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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)

Posted in Cardiac & Vascular Repair Tools Subsegment, Cardiac and Cardiovascular Surgical Procedures, Ecosystems & Industrial Concentration in the Medical Device Sector, FDA Regulatory Affairs, Frontiers in Cardiology and Cardiovascular Disorders, Health Economics and Outcomes Research, Interviews with Scientific Leaders, Mechanical Assist Devices: LVAD, RVAD, BiVAD, Artificial Heart, Medical Devices R&D and Inventions, Medical Devices R&D Investment, Mitral Valve: Repair and Replacement, PCI, Regulated Clinical Trials: Design, Methods, Components and IRB related issues, Statistical Methods for Research Evaluation, Stents & Tools, Technology Transfer: Biotech and Pharmaceutical, tagged Cardiogenic Shock, Cleveland Clinic, Conventional PCI, Doctor of Philosophy, Food and Drug Administration, IABP, Intra-aortic balloon pump, Left ventricle, New England Journal of Medicine, Percutaneous coronary intervention, Sutter Medical Center, Thoratec, Thrombus, Ventricular assist device on July 17, 2013| 2 Comments »

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 BARRY MEIER

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 Medicine posted 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

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

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 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.

http://www.texasheartinstitute.org/Research/Devices/impella.cfm

The Pump

The Impella Recover LD 5.0 showing implantation via direct placement into the left ventricle.

Insert B – location in LV

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

Potential Algorithm for Device Selection during Cardiogenic Shock

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 Shock: traditional 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

myocardial infarction complicated by cardiogenic shock or ventricular septal defect,
cardiomyopathy with acute decompensation,
postcardiotomy shock,
off-pump coronary artery bypass grafting surgery, or
heart transplant rejection and
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

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.

Improvements in cardiac index were greater with the Impella (P=.02).
The diastolic pressure increased more with Impella (P=.002).
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

Acute myocardial infarction,
mortality,
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.

CONCLUSIONS:

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

Travis gets booster device to help his heart pump blood (usatoday.com)
Opening Blocked Arteries With PTCA (heartdisease.answers.com)
Survivals Comparison of Coronary Artery Bypass Graft (CABG) and Percutaneous Coronary Intervention (PCI) / Coronary Angioplasty (emberbranch.wordpress.com)
Boston Scientific launches stent-placing device (bizjournals.com)
Unclogging Heart Arteries Via Wrists On The Rise; Minimizes Bleeding Complications (hngn.com)
Dual Antiplatelet Therapy Following Coronary Stent Implantation Associated With Significant Improvement (medindia.net)

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

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

Ventricular Assist Device (VAD): A Recommended Approach to the Treatment of Intractable Cardiogenic Shock

Posted in Cardiac & Vascular Repair Tools Subsegment, Cardiac and Cardiovascular Surgical Procedures, Cardiovascular Pharmacogenomics, Chemical Biology and its relations to Metabolic Disease, Coagulation Therapy and Internal Bleeding, Electrophysiology, Medical Devices R&D and Inventions, Medical Devices R&D Investment, Origins of Cardiovascular Disease, Pharmacotherapy of Cardiovascular Disease, Technology Transfer: Biotech and Pharmaceutical, tagged Cardiogenic Shock, Cardiovascular Disorders, Columbia University Medical Center, Conditions and Diseases, Electrocardiography, Heart disease, myocardial infarction, Thoratec, United States, Ventricular assist device on June 18, 2013| 7 Comments »

Ventricular Assist Device (VAD): A Recommended Approach to the Treatment of Intractable Cardiogenic Shock

Writer: Larry H Bernstein, MD, FCAP

and

Curator: Aviva Lev-Ari, PhD, RN

A ventricular assist device (VAD) is an implantable mechanical pump that helps pump blood from the lower chambers of your heart (the ventricles) to the rest of your body. VADs are used in people who have weakened hearts or heart failure. Although VADs can be placed in the left, right or both ventricles of your heart, they are most frequently used in the left ventricle. When placed in the left ventricle they are called left ventricular assist devices (LVADs).

