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Posts Tagged ‘Intra-aortic balloon pump’


Treatment Options for Left Ventricular Failure  –  Temporary Circulatory Support: Intra-aortic balloon pump (IABP)Impella Recover LD/LP 5.0 and 2.5, Pump Catheters (Non-surgical) vs Bridge Therapy: Percutaneous Left Ventricular Assist Devices (pLVADs) and LVADs (Surgical) 

Author: Larry H Bernstein, MD, FCAP
And
Curator: Justin D Pearlman, MD, PhD, FACC

 

UPDATED on 12/2/2013 – HeartMate II – LVAD

http://www.nytimes.com/2013/11/28/business/3-hospital-study-links-heart-device-to-blood-clots.html?pagewanted=1&_r=0&emc=eta1

Hospital Studies Link Heart Device to Clots

David Maxwell for The New York Times

Dr. Randall Starling, right, said that he could only speculate about the reason for the rapid rise in early blood clots.

By 
Published: November 27, 2013

Doctors at the Cleveland Clinic began to suspect in 2012 that something might be wrong with a high-tech implant used to treat patients with advanced heart failure like former Vice President Dick Cheney.

Thoratec Corportation

The HeartMate II is a left ventricular assist device, which contains a pump that continuously pushes blood through the heart.

The number of patients developing potentially fatal blood clots soon after getting the implant seemed to be rising. Then early this year, researchers completed a check of hospital records and their concern turned to alarm.

The data showed that the incidence of blood clots among patients who got the device, called the HeartMate II, after March 2011 was nearly four times that of patients who had gotten the same device in previous years. Patients who developed pump-related clots died or needed emergency steps like heart transplants or device replacements to save them.

“When we got the data, we said, ‘Wow,’ ” said Dr. Randall C. Starling, a cardiologist at Cleveland Clinic.

On Wednesday, The New England Journal of Medicineposted a study on its website detailing the findings from the Cleveland Clinic and two other hospitals about the device. The HeartMate II belongs to a category of products known as a left ventricular assist device and it contains a pump that continuously pushes blood through the heart.

The abrupt increase in pump-related blood clots reported in the study is likely to raise questions about whether its manufacturer, Thoratec Corporation, modified the device, either intentionally or accidentally. By March, the Cleveland Clinic had informed both Thoratec and the Food and Drug Administration about the problems seen there, Dr. Starling said.

Officials at Thoratec declined to be interviewed. But in a statement, the company, which is based in Pleasanton, Calif., said that the HeartMate II had been intensively studied and used in more 16,000 patients worldwide with excellent results. It added that the six-month survival rate of patients who received the device had remained consistently high.

“Individual center experience with thrombosis varies significantly, and Thoratec actively partners with clinicians at all centers to minimize this risk,” the company said in a statement.

Thoratec and other cardiologists also pointed to a federally funded registry that shows a smaller rise in the rate of blood clots, or thrombosis, among patients getting a HeartMate II than the one reported Wednesday by the three hospitals. In the registry, which is known as Intermacs, the rate of pump-related blood clot associated with the HeartMate II rose to about 5 percent in devices implanted after May 2011 compared with about 2 percent in previous years.

The data reported on Wednesday in The New England Journal of Medicine found rates of clot formation two months after a device’s implant had risen to 8.4 percent after March 2011 from 2.2 percent in earlier years. Researchers also suggested in the study that the Intermacs registry might not capture all cases of pump-related blood clots, such as when patients gets emergency heart transplants after a clot forms.

Not only did the rate of blood clots increase, but the clots also occurred much sooner than in the past, according to the study. After March 2011, the median time before a clot was 2.7 months, compared with 18.6 months in previous years. In addition to the Cleveland Clinic, the report on Wednesday included data from Duke University and Washington University in St. Louis.

All mechanical heart implants are prone to producing blood clots that can form on a device’s surface. And experts say that the rate of blood clot formation can be affected by a variety of factors like changes in the use of blood-thinning drugs or the health of a patient.

In a telephone interview, Dr. Starling described the Thoratec officials as cooperative, adding that they have been looking into the problem since March to understand its cause. He said that he could only speculate about the reason for the rapid rise in early blood clots but believed it was probably device-related.

“My belief is that it is something as subtle as a change in software that affects pump flow or heat dissipation near a bearing,” said Dr. Starling, who is a consultant to Thoratec.

Asked about his comments, Thoratec responded that it had yet to determine the reason for even the smaller rise in blood clots seen in the federally funded database. “We have performed extensive analysis on HeartMate II and have not identified any change that would cause the increase observed in the Intermacs registry,” the company said.

In a statement, the F.D.A. said that it was reviewing the findings of the study. “The agency shares the authors concerns about the possibility of increased pump thrombosis,” the F.D.A. said in a statement.

The fortunes of Thoratec, which has been a favorite of Wall Street investors, may depend on its ability to find an answer to the apparent jump in pump-related blood clots. Over the last two years, the company’s stock has climbed from about $30 a share to over $43 a share. In trading Wednesday, Thoratec stock closed at $42.12 a share, up 61 cents. (The New England Journal of Medicine article was released after the stock market closed.)

The HeartMate II has been a lifesaver for many patients like Mr. Cheney in the final stages of heart failure, who got his device in 2010, sustaining them until they get a heart transplant or permanently assisting their heart. Dr. Starling said that he planned to keep using the HeartMate II in appropriate patients at the Cleveland Clinic because those facing death from heart failure had few options.

