasma IL-18 levels were measured in 16633 patients. Of these, 9340 were successfully genotyped using Illumina HumanOmni2.5 or HumanOmniExpressExome BeadChip and SNPs imputed using 1000 Genomes Phase I integrated variant set. Seven independent associations, in five chromosomal regions, were identified. The first region, with two independent (r2 = 0.11) association signals (rs34649619, p = 1.17*10−50 and rs360718, p = 2.03*10−12), is located within IL18. Both top SNPs are located in predicted promoter regions, and the insertion polymorphism rs34649619 (T/TA) disrupts a transcription factor binding site for FOXI1, FOXD3 and FOXA2. The second region, also represented by two independent (r2 = 0.003) association signals (rs385076, p = 6.99*10−72 and rs149451729, p = 3.79*10−16), is located in NLRC4. While rs385076 overlaps with a regulatory region, rs149451729 is a rare coding variant resulting in an amino acid substitution, predicted to be deleterious. The third region is located upstream of CARD16, CARD17, and CARD18 and one of the top SNPs (rs17103763, p = 6.19*10−9) has previously been associated with expression levels of CARD16. The two remaining chromosomal regions are located within GSFMF/MROH6 (rs2290414, p = 5.66*10−17) and RAD17 (rs17229943, p = 5.00*10−12).

While the latter genes have not been associated with IL-18 production previously, others are known to be involved in IL-18 release. NLRC4 is an inflammasome that activates the inflammatory cascade in the presence of bacterial molecules. It recruits and activates procaspase-1, which in its turn is responsible for the maturation of pro-IL-18. CARD16-18, also known as COP1, INCA and ICEBERG, encode caspase inhibitors, known to bind to and prevent procaspase-1 activation. Our results suggest that SNPs in IL18 and caspase-1-associated genes are important for IL-18 production. By combining the identified SNPs in a Mendelian randomization study, the causal effect of IL-18 on clinical endpoints could be further evaluated in a longitudinal study.

Thoracic Aortic Aneurysmal Genes

374/3:45 Prevalence and predictors of pneumothorax in patients with connective tissue disorders enrolled in the GenTAC (National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions) Registry. J. P. Habashi, G. L. Oswald, K. W. Holmes, E. M. Reynolds, S. LeMaire, W. Ravekes, N. B. McDonnell, C. Maslen, R. V. Shohet, R. E. Pyeritz, R. Devereux, D. M. Milewicz, H. C. Dietz, GenTAC Registry Consortium.

Prevalence and Predictors of Pneumothorax in Patients with Connective Tissue Disorders Enrolled in the GenTAC (National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions) Registry.

J.P. Habashi1, G.L. Oswald2, K.W. Holmes1,5, E.M.

Reynolds10, S. LeMaire3, W. Ravekes1, N.B. McDonnell4, C. Maslen5, R.V.

Shohet6, R.E. Pyeritz7, R. Devereux8, D.M. Milewicz9, H.C. Dietz2, GenTAC

Registry Consortium.

1) Dept Pediatric Cardiology, Johns Hopkins Univ, Baltimore, MD;

2) Dept. Medical Genetics, Johns Hopkins Univ, Baltimore, MD;

3) Baylor College of Medicine, Houston TX;

4) NIA at Harbor Hospital, Baltimore, MD;

5) Oregon Health & Science University, Portland, OR;

6) Queen’s Medical Center, Honolulu, HI;

7) The University of Pennsylvania, Philadelphia, PA; 8) Weill Cornell Medical College of Cornell University, New York NY;

9) University of Texas Medical School at Houston, Houston, TX;

10) University of Maryland, Baltimore, MD.

Spontaneous pneumothorax—described as escape of air into the pleural space surrounding the lung in the absence of traumatic injury—is a rare occurrence in the general population (0.1-0.5%), however is well recognized in Marfan syndrome (MFS)(4-5%). Associations between pneumothorax and other connective tissue disorders (CTDs) are less well recognized. We sought to examine potential associations of

  • pneumothorax with MFS,
  • vascular Ehlers-Danlos syndrome (vEDS) and other CTDs.

 

Phenotypic data were analyzed on all GenTAC patients with confirmed diagnoses of

  • MFS,
  • vEDS,
  • Loeys-Dietz syndrome (LDS),
  • bicuspid aortic valve with aortic enlargement (BAVe) or
  • familial thoracic aortic aneurysm and dissection (FTAAD)

to assess the prevalence of pneumothorax and associated features (1918 total pts).

Of 695 patients with Ghent criteria-confirmed MFS, 73 had experienced a spontaneous pneumothorax (prevalence 10.5%), higher than reported in the literature. The frequency of pneumothorax in vEDS patients (16/107, 15%) was similar to the frequency in the MFS group. The prevalences of pneumothorax in LDS (4/73, 5.5%), FTAAD (13/237, 5.5%), and BAVe (19/ 806, 2.4%) were significantly less than that for MFS and vEDS (p<0.001), yet greater than reported for the general population. In MFS patients with a pneumothorax, there was a three-fold increase in reported skeletal features of pectus carinatum, pectus excavatum, scoliosis and/or kyphosis compared to those without pneumothorax. Similarly, in vEDS, there was a four-fold increase in pectus carinatum, scoliosis and kyphosis in those patients with a pneumothorax compared to those without pneumothorax. In a subset of patients with self-reported data (n=846), smoking was not associated with increased prevalence of pneumothorax. Gender was not a predictor of pneumothorax in any of the diagnostic categories analyzed despite literature reports of increased prevalence in males. In patients enrolled in the GenTAC registry with a diagnosis of MFS, vEDS, BAVe, FTAAD or LDS, the prevalence of pneumothorax was significantly increased in all CTDs analyzed as compared to the general population. The prevalence of pneumothorax was significantly higher in patients with MFS or vEDS than in the other CTDs.

These data suggest that skeletal features may be a predictor for pneumothorax. Patients presenting with a spontaneous pneumothorax should be evaluated for several potential CTDs; such an evaluation could unmask an undiagnosed aortic aneurysm.

 

375/4:00 Surprising clinical lessons from targeted next-generation sequencing of thoracic aortic aneurysmal genes. B. Loeys, D. Proost, G. Vandeweyer, S. Salemink, M. Kempers, G. Oswald, H. Dietz, G. Mortier, L. Van Laer.

Surprising clinical lessons from targeted next generation sequencing of thoracic aortic aneurysmal genes. B. Loeys1,2, D. Proost1, G. Vandeweyer1, S. Salemink2, M. Kempers2, G. Oswald3, H. Dietz3, G. Mortier1, L. Van Laer1.

1) Center for Medical Genetics, University of Antwerp/ Antwerp University Hospital, Antwerp, Belgium;

2) Department of Genetics, Radboud University Medical Center, Nijmegen, The Netherlands;

3) Mc Kusick Nathans Institute for Genetic Medicine, Johns Hopkins University Hospital, Baltimore, USA.

Thoracic aortic aneurysm/dissection (TAA), an important cause of death in the industrialized world, is genetically heterogeneous and at least 14 causative genes have been identified, accounting for both syndromic and non-syndromic forms. The diagnosis is not always straightforward because a considerable clinical overlap exists between patients with mutations in different genes, and mutations in the same gene cause a wide phenotypic variability. Molecular confirmation of the diagnosis is becoming increasingly important for gene-tailored patient management but consecutive, conventional molecular TAA gene screening is expensive and labor-intensive. To shorten the turn-around-time, to increase mutation-uptake and to reduce the overall cost of molecular testing, we developed a TAA gene panel for next generation sequencing (NGS) of 14 TAA genes (ACTA2, COL3A1, EFEMP2, FBN1, FLNA, MYH11, MYLK, NOTCH1, SKI, SLC2A10, SMAD3, TGFB2, TGFBR1 and TGFBR2). We obtained enrichment with Haloplex technology and performed 2×150 bp paired-end runs on a Miseq sequencer in a series of 57 consecutive TAA patients, both syndromic and non-syndromic.

The sensitivity and false positive rate were previously shown to be 100% and 3%, respectively. Applying our NGS approach, we identified a causal mutation in 16 patients (28%). This uptake is really high as on average one molecular study per patient (range 0-6) was performed prior to inclusion in this study. One mutation was found in each of the 6 following genes: ACTA2, COL3A1, TGFBR1, MYLK, SMAD3, SLC2A10 (homozygous); two mutations inNOTCH1and eight in FBN1. An additional 6 variants of unknown significance were identified: 2 in FLNA, 2 in NOTCH1, 1 in FBN1 and 1 heterozygous in EFEMP2. All variants were confirmed by Sanger sequencing.

Remarkably, from the eight FBN1 positive patients, three patients had previously been tested FBN1 negative by certified labs, indicating that the sensitivity of Sanger sequencing is not 100%. Interestingly, in two FBN1 mutation positive patients

  • the clinical diagnosis of Marfan syndrome was unsuspected. Similarly,
  • the clinical diagnosis of vascular Ehlers-Danlos syndrome (COL3A1) had not been made. Finally,
  • the ACTA2 mutation was identified postmortem from paraffin-embedded extracted DNA.

We conclude that our NGS approach for TAA genetic testing overcomes the intrinsic hurdles of Sanger sequencing and becomes a powerful tool in the elaboration of clinical phenotypes assigned to different genes.

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Comment by Cardiologists posted on LinkedIn’s

European Cardiovascular Medical Devices Group, a subgroup of Cardiovascular Medical Devices Group

on Stenting for Proximal LAD Lesions: In Reference to the Invasive Procedure performed on former President George W. Bush

UPDATED on 8/7/2018

Long-Term Outcomes of Stenting the Proximal LAD

Study Questions:

What are the outcomes of patients undergoing drug-eluting stent (DES) implantation according to lesion location within or outside the proximal left anterior descending (LAD) artery?

Methods:

Among the 8,709 patients enrolled in PROTECT (Patient Related Outcomes With Endeavor Versus Cypher Stenting Trial), a multicenter percutaneous coronary intervention (PCI) trial, the investigators compared the outcomes of 2,534 patients (29.1%; 3,871 lesions [31.5%]) with stents implanted in the proximal LAD with 6,172 patients (70.9%; 8,419 lesions [68.5%]) with stents implanted outside the proximal LAD. For each event, a multivariate model was constructed that examined the effect of several individual baseline clinical and angiographic characteristics, including proximal LAD target lesion, on outcomes (i.e., MACE [major adverse cardiac events], target vessel failure [TVF], and myocardial infarction [MI]).