You may have a VAD implanted while you wait for a heart transplant or for your heart to become strong enough to effectively pump blood on its own. Your doctor may also recommend having a VAD implanted as a long-term treatment if you have heart failure and you’re not a good candidate for a heart transplant.

The procedure to implant a VAD requires open-heart surgery and has serious risks. However, a VAD can be lifesaving if you have severe heart failure.

http://www.mayoclinic.com/health/lvad/MY01077

This is an assessment of the development and progression of cardiogenic shock and review of the use of ventricular assist devices in that setting. It is another piece of the chapter on cardiothoracic surgical management at Columbia University Medical Center, New York, NY.

Heart Lung. 2012 Sep-Oct;41(5):500-4. http://dx.doi.org/10.1016/j.hrtlng.2012.03.007.___Epub 2012 May 16.

A stepwise progression in the treatment of cardiogenic shock.

Pollack A, Uriel N, George I, Kodali S, Takayama H, Naka Y, Jorde U.

Source

Department of Medicine, New York Presbyterian Hospital/Columbia University Medical Center, New York, New York, USA.

Abstract

Cardiogenic shock remains a deadly complication of acute myocardial infarction (MI). Early revascularization, inotropic support, and intraaortic balloon counterpulsation are the mainstays of treatment, but these are not always sufficient. New mechanical approaches, both percutaneous and surgical, are available in this high-risk population. We present a case of a young woman with a massive anterior wall MI and subsequent cardiogenic shock who was treated with advanced mechanical circulatory support. This case serves as an illustration of the stepwise escalation of mechanical support that can be applied in a patient with an acute MI complicated by refractory cardiogenic shock. We also review the literature with regard to the use of percutaneous left ventricular assist devices in the setting of cardiogenic shock.

PMID: 22608034

Care of the Critically Ill: A Stepwise Progression in the Treatment of Cardiogenic Shock.

Pollack A, Uriel N, George I, Kodali S, Takayama H, Naka Y, Jorde U

J Heart & Lung 2012; 41:500-504.

http://dx.doi.org/10.1016/j.hrtlng.2012.03.007

Initial Presentation

A 21-year-old woman with a history of migraine headaches was admitted to the hospital with nonradiating substernal chest pain onset that morning. When she presented to another hospital she had a normal electrocardiogram (EKG) and was discharged. When the patient’s chest discomfort became crushing she presented again to the same hospital where her EKG revealed ST-segment elevations in an anterolateral distribution. Her peak (hs) troponin was 229 ng/mL and peak creatinine kinase was 6900 U/L. This was an elevation of CK far out of proportion to the troponin increase (suggestive of decreased peripheral circulation with massive release of CK from muscle). There was no family history of early myocardial infarction (MI), sudden cardiac death, clotting disorders, or hypercholesterolemia. She had been taking amitriptyline for migraines and oral contraceptives for 3 years. The patient developed significant hypotension, after she was given metoprolol and morphine, for which dobutamine and dopamine were administered. Medication was switched to norepinephrine because of excessive tachycardia. Cardiac catheterization was performed emergently approximately 12 hours after the onset of the patient’s chest pain.

Thrombectomy of an angiographically identified clot in the proximal portion of the left anterior descending artery was performed, followed by placement of a bare metal stent with no residual occlusion. An intraaortic balloon bump (IABP) was placed. The initial transthoracic echocardiogram revealed an ejection fraction of 25% and global hypokinesis with regional wall motion abnormalities, worst in the anterior, apical, and lateral walls. She was intubated and required significant hemodynamic support with norepinephrine. Her antiplatelet regimen consisted of oral aspirin, clopidogrel, and intravenous eptifibatide. The patient was transferred to the New York Presbyterian Hospital/Columbia University Medical Center approximately 12 hours after revascularization.