But the company has also been pushing to expand the device’s use beyond patients who face imminent death from heart failure. For example, the F.D.A. approved a clinical trial for patients with significant, but less severe, heart failure to receive a HeartMate II to compare their outcomes with patients who take drugs for the same condition. Researchers at the University of Michigan Medical Center who are leading the trial said on Wednesday that, based on the lower rates of blood clots seen in the Intermacs registry, they are planning to move forward with the trial.

Dr. Starling and researchers at the Cleveland Clinic tried this spring to get The New England Journal of Medicine to publish a report about the findings at that hospital, but the publication declined, saying the data might simply represent the experience of one facility. As a result, Dr. Starling contacted Duke University and Washington University for their data. When analyzed, it mirrored events at the Cleveland Clinic, he said.

The problems seen with the HeartMate II at the three hospitals were continuing as recently as this summer, when researchers paused the collection of data to prepare Wednesday’s study. The study also noted that a preliminary analysis of data provided by a fourth hospital, the University of Pennsylvania, showed the same pattern of blood clot formation, but that the data had been submitted too late for full analysis.

 SOURCE

 

This article presents the following four Sections:

I.     Impella LD – ABIOMED, Inc.

II.   IABP VS. Percutaneous LVADS

III. Use of the Impella 2.5 Catheter in High-Risk Percutaneous Coronary Intervention

IV.  PROTECT II Study – Experts Discussion

This account is a vital piece of recognition of very rapid advances in cardiothoracic interventions to support cardiac function mechanically by pump in the situation of loss of contractile function and circulatory output sufficient to sustain life, as can occur with the development of cardiogenic shock.  This has been mentioned and its use has been documented in other portions of this series.   On the one hand, PCI has a long and steady history in the development of interventional cardiology. This necessitated the availability of thoracic-surgical operative support. The situation is changed, and is more properly, conditional.

I. Impella LD – ABIOMED, Inc.

This micro-axial blood pump can be inserted into the left ventricle via open chest procedures. The Impella LD device has a 9 Fr catheter-based platform and a 21 Fr micro-axial pump and is  inserted through the ascending aorta, across the aortic and mitral valves and into the left ventricle.  It requires minimal bedside support and a 9 Fr single-access point  requires no priming outside the body.

Impella.LD_

Impella Recover LD/LP 5.0

The Impella Recover miniaturized impeller pump located within a catheter. The Impella Recover LD/LP 5.0 Support System has been developed to address the need for ventricular support in patients who develop heart failure after heart surgery (called cardiogenic shock) and who have not responded to standard medical therapy. The system is designed to provide immediate support and restore hemodynamic stability for a period of up to 7 days. Used as a bridge to therapy, it allows time for developing a definitive treatment strategy.

The Pump

The Impella Recover LD 5.0 showing implantation via direct placement into the left ventricle.
 Insert B – location in LV
imeplla-LD-video
The Impella Recover system is a miniaturized impeller pump located within a catheter. The device can provide support for the left side of the heart using either the
  • Recover LD 5.0 (implanted via direct placement into the left ventricle) or the
  • Recover LP 5.0 LV (placed percutaneously through the groin and positioned in the left ventricle).
The microaxial pump of the Recover LP/LD 5.0 can pump up to 4.5 liters per minute at a speed of 33,000 rpm. The pump is located at the distal end of a 9 Fr catheter.

II.   IABP VS. Percutaneous LVADS

An intra-aortic balloon pump (IABP) remains the method of choice for mechanical assistance1 in patients experiencing LV failure because of its

  • proven hemodynamic capabilities,
  • prompt time to therapy, and
  • low complication rates.

Percutaneous left ventricular assist devices (pLVADs), such as described above, represent an emerging option for partial or total circulatory support2 and several studies have compared the and efficacy of these devices with intra-aortic balloon pump (IABP) (IABP.)

Despite some randomized controlled trials demonstrating better hemodynamic profiles for pLVADs compared with IABP, there is no difference in  30-day survival or trend toward a reduced 30-day mortality rate associated with pLVADs.  Patients treated with pLVADs tended to have a
  • higher incidence of leg ischemia and
  • device related bleeding.3
Further, no differences have been detected in the overall use of
  • positive inotropic drugs or
  • vasopressors in patients with pLVADs.4,5
However, pLVADs may increase their use for patients not responding to
  • PCI,
  • fluids,
  • inotropes, and
  • IABP
Therefore, the decision making process on how to treat requires an integrated stepwise approach. A pLVAD might be considered on the basis of
  • anticipated individual risk,
  • success rates, and for
  • postprocedural events.6

Potential Algorithm for Device Selection during High-Risk PCI

PADS_HRPCI cardiac assist device selection

Potential Algorithm for Device Selection during Cardiogenic Shock
device_selection_CS
Until an alternative modality, characterized by improved efficacy and safety features compared with IABP, is developed, IABP remains the cornerstone of temporary circulatory support.2

Device Comparison for Treatment of Cardiogenic Shocktraditional intra-aortic balloon therapy with Impella 2.5 percutaneous ventricular assist device