Results:

At 4-year follow-up, death rates were the same (5.8% vs. 5.8%; p > 0.999), but more MIs occurred in the proximal LAD group (6.2% vs. 4.9%; p = 0.015). The rates of clinically driven TVF (14.8% vs. 13.5%; p = 0.109), MACE (15.0% vs. 13.7%; hazard ratio, 1.1; 95% CI, 0.97-1.31; p = 0.139), and stent thrombosis (2.1% vs. 2.0%; p = 0.800) were similar. DES type had no interaction with MACE or TVF. In multivariate analysis, the proximal LAD was a predictor for MI (p = 0.038), but not for TVF (p = 0.149) or MACE (p = 0.069).

Conclusions:

The authors concluded that proximal LAD location was associated with higher rates of MI during the long-term follow-up, but there were no differences in stent thrombosis, death, TVF, or overall MACE.

Perspective:

This post hoc analysis of a prospective, multicenter study reports no difference in the rates of death, MACE, or TVF at 4 years according to intervention at a proximal LAD or nonproximal LAD lesion. The occurrence of the predefined primary endpoint of stent thrombosis was also not dependent on whether a proximal LAD or nonproximal LAD site was treated. However, of note, stenting of proximal LAD lesions was associated with significantly higher rates of MI compared with stenting of nonproximal LAD lesions. Overall, these findings appear to suggest that proximal LAD lesions may not have additional risk in the contemporary DES era, but the higher risk of MI needs to be studied further. Future studies should compare longer-term clinical outcomes between proximal LAD PCI with DES and minimally invasive left internal mammary artery to LAD.

SOURCE

https://www.acc.org/latest-in-cardiology/journal-scans/2017/03/22/15/11/long-term-outcomes-of-stenting-the-proximal-lad

 

Stenting for Proximal LAD Lesions

Curator: Aviva Lev-Ari, PhD, RN

Michael Reinhardt • First, the media really should not be calling this “stent surgery” its a stent procedure just ask any post-CABG patient… Anyway it really is not possible to determine whether or not is was “unnecessary” without all the relevant patient data; which coronary vessel(s) involved, percent stenosis, etc. Actually I find it interesting that they apparently decided to stent the former president on the basis of a CT Angiogram which is not the standard of care for coronary imaging. I have to assume they performed an additional testing like a CT perfusion analysis and saw a clinically relevant defect and this support the decision to stent. Regarding the post-stent drugs cloplidigrel is not a benign drug but benefits far outweigh the downside of a sub-acute thrombosis which might result in a more serious future event = acute MI.

Rafael Beyar • This was absolutely an indicated procedure and almost all rational physician will treat a young patient with proximal LAD lesions with either a stent or bypass surgery

Dov V Shimon MD • No doubt! Proximal (‘close to origin’) LAD lesions are the leading “Widow makers”. Reestablishing of flow in the artery is saving from cardiac damage and death. Drug eluting stent have 2nd and 3rd generations with very low and acceptable reclosure rates and almost no abrupt closure (thrombosis). True, CTA is a screening test, but it astablishes the need for diagnostic and therapeutic angiogram. We, heart surgeons can provide long-term patency to the LAD using LIMA arterial bypass. The current advantage of stent is the incovenience and pain of surgery. Any responsible physician would opt the procedure even for himself, his relatives , his patients and for definitely for GW Bush.

http://www.linkedin.com/groupItem?view=&gid=3358310&type=member&item=265974376&commentID=157366758&goback=%2Egmr_3358310&report%2Esuccess=8ULbKyXO6NDvmoK7o030UNOYGZKrvdhBhypZ_w8EpQrrQI-BBjkmxwkEOwBjLE28YyDIxcyEO7_TA_giuRN#commentID_157366758

Coronary anatomy and anomalies

On the left an overview of the coronary arteries in the anterior projection.

Coronary anatomy and anomalies

RCA, LAD and Cx in the anterior projection

On the left an overview of the coronary arteries in the lateral projection.

  • Left Main or left coronary artery (LCA)
    • Left anterior descending (LAD)
      • diagonal branches (D1, D2)
      • septal branches
    • Circumflex (Cx)
      • Marginal branches (M1,M2)
  • Right coronary artery
    • Acute marginal branch (AM)
    • AV node branch
    • Posterior descending artery (PDA)

Eur J Cardiothorac Surg. 2004 Apr;25(4):567-71.

Isolated high-grade lesion of the proximal LAD: a stent or off-pump LIMA?

Source

Thoraxcentre, Groningen University Hospital, Groningen, The Netherlands.

Abstract

OBJECTIVES:

The objective of this study was to compare the long-term outcome of patients with an isolated high-grade stenosis of the left anterior descending (LAD) coronary artery randomized to percutaneous transluminal coronary angioplasty with stenting (PCI, stenting) or to off-pump coronary artery bypass grafting (surgery).

METHODS:

Patients with an isolated high-grade stenosis (American College of Cardiology/American Heart Association classification type B2/C) of the proximal LAD were randomly assigned to stenting (n=51) or to surgery (n=51) and were followed for 3-5 years (mean 4 years). Primary composite endpoint was freedom from major adverse cardiac and cerebrovascular events (MACCEs), including cardiac death, myocardial infarction, stroke and repeat target vessel revascularization. Secondary endpoints were angina pectoris status and need for anti-anginal medication at follow-up. Analysis was by intention to treat.

RESULTS:

MACCEs occurred in 27.5% after stenting and 9.8% after surgery (P=0.02; absolute risk reduction 17.7%). Freedom from angina pectoris was 67% after stenting and 85% after surgery (P=0.036). Need for anti-anginal medication was significantly lower after surgery compared to stenting (P=0.002).

CONCLUSION:

Patients with an isolated high-grade lesion of the proximal LAD have a significantly better 4-year clinical outcome after off-pump coronary bypass grafting than after PCI.

Daily Dose

08/12/2013 | 5:48 PM

Was George Bush’s stent surgery really unnecessary?

By Deborah Kotz / Globe Staff

VIEW VIDEO

Ever since President George W. Bush had stent surgery last Tuesday to open a blocked artery, leading physicians who weren’t involved in his care have wondered publically why he had this “unnecessary” procedure. Large clinical trials have demonstrated that stent placement doesn’t extend lives or prevent a future heart attack or stroke in those with stable heart disease.

What’s more, Bush could wind up with complications like a reblockage where the stent was placed or excessive bruising or internal bleeding from the blood thinners that he must take likely for the next year.

Dr Richard Besser, the chief medical correspondent for ABC News, questioned why Bush had an exercise stress test as part of his routine physical exam given that he had no symptoms like chest pain or shortness of breath. The stress test indicated signs of an artery blockage.

“In people who are not having symptoms, the American Heart Association says you should not do a stress test,” Besser said, “since the value of opening that artery is to relieve the symptoms.”

Cleveland Clinic cardiologist Dr. Steve Nissen agreed in his interview with USA Today. Bush, he said, likely “got the classical thing that happens to VIP patients, when they get so-called executive physicals and they get a lot of tests that aren’t indicated. This is American medicine at its worst.”

Two physicians wrote in an Washington Post op-ed column titled “President Bush’s unnecessary surgery” that they worry that the media coverage of Bush’s stent will lead “patients to pressure their own doctors for unwarranted and excessive care.”

But none of these doctors actually treated Bush or examined his medical records, so I’m a little surprised they’re making such firm calls.

Bush, an avid biker who recently completed a 100-kilometer ride, probably shouldn’t have had the exercise stress test if he wasn’t having any heart symptoms. “Routine stress testing used to be done 20 years ago, but isn’t recommended any longer since it doesn’t have any benefit,” said Brigham and Women’s cardiologist Dr. Christopher Cannon.

But Bush’s spokesman insisted the stent was necessary after followup heart imaging via a CT angiogram “confirmed a blockage that required opening.”

Cannon said Bush’s doctors may have seen signs that blood flow wasn’t getting to a significant part of the heart muscle, a condition known as ischemia. Researchers have found that those with moderate to severe ischemia appear to experience a reduction in fatal heart attacks when they have a stent placement along with medical therapy, rather than just taking medications alone. (Larger studies, though, are needed to confirm this finding.)

“If a blockage occurs at the very start of the artery and it’s extensive—95 percent blocked—then chances are it will cause significant ischemia,” Cannon said. While severe ischemia usually causes light-headedness or dizziness during exercise, Bush may have had more moderate ischemia that didn’t cause such symptoms.

It’s impossible to know for certain, he added, without seeing his medical records firsthand.

http://www.boston.com/lifestyle/health/blogs/daily-dose/2013/08/12/was-george-bush-stent-surgery-really-unnecessary/DzklhNCGVlgriNxgpKZtuO/blog.html

President Bush’s unnecessary heart surgery

  • By Vinay Prasad and Adam Cifu, Published: August 9

Vinay Prasad is chief fellow of medical oncology at the National Cancer Institute and the National Institutes of Health. Adam Cifu is a professor of medicine at the University of Chicago.

Former president George W. Bush, widely regarded as a model of physical fitness, received a coronary artery stent on Tuesday. Few facts are known about the case, but what is known suggests the procedure was unnecessary.

Before he underwent his annual physical, Mr. Bush reportedly had no symptoms. Quite the opposite: His exercise tolerance was astonishing for his age, 67. He rode more than 30 miles in the heat on a bike ride for veterans injured in the wars in Iraq and Afghanistan.

If Mr. Bush had visited a general internist practicing sound, evidence-based care, he would not have had cardiac testing. Instead, the doctor would have had conducted age-appropriate cancer screening. For the former president, this would include only colon cancer screening. It no longer would include even prostate-specific antigen testing for cancer. The doctor would have screened for cholesterol, checked for hypertension and made sure the patient was up to date on age-appropriate vaccinations, including those for pneumococcal pneumonia and shingles. Presumably Mr. Bush got these things, and he got the cardiac test as well.What value does a stress test add for an otherwise healthy 67-year-old?No study has shown that this examination improves outcomes. The trials that have been done for so-called routine stress testing examined higher-risk patients. They found that performing stress tests on people at high risk of cardiovascular disease may detect blockages but does not improve symptoms or survival. Routine stress testing does, however, increase the use of procedures such as coronary stenting.Unfortunately, Mr. Bush, like many VIPs, may be paying the price of these in-depth investigations. His stress test revealed an abnormality, prompting another test: a CT angiogram. This study showed a blockage, which was stented open during an invasive procedure. It is worth noting that at least two large randomized trials show that stenting these sorts of lesions does not improve survival. Because Mr. Bush had no symptoms, it is impossible that he felt better after these procedures.

Instead, George W. Bush will have to take two blood thinners, aspirin and Plavix, for at least a month and probably a year. (The amount of time a blood thinner is needed depends on the type of stent placed). While he takes these medications, he will have a higher risk of bleeding complications with no real benefit.