Transfer to NY Presbyteran Columbia Hospital

On arrival, the patient was intubated and sedated. Her blood pressure was 80/51mmHg, pulse rate was 140 beats/min, and oral temperature was 101F. On examination, she was tachycardic with warm extremities. The jugular veins were not distended. Her lactate was 7.0 mmol/L. (If she was so severely hypotensive with lactic acidemia, possibly from impaired liver and/or muscle circulation with aerobic glycolysis, then why was the temperature 101 deg F?) The patient was not tested for procalcitonin (Brahms, BioMerieux), but sepsis is now considered bacterial or abacterial. Whether there was release of bacterial endotoxin secondary to poor decreased circulation in the superior mesenteric artery is not known, which complicates the situation more. In a study of acute phase changes in liver proteins by Bernstein and associates [Transthyretin as a marker to predict outcome in critically ill patients. Devakonda A, George L, Raoof S, Esan A, Saleh A, Bernstein LH. Clin Biochem 2008; 41(14-15):1126-1130. ICID: 939927], and another on procalcitonin and sepsis [The role of procalcitonin in the diagnosis of sepsis and patient assignment to medical intensive care. Bernstein LH, Devakonda A, Engelman E, Pancer G, Ferrar J, Rucinski J, Raoof S, George L, Melniker L. J Clin Ligand Assay] there was a notable case of negative bacterial culture in a patient with highly elevated procalcitonin, considered a reliable early indicator of sepsis.

Procalcitonin (PCT) is a sensitive and specific inflammation marker, which can be used to detect both inflammatory infections and noninflammatory complications in postsurgical monitoring of patients after cardiac surgery using extracorporeal circulation. The optimum cut-off value for PCT levels, as a predictor of postoperative complications, appears to be 1.2 ng/mL with a sensitivity of 80% and a specificity of 90%. PCT may be used to monitor response to therapy because blood concentrations increase in an inflammatory disease relapse. Importance of procalcitonin in post-cardiosurgical patients. Topolcan O, Bartunek L, Holubec Jr L, Polivkova V, eta al. Journal of Clinical Ligand Assay 2008; 31(1-4): 57-60.]This might be expected to be associated with a CRP increase over 50-70 mg/ml. In addition, the hemogram would have been of some interest, perhaps raising the question of whether the cardiovascular impairment triggered other events [Validation and Calibration of the Relationship between Granulocyte Maturation and the Septic State. Bernstein LH and Rucinski J. Clin Chem Lab Med 2011; 49. Walter de Gruyter . http://dx.doi.org/10.1515cclm.2011.688. Converting Hematology Based Data into an Inferential Interpretation. Bernstein LH, David G, Rucinski J and Coifman RR. In Hematology – Science and Practice, 2012. Chapter 22, pp 541-552. InTech Open Access Publ. Croatia].

A chest radiograph showed pulmonary edema. Her EKG revealed sinus tachycardia at 121 beats/min with ST-segment elevation of 3 mm in leads V1 to V4 and poor R-wave progression throughout the precordial leads with pathologic Q waves in V1 to V6, I, and aVL. Eptifibatide (Integrilin, Merck & Co., Inc., Whitehouse Station, NJ) was stopped, and norepinephrine was continued at 20 mg/min. Dobutamine 2.5 mg/min and broad-spectrum antibiotics were administered. During the next 4 hours, the patient’s mean arterial pressure fluctuated between 60 and 70 mm Hg with a heart rate between 120 and 140 beats/min on 20 mg/min of norepinephrine, 2.5 mg/min of dobutamine, and the IABP. Rapid escalation of mechanical support with a left ventricular assist device (LVAD) was deemed necessary. Right-sided heart catheterization after placement of an Impella 2.5 assist device (ABIOMED, Inc.) revealed a cardiac output of 3.3 L/min and a cardiac index (CI) of 2.1 L/min/m2, despite addition of 3 ug/min and 4 U/h of vassopressin.

Day 2

On the second day after transfer she was severely hyponatremic, but her plasma sodium stabilized at 131 to 138 mmol/L after discontinuing the vasopressin. She also developed significant bleeding at the site of the Impella and hemolysis requiring several blood transfusions. Her hemoglobin on transfer was 10.4 g/dL, which trended down to 7.8 g/dL after Impella placement. The patient’s lactate dehydrogenase was 1980 U/L (probably reflecting poor liver perfusion), and total bilirubin was 2.6 mg/dL on day 2 of her hospitalization compared with 1.1 mg/dL on transfer.