 
1. Percutaneous LVADs in AMI complicated by cardiogenic shock. H Thiele, et al. EHJ 2007;28:2057-2063
2. Cardiogenic shock current concepts and improving outcomes. H R Reynolds et al. Circulation 2008 ;117 :686-697
3. Percutaneous left ventricular assist devices vs. IABP counterpulsation for treatment of cardiogenic shock. J M Cheng, et al. EHJ doi:10.1093/eurheart/ehp292
4. A randomized clinical trial to evaluate the safety and efficacy of a pLVAD vs. IABP for treatment of cardiogenic shock caused by MI. M Seyfarth, et al. JACC 2008;52:1584-8
5. A randomized multicenter clinical study to evaluate the safety and efficacy of the tandem heart pLVAD vs. conventional therapy with IABP for treatment of cardiogenic shock.
6. Percutaneous LVADs in AMI complicated by cardiogenic shock. H Thiele, et al. EHJ 2007;28:2057-2063

III. Use of the Impella 2.5 Catheter in High-Risk Percutaneous Coronary Intervention

Brenda McCulloch, RN, MSN
Sutter Heart and Vascular Institute, Sutter Medical Center, Sacramento, California
Crit Care Nurse 2011; 31(1): e1-e16    http://dx.doi.org/10.4037/ccn2011293
Abstract
The Impella 2.5 is a percutaneously placed partial circulatory assist device that is increasingly being used in high-risk coronary interventional procedures to provide hemodynamic support. The Impella 2.5 is able to unload the left ventricle rapidly and effectively and increase cardiac output more than an intra-aortic balloon catheter can. Potential complications include bleeding, limb ischemia, hemolysis, and infection. One community hospital’s approach to establishing a multidisciplinary program for use of the Impella 2.5 is described.
Patients who undergo high-risk percutaneous coronary intervention (PCI), such as procedures on friable saphenous vein grafts or the left main coronary artery, may have an intra-aortic balloon catheter placed if they require hemodynamic support during the procedure. Currently, the intra-aortic balloon pump (IABP) is the most commonly used device for circulatory support. A newer option that is now available for select patients is the Impella 2.5, a short-term partial circulatory support device or percutaneous ventricular assist device (VAD).
In this article, I discuss the Impella 2.5, review indications and contraindications for its use, delineate potential complications of the Impella 2.5, and discuss implications for nursing care for patients receiving extended support from an Impella 2.5. Additionally, I share our experiences as we developed our Impella program at our community hospital. Routine management of patients after PCI is not addressed.

IABP Therapy: Background

  • decreases after-load,
  • decreases myocardial oxygen consumption,
  • increases coronary artery perfusion, and
  • modestly enhances cardiac output.1,2
The IABP cannot provide total circulatory support. Patients must have some level of left ventricular function for an IABP to be effective.
Optimal hemodynamic effect from the IABP is dependent  on:
  • the balloon’s position in the aorta,
  • the blood displacement volume,
  • the balloon diameter in relation to aortic diameter,
  • the timing of balloon inflation in diastole and deflation in systole, and
  • the patient’s own blood pressure and vascular resistance.3,4

Impella 2.5 Catheter – ABIOMED, Inc.

Effect
  • reduces myocardial oxygen consumption,
  • improves mean arterial pressure, and
  • reduces pulmonary capillary wedge pressure.2

The Impella 2.5 has been used for

  • hemodynamic support during high-risk PCI and for
  • hemodynamic support of patients with
  1. myocardial infarction complicated by cardiogenic shock or ventricular septal defect,
  2. cardiomyopathy with acute decompensation,
  3. postcardiotomy shock,
  4. off-pump coronary artery bypass grafting surgery, or
  5. heart transplant rejection and
  6. as a bridge to the next decision.9
The Impella provides a greater increase in cardiac output than the other IABP provides. In one trial5 in which an IABP was compared with an Impella in cardiogenic shock patients, after 30 minutes of therapy, the cardiac index (calculated as cardiac output in liters per minute divided by body surface area in square meters) increased by 0.5 in the patients with the Impella compared with 0.1 in the patients with an IABP.
Unlike the IABP, the Impella does not require timing, nor is a trigger from an electrocardiographic rhythm or arterial pressure needed (Table 1). The device received 510(k) clearance from the Food and Drug Administration in June 2008 for providing up to 6 hours of partial circulatory support. In Europe, the Impella 2.5 is approved for use up to 5 days. Reports of longer duration of therapy in both the United States and Europe have been published.8,9
Table IABT vs Impella

Clinical Research and Registry Findings

Abiomed has sponsored several trials, including PROTECT I, PROTECT II, RECOVER I, RECOVER II, and ISAR-SHOCK.
The PROTECT I study was done to assess the safety and efficacy of device placement in patients undergoing high-risk PCI.10

Twenty patients who had

  • poor ventricular function (ejection fraction =35%) and had
  • PCI on an unprotected left main coronary artery or the
  • last remaining patent coronary artery or graft.

The device was successfully placed in all patients, and the duration of support ranged from 0.4 to 2.5 hours. Following this trial, the Impella 2.5 device received its 510(k) approval from the Food and Drug Administration.

The ISAR-SHOCK trial was done to evaluate the safety and efficacy of the Impella 2.5 versus the IAPB in patients with cardiogenic shock due to acute myocardial infarction.5 Patients were randomized to support from an IABP (n=13) or an Impella (n=12).

The trial’s primary end point of hemodynamic improvement was defined as improved cardiac index at 30 minutes after implantation.