Although this may seem like an issue important only to the former president, consider the following: Although the price of excessive screening of so-called VIPs is usually paid for privately, follow-up tests, only “necessary” because of the initial unnecessary screening test, are usually paid for by Medicare, further stressing our health-care system. The media coverage of interventions like Mr. Bush’s also leads patients to pressure their own doctors for unwarranted and excessive care.

http://www.washingtonpost.com/opinions/president-bushs-unnecessary-heart-surgery/2013/08/09/c91c439c-0041-11e3-9a3e-916de805f65d_story.html

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AHA, ACC Change in Requirement for Surgical Support for PCI Performance: Class IIb -> Class III, Level of Evidence A: Support Nonemergent PCI without Surgical Backup (Change of class IIb, Level of evidence B).


AHA, ACC Change in Requirement for Surgical Support:  Class IIb -> Class III, Level of Evidence A: Supports Nonemergent PCI without Surgical Backup (Change of class IIb, Level of Evidence B).

Larry H Bernstein, MD, FCAP, Author, Curator, Volumes 1,2,3,4,5,6 Co-Editor and Author, Volume Two & Five, Co-Editor and Justin Pearlman, MD, PhD, FACC, Content Consultant to Six-Volume e-SERIES A: Cardiovascular Diseases

 

Voice of content consultant: Justin Pearlman, MD, PhD, FACC

The American Heart Association (AHA) and the American College of Cardiology (ACC) have convened teams of experts to summarize evidence and opinion regarding a wide range of decisions relevant to cardiovascular disease. The system accounts for some of the short comings of “evidence based medicine” by allowing for expert opinion in areas where evidence is not sufficient. The main argument for evidence-based medicine is the existence of surprises, where a plausible decision does not actually appear to work as desired when it is tested. A major problem with adhesion to evidence based medicine is that it can impede adaptation to individual needs (we are all genetically and socially/environmentally unique) and impede innovation. Large studies carry statistical weight but do not necessary consider all relevant factors. Commonly, the AFFIRM trial is interpreted as support that rate control suffices for most atrial fibrillation (AFIB), but half of those randomized to rhythm control were taken off anticoagulation without teaching patients to check their pulse daily for recurrence of AFIB. Thus the endorsed “evidence” may have more to do with the benefits of anticoagulation for both persisting and recurring AFIB and rhythm control may yet prove better than rate control. However, with wide acceptance of a particular conclusion, randomizing to another treatment may be deemed unethical, or may simply not get a large trial due to lack of economic incentive, leaving only the large trial products as the endorsed options. A medication without patent protection, such as bismuth salts for H Pylori infection, lacks financial backing for large trials.

The American Heart Association Evidence-Based Scoring System
Classification of Recommendations

● Class I: Conditions for which there is evidence, general

agreement, or both that a given procedure or treatment is

useful and effective.

● Class II: Conditions for which there is conflicting evidence,

a divergence of opinion, or both about the usefulness/

efficacy of a procedure or treatment.

● Class IIa: Weight of evidence/opinion is in favor of

usefulness/efficacy.

● Class IIb: Usefulness/efficacy is less well established by

evidence/opinion.

● Class III: Conditions for which there is evidence, general

agreement, or both that the procedure/treatment is not useful/

effective and in some cases may be harmful.

Level of Evidence

● Level of Evidence A: Data derived from multiple randomized

clinical trials

● Level of Evidence B: Data derived from a single randomized

trial or nonrandomized studies

● Level of Evidence C: Consensus opinion of experts

Circulation 2006 114: 1761 – 1791.

Assessment of Coronary Artery Disease by Cardiac Computed Tomography

A Scientific Statement From the American Heart Association Committee on Cardiovascular Imaging and Intervention, Council on Cardiovascular Radiology and Intervention, and Committee on Cardiac Imaging, Council on Clinical Cardiology

Reported by Chris Kaiser, Cardiology Editor, MedPage  7/2013  

 

Action Points

  1. Patients with indications for nonemergency PCI who presented at hospitals without on-site cardiac surgery, were randomly assigned to undergo PCI at a hospital without on-site cardiac surgery or at a hospital with on-site cardiac surgery.
  2. The rates of death, myocardial infarction, repeat revascularization, and stroke did not differ significantly between the groups.
  3. Community hospitals without surgical services can safely perform percutaneous coronary intervention (PCI) in low-risk patients — and not refuse higher-risk patients either, the MASS COMM trial found.

Summary

  • The co-primary endpoint of major adverse cardiac events (MACE) at 30 days occurred at a rate of 9.5% in the 10 hospitals without surgical backup versus 9.4% in the seven hospitals with onsite surgery (P<0.001 for noninferiority), Alice K. Jacobs, MD, of Boston University School of Medicine, and colleagues found.
  • The other co-primary endpoint of MACE at 12 months was also significant, occurring in 17.3% of patients in hospitals without backup versus 17.8% in centers with surgical services (P<0.001 for non-inferiority), they reported in the study published online by the New England Journal of Medicine. The findings were also reported at the American College of Cardiology meeting.

Study Characteristics and Results

Primary Endpoints

  1. death
  2. myocardial infarction
  3. repeat revascularization
  4. stroke
no significant differences between the two groups at 30 days and at 12 months.

Rate of stent thrombosis at 30 days

similar in both groups (0.6% versus 0.8%) and at 12 months (1.1% versus 2.1%).
Jacobs and colleagues noted that the 2011 PCI guidelines lacked evidence to fully support nonemergent PCI without surgical backup (class IIb, level of evidence B).

CPORT – E trial

Even though those guidelines came out before the results of the CPORT-E trial were published, CPORT-E trial showed similar non-inferiority at 9 months between centers that perform PCI with or without surgical backup in a cohort of nearly 19,000 non-emergent patients. The CPORT-E results were published in the March 2012 issue of the New England Journal of Medicine, and in May three cardiology organizations published an update to cath lab standards allowing for PCI without surgical.

 MASS COMM study

To further the evidence, Jacobs and colleagues in 2006  had designed and carried out the Randomized Trial to Compare Percutaneous Coronary Intervention between Massachusetts Hospitals with Cardiac Surgery On-Site and Community Hospitals without Cardiac Surgery On-Site (MASS COMM) in collaboration with the Massachusetts Department of Public Health who collaborated to obtain “evidence on which to base regulatory policy decisions about performing non-emergent PCI in hospitals without on-site cardiac surgery.”

  • Hospitals without backup surgery were required to perform at least 300 diagnostic catheterizations per year, and operators were mandated to have performed a minimum of 75 PCI procedures per year.
  • The researchers randomized 3,691 patients to each arm in a 3:1 ratio (without/with backup). The median follow-up was about 1 year.
  • The median age of patients was 64, one-third were women, and 92% were white. Both groups had similar median ejection fractions at baseline (55%).
  • The mean number of vessels treated was 1.17 and most patients (84%) had one vessel treated. The mean number of lesions treated was 1.45 and most patients (67%) had one lesion treated.

The indications for PCI were:

1. ST-segment elevated MI (>72 hours before PCI of infarct-related or non–infarct-related artery — 19% and 17%
2. Unstable angina — 45% and 47%
3. Stable angina — 27% and 28%
4. Silent ischemia — 5% and 6%
5. Other — 2.5% and 2.8%
Regarding secondary endpoints, both groups had similar rates of emergency CABG and urgent or emergent PCI at 30 days. Results at 30 days and 12 months were similar for rates of ischemia-driven target-vessel revascularization and target-lesion revascularization. Other endpoints as well were similar at both time points, including
  • all-cause death
  • repeat revascularization
  • stroke
  • definite or probable stent thrombosis
  • major vascular complications
Researchers adjusted for a 1.3 greater chance of MACE occurring at a randomly selected hospital compared with another randomly selected hospital and found
  • the relative risks at 30 days and 12 months “were consistent with those of the primary results” (RR 1.02 and 0.98, respectively).

However, they cautioned that new sites perhaps should be monitored as they gain experience.

A prespecified angiographic review of 376 patients who were in the PCI-without-backup arm and 87 in the other arm showed no differences in
  1. rates of procedural success,
  2. proportion with complete revascularization, or
  3. the proportion of guideline-indicated appropriate lesions for PCI.
Such results show consistent practice patterns between the groups, they noted.
The study had several limitations including the
  • loss of data for 13% of patients, the
  • exclusion of some patients for certain clinical and anatomical features, and
  • not having the power to detect non-inferiority in the separate components of the primary endpoint, researchers wrote.

Cardio Notes: Score Predicts PCI Readmission

Published: Jul 15, 2013

By Chris Kaiser, Cardiology Editor, MedPage Today
  

A simple calculation of patient variables before PCI may help stem the tide of readmission within the first month. Also this week, two blood pressure drugs that benefit diabetics and imaging cardiac sympathetic innervation.

Pre-PCI Factors Predict Return Trip

A new 30-day readmission risk prediction model for patients undergoing percutaneous coronary intervention (PCI) showed it’s possible to predict risk using only variables known before PCI, according to a study published online in Circulation: Cardiovascular Quality and Outcomes.

After multivariable adjustment, the 10 pre-PCI variables that predicted 30-day readmission were older age (mean age 68 in this study), female sex, insurance type (Medicare, state, or unknown), GFR category (less than 30 and 30-60 mL/min per 1.73m2), current or history of heart failure, chronic lung disease, peripheral vascular disease, cardiogenic shock at presentation, admit source (acute and non-acute care facility or emergency department), and previous coronary artery bypass graft surgery.

Additional significant variables post-discharge that predicted 30-day readmission were beta-blocker prescribed at discharge, post-PCI vascular or bleeding complications, discharge location, African American race, diabetes status and modality of treatment, any drug-eluting stent during the index procedure, and extended length of stay.

A risk score calculator using the pre-PCI variables will be available online soon, according to Robert W. Yeh, MD, MSc, of Massachusetts General Hospital in Boston, and colleagues.

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Mechanical Circulatory Assist Devices as a Bridge to Heart Transplantation or as “Destination Therapy“: Options for Patients in Advanced Heart Failure

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

and

Curator: Aviva Lev-Ari, PhD, RN 

 

UPDATED on 10/22/2018

HeartMate 3 gets FDA approval for extended use

Revamped Abbott Labs device is seen as an option for cardiac patients who are unlikely to get transplants.

“When heart failure (HF) progresses to an advanced stage, difficult decisions must be made,” the AHA says on its website. “Do I want to receive aggressive treatment? Is quality of life more important than living as long as possible? How do I feel about resuscitation?”

LVADs can take over the pumping function of a failing heart, but they also present some of the most expensive implantable-device surgeries. An article in the peer-reviewed journal JACC: Heart Failure reported last year that the average total cost to implant an LVAD in Medicare beneficiaries was $175,000, more than double the cost of a heart transplant.

