Chronic Mechanical Circulatory Support for Inotrope-Dependent Heart Failure Patients Who Are Not Transplant Candidates

Molecular risk stratification in advanced heart failure patients

Risk stratification in advanced heart failure (HF) is crucial for the individualization of therapeutic strategy, in particular for heart transplantation and ventricular assist device implantation. We tested the hypothesis that cardiac gene expression profiling can distinguish between HF patients with different disease severity. We obtained tissue samples from both left (LV) and right (RV) ventricle of explanted hearts of 44 patients undergoing cardiac transplantation or ventricular assist device placement. Gene expression profiles were obtained using an in-house microarray containing 4217 muscular organ-relevant genes. Based on their clinical status, patients were classified into three HF-severity groups: deteriorating (n= 12), intermediate (n= 19) and stable (n= 13). Two-class statistical analysis of gene expression profiles of deteriorating and stable patients identified a 170-gene and a 129-gene predictor for LV and RV samples, respectively. The LV molecular predictor identified patients with stable and deteriorating status with a sensitivity of 88% and 92%, and a specificity of 100% and 96%, respectively. The RV molecular predictor identified patients with stable and deteriorating status with a sensitivity of 100% and 96%, and a specificity of 100% and 100%, respectively. The molecular prediction was reproducible across biological replicates in LV and RV samples. Gene expression profiling has the potential to reproducibly detect HF patients with highest HF severity with high sensitivity and specificity. In addition, not only LV but also RV samples could be used for molecular risk stratification with similar predictive power.

Destination therapy: current results and future promise

The landmark Randomized Evaluation of Mechanical Assistance in the Treatment of Congestive Heart Failure (REMATCH) trial demonstrated that the implantation of left ventricular assist devices (LVADs) as an alternative to heart transplantation, or destination therapy (DT) is superior to any known medical therapy in patients with end-stage heart failure who are not eligible for transplantation. In this article, we review results of the first United States and European clinical trials of DT, including the REMATCH, the Investigation of the Non-Transplant Eligible Patients who are Inotrope Dependent (INTREPID), and the Clinical Utility Baseline Study (CUBS) trials, as well as the outcomes of the first DT implantations in the post-REMATCH era in the United States. The article summarizes the current state of knowledge and future directions in the field of permanent mechanical circulatory support therapy as an alternative to heart transplantation.

Circulatory assist devices in heart failure patients

Optimal medical therapy may ameliorate acute cardiogenic shock and long-term congestive heart failure symptoms; however, in certain cases mechanical circulatory assistance may be helpful or even required. Different devices can be considered based on the anticipated duration of need and the acuity of the cardiovascular failure being treated. A working knowledge of balloon pumps and ventricular assist devices, their indications, function, and potential complications, allows the physician to provide optimal care for those patients presenting with such a device.

Panoramic view of the Fifth International Symposium on Stem Cell Therapy and Applied Cardiovascular Biotechnology, April 2008, Madrid (Spain)

The Fifth International Symposium on Stem Cell Therapy and Applied Cardiovascular Biotechnology was held on April 24th-25th, 2008, at the Auditorium of the High Council of Scientific Research of Spain (CSIC) in Madrid, as a continuation of a series of yearly meetings, organized in an attempt to encourage translational research in this field and facilitate a positive interaction among experts from several countries, along with industry representatives and journalists. In addition, members of the Task Force of the European Society concerning the clinical investigation of the use of autologous adult stem cells for repair of the heart gathered and discussed an update of the previous consensus, still pending of publication. In this article, we summarize some of the main topics of discussion, the state-of-the-art and latest advances in this field, and new challenges brought up for the near future.

Utility of the Seattle Heart Failure Model in patients with advanced heart failure

OBJECTIVES

The aim of this study was to validate the Seattle Heart Failure Model (SHFM) in patients with advanced heart failure (HF).

BACKGROUND

The SHFM was developed primarily from clinical trial databases and extrapolated the benefit of interventions from published data.

METHODS

We evaluated the discrimination and calibration of SHFM in 445 advanced HF patients (age 52 +/- 12 years, 68.5% male, 52.4% white, ejection fraction 18 +/- 8%) referred for cardiac transplantation. The primary end point was death (n = 92), urgent transplantation (n = 14), or left ventricular assist device (LVAD) implantation (n = 3); a secondary analysis was performed on mortality alone.

RESULTS

Patients were receiving optimal therapy (angiotensin-II modulation 92.8%, beta-blockers 91.5%, aldosterone antagonists 46.3%), and 71.0% had an implantable device (defibrillator 30.4%, biventricular pacemaker 3.4%, combined 37.3%). During a median follow-up of 21 months, 109 patients (24.5%) had an event. Although discrimination was adequate (c-statistic >0.7), the SHFM overall underestimated absolute risk (observed vs. predicted event rate: 11.0% vs. 9.2%, 21.0% vs. 16.6%, and 27.9% vs. 22.8% at 1, 2, and 3 years, respectively). Risk underprediction was more prominent in patients with an implantable device. The SHFM had different calibration properties in white versus black patients, leading to net underestimation of absolute risk in blacks. Race-specific recalibration improved the accuracy of predictions. When analysis was restricted to mortality, the SHFM exhibited better performance.