  1. Improvements in cardiac index were greater with the Impella (P=.02).
  2. The diastolic pressure increased more with Impella (P=.002).
  3. There was a nonsignificant difference in the MAP (P=.09), as was the use of inotropic agents and vasopressors similar in both groups of patients.

Device Design: Impella 2.5 Catheter

The Impella 2.5 catheter contains a nonpulsatile microaxial continuous flow blood pump that pulls blood from the left ventricle to the ascending aorta, creating increased forward flow and increased cardiac output. An axial pump is one that is made up of impellar blades, or rotors, that spin around a central shaft; the spinning of these blades is what moves blood through the device.13

The Impella 2.5 catheter has 2 lumens. A tubing system called the Quick Set-Up has been developed for use in the catheterization laboratory. It is a single tubing system that bifurcates and connects to each port of the catheter. This arrangement allows rapid initial setup of the console so that support can be initiated quickly. When the Quick Set-Up is used, the 10% to 20% dextrose solution used to purge the motor is not heparinized. One lumen carries fluid to the impellar blades and continuously purges the motor to prevent the formation of thrombus. The proximal port of this lumen is yellow. The second lumen ends near the motor above the level of the aortic valve and is used to monitor aortic pressure.
The components required to run the device are assembled on a rolling cart and include the power source, the Braun Vista infusion pump, and the Impella console. The Impella console powers the microaxial blood pump and monitors the functioning of the device, including the purge pressure and several other parameters. The console can run on a fully charged battery for up to 1 hour.

Placement of the Device

The Impella 2.5 catheter is placed percutaneously through the common femoral artery and advanced retrograde to the left ventricle over a guidewire. Fluoroscopic guidance in the catheterization laboratory or operating room is required. After the device is properly positioned, it is activated and blood is rapidly withdrawn by the microaxial blood pump from the inlet valve in the left ventricle and moved to the aorta via the outlet area, which sits above the aortic valve in the aorta.
If the patient tolerates the PCI procedure and hemodynamic instability does not develop, the Impella 2.5 may be removed at the end of the case, or it can be withdrawn, leaving the arterial sheath in place, which can be removed when the patient’s activated clotting time or partial thromboplastin time has returned to near normal levels. For patients who become hemodynamically unstable or who have complications during the PCI (eg, no reflow, hypotension, or lethal arrhythmias), the device can remain in place for continued partial circulatory support, and the patient is transported to the critical care setting.

Potential Complications of Impella Therapy

The most commonly reported complications of Impella 2.5 placement and support include

  • limb ischemia,
  • vascular injury, and
  • bleeding requiring blood transfusion.6,9
Hemolysis is an inherent risk of the axial construction, and results in transfusions.5,10
Hemolysis can be mechanically induced when red blood cells are damaged as they pass through the microaxial pump. Other potential complications include
  • aortic valve damage,
  • displacement of the distal tip of the device into the aorta,
  • infection, and
  • sepsis.
  • Device failure, although not often reported, can occur.
Patients on Impella 2.5 support who may require
  • interrogation of a permanent pacemaker or
  • implantable cardioverter defibrillator
present an interesting situation. In order for the interrogator to connect with the permanent pacemaker or implantable cardioverter defibrillator, the Impella console must be turned off for a few seconds while the signal is established. As soon as the signal has been established, Impella support is immediately restarted.

Impella 2.5 Console Management

The recommended maximum performance level for continuous use is P8. At P8, the flow rate is 1.9 to 2.6 L/min and the motor is turning at 50000 revolutions per minute. When activated, the console is silent. No sound other than alarms is audible during Impella support, unlike the sound heard with an IABP. Ten different performance levels ranging from P0 to P9 are available. As the performance level increases, the flow rate and number of revolutions per minute increase. At maximum performance (P9), the pump rotates at 50000 revolutions per minute and delivers a flow rate of 2.1 to 2.6 L/min. P9 can be activated only for 5-minute intervals when the Impella 2.5 is in use.

IV.  PROTECT II Study – Experts Discussion

the use of the Impella support device and the intraortic balloon pump for high-risk percutaneous coronary intervention
 