Amador said between 5,000 and 5,500 Americans will have LVAD implants this year. That compares with 2,200 adult heart transplants that happen annually in the U.S., according to the JACC article.

Starling RC.
Cleve Clin J Med. 2013 Jan; 80(1):33-40. http://dx.doi.org/10.3949/ccjm.80gr.12003

For patients with advanced heart failure, outcomes are good after heart transplantation, but not enough donor hearts are available. Fortunately, mechanical circulatory assist devices have become an excellent option and should be considered either as a bridge to transplantation or as “destination therapy.” Current mechanical circulatory assist devices improve quality of life in patients who are candidates.
For some patients, conventional treatments are inadequate to relieve the effects of heart failure. Under these circumstances, mechanical circulatory support is considered. There are now a variety of devices capable of pumping blood to restore circulation of vital organs, even temporarily replacing the function of the native heart.

The ABIOMED AB5000™ Circulatory Support System is a short-term mechanical system that can provide left, right, or biventricular support for patients whose hearts have failed but have the potential for recovery. The AB5000™ can be used to support the heart, giving it time to rest – and potentially recover native heart function. The device can also be used as a bridge to definitive therapy.

http://med.umich.edu/cardiac-surgery/images/content/Abiomed_AB5000.jpg

Abiomed_AB5000

CardioWest™ temporary Total Artificial Heart (TAH-t) http://www.syncardia.com/cardiowesttaht/index.php
This medical device is the modern version of the Jarvik 7 artificial heart first implanted into Barney Clark in 1982. The CardioWest™ temporary Total Artificial Heart is the only FDA approved temporary total artificial heart in the world.
The TAH-t is used as a bridge to heart transplant for eligible patients suffering from end-stage biventricular failure.
http://med.umich.edu/cardiac-surgery/images/content/Cardiowest_TAHt_Photo.jpg

Cardiowest_TAHt_Photo

Other related articles published on this Scientific Journal include the following:

Ventricular Assist Device (VAD): A Recommended Approach to the Treatment of Intractable Cardiogenic Shock (larryhbern)
https://pharmaceuticalintelligence.com/2013/06/18/a-recommended-approach-to-the-treatmnt-of-intractable-cardiogenic-shock/

Trans-apical Transcatheter Aortic Valve Replacement in a Patient with Severe and Complex Left Main Coronary Artery Disease (LMCAD) (larryhbern)
https://pharmaceuticalintelligence.com/2013/06/17/management-of-difficult-trans-apical-transcatheter-aortic-valve-replacement-in-a-patient-with-severe-and-complex-arterial-disease/
Clinical Indications for Use of Inhaled Nitric Oxide (iNO) in the Adult Patient Market: Clinical Outcomes after Use, Therapy Demand and Cost of Care (Aviva 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

Gene Therapy Into Healthy Heart Muscle: Reprogramming Scar Tissue In Damaged Hearts
(Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2013/01/09/gene-therapy-into-healthy-heart-muscle-reprogramming-scar-tissue-in-damaged-hearts/

Heart Renewal by pre-existing Cardiomyocytes: Source of New Heart Cell Growth Discovered
(Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2012/12/23/heart-renewal-by-pre-existing-cardiomyocytes-source-of-new-heart-cell-growth-discovered/

Heart Remodeling by Design – Implantable Synchronized Cardiac Assist Device: Abiomed’s Symphony (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2012/07/23/heart-remodeling-by-design-implantable-synchronized-cardiac-assist-device-abiomeds-symphony/

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 (Aviva Lev-Ari)
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/

Stenosis, Ischemia and Heart Failure (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2013/05/16/stenosis-ischemia-and-heart-failure/

Congestive Heart Failure & Personalized Medicine: Two-gene Test predicts response to Beta Blocker Bucindolol (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2012/10/17/chronic-heart-failure-personalized-medicine-two-gene-test-predicts-response-to-beta-blocker-bucindolol/

Phrenic Nerve Stimulation in Patients with Cheyne-Stokes Respiration and Congestive Heart Failure (larryhbern)
https://pharmaceuticalintelligence.com/2013/06/20/phrenic-nerve-stimulation-in-patients-with-cheyne-stokes-respiration-and-congestive-heart-failure/

First Drug to improve Heart Failure Mortality in Over a Decade – HealthCanal.com (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2013/06/03/first-drug-to-improve-heart-failure-mortality-in-over-a-decade-healthcanal-com/

Meta-analysis: Heart Failure Worsens Short-term Prognosis of NSTE-ACS Patients – TCTMD
(Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2013/06/06/meta-analysis-heart-failure-worsens-short-term-prognosis-of-nste-acs-patients-tctmd/

THYMOSIN (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2013/02/28/the-heart-vasculature-protection-a-concept-based-pharmacological-therapy-including-thymosin/

Resident-cell-based Therapy (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2012/04/30/93/

Amyloidosis with Cardiomyopathy (larryhbern)
https://pharmaceuticalintelligence.com/2013/03/31/amyloidosis-with-cardiomyopathy/

Blood-vessels-generating stem cells discovered (ritu.saxena)
https://pharmaceuticalintelligence.com/2012/10/22/blood-vessel-generating-stem-cells-discovered/

Stem Cell Research — The Frontier is at the Technion in Israel (A Lev-Ari)
https://pharmaceuticalintelligence.com/2012/09/06/stem-cell-research-the-frontier-is-at-the-technion-in-israel/

Implantable Synchronized Cardiac Assist Device Designed for Heart Remodeling: Abiomed’s Symphony

Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2012/07/11/implantable-synchronized-cardiac-assist-device-designed-for-heart-remodeling-abiomeds-symphony/

 

What is Acute Heart Failure?

What is Acute Heart Failure? (Photo credit: Novartis AG)

English: The CardioWest™ temporary Total Artif...

English: The CardioWest™ temporary Total Artificial Heart (Photo credit: Wikipedia)

English: Graph showing the correlation between...

English: Graph showing the correlation between BNP serum level and mortality. Source: Inder S. Anand, Lloyd D. Fisher, Yann-Tong Chiang, Roberto Latini, Serge Masson,Aldo P. Maggioni, Robert D. Glazer, Gianni Tognoni, Jay N. Cohn (24th Feb 2003). Changes in Brain Natriuretic Peptide and Norepinephrine Over Time and Mortality and Morbidity in the Valsartan Heart Failure Trial (Val-HeFT). Circulation 107: 1278-83. DOI: 10.1161/01.CIR.0000054164.99881.00 (Photo credit: Wikipedia)

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After Cardiac Transplantation: Sirolimus acts as immunosuppressant Attenuates Allograft Vasculopathy

Writer and Curator: Larry H Bernstein, MD, FCAP

and

Curator: Aviva Lev-Ari, PhD, RN 

 

Sirolimus as primary immunosuppression attenuates allograft vasculopathy with improved late survival and decreased cardiac events after cardiac transplantation

Topilsky Y, Hasin T, Raichlin E, Boilson BA, Schirger JA, et al.
Circulation. 2012 Feb 7;125(5):708-20.    http://dx.doi.org/10.1161/CIRCULATIONAHA.111.040360. Epub 2011 Dec 29

BACKGROUND: We retrospectively analyzed the potential of sirolimus as a primary immunosuppressant

  1. in the long-term attenuation of cardiac allograft vasculopathy progression and
  2. the effects on cardiac-related morbidity and mortality.
METHODS:  Forty-five cardiac transplant recipients were converted to sirolimus 1.2 years (0.2, 4.0) after transplantation with complete calcineurin inhibitor withdrawal. Fifty-eight control subjects 2.0 years (0.2, 6.5 years) from transplantation were maintained on calcineurin inhibitors.
  • Age,
  • sex,
  • ejection fraction, and
  • time from transplantation to baseline intravascular ultrasound study were not different (P>0.2 for all) between the groups;
  • neither were secondary immunosuppressants and
  • use of steroids.

Three-dimensional intravascular ultrasound studies were performed at baseline and 3.1 years (1.3, 4.6 years) later.

RESULTS:  Plaque index progression (plaque volume/vessel volume) was attenuated in the sirolimus group (0.7±10.5% versus 9.3±10.8%; P=0.0003) owing to
  1. reduced plaque volume in patients converted to sirolimus early (<2 years) after transplantation (P=0.05) and
  2. improved positive vascular remodeling (P=0.01) in patients analyzed late (>2 years) after transplantation.
Outcome analysis in 160 consecutive patients maintained on 1 therapy was performed regardless of performance of intravascular ultrasound examinations.
  1. Five-year survival was improved with sirolimus (97.4±1.8% versus 81.8±4.9%; P=0.006),
  2. There was freedom from cardiac-related events (93.6±3.2% versus 76.9±5.5%; P=0.002).
CONCLUSIONS:  Substituting calcineurin inhibitor with sirolimus as primary immunosuppressant
  1. attenuates long-term cardiac allograft vasculopathy progression and
  2. may improve long-term allograft survival owing to favorable coronary remodeling.
Because of the lack of randomization and retrospective nature of our analysis, the differences in outcome should be interpreted cautiously, and prospective clinical trials are required.

Related articles

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

Svelte Drug-Eluting Stent Utilizing New Class of Bioabsorbable Drug Coating Attains 0% Clinically-Driven Events Through 12-Months in First-In-Man Study
Aviva Lev-Ari, PhD, RN
Biomaterials Technology: Models of Tissue Engineering for Reperfusion and Implantable Devices for Revascularization
Larry h Benstein, MD, FCAP
Vascular Repair: Stents and Biologically Active Implants
Larry h Benstein, MD, FCAP
New Drug-Eluting Stent Works Well in STEMI
Aviva Lev-Ari, PhD, RN
Coronary Artery DiseaseMedical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents
Aviva Lev-Ari, PhD, RN
Table 1 Illustration

Table 1 Illustration (Photo credit: Libertas Academica)

Photograph of the Taxus drug-eluting stent, fr...

Photograph of the Taxus drug-eluting stent, from the web site of the U.S. Food and Drug Administration. (Photo credit: Wikipedia)

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

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

and

Curator: Aviva Lev-Ari, PhD, RN 

 

This article examines 10-year to 15-year survivals from arterial bypass grafts using arterial vs saphenous venous grafts.