Day 3

After the Impella device was removed on day 3 because of persistent bleeding, the patient’s hemoglobin, bilirubin, and platelet count stabilized, but while the patient was able to maintain end-organ perfusion initially as manifested by a normal creatinine, as the day progressed, the patient’s systemic blood pressure trended downward and urine output decreased, and she could not tolerate discontinuation of the vasoactive agents being administered. Pulmonary hypertension developed with a rate-dependent cardiac output as manifested by persistent tachycardia, and had an ejection fraction of 20% with severe hypokinesis of all segments except the basal inferior and inferolateral walls. As a consequence of the enduring cardiogenic shock and the low likelihood for recovery of left ventricular function, it was evident the patient required long-term mechanical support. A continuous flow LVAD (HeartMate II; Thoratec Corporation) was implanted as a rescue therapy, and the patient was emergently listed for transplantation.

Recovery

A comprehensive heart failure regimen was introduced, and the patient was discharged with warfarin 25 days after her transfer. A comprehensive hypercoagulability workup performed while the patient was receiving anticoagulation with negative results. Aside from oral contraceptive use, no other obvious risk factor for an acute arterial thrombosis could be identified, which is not surprising given that up to 40% of all thrombotic events occur in patients without a recognizable risk factor. Early revascularization, inotropic support, and intraaortic balloon counterpulsation are the mainstays of treatment, but these are not always sufficient. New mechanical approaches, both percutaneous and surgical, are available in this high-risk population. This case serves as an illustration of the stepwise escalation of mechanical support that can be applied in a patient with an acute MI complicated by refractory cardiogenic shock. We also review the literature with regard to the use of percutaneous left ventricular assist devices in the setting of cardiogenic shock.

Recommendation

The authors recommend the following protocol for patients with cardiogenic shock superimposed on acute MI. Treatment of cardiogenic shock. PCI, percutaneous coronary intervention; IABP, intraaortic balloon pump; VAD, ventricular assist device; VA-ECMO, venoarterial extracorporeal membrane oxygenation; OHT, orthotopic heart transplantation; pVAD, percutaneous ventricular assist device. It is important to note that it includes immediate revascularization in conjunction with IABP placement. In patients with refractory cardiogenic shock who are unable to be weaned from the IABP, mechanical circulatory support using a percutaneous or surgical device is the next essential measure to be taken. The type of mechanical support to be used depends on many factors, including the reversibility of the shock state, chances of ventricular recovery, and risk of bleeding. Mechanical circulatory support with left ventricular assists devices can improve cardiac performance and reduce myocardial ischemic injury. Principle mechanisms include unloading of the left ventricle, thereby decreasing myocardial oxygen demand and improvement of systemic hypotension, thus increasing coronary perfusion.

Although there were complications related to the use of the device, its deployment resulted in the improvement of the patient’s surgical candidacy by virtue of maintaining her end-organ function. After the removal of the Impella device, we thought the left ventricle in this patient would not recover, and for this reason, we chose a definitive surgical procedure as opposed to alternative temporary support device. Clinical studies focusing on the use of VA-ECMO in refractory cardiogenic shock after an acute MI are limited. Observational and retrospective series have thus far demonstrated a high mortality rate in these patients. However, a recent retrospective study of 33 patients who received ECMO support for advanced refractory cardiogenic shock after an acute MI demonstrated a mortality rate of 46% and 52% at 30 days and 1 year, respectively. In addition to mny complications with VA-ECMO, the procedure also can lead to increased afterload from the retrograde flow of peripheral cannulation., which may to lead to increased left ventricular pressure and wall stress, thereby compromising myocardial recovery and worsening pulmonary edema, both of which were major concerns

in this patient.

Conclusions

This case demonstrates that a sequential approach using percutaneous mechanical support as a bridge to surgical mechanical support is feasible in this high-risk population (Figure ). Advantages of percutaneous mechanical support include its rapid and straightforward placement. Disadvantages include its limited cardiac output and bleeding. Future technology should focus on a device that is capable of providing significant cardiac output and that can be easily placed, like the Impella. Such a device could alter the natural history of intractable cardiogenic shock.