DR. SMALLING: Well, the idea about the PROTECT trial is that it would show that using the Impella device to support high-risk angioplasty was not inferior to utilizing the balloon pump for the same patient subset. Ejection fraction’s were in the 30%–35% range. Supposedly last remaining vessel or left main disease or left-main plus three-vessel disease and low EF; so I think that was the screening for entry into the trial.
major adverse cardiac event endpoints
  1. Acute myocardial infarction,
  2. mortality,
  3. bleeding,
mortality was the same. Their endpoints really didn’t show that much difference. In subgroup analysis, they felt that they Impella may have had a little advantage over balloon pump.
DR. KERN: So do you think this study would tip the interventionalist to move in one direction or the other for high-risk angioplasty?
DR. SMALLING: That’s an interesting concept, you know? One has to get to: What is really a high-risk angioplasty. I think you and I are both old enough to remember that back in the mid-’80s, we determined that high-risk angioplasty was a patient with an ejection fraction of 25% or less, with a jeopardy score over 6. The EFs were a little higher. And, I guess, based on our prior experience with other support devices — like, for instance, CPS and then, later on, the Tandem Heart — there really was not an advantage of so-called more vigorous support systems. And so, the balloon pump served as well.
DR. SMALLING:
Those of us that have looked carefully at what it can really do, I think it may get one liter a minute at most, maybe more.1-6 But I think, for all intents and purposes, it doesn’t support at a very vigorous level. So I think personally, if I had someone I was really worried about, I would opt for something more substantial like, for instance, a Tandem Heart device.
DR. KERN: I think this is a really good summary of the study and the. Are there any final thoughts for those of us who want to read the PROTECT II study when it comes out?
DR. SMALLING: We have to consider a $20,000, $25,000 device. Is that really necessary to do something that we could often do without any support at all, or perhaps with a less costly device like a balloon pump.
DR. KERN: We’re going to talk for a few minutes about the PROTECT II study results that were presented here in their form. And Ron, I know you’ve been involved with following the work of the PROTECT II investigators. Were you a trial site for this study?
DR. WAKSMAN: No, actually, we were not, but we have a lot of interest in high-risk PCI and using devices to make this safe — mainly safe — and also effective. We were not investigators, but we did try to look, based on the inclusion/exclusion criteria, on our own accord with the balloon pump. If you recall, this study actually was comparing balloon time to the Impella device for patients who are high-risk PCI.
The composite endpoint was very complicated. They added like probably nine variables there, which is unusual for a study design. … They basically estimated that the event rate on the balloon pump would be higher than what we thought it should be. So we looked at our own data, and we found out that the actual — if you go by the inclusion/exclusion criteria and their endpoints — the overall event rate in the balloon pump would be much lower than they predicted and built in their sample size.
DR. KERN: And, so, the presentation of the PROTECT II trial, was it presented as a positive study or a negative study.
DR. WAKSMAN: Overall the study did not meet the endpoint. So the bottom line, you can call it the neutral study, which is a nice way to say it.
if you go and do all those analyses, you may find some areas that you can tease a P value, but I don’t think that this has any scientific value, and people should be very careful. We’re not playing now with numbers or with statistics, this is about patient care. You’re doing a study — the study, I think, has some flaws in the design to begin with — and we actually pointed that out when we were asked to participate in the study. But if the study did not meet the endpoint, then I think all those subanalyses, subgroups, you extract from here, you add to there, and you get a P value, that means nothing. So we have to be careful when we interpret this, other than as a neutral study that you basically cannot adopt any of the … it did not meet the hypothesis, that’s the bottom line.

A first-in-man study of the Reitan catheter pump for circulatory support in patients undergoing high-risk percutaneous coronary intervention.

Smith EJ, Reitan O, Keeble T, Dixon K, Rothman MT.
Department of Cardiology, London Chest Hospital, United Kingdom.
Catheter Cardiovasc Interv. 2009 Jun 1;73(7):859-65.
http://dx.doi.org/10.1002/ccd.21865.

To investigate the safety of a novel percutaneous circulatory support device during high-risk percutaneous coronary intervention (PCI).

BACKGROUND:

The Reitan catheter pump (RCP) consists of a catheter-mounted pump-head with a foldable propeller and surrounding cage. Positioned in the descending aorta the pump creates a pressure gradient, reducing afterload and enhancing organ perfusion.

METHODS:

Ten consecutive patients requiring circulatory support underwent PCI; mean age 71 +/- 9; LVEF 34% +/- 11%; jeopardy score 8 +/- 2.3. The RCP was inserted via the femoral artery. Hemostasis was achieved using Perclose sutures. PCI was performed via the radial artery. Outcomes included in-hospital death, MI, stroke, and vascular injury. Hemoglobin (Hb), free plasma Hb (fHb), platelets, and creatinine (cre) were measured pre PCI and post RCP removal.

RESULTS:

The pump was inserted and operated successfully in 9/10 cases (median 79 min). Propeller rotation at 10,444 +/- 1,424 rpm maintained an aortic gradient of 9.8 +/- 2 mm Hg.  Although fHb increased,

  • there was no significant hemolysis (4.7 +/- 2.4 mg/dl pre vs. 11.9 +/- 10.5 post, P = 0.04, reference 20 mg/dl).
  • Platelets were unchanged (pre 257 +/- 74 x 10(9) vs. 245 +/- 63, P = NS).
  • Renal function improved (cre pre 110 +/- 27 micromol/l vs. 99 +/- 28, P = 0.004).

All PCI procedures were successful with no deaths or strokes, one MI, and no vascular complications following pump removal.

14F RCP first in man mechanical device post PCI LVEF 25% JS 10

CONCLUSIONS:

The RCP can be used safely in high-risk PCI patients.

(c) 2009 Wiley-Liss, Inc.  PMID: 19455649

Todd J. Brinton, MD and Peter J. Fitzgerald, MD, PhD, Chapter 14: VENTRICULAR ASSIST TECHNOLOGIES

http://www.sis.org/docs/2006Yearbook_Ch14.pdf

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

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

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

English: Simulation of a wave pump human ventr...

English: Simulation of a wave pump human ventricular assist device (Photo credit: Wikipedia)

English: Figure A shows the structure and bloo...

English: Figure A shows the structure and blood flow in the interior of a normal heart. Figure B shows two common locations for a ventricular septal defect. The defect allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood in the right ventricle. (Photo credit: Wikipedia)

 

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Evidence for Overturning the Guidelines in Cardiogenic Shock

Reporter: Aviva Lev-Ari, PhD, RN

 

Christopher M. O’Connor, M.D., and Joseph G. Rogers, M.D.