Locker C, Schaff HV, Dearani JA, Joyce LD, Park SJ, et al.
Division of Cardiovascular Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA. lekerlocker.chaim@mayo.edu
Circulation. 2012 Aug 28;126(9):1023-30.   PMID: 22811577 http://dx.doi.org/10.1161/CIRCULATIONAHA.111.084624. Epub 2012 Jul 18. Review.
Coronary artery bypass surgery (CABG) , is performed to relieve angina and reduce the risk of death from coronary artery disease. Arteries or veins from elsewhere in the patient’s body are grafted to the coronary arteries to bypass atherosclerotic narrowings and improve the blood supply to the coronary circulation supplying the myocardium. This surgery is usually performed with the heart stopped, necessitating the usage of cardiopulmonary bypass; techniques are available to perform CABG on a beating heart, so-called “off-pump” surgery.
Russian cardiac surgeon, Dr. Vasilii Kolesov, performed the first successful internal mammary artery–coronary artery anastomosis in 1964. Using a standard suture technique in 1964, and over the next five years he performed 33 sutured and mechanically stapled anastomoses in St. Petersburg, Russia.
Dr. René Favaloro, an Argentine surgeon, achieved a physiologic approach in the surgical management of coronary artery disease—the bypass grafting procedure—at the Cleveland Clinic in May 1967. His new technique used a saphenous vein autograft to replace a stenotic segment of the right coronary artery, and he later successfully used the saphenous vein as a bypassing channel, which has become the typical bypass graft technique we know today; in the U.S., this vessel is typically harvested endoscopically, using a technique known as endoscopic vessel harvesting (EVH). Soon Dr. Dudley Johnson extended the bypass to include left coronary arterial systems. In 1968, Doctors Charles Bailey, Teruo Hirose and George Green used the internal mammary artery instead of the saphenous vein for the grafting.
A person with a large amount of coronary artery disease (CAD) may receive fewer bypass grafts owing to the lack of suitable “target” vessels. A coronary artery may be unsuitable for bypass grafting if
  • it is small (< 1 mm or < 1.5 mm depending on surgeon preference),
  • heavily calcified (meaning the artery does not have a section free of CAD) or
  • intramyocardial (the coronary artery is located within the heart muscle rather than on the surface of the heart).
Similarly, a person with a single stenosis (“narrowing”) of the left main coronary artery requires only two bypasses (to the LAD and the LCX). However, a left main lesion places a person at the highest risk for death from a cardiac cause.
  • Both PCI and CABG are more effective than medical management at relieving symptoms, (e.g. angina, dyspnea, fatigue).
  • CABG is superior to PCI for some patients with multivessel CAD.
The Surgery or Stent (SoS) trial was a randomized controlled trial that compared CABG to PCI with bare-metal stents. The SoS trial demonstrated CABG is superior to PCI in multivessel coronary disease.
The SYNTAX trial was a randomized controlled trial of 1800 patients with multivessel coronary disease, comparing CABG versus PCI using drug-eluting stents (DES). The study found that
  • rates of major adverse cardiac or cerebrovascular events at 12 months were significantly higher in the DES group (17.8% versus 12.4% for CABG; P=0.002).
This was primarily driven by
  • higher need for repeat revascularization procedures in the PCI group with no difference in repeat infarctions or survival.
  • Higher rates of strokes were seen in the CABG group.

http://upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Coronary_artery_bypass_surgery_Image_657C-PH.jpg/230px-Coronary_artery_bypass_surgery_Image_657C-PH.jpg

http://upload.wikimedia.org/wikipedia/commons/thumb/3/30/Heart_saphenous_coronary_grafts.jpg/220px-Heart_saphenous_coronary_grafts.jpg

220px-Heart_saphenous_coronary_grafts

Left Internal Mammary Artery Usage in Coronary Artery Bypass Grafting: A Measure of Quality Control

S Karthik and BM Fabri
Ann R Coll Surg Engl 2008; 85(4):367-69.

Over the last two decades, many studies have shown better long-term patency rates and survival in patients undergoing coronary artery bypass grafting (CABG) with left internal mammary artery (LIMA) to the left anterior descending artery (LAD).
Although the current focus in the UK is on mortality rates, we believe that it will not be long before this will also include the incidence of major morbidity after CABG such as stroke, myocardial infarction (MI), renal failure and sternal wound problems. We also believe that we should now consider LIMA usage as a marker of quality control in CABG. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1964611/

This study very clearly demonstrated that:

  1. Approximately 4% of all patients undergoing first-time CABG do not need a graft to the LAD.
  2. Of the rest, about 92% receive LIMA to LAD.

Six sub-groups of patients in whom LIMA usage was significantly less were:

(i) the elderly (> 70 years of age);

(ii) females;

(iii) diabetics;

(iv) patients having emergency CABG;

(v) poor left ventricular (LV) function (ejection fraction [EF] < 30%); and

(vi) respiratory disease.

LIMA usage was also reduced in patients undergoing combined CABG and valve procedures.

Multiple arterial grafts improve late survival of patients undergoing CABG

BACKGROUND: Use of the left internal mammary artery (LIMA) in multivessel coronary artery disease improves survival after coronary artery bypass graft surgery; however, the survival benefit of multiple arterial (MultArt) grafts is debated. (Perhaps not without reason. One problem is the small size of the left circumflex artery, and where does the right coronary artery have a place?)
METHODS : We reviewed 8622 Mayo Clinic patients who had isolated primary coronary artery bypass graft surgery for multivessel coronary artery disease from 1993 to 2009. Patients were stratified by number of arterial grafts into the LIMA plus saphenous veins (LIMA/SV) group (n=7435) or the MultArt group (n=1187). Propensity score analysis matched 1153 patients.
RESULTS: Operative mortality was 0.8% (n=10) in the MultArt and 2.1% (n=154) in the LIMA/SV (P=0.005) group.This result was not statistically different (P=0.996) in multivariate analysis or the propensity-matched analysis (P=0.818).
Late survival was greater for MultArt versus LIMA/SV (10- and 15-year survival rates were 84% and 71% versus 61% and 36%, respectively [P<0.001], in unmatched groups and 83% and 70% versus 80% and 60%, respectively [P=0.0025], in matched groups). The large difference between the MultiArt versus the LIMA/SV appears to be the 61% and 36% in unmatched and 80% and 60% in matched, evident at 15-years, favorable for the MultiArt group.
MultArt subgroups with bilateral internal mammary artery/SV (n=589) and

  • bilateral internal mammary artery only (n=271) had improved 15-year survival (86% and 76%; 82% and 75% at 10 and 15 years [P<0.001]), and
  • bilateral internal mammary artery/radial artery (n=147) and LIMA/radial artery (n=169) had greater 10-year survival (84% and 78%; P<0.001) versus LIMA/SV.

In multivariate analysis, MultArt grafts remained a strong independent predictor of survival (hazard ratio, 0.79; 95% confidence interval, 0.66-0.94; P=0.007).

CONCLUSIONS:

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 (SV) grafting.

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

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

Competition in the Ecosystem of Medical Devices in Cardiac and Vascular Repair: Heart Valves, Stents, Catheterization Tools and Kits for Open Heart and Minimally Invasive Surgery (MIS) (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2012/06/22/competition-in-the-ecosystem-of-medical-devices-in-cardiac-and-vascular-repair-heart-valves-stents-catheterization-tools-and-kits-for-open-heart-and-minimally-invasive-surgery-mis/
Bioabsorbable Drug Coating Scaffolds, Stents and Dual Antiplatelet Therapy (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2013/05/29/bioabsorbable-drug-coating-scaffolds-stents-and-dual-antiplatelet-therapy/

Vascular Repair: Stents and Biologically Active Implants (larryhbern)
https://pharmaceuticalintelligence.com/2013/05/04/stents-biologically-active-implants-and-vascular-repair/

Drug Eluting Stents: On MIT’s Edelman Lab’s Contributions to Vascular Biology and its Pioneering Research on DES (larryhbern)
https://pharmaceuticalintelligence.com/2013/04/25/contributions-to-vascular-biology/

Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents (Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2012/08/13/coronary-artery-disease-medical-devices-solutions-from-first-in-man-stent-implantation-via-medical-ethical-dilemmas-to-drug-eluting-stents/

Survivals Comparison of Coronary Artery Bypass Graft (CABG) and Percutaneous Coronary Intervention (PCI) / Coronary Angioplasty (larryhbern)
https://pharmaceuticalintelligence.com/2013/06/23/comparison-of-cardiothoracic-bypass-and-percutaneous-interventional-catheterization-survivals

Svelte Medical Systems’ Drug-Eluting Stent: 0% Clinically-Driven Events Through 12-Months in First-In-Man Study (Aviva Lev-Ari
https://pharmaceuticalintelligence.com/2013/05/28/svelte-medical-systems-drug-eluting-stent-0-clinically-driven-events-through-12-months-in-first-in-man-study/

Acute and Chronic Myocardial Infarction: Quantification of Myocardial Perfusion Viability – FDG-PET/MRI vs. MRI or PET alone (Justin Pearlman, Aviva Lev-Ari)
https://pharmaceuticalintelligence.com/2013/05/22/acute-and-chronic-myocardial-infarction-quantification-of-myocardial-viability-fdg-petmri-vs-mri-or-pet-alone/

Biomaterials Technology: Models of Tissue Engineering for Reperfusion and Implantable Devices for Revascularization (larryhbern)
https://pharmaceuticalintelligence.com/2013/05/05/bioengineering-of-vascular-and-tissue-models/

Revascularization: PCI, Prior History of PCI vs CABG (A Lev-Ari)
https://pharmaceuticalintelligence.com/2013/04/25/revascularization-pci-prior-history-of-pci-vs-cabg/

Accurate Identification and Treatment of Emergent Cardiac Events (larryhbern)
https://pharmaceuticalintelligence.com/2013/03/15/accurate-identification-and-treatment-of-emergent-cardiac-events/

FDA Pending 510(k) for The Latest Cardiovascular Imaging Technology (A Lev-Ari)
https://pharmaceuticalintelligence.com/2013/01/28/fda-pending-510k-for-the-latest-cardiovascular-imaging-technology/

The ACUITY-PCI score: Will it Replace Four Established Risk Scores — TIMI, GRACE, SYNTAX, and Clinical SYNTAX (A Lev-Ari)
https://pharmaceuticalintelligence.com/2013/01/03/the-acuity-pci-score-will-it-replace-four-established-risk-scores-timi-grace-syntax-and-clinical-syntax/

CABG or PCI: Patients with Diabetes – CABG Rein Supreme (A Lev-Ari)
https://pharmaceuticalintelligence.com/2012/11/05/cabg-or-pci-patients-with-diabetes-cabg-rein-supreme/

To Stent or Not? A Critical Decision (A Lev-Ari)
https://pharmaceuticalintelligence.com/2012/10/23/to-stent-or-not-a-critical-decision/

The internal mammary artery and its branches.

The internal mammary artery and its branches. (Photo credit: Wikipedia)

Coronary artery bypass surgery, the usage of c...