CONCLUSIONS

In patients with advanced HF, the SHFM offers adequate discrimination, but absolute risk is underestimated, especially in blacks and in patients with devices. This is more prominent when including transplantation and LVAD implantation as an end point.

[Advances in heart failure]

This article reports on the most significant developments in the field of heart failure in the past year. Principal innovations in the management of chronic heart failure are explained, including the most important features of new management models for patients with chronic heart failure and the main advances in drug therapy and in the use of and indications for cardiac devices in these patients. In addition, recent progress in the treatment of advanced heart failure, with particular emphasis on acute heart failure, is reviewed. Novel approaches to the surgical management of patients with heart failure, including new contributions in the field of the circulatory support, are also highlighted in this update.

Update on ventricular assist device management in the ICU

PURPOSE OF REVIEW

Mechanical circulatory support has a progressively increasing impact in the treatment of heart failure. The results of mechanical circulatory support are limited not only by the severity of the disease, which necessitated initiation of support, but also by the serious device-related adverse events. Optimized patient selection, improved patient management, and advanced device technology are interdependent key factors that contributed to the recently improved outcomes. The aim of this article is to summarize the current experience in application of mechanical circulatory support, focusing on the ICU management.

RECENT FINDINGS

Management should aim to prevent rather than treat serious complications and adverse events. Timing of intervention, optimization of the preimplantation patient status, patient and device management to ensure optimal hemodynamics, infection prevention, nutritional support, careful anticoagulation, and vigilance for early recognition and prompt treatment of 'minor' events before progression into major complications are essential elements of successful treatment.

SUMMARY

Critical patient care is a valuable adjunct to successful application of mechanical circulatory support, but it cannot counterbalance a late intervention, neither can it be fruitful in treating irreversible organ damage. Current management includes careful application of treatment protocols adjusted to recent experience, and also individualized care by a specialized team.

Long-term outcomes and costs of ventricular assist devices among Medicare beneficiaries

CONTEXT

In 2003, Medicare expanded coverage of ventricular assist devices as destination, or permanent, therapy for end-stage heart failure. Little is known about the long-term outcomes and costs associated with these devices.

OBJECTIVE

To examine the acute and long-term outcomes of Medicare beneficiaries receiving ventricular assist devices alone or after open-heart surgery.

DESIGN, SETTING, AND PATIENTS

Analysis of inpatient claims from the Centers for Medicare & Medicaid Services for the period 2000 through 2006. Patients were Medicare fee-for-service beneficiaries who received a ventricular assist device between February 2000 and June 2006 alone as primary therapy (primary device group; n = 1476) or after cardiotomy in the previous 30 days (postcardiotomy group; n = 1467).

MAIN OUTCOME MEASURES

Cumulative incidence of device replacement, device removal, heart transplantation, readmission, and death, accounting for censoring and competing risks. Patients were followed up for at least 6 months and factors independently associated with long-term survival were identified. Medicare payments were used to calculate total inpatient costs and costs per day outside the hospital.

RESULTS

Overall 1-year survival was 51.6% (n = 669) in the primary device group and 30.8% (n = 424) in the postcardiotomy group. Among primary device patients, 815 (55.2%) were discharged alive with a device. Of those, 450 (55.6%) were readmitted within 6 months and 504 (73.2%) were alive at 1 year. Of the 493 (33.6%) postcardiotomy patients discharged alive with a device, 237 (48.3%) were readmitted within 6 months and 355 (76.6%) were alive at 1 year. Mean 1-year Medicare payments for inpatient care for patients in the 2000-2005 cohorts were $178,714 (SD, $142,549) in the primary device group and $111,769 (SD, $95,413) in the postcardiotomy group.

CONCLUSIONS

Among Medicare beneficiaries receiving a ventricular assist device, early mortality, morbidity, and costs remain high. Improving patient selection and reducing perioperative mortality are critical for improving overall outcomes.