August 27, 2012 (10.1056/NEJMe1209601)

Cardiogenic shock complicating acute myocardial infarction continues to be a devastating event associated with extremely high mortality. The results of the Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial,1 now reported in the Journal, show that in patients with acute myocardial infarction and hemodynamic compromise who undergo revascularization, the routine use of an intraaortic balloon pump (IABP), as compared with standard therapy, does not improve survival.1

Introduced nearly five decades ago,2 IABP is now routinely used as an adjuvant treatment for myocardial infarction complicated by cardiogenic shock, on the basis of evidence that it is associated with hemodynamic improvements accompanied by enhanced coronary blood flow, increased perfusion of vital organs, maintenance of infarct-artery patency, and decreased systemic inflammation.3 Until recently, few alternatives have been available to support patients with severely compromised hemodynamics. Despite a lack of robust data from outcomes trials and meta-analyses4,5 that have shown limited efficacy, international guidelines endorse the use of IABP for treating post-myocardial infarction shock, with a class I recommendation.6,7

The IABP-SHOCK II trial could have affirmed contemporary clinical practice and guidelines. Instead, it revealed surprising results. In a comparison of IABP with standard therapy, the investigators found no difference in 30-day mortality or in any key secondary end points. Although IABP was safe, there was no evidence that it was associated with hemodynamic improvement — a mechanistic effect of IABP that has long been considered to be critical for its clinical application. Moreover, there were no benefits with respect to renal function or attenuation in lactate or C-reactive protein levels.

Conducting a randomized clinical trial in the emergency setting of acute myocardial infarction with shock is exceptionally difficult. In an era of rapid intervention in the catheterization laboratory and a pervasive perception of lack of equipoise, the IABP-SHOCK II investigators should be commended for completing a moderate-sized trial in 3 years at 37 sites. The results of the trial have important clinical implications, but several issues must be addressed. First, this 600-patient study could be considered too small to be definitive. However, the conclusions are bolstered by more than 240 primary end-point events, making them far more robust than might be surmised from the sample size alone. Second, the patients represented a moderate-risk cohort, with a 30-day mortality of 40%. This rate is lower than that reported in other trials involving patients with cardiogenic shock, so the results may not be applicable to the highest-risk patients. In the decade since the original Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock (SHOCK) trial was reported,8 emphasis on early revascularization and increased use of background medical therapies would be anticipated to have favorably altered the natural history of cardiogenic shock occurring after myocardial infarction, leading to lower 30-day mortality. Third, asymmetry in the number of crossovers may have influenced the final results analyzed according to the intention-to-treat principle. However, a per-protocol analysis (which included all the patients who had confirmed acute myocardial infarction, with the exclusion of those who crossed over) and an adjusted multivariate model showed similar nonsignificant results. Finally, favorable trends with IABP were observed in younger patients and in those with a first myocardial infarction, although these findings can be considered only as hypothesis-generating. Given the concordance of data from the meta-analyses and the current trial, the data do not support the routine use of IABP in patients with acute myocardial infarction complicated by cardiogenic shock, and the level I guideline recommendation is now strongly challenged. Members of guideline committees and clinicians should take note of another example of a recommendation that is based on insufficient data.

The results of the IABP-SHOCK II trial parallel those from many recent outcome trials that have challenged our understanding of the management of acute and chronic heart failure, including those regarding the use of pulmonary artery catheters9 and the role of revascularization in ischemic cardiomyopathy.10

Therapeutic strategies for patients with cardiogenic shock have changed abruptly and are ready for renewed growth and development. Although many will find the results of the IABP-SHOCK II trial disappointing, we must recognize the opportunity to develop novel and innovative strategies to treat this condition. Integrated systems to ensure rapid reperfusion may reduce the incidence of shock among patients who have had an acute myocardial infarction.11 Secondary analyses of data from the IABP-SHOCK II trial may help us understand the mechanisms of the failed response. Comparing the patient populations and outcomes of the IABP-SHOCK II study groups and the concurrent registry cohort may yield important insights, with therapeutic implications for the use of other mechanical devices for circulatory support. On the basis of the findings of the IABP-SHOCK II trial, we must move forward with the understanding that a cardiovascular condition with 40% mortality at 30 days remains unacceptable. Most important, we hope that the results of this trial will galvanize a broadly based mandate to address this devastating clinical problem by reestablishing equipoise and international engagement in research on novel devices and pharmacologic therapies.

This article was published on August 27, 2012, at NEJM.org.

Source Information

From Duke University, Durham, NC.

http://www.nejm.org/doi/full/10.1056/NEJMe1209601

 

Intraaortic Balloon in Cardiogenic Shock 

Original Article

Intraaortic Balloon Support for Myocardial Infarction with Cardiogenic Shock

H. Thiele and Others

In current international guidelines, intraaortic balloon counterpulsation (IABP) is considered to be a class I treatment for cardiogenic shock complicating acute myocardial infarction. However, evidence is based mainly on registry data, and there is a paucity of randomized clinical trials.

Clinical Pearls

  What were the results of this study, which compared intraaortic balloon counterpulsation or no intraaortic balloon counterpulsation in patients with cardiogenic shock complicating acute myocardial infarction?

At 30 days, mortality was similar among patients in the IABP group and those in the control group (39.7% and 41.3%, respectively; relative risk with IABP, 0.96; 95% confidence interval, 0.79 to 1.17; P=0.69).