Coronary artery bypass surgery, the usage of cardiopulmonary bypass Русский: Коронарное шунтирование (Photo credit: Wikipedia)

A coronary angiogram that shows the LMCA, LAD ...

A coronary angiogram that shows the LMCA, LAD and LCX. (Photo credit: Wikipedia)

Micrograph of an artery that supplies the hear...

Micrograph of an artery that supplies the heart with significant atherosclerosis and marked luminal narrowing. Tissue has been stained using Masson’s trichrome. (Photo credit: Wikipedia)

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Improved Results for Treatment of Persistent type 2 Endoleak after Endovascular Aneurysm Repair: Onyx Glue Embolization

Writer, Curator: Larry H Bernstein, MD, FCAP

and

Curator: Aviva Lev-Ari, PhD, RN 

 

 

This report is an evaluation of onyx glue use in endovascular aneurysm repair. Onyx® is a non-adhesive liquid embolic agent used for the pre-surgical embolization of brain Arteriovenous malformations (bAVM).
Onyx is comprised of EVOH (ethylene vinyl alcohol) copolymer dissolved in DMSO (dimethyl sulfoxide), and suspended micronized tantalum powder to provide contrast for visualization under fluoroscopy.
A DMSO compatible delivery micro catheter that is indicated for use in the neuro vasculature (e.g. Marathon™, Rebar® or UltraFlow™ HPC catheters) is used to access the embolization site.
Onyx is available in two product formulations, Onyx 18 (6% EVOH) and Onyx 34 (8% EVOH).
ONYX glue

Improved results using Onyx glue for the treatment of persistent type 2 endoleak after endovascular aneurysm repair. 

Abularrage CJ, Patel VI, Conrad MF, Schneider EB, Cambria RP, Kwolek CJ
Division of Vascular and Endovascular Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Mass 02114, USA.
J Vasc Surg. 2012 Sep;56(3):630-6.  http://dx.doi.org/10.1016/j.jvs.2012.02.038.  Epub 2012 May 8.
Persistent type 2 (PT2) endoleaks (present ≥ 6 months) after endovascular aneurysm repair are associated with adverse outcomes, and
  • selective secondary intervention is indicated in those patients with an expanding aneurysm sac.

This study evaluated the outcomes of secondary intervention for PT2.

From 1999 to 2007, 136 patients who underwent endovascular aneurysm repair developed PT2 and comprised the study cohort. Primary end points included
  • PT2 resolution (secondary interventional success) and
  • survival
 both  were evaluated using multiple logistic regression and Kaplan-Meier analyses
Fifty-one patients underwent a total of 68 secondary interventions for PT2 with expanding aneurysm sacs
  • with a median postsecondary interventional follow-up of 13.7 months.

Secondary interventions included

  • 20 inferior mesenteric artery coil embolizations,
  • 17 Onyx glue embolizations,
  • 11 aneurysm sac coil embolizations,
  • 10 non-Onyx glue embolizations,
  • 7 lumbar artery coil embolizations,
  • 2 open lumbar ligations, and 1 graft explant.
The overall secondary interventional success rate was 43% (29 of 68). Onyx glue embolization was associated with
  • a greater success rate when used as the initial secondary intervention (odds ratio, 59.61; 95% confidence interval, 4.78-742.73; P < .001). 
There was no difference in success between the different techniques when multiple secondary interventions were required. Five-year survival was 72% ± 0.08% and
  • was unrelated to any of the secondary interventional techniques.
Secondary intervention for PT2 is associated with success in less than half of all cases. Onyx glue embolization was associated with greater long-term success
  • when used as the initial secondary intervention.
Competition in the Ecosystem of Medical Devices in Cardiac and Vascular Repair: Heart Valves, Stents, Catheterization Tools and Kits for Open Heart and Minimally Invasive Surgery (MIS)  (Aviva Lev-Ari)
Vascular Repair: Stents and Biologically Active Implants (larryhbern)
Drug Eluting Stents: On MIT’s Edelman Lab’s Contributions to Vascular Biology and its Pioneering Research on DES  (larryhbern)
Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents  (Aviva Lev-Ari)
Trans-apical Transcatheter Aortic Valve Replacement in a Patient with Severe and Complex Left Main Coronary Artery Disease (LMCAD) (larryhbern)
Transcatheter Aortic Valve Replacement (TAVR): Postdilatation to Reduce Paravalvular Regurgitation During TAVR with a Balloon-expandable Valve  (larryhbern)
Svelte Medical Systems’ Drug-Eluting Stent: 0% Clinically-Driven Events Through 12-Months in First-In-Man Study  (Aviva Lev-Ari)
Acute and Chronic Myocardial Infarction: Quantification of Myocardial Perfusion Viability – FDG-PET/MRI vs. MRI or PET alone  (Justin Pearlman, Aviva Lev-Ari)
Biomaterials Technology: Models of Tissue Engineering for Reperfusion and Implantable Devices for Revascularization (larryhbern)
Revascularization: PCI, Prior History of PCI vs CABG  (A Lev-Ari)
The ACUITY-PCI score: Will it Replace Four Established Risk Scores — TIMI, GRACE, SYNTAX, and Clinical SYNTAX  (A Lev-Ari)
Absorb™ Bioresorbable Vascular Scaffold: An International Launch by Abbott Laboratories (Aviva Lev-Ari)
Carotid Stenting: Vascular surgeons have pointed to more minor strokes in the stenting group and cardiologists to more myocardial infarctions in the CEA cohort. (A Lev-Ari)
Endovascular repair of cerebral aneurysm.

Endovascular repair of cerebral aneurysm. (Photo credit: Wikipedia)

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Trans-apical Transcatheter Aortic Valve Replacement in a Patient with Severe and Complex Left Main Coronary Artery Disease (LMCAD)

Writer: Larry H Bernstein, MD, FCAP

and

Curator: Aviva Lev-Ari, PhD, RN

Significant, defined as a greater than 50 percent narrowing, left main coronary artery disease (LMCAD) is found in 4 to 6 percent of all patients who undergo coronary arteriography [1]. When present, it is associated with multivessel coronary artery disease (MVCAD) about 70 percent of the time [2,3].

Most patients are symptomatic and at high risk of cardiovascular events, since occlusion of this vessel compromises flow to at least 75 percent of the left ventricle, unless it is protected by collateral flow or a patent bypass graft to either the left anterior descending or circumflex artery. Studies performed before revascularization with coronary artery bypass graft surgery (CABG) became the standard of care revealed a poor prognosis for these patients, with three-year survival as low as 37 percent [4]. CABG, when directly compared to medical therapy, is associated with significantly better cardiovascular outcomes, including mortality [5].

Percutaneous coronary intervention (PCI) with stenting has generally been restricted to such patients considered inoperable or at high risk for CABG, or with prior CABG and at least one patent graft to the left anterior descending or circumflex artery (so-called “protected” left main disease). Graft patency is important in this setting in the event of acute or late closure after PCI. However, evidence is increasing to support the use of PCI with stenting in some cases. (See ‘PCI versus CABG’ below.)

Asymptomatic patients with left main lesions felt to not be hemodynamically significant should be managed with preventative therapies. Patients with anginal symptoms attributable to lesions elsewhere should be managed with therapies similar to those used in other patients with coronary artery disease. (See “Overview of the care of patients with stable ischemic heart disease”.)

This topic will discuss most aspects of the management of patients with LMCAD. The approach to patients with multivessel coronary artery disease without LMCAD is discussed elsewhere. (See “Bypass surgery versus percutaneous intervention in the management of stable angina pectoris: Recommendations”.)

http://www.uptodate.com/contents/management-of-left-main-coronary-artery-disease

 

Management of significant left main coronary disease before and after trans-apical transcatheter aortic valve replacement in a patient with severe and complex arterial disease.

Source

Columbia University Medical Center, New York, New York; Cardiovascular Research Foundation, New York, New York.

Abstract

We report the case of an 81-year-old woman with symptomatic severe aortic stenosis, extremely significant peripheral arterial disease, and obstructive coronary artery disease who underwent percutaneous coronary intervention via a transaxillary conduit immediately before a trans-apical transcatheter aortic valve replacement performed with a transfemoral device. After deployment of the transcatheter heart valve, there was a left main coronary obstruction and the patient required an emergent PCI. This multifaceted case clearly underlines the importance of a well functioning heart team including the interventional cardiologist, the cardiovascular surgeon, and the echocardiographer. © 2013 Wiley Periodicals, Inc.

Copyright © 2013 Wiley Periodicals, Inc.

This is an interesting surgical case presented by the Columbia University Cardiovascular Surgery team, illustrating the importance of combined team skills in the most difficult of cases.  It is part of a series on cardiovascular surgery.

Management of significant left main coronary disease before and after trans-apical transcatheter aortic valve replacement in a patient with severe and complex arterial disease.

Paradis JM, George I, and Kodali S
Catheterization and Cardiovascular Interventions  (2013)

Introduction

Transcatheter aortic valve replacement (TAVR) with the Edwards SAPIEN transcatheter heart valve (THV) (Edwards Lifesciences, Irvin, CA) has been shown to reduce mortality when compared to medical therapy alone for patients with symptomatic severe aortic stenosis deemed unsuitable for surgical aortic valve replacement due to multiple co-morbidities. The Edwards SAPIEN THV, sizes 23 and 26 mm, and the RetroFlex 3 transfemoral delivery system, have been recently approved by the US Food and Drug Administration (FDA) for commercial use outside of the PARTNER clinical trial for patients considered inoperable.  However, an alternative site needs to be selected for patients with peripheral arteries inadequate for transfemoral TAVR.  Although not fully validated, the transapical approach or the transaortic route using a balloon expandable THV,  appears to be appropriate for this specific purpose.  Significant coronary artery disease (CAD) is often found in patients with severe aortic stenosis. in > 50% of patients with aortic stenosis over 70 years of age and in > 65% of patients who are  over 80 years of age. There is no established guideline for managing significant CAD in the context of TAVR, including the appropriate revascularization strategy as well as the timing of interventions.