Ethical challenges with the left ventricular assist device as a destination therapy

The left ventricular assist device was originally designed to be surgically implanted as a bridge to transplantation for patients with chronic end-stage heart failure. On the basis of the REMATCH trial, the US Food and Drug Administration and the US Centers for Medicare & Medicaid Services approved permanent implantation of the left ventricular assist device as a destination therapy in Medicare beneficiaries who are not candidates for heart transplantation. The use of the left ventricular assist device as a destination therapy raises certain ethical challenges. Left ventricular assist devices can prolong the survival of average recipients compared with optimal medical management of chronic end-stage heart failure. However, the overall quality of life can be adversely affected in some recipients because of serious infections, neurologic complications, and device malfunction. Left ventricular assist devices alter end-of-life trajectories. The caregivers of recipients may experience significant burden (e.g., poor physical health, depression, anxiety, and posttraumatic stress disorder) from destination therapy with left ventricular assist devices. There are also social and financial ramifications for recipients and their families. We advocate early utilization of a palliative care approach and outline prerequisite conditions so that consenting for the use of a left ventricular assist device as a destination therapy is a well informed process. These conditions include: (1) direct participation of a multidisciplinary care team, including palliative care specialists, (2) a concise plan of care for anticipated device-related complications, (3) careful surveillance and counseling for caregiver burden, (4) advance-care planning for anticipated end-of-life trajectories and timing of device deactivation, and (5) a plan to address the long-term financial burden on patients, families, and caregivers.Short-term mechanical circulatory devices (e.g. percutaneous cardiopulmonary bypass, percutaneous ventricular assist devices, etc.) can be initiated in emergency situations as a bridge to permanent implantation of ventricular assist devices in chronic end-stage heart failure. In the absence of first-person (patient) consent, presumed consent or surrogate consent should be used cautiously for the initiation of short-term mechanical circulatory devices in emergency situations as a bridge to permanent implantation of left ventricular assist devices. Future clinical studies of destination therapy with left ventricular assist devices should include measures of recipients' quality of end-of-life care and caregivers' burden.

Advances in the surgical treatment of heart failure

PURPOSE OF REVIEW

Despite advancements in medical therapy, morbidity and mortality remain high. Surgical treatment of heart failure has been the subject of renewed focus, with a particular emphasis on applying the principles of evidence-based medicine to the evaluation of surgical therapies. The purpose of this review is to discuss emerging surgical therapies in heart failure, in particular, mechanical cardiac support and mitral valve repair.

RECENT FINDINGS

The most widely established surgical therapy for heart failure is cardiac transplantation, but its impact is limited due to the limited number of donors. The Surgical Treatment for Ischemic Heart Failure study, a landmark evaluation of the role of coronary artery bypass grafting and surgical ventricular restoration in patients with ischemic heart disease and heart failure, has recently completed enrollment. Improvements in device design and patient selection appear likely to continue to improve outcomes with mechanical cardiac support in patients who are not deemed transplant candidates (destination therapy). Surgical repair of secondary mitral regurgitation is undergoing evaluation in the soon to be launched Surgery vs. Medical Treatment Alone for Patients with Mitral Regurgitation and Nonischemic study.

SUMMARY

A variety of surgical therapies for heart failure are currently undergoing evaluation in randomized controlled trials. Data from these landmark studies will guide the application of surgical therapy in heart failure for the foreseeable future.

Mechanical circulatory support devices for acute heart failure syndromes: considerations for clinical trial design

Mechanical circulatory support (MCS) devices are a guideline-recommended treatment option for a small subset of advanced heart failure patients. MCS has the potential to become more prominent in the management of Acute Heart Failure Syndromes (AHFS) as device technology advances and as clinical trials consistently discover neutral or harmful effects with pharmacologic therapies hypothesized to be beneficial in this population. While it is now possible to identify AHFS patients who are at high risk of death, the therapeutic options available to improve their long-term outcomes are limited. MCS therapy in this population offers a "bridge to recovery" strategy; these patients may have viable myocardium that responds favorably to the influence of MCS on neurohormones, cytokines, and/or reverse remodeling. Patients at high risk for mortality who have a substantial likelihood of benefiting from MCS can be easily identified using standard clinical criteria developed from large observational databases. MCS technology is rapidly evolving, and risks related to implantation are declining. It is evident that rigorous clinical trial testing of the potential risks, benefits, and economic implications of MCS in patients with AHFS will need to be conducted before the "routine" application of this aggressive therapy. This paper examines the rationale for conducting trials of MCS devices in patients with AHFS, and it explores considerations for patient selection and appropriate endpoints. This manuscript was generated from discussions on this issue during the third international meeting of the International Working Group on AHFS held in Washington, DC, April 8-9, 2006.

New strategies for surgical management of ischemic cardiomyopathy

Ischemic cardiomyopathy affects an estimated 3 million people in the USA and is the most common cause of heart failure. Traditional operations have included heart transplantation, myocardial revascularization, mitral valve repair, left ventricular reconstruction, first-generation left ventricular assist devices and cardiac resynchronization therapy. These operations have become safer in recent times, due to improved technologies. Current technologies and surgical approaches can benefit a significant number of patients. However, there remains a large group of patients in whom traditional approaches can not be offered. Newer generation ventricular assist devices, passive ventricular restraint devices and cellular-based therapies (including skeletal- and bone marrow-derived stem cells) have the potential to be more universal in their applications. Ongoing investigations with each of these modalities will allow surgeons to offer treatment to patients who are not considered surgical candidates at this time.