Table 3.Clinical Outcomes.

Figure 1. Time-to-Event Curves for the Primary End Point.

  Among patients who received IABP, did results differ between those who had the IABP inserted before versus after revascularization?

Among patients in the IABP group, there was no significant difference in mortality between the patients (13.4%) in whom the balloon pump was inserted before revascularization and the patients (86.6%) in whom the balloon pump was inserted after revascularization (mortality, 36.4% and 36.8%, respectively; P=0.96).

Morning Report Questions

Q. Did safety end points differ between the two groups? 

A. There were no significant differences between the IABP group and the control group with respect to the rates of stroke, bleeding, sepsis, or peripheral ischemic complications requiring intervention in the hospital. There were also no significant differences in the rates of reinfarction or stent thrombosis.

Q. How do the authors explain the effect of intraaortic balloon counterpulsation in this trial on the factors that are known to cause death in patients with cardiogenic shock? 

A. Death in patients with cardiogenic shock can result from one or more of three factors: hemodynamic deterioration, occurrence of multiorgan dysfunction, and development of the systemic inflammatory response syndrome. There was no immediate improvement in blood pressure or heart rate among patients in whom an intraaortic balloon pump was inserted, as compared with those who did not have a balloon pump inserted. Although there was a positive effect of intraaortic balloon counterpulsation on multiorgan dysfunction at day 2 and day 3, this effect was not evident at day 4. There were also no significant effects on C-reactive protein level or serum lactate level, which were assessed as measures of inflammation and tissue oxygenation. Experimental and clinical studies have indicated that intraaortic balloon counterpulsation results in a hemodynamic benefit as a result of afterload reduction and diastolic augmentation with improvement in coronary perfusion. The authors postulate that the effects on cardiac output are modest and might not be sufficient to reduce mortality.

 source:

NEJM Resident E-Bulletin <resebulletin@nejm.org> on 10/3/2012

References

    1. 1Thiele H, Zeymer U, Neumann F-J, et al. Intraaortic balloon support for myocardial infarction with cardiogenic shock. N Engl J Med 2012. DOI: 10.1056/NEJMoa1208410.

    1. 2Kantrowitz A, Tjonneland S, Freed PS, Phillips SJ, Butner AN, Sherman JL Jr. Initial clinical experience with intraaortic balloon pumping in cardiogenic shock. JAMA 1968;203:113-118
      CrossRef | Web of Science | Medline

    1. 3Ohman EM, George BS, White CJ, et al. Use of aortic counterpulsation to improve sustained coronary artery patency during acute myocardial infarction: results of a randomized trial. Circulation 1994;90:792-799
      CrossRef | Web of Science

    1. 4Sjauw KD, Engstrom AE, Vis MM, et al. A systematic review and meta-analysis of intra-aortic balloon pump therapy in ST-elevation myocardial infarction: should we change the guidelines? Eur Heart J 2009;30:459-468
      CrossRef | Web of Science

    1. 5Unverzagt S, Machemer MT, Solms A, et al. Intra-aortic balloon pump counterpulsation (IABP) for myocardial infarction complicated by cardiogenic shock. Cochrane Database Syst Rev 2011;7:CD007398-CD007398

    1. 6Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1999 Guidelines for the Management of Patients with Acute Myocardial Infarction). Circulation 2004;110:e82-e292[Erratum, Circulation 2005;111:2013-4, 2007;115(5):e411, 2010;121(23):e441.]
      CrossRef | Medline

    1. 7Van de Werf F, Bax J, Betriu A, et al. Management of acute myocardial infarction in patients presenting with persistent ST-segment elevation. Eur Heart J 2008;29:2909-2945
      CrossRef | Web of Science | Medline

    1. 8Hochman JS, Sleeper LA, Webb JG, et al. Early revascularization in acute myocardial infarction complicated by cardiogenic shock. N Engl J Med 1999;341:625-634
      Full Text | Web of Science | Medline

    1. 9Binanay C, Califf RM, Hasselblad V, et al. Evaluation study of congestive heart failure and pulmonary artery catheterization effectiveness: the ESCAPE trial. JAMA 2005;294:1625-1633
      CrossRef | Web of Science | Medline

    1. 10Velazquez EJ, Lee KL, Deja MA, et al. Coronary-artery bypass surgery in patients with left ventricular dysfunction. N Engl J Med 2011;364:1607-1616
      Full Text | Web of Science | Medline

  1. 11Jollis JG, Roettig ML, Aluko AO, et al. Implementation of a statewide system for coronary reperfusion for ST-segment elevation myocardial infarction. JAMA 2007;298:2371-2380
    CrossRef | Web of Science | Medline

Related posts to this topic on this Scientific Web Site:

Foreseen changes in Guideline of Treatment of Cardiogenic Shock with Intra-aortic Balloon counterPulsation (IABP)

https://pharmaceuticalintelligence.com/2012/08/27/foreseen-changes-in-guideline-of-treatment-of-cardiogenic-shock-with-intra-aortic-balloon-counterpulsation-iabp/

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Reporter: Aviva Lev-Ari, PhD, RN

SHOCK II: IABP Use Questioned

When myocardial infarction (MI) is complicated by cardiogenic shock, use of intraaortic balloon counterpulsation (IABP) did not reduce mortality among patients scheduled for revascularization–a finding that calls into question current guidelines for treating cardiogenic shock in this population.