Case Report

An 81-year-old woman  presented with symptomatic severe aortic stenosis, extremely significant peripheral arterial disease, and obstructive coronary artery disease. She had a six-month history prior to admission of progressive exertional shortness of breath and fatigue, and a long history fo hypertension, hyperlipidemia, obesity, and severe peripheral vascular disease.  In 2003, she underwent a coronary artery bypass graft (CABG) surgery, with grafting of the left internal mammary artery (LIMA) to the left anterior descending (LAD) artery, a saphenous vein graft (SVG) to the first obtuse marginal (OM) branch, and a SVG to the right coronary artery (RCA). Due to associated severe mitral regurgitation, a mitral valve ring annuloplasty was also performed. A transthoracic echocardiogram (TTE) revealed severe aortic stenosis with a peak gradient across the aortic valve of 63 mm Hg, a mean gradient of 39 mm Hg, and an aortic valve area of 0.8 cm2.  The left ventricular ejection fraction (LVEF) was 64% while the pulmonary artery systolic pressure was measured at 28 mm Hg.  Extreme calcification and tortuosity precluded the advancement of any wire, catheter, or sheath, contributing to two attempts at cardiac catheterization prior to transfer with a total occlusion of the distal abdominal aorta, at the level of the aorto-iliac bifurcation, and the left main, proximal LAD, proximal left circumflex, and the proximal RCA all had greater than 70% coronary lesions. In addition, ostial total occlusions were seen in both SVGs.
left main coronary artery
After transfer, a cardiac catheterization through the right radial artery was attempted without success due to calcification and tortuosity in the arterial bed.  An 80% distal left main lesion was clearly identified with a Judkins left 3.5 guiding catheter.  There was non-flow limiting coronary disease in the left circumflex and competitive retrograde flow seen in the LIMA graft, but they still were unable to cannulate the RCA and the SVGs. It was determined that the patient was inoperable, on grounds of her significant frailty, reoperative status and overall comorbid state (Society of Thoracic Surgeons (STS) risk score of 11%). Furthermore, due to the occlusion of the distal aorta, the patient was unsuitable for a TAVR via the transfemoral approach.
They chose to approach her PCI via a conduit on the right axillary artery and perform a concomitant TAVR from a trans-apical approach due to the serious limiting condition of the patient.  She underwent percutaneous coronary intervention via a transaxillary conduit immediately before a trans-apical transcatheter aortic valve replacement performed with a transfemoral device.  Excellent flow from the conduit was noted. A 7 French (Fr) sheath was connected to the end of the conduit, which was kept long to allow better maneuverability (Fig. 1). A Rosen wire was passed with some difficulty to the aortic root, and was switched to a stiff wire in an attempt to straighten the vessel.
PowerPoint Presentation
Fig. 1. Transaxillary conduit used during the procedure. A 7 French sheath was connected to an 8 mm dacron graft, which was previously sewn to the axillary artery.
After deployment of the transcatheter heart valve, there was a left main coronary obstruction and the patient required an emergent PCI.  This multifaceted case clearly underlines the importance of a well functioning heart team including the interventional cardiologist, the cardiovascular surgeon, and the echocardiographer. A Xience
V everolimus eluting stent 3.5 mm  18 mm was implanted starting 2 mm distal to the ostium of the left main, extending in the proximal portion of the left circumflex artery. After one post-dilatation with a non-compliant balloon, the final angiographic result was excellent.
They used a Retroflex 3 transfemoral delivery sheath to perform the trans-apical TAVR. They estimated the size and length of the ventricular cavity, and then placed markers on the delivery sheath (prior to insertion) indicating the appropriate length of sheath to remain outside the heart (Fig. 2).
PowerPoint Presentation
Fig. 2. Marker placed on the RetroFlex 3 transfemoral sheath to safely guide its insertion inside the left ventricular cavity during the trans-apical transcatheter aortic valve replacement.
A 23 mm Edwards SAPIEN valve was selected and deployed under fluoroscopic and transesophageal echocardiographic guidance. Immediately after deployment, turbulent flow was noted within the left main with the color Doppler on TEE, indicating a new obstruction of the left main, which a left coronary angiogram showed to be a severe proximal lesion.  Through the trans-axillary conduit, a  guiding catheter was laboriously brought in the ascending aorta and cannulated the left main artery which permitted a predilation and a stent insertion in the ostial portion of the left main.  She was discharged to a rehabilitation facility 7 days after the procedure.
On follow-up TTE, the LVEF was 55% without any significant wall motion abnormality. There was no aortic regurgitation, and the peak and mean gradients were 14.9 mm Hg and 8.0 mm Hg, respectively. The patient is still doing well more than 6 months after the procedure. She is now in NYHA class 2 and has not had any recurrent hospitalization for congestive heart failure.
Discussion
This report is a case of a complex percutaneous coronary intervention of the left main coronary artery via a right axillary conduit followed immediately by an off label commercial transapical TAVR using the Retro-Flex 3 trans-femoral introducer sheath, complicated finally by a new left main coronary obstruction mandating another PCI. It is the first description of a TAVR procedure preceded and followed by a left main trans-axillary PCI. The role of TEE (color Doppler) in the diagnosis of a very rare TAVR complication is also noteworthy. In a recent meta-analysis of 3,519 patients from 16 studies using the Valve Academic Research Consortium (VARC) definitions, the pooled estimate rate of coronary
obstruction following TAVR was only 0.7%. Obviously, the early recognition and treatment of this hazard is imperative.
The surgical management of this patient also warrants discussion. The hybrid surgical approach of accessing the axillary artery via a conduit provides numerous advantages:
(1) the ascending aorta, coronaries, and aortic valve are easily accessible;
(2) transition to cardiopulmonary bypass or extra-corporeal membrane oxygenation, if needed, is quick; and
(3) long-term morbidity is minimal for the patient when compared to aorto-iliac, aortic, or femoral conduits.
Finally, the heart team approach not only allowed the realization of a difficult coronary
stent implantation through an unusual transaxillary graft followed by a transapical TAVR in a patient with significant peripheral arterial disease, but also permitted the early  recognition and management of a potentially fatal left main obstruction. Considerations such as team-based care, close communication between the different specialties
involved and careful planning for outlining management of potential complications are therefore essential for the success of a TAVR program.

REFERENCES

 1. Leon MB, Smith CR, Mack M, Miller DC, Moses JW, Svensson LG, et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med 2010;363:1597–1607.
2. Iung B. Interface between valve disease and ischaemic heart disease. Heart 2000;84:347–352.
3. Wenaweser P, Pilgrim T, Guerios E, Stortecky S, Huber C, Khattab AA, et al. Impact of coronary artery disease and percutaneous coronary intervention on outcomes in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation.
EuroIntervention 2011;7:541–548.
4. Genereux P, Head SJ, Van Mieghem NM, Kodali S, Kirtane AJ, Xu K, et al. Clinical outcomes after transcatheter aortic valve replacement using valve academic research consortium definitions: A weighted meta-analysis of 3,519 patients from 16 studies.
J Am Coll Cardiol 2012;59:2317–2326.
Three coronary artery bypass grafts, a LIMA to...

Three coronary artery bypass grafts, a LIMA to LAD and two saphenous vein grafts – one to the right coronary artery (RCA) system and one to the obtuse marginal (OM) system. (Photo credit: Wikipedia)

heart with coronary arteries

heart with coronary arteries (Photo credit: Wikipedia)

Micrograph of an artery that supplies the hear...

Micrograph of an artery that supplies the heart with significant atherosclerosis and marked luminal narrowing. Tissue has been stained using Masson’s trichrome. (Photo credit: Wikipedia)

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The Implications of a Newly Discovered  CYP2J2 Gene Polymorphism  Associated with Coronary Vascular Disease in the Uygur Chinese Population

Author, Curator: Larry H Bernstein, MD, FCAP

This is an interesting genomic study of the relationship of genetic polymorphism in the Chinese Uygur population that highlights the difficulty in CVD genomics, and casts a promising light on difficulties over
1.  possibly no more than 8 genetic signatures to account for all of human CVD conditions
2.  genetic signatures may no be equally distributed over studied populations
3.  genetic signatures may be more pronounced in different populations
4.  there is little predictable validity in such studies over large assimilated populations (such as African-Americans
5.  the best genomic evidence for meaningful associations does appear to tie in with endothelial metabolism
6.  the greatest difficulty in all studies is the small dose of information provided by an such linkage
7.  there has been too little information provided in studies of the effect of dietary factors on the affected population, which would entail nutrigenomics.
8.  there is an association between certain distinct CVD’s and later development of coronary heart disease (CHD).
This study concepts, methods and difficulties were recently reviewed in the following articles:
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Aviva Lev-Ari, PhD, RN
Genomics & Genetics of Cardiovascular Disease Diagnoses: A Literature Survey of AHA’s Circulation Cardiovascular Genetics, 3/2010 – 3/2013
Aviva Lev-Ari, PhD, RN and Larry H Bernstein, MD, FCAP
Diagnosis of Cardiovascular Disease, Treatment and Prevention: Current & Predicted Cost of Care and the Promise of Individualized Medicine Using Clinical Decision Support Systems
Aviva Lev-Ari, PhD, RN and Larry H Bernstein, MD, FCAP
Hypertension and Vascular Compliance: 2013 Thought Frontier – An Arterial Elasticity Focus
Justin D. Pearlman, MD, PhD, and Aviva Lev-Ari, PhD, RN
Clinical Trials Results for Endothelin System: Pathophysiological role in Chronic Heart Failure, Acute Coronary Syndromes and MI – Marker of Disease Severity or Genetic Determination?
Aviva Lev-Ari, PhD, RN
Vascular Medicine and Biology: CLASSIFICATION OF FAST ACTING THERAPY FOR PATIENTS AT HIGH RISK FOR MACROVASCULAR EVENTS Macrovascular Disease – Therapeutic Potential of cEPCs
Aviva Lev-Ari, PhD, RN
Endothelial Function and Cardiovascular Disease
Larry H Bernstein, MD, FCAP
Reversal of Cardiac Mitochondrial Dysfunction
Larry H Bernstein, MD, FCAP
A Second Look at the Transthyretin Nutrition Inflammatory Conundrum
Larry H Bernstein, MD, FCAP

A Novel Polymorphism of the CYP2J2 Gene is Associated with Coronary Artery Disease in Uygur Population in China

Qing Zhu, Zhenyan Fu, Yitong Ma, Hong Yang, Ding Huang, Xiang Xie, Fen Liu, Yingying Zheng, Erdenbat Cha
PII: S0009-9120(13)00174-4    Available online 15 May 2013
Reference: CLB 8375
To appear in: Clinical Biochemistry
Received date: 17 February 2013
Revised date: 13 April 2013
Accepted date: 3 May 2013
Background: Cytochrome P450 (CYP) 2J2 is expressed in the vascular endothelium and metabolizes arachidonic acid to biologically active epoxyeicosatrienoic acids (EETs).
  • The EETs are potent endogenous vasodilators and
  • inhibitors of vascular inflammation.
The aim of the present study was to assess the association between the human CYP2J2 gene polymorphism and coronary artery disease (CAD) in a Han and Uygur population of China.
We use two independent case-control studies:
  1. a Han population (206 CAD patients and 262 control subjects) and
  2. a Uygur population (336 CAD patients and 448 control subjects).
All CAD patients  and controls were genotyped for the same three single nucleotide polymorphisms (SNPs)
  1. rs890293
  2. rs11572223
  3. rs2280275
of CYP2J2 gene by a Real-time PCR instrument.
Results: In the Uygur population, for total, the distribution of SNP3 (rs2280275) genotypes showed a significant difference between CAD and control participants (P=0.048).
For total and men, the distribution of SNP3 (rs2280275) alleles and the dominant model (CC vs CT + TT)
  • showed a significant difference between CAD and control participants (for allele: P=0.014 and P=0.035, respectively; for dominant model: P=0.014 and P=0.034, respectively).
The significant difference in dominant model was retained after adjustment for covariates (OR: 0.279, 95% confidence interval [CI]: 0.176-0.440, P=0.001; OR: 0.240, 95% CI: 0.128-0.457, P=0.001, respectively).
Conclusions: The CC genotype of rs2280275 in CYP2J2 gene could be a protective genetic marker of CAD and T allele may be a risk genetic marker of CAD in men of Uygur population in China.
Highlights:
1. We used two independent case-control studies: one was in a Han population and the other was in a Uygur population.
2. The CC genotype of rs2280275 in CYP2J2 gene could be a protective genetic marker of CAD and T allele may be a risk genetic marker of CAD in men of Uygur population in China.
3. Polymorphism of the CYP2J2 gene can affect the synthesis of epoxyeicosatrienoic acids (EETs).
Reviewer Observations:
This article describes the association between CYP2J2 polymorphism(SNP1, SNP2 and SNP3) and coronary artery disease (CAD) in two populations of China (Han and Uygur).
Results show that
  1. the frequency of T allele of rs2280275 (SNP3 of the CYP2J2) is higher in CAD patients than in control subjects and
  2. that CC genotype of rs 2280275 is significantly lower in CAD patients than in control subjects.
  3. “T allele of rs2280275 was significantly higher in CAD patients than in control participants. CC genotype of rs2280275 was significantly lower in CAD patients than in control participants.”;
  4. It appears that CC is the homozygous and dominant state of this SNP3 sequence in a pairing-combination.
  5. The effect of decreased CHD is seen only in the CC double combination, in men and not women. The difference between men and women with CAD is in LDL.
For Uygur population,
(1) after adjusting major confounding factors such as Glu、LDL、EH、DM and smoking, the effect of decreased CAD is seen only in the CC double combination, in men and not women.
(2) for men, the LDL level is higher in CAD than in control, for women, there isn’t a difference of LDL level between CAD and control.
(3) for men, the distribution of T and C allele is different between CAD and control (p=0.035), and not in women (p=0.118).
The T allele of SNP3 is increased in CAD. So the C allele is important, and a CT pair is neutral. Neither SNP1 or SNP2, or presumably both have lower incidence.

I might conjecture that having(heterozygous rs2280275), a C & a T, and eating a lot of fish and/or flax seed would show a difference

  • because of the intimal enzymatic conversion of arachidonic acid to EETs.

Arachidonic acid is a derivative of linoleic acid,an n-6 PUFA, while linolenic acid is an omega-3 PUFA. Substantial documentation of the effect of EETs is given. The anti-inflammatory advantage of an n-3 PUFA is also known.
It appears that the intimal conversion results in an omega-3 product.  In addition, the EET activates eNOS, so that there is endothelial NO produced.

The studies of both Spiecker and Ping Yin Liu showed the polymorphism of CYP2J2 (rs890293, SNP1) has relation with CAD. However, in this study, the authors found there was no association between the polymorphism of CYP2J2 (rs890293, SNP1) and CAD in Han population and Uygur population. We found (rs 2280275, SNP3) has association with CAD.
  • “The CC genotype of rs2280275 in CYP2J2 gene could be a protective genetic marker of CAD and T allele may be a risk genetic marker of CAD in men of Uygur population in China”
All participants had a differential diagnosis for chest pain encountered in the Cardiac Catheterization Laboratory of First Affiliated Hospital of Xinjiang Medical University. We recruited randomly CAD group and control group, subjects with valvular disease were excluded, control subjects were not healthy individuals, some of them have hypertension, some of them have DM, some of them have hyperlipidemia, which means control group expose to the same risk factors of CAD while the results of coronary angiogram is normal. All control subjects underwent a coronary angiogram and have no coronary artery stenosis.
The analysis was a logistic regression analysis, we used the major variables of CAD to analysis and found the CC genotype was the dependent useful factor after adjusting for major confounding factors such as Glu、LDL、EH、DM and smoking.
Schematic of EET interactions with cardiovascularion channels.
A: In the cardiac myocyte, EETs activate sarcolemmal or mitochondrial KATP channels.
B: In the vasculature, EETs activate endothelial small-(SKCa) or intermediate (IKCa)–conductance calcium-activated channels to cause hyperpolarization, which can be transmitted to the vascular smooth muscle via myoendothelial gap junctions. EETs also activate TRPV4 channels to activate Ca2+influx. In the vascular smooth muscle, EETs activate large conductance, calcium-activated (BK-Ca) channels through a G protein-Coupled event.
C: In platelets, EETs activate BK-Ca channels.calcium-activated (BK-Ca) channels through a G-protein-coupled event. C, In platelets, EETs activate BK-Ca channels.

Association of the ADRA2A polymorphisms with the risk of type 2 diabetes: A meta-analysis

Xi Chen, Lei Liu, Wentao He, Yu Lu, Delin Ma, Tingting Du, Qian Liu, Cai Chen, Xuefeng Yu
Clinical Biochemistry 2013;  46 (9): 722–726   http://dx.doi.org/10.1016/j.clinbiochem.2013.02.004
Results from the published studies on the association of ADRA2A (adrenoceptor alpha 2A) variants with type 2 diabetes (T2D) are conflicting and call for further assessment. The aim of this meta-analysis was to quantitatively summarize the effects of the two recently reported ADRA2A single nucleotide polymorphisms (SNPs) rs553668 and rs10885122 on T2D risk.
Results
Twelve studies with 40,828 subjects from seven eligible papers were included in the meta-analysis. Overall, the present meta-analysis failed to support a positive association between ADRA2A SNPs (rs553668 and rs10885122) and susceptibility to T2D (OR = 1.05, p = 0.17, 95% CI: 0.98, 1.12; and OR = 1.06, p = 0.11, 95% CI: 0.99, 1.13; respectively).
However, in the subgroup analysis by ethnicity, the significant association between rs553668 and the risk of T2D was obtained in Europeans under the recessive genetic model (OR = 1.36, p = 0.02, 95% CI: 1.05, 1.76).
Conclusion
The results of the meta-analyses indicated that both SNPs were associated with CHD in Caucasians (P < 0.05) but not in Asians. The results from our case-control study and meta-analyses might be explained by genetic heterogeneity in the susceptibility of CHD and ethnic differences between Asians and Caucasians.

Association between PCSK9 and LDLR gene polymorphisms with coronary heart disease: Case-control study and meta-analysis

Lina Zhang, Fang Yuan, Panpan Liu, Lijuan Fei, Yi Huang, Limin Xu, et al.
Clinical Biochemistry 2013; 46 (9): 727–732
► Association of rs11206510 and rs1122608 with CHD in 813 Chinese participants.
► The first association test of rs1122608 with the risk of CHD in Han Chinese.
► Meta-analyses were performed for rs11206510 and rs1122608.
► The two SNPs were associated with CHD in Caucasians but not in Asians.
Objective
To explore the association of rs11206510 (PCSK9 gene) and rs1122608 (LDLR gene) polymorphisms with coronary heart disease (CHD) in Han Chinese.
Methods
A total of 813 participants (290 CHD cases, 193 non-CHD controls and 330 healthy controls) were recruited in the case-control study. DNA genotyping was performed on the SEQUENOM® Mass–ARRAY iPLEX® platform. χ2-test was used to compare the genotype distribution and allele frequencies. Two meta-analyses were performed to establish the association between the two polymorphisms with CHD.
Results
No significant associations between the two SNPs and the risk of CHD were observed in the present study. The meta-analysis of rs11206510 of PCSK9 gene comprises 11 case-control studies with a total of 69,054 participants. Significant heterogeneity was observed in Caucasian population in subgroup analysis of the association studies of rs11206510 with CHD (P = 0.003, I2 = 67.2%). The meta-analysis of LDLR gene rs1122608 polymorphism comprises 7 case-control studies with a total of 20,456 participants and the heterogeneity of seven studies was minimal (P = 0.148, I2 = 36.7%).
Conclusion
The results of the meta-analyses indicated that both SNPs were associated with CHD in Caucasians (P < 0.05) but not in Asians.

The effect of hyperhomocysteinemia on aortic distensibility in healthy individuals

I Eleftheriadou, P Grigoropoulou, I Moyssakis, A Kokkinos. et al.
Nutrition 18 Feb 2013; 29 (6): 876-880, PII: S0899-9007(13)00015-4
Elevated plasma homocysteine (HCY) levels have been associated with increased risk for cardiovascular disease. Aortic distensibility and aortic pulse wave velocity (PWV) are indices of aortic elasticity. The aim of the present study was to determine the effect of acute methionine-induced HHCY on aortic distensibility and PWV in healthy individuals and the effect of acute HHCY on myocardial performance of the left ventricle (Tei index).
Thirty healthy volunteers were included in this crossover study. Aortic distensibility and Tei index were determined non-invasively by ultrasonography at baseline and 3 h after methionine or water consumption, while PWV was measured by applanation tonometry at baseline and every 1 h for the same time interval.
Oral methionine induced an increase in total plasma HCY concentrations (P < 0.001), whereas HCY concentrations did not change after water consumption. Aortic distensibility decreased 3 h after methionine load (P < 0.001) and Tei index increased (P < 0.001), suggesting worsening compared with baseline values. Water consumption had no effect on aortic distensibility or Tei index values. PWV values did not change after either methionine or water consumption.
Acute methionine-induced HHCY reduces aortic distensibility and worsens myocardial performance in healthy individuals. Further research is warranted to examine in the long term the direct effects of HHCY on cardiovascular function and the indirect effects on structural remodeling.
Micrograph of an artery that supplies the hear...

Micrograph of an artery that supplies the heart with significant atherosclerosis and marked luminal narrowing. Tissue has been stained using Masson’s trichrome. (Photo credit: Wikipedia)

Estimated propability of death or non-fatal my...

Estimated propability of death or non-fatal myocardial-infarction over one year corresponding ti selectet values of the individual scores. Ordinate: individual score, abscissa: Propability of death or non-fatal myocardial infarction in 1 year (in %) (Photo credit: Wikipedia)

 

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