 SHOCK II: IABP Use Questioned

By Peggy Peck, Editor-in-Chief, MedPage Today
Published: August 27, 2012

Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco

Action Points

 

Action Points

 

  • When myocardial infarction (MI) is complicated by cardiogenic shock, use of intraaortic balloon counterpulsation (IABP) did not reduce mortality among patients scheduled for revascularization, a finding that calls into question current guidelines for treating cardiogenic shock in this population.
  • Note that authors of an editorial wrote that data from IABP-SHOCK II, and a number of recent meta-analyses, “do not support the routine use of IABP in patients with acute myocardial infarction complicated by cardiogenic shock, and the level I guideline recommendation is now strongly challenged.”

When myocardial infarction (MI) is complicated by cardiogenic shock, use of intraaortic balloon counterpulsation (IABP) did not reduce mortality among patients scheduled for revascularization — a finding that calls into question current guidelines for treating cardiogenic shock in this population.

At 30 days, only 60% of the patients treated with IABP were still alive, a mortality that was no different from the rate in the control group (39.7% versus 41.3% relative risk 0.96, 95% CI 0.79-1.17, P=0.69), according to findings from the IABP-SHOCK II trial reported online by the New England Journal of Medicine.

The findings were simultaneously reported as a Hot Line presentation at the European Society of Cardiology meeting in Munich.

Holger Thiele, MD, from University of Leipzig-Heart Center, Leipzig, Germany, and colleagues recruited 600 patients for a randomized, prospective, open-label, multicenter trial and assigned 300 to IABP.

 While there was no mortality benefit for IABP, there also was no apparent harm:

Rates of major bleeding: 3.3% versus 4.4% in controls (P=0.53)
Rates of sepsis: 15.7% versus 20.5% (P=0.15)
Rates of stroke: 0.7% versus 1.7% (P=0.28)
Rates of peripheral ischemic complications: 4.3% versus 3.4% (P=0.53)
Current American College of Cardiology/American Heart Association guidelines for treatment of STEMI support use of IABP in this population, but that recommendation comes from a trial “that did not address this question, it really looked at the question of revascularization of these patients,” said Mariell Jessup, MD, of the University of Pennsylvania Perelman School of Medicine in Philadelphia.

The earlier trial, called SHOCK (Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock), “was really about bypass surgery in these patients,” she said.

Jessup, who is president-elect of the American Heart Association, told MedPage Today, that the results of the IABP-SHOCK II trial “may very well be the most important finding to be reported at this meeting.”

She said the current Class I recommendation is for use of IABP when the patient is not stable. “It is possible that this [IABP-SHOCK II] could completely change this guideline.”

Jessup noted that use of IABP has become the norm for treating these patients and she suggested that physicians will find it hard to resist using IABP because “it is hard for physicians to not do something for these patients.”

Christopher O’Connor, MD, and Joseph Rogers, MD, echoed Jessup’s view in an NEJM editorial. They are from Duke University in Durham, N.C.

Under the title, “Evidence for Overturning the Guidelines in Cardiogenic Shock” O’Connor and Rogers wrote that data from IABP-SHOCK II, and a number of recent meta-analyses, “do not support the routine use of IABP in patients with acute myocardial infarction complicated by cardiogenic shock, and the level I guideline recommendation is now strongly challenged. Members of guideline committees and clinicians should take note of another example of a recommendation that is based on insufficient data.”

Patients in the IAPB-SHOCK trial were recruited from June 16, 2009 through March 3, 2012 at 37 centers in Germany.

Thirty of the 299 patients assigned to the control group did eventually undergo IABP, usually within 24 hours of randomization, and 26 of those patients were classified as protocol violations. Likewise, 13 patients assigned to IABP did not undergo the treatment, with death being the most common reason.

The authors noted a number of limitations, starting with lack of blinding, and the failure to obtain “hemodynamic measurements or assess laboratory inflammatory markers other than blood pressure, heart rate, and C-reactive protein levels.”

Also, the mortality rate in both arms was lower than anticipated — 40% versus a range of 42% to 48% in other studies — suggesting that most patients in this study had mild or moderate cardiogenic shock, which could limit the generalizability of these results, they cautioned.

“Finally, we do no yet have any information about longer-term outcomes. Since a balloon intraaortic counterpulsation was used for a median of only 3 days, it seems unlikely that any beneficial effect will become evident later than 30 days,” they wrote.

The trial was supported by the German Research Foundation, the German Heart Foundation, the German Cardiac Society, Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte, the University of Leipzig-Heart Center, Marquet Cardiopulmonary, and Teleflex Medical.

Thiele disclosed financial support from Eli Lilly, Terumo, AstraZeneca, Boehringer Ingelheim, Daiichi Sankyo, Eli Lilly, and the Medicines Company.

Primary source: New England Journal of Medicine

Source reference:

Thiele H, et al. “Intraaortic balloon support for myocardial infarction with cardiogenic shock” N Engl J Med 2012; DOI: 10.1056/NEJMoal208410.

Additional source: New England Journal of Medicine

Source reference:
O’Connor CM, Rogers JG. “Evidence for overturning the guidelines in cardiogenic shock” N Engl J Med 2012; DOI: 10.1056/NEJMel209601.

http://www.medpagetoday.com/Cardiology/PCI/34387

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