Patient selection for left ventricular assist device therapy

[Patient selection for left ventricular assist device implantation. The main problems]

AIM

To analyze the experience of Chazov National Medical Research Center of Cardiology in patient selection for left ventricular assist device (LVAD) implantation.

MATERIALS AND METHODS

901 patients, whose documents were sent to Chazov National Medical Research Center of Cardiology from regional medical and prophylactic institutions, were screened as selection for LVAD implantation. Firstly, all patients underwent transthoracic echocardiography performed according to the extended protocol with a comprehensive assessment of the left and right ventricle size and function. Patients who underwent the screening procedure underwent further examination including both laboratory and instrumental diagnostic methods. In addition, the polyclinic database of patients diagnosed with chronic heart failure (CHF) and dilated cardiomyopathy was also analyzed.

RESULTS

Among 901 screened patients 7.9% were suitable candidates for LVAD implantation and only 23 (2.6%) patients underwent surgery. Among those not eligible for surgery: 208 (29%) patients were not on optimal medical therapy, 15% of patients had indications for other surgical treatment of CHF, 12% of patients had severe right ventricular failure, 9.8% had severe comorbidities, 6.8% of patients refused surgery.

CONCLUSIONS

The main problems of selection for LVAD implantation were: low awareness of doctors about the introduction of new treatment methods, poor quality of transthoracic echocardiography, a large percentage of patients not receiving basic therapy for CHF, untimely referral of patients for other types of surgical treatment.

Cost-effectiveness of a centrifugal-flow pump for patients with advanced heart failure in Argentina

Background

Centrifugal-flow pumps are novel treatment options for patients with advanced heart failure (HF). This study estimated the incremental cost-effectiveness ratio (ICER) of centrifugal-flow pumps for patients with advanced HF in Argentina.

Methods

Two Markov models were developed to estimate the cost-effectiveness of a centrifugal-flow pump as destination therapy (DT) in patients with contraindication for heart transplantation, and as bridge-to-transplant (BTT), with a lifetime horizon using the third-party payer Social Security (SS) and Private Sector (PS) perspectives. Clinical, epidemiological, and quality-adjusted life years (QALY) parameters were retrieved from the literature. Direct medical costs were estimated through a micro-costing approach (exchange rate USD 1 = ARS 59.95).

Results

The centrifugal-flow pump as a DT increased the per patient QALYs by 3.5 and costs by ARS 8.1 million in both the SS and PS, with an ICER of ARS 2.3 million per QALY. Corresponding values for a centrifugal-flow pump as BTT were 0.74 QALYs and more than ARS 8 million, yielding ICERs of ARS 11 million per QALY (highly dependent on waiting times). For the 1, 3, and 5 GDP per QALY thresholds, the probability of a centrifugal-flow pump to be cost-effective for DT/BTT was around 2%/0%, 40%/0%, and 80%/1%, respectively.

Conclusion

The centrifugal-flow pump prolongs life and improves the quality of life at significantly higher costs. As in Argentina there is no current explicit cost-effectiveness threshold, the final decision on reimbursement will depend on the willingness to pay in each subsector. Nevertheless, the centrifugal-flow pump as a DT was more cost-effective than as a BTT.

Right Ventricular Strain to Assess Early Right Heart Failure in the Left Ventricular Assist Device Candidate

PURPOSE OF REVIEW

Right heart failure (RHF) following left ventricular assist device implantation (LVAD) remains the primary cause of postoperative mortality and morbidity, and prediction of RHF is the main interest of the transplantation community. In this review, we outline the role and impact of right ventricular strain in the evaluation of the right ventricle function before LVAD implantation.

RECENT FINDINGS

Accumulating data suggest that measurement of right ventricular longitudinal strain (RVLS) has a critical role in predicting RHF preoperatively and may improve morbidity and mortality following LVAD implantation. However, the significant intraobserver, interobserver variability, the lack of multicenter, prospective studies, and the need for a learning curve remain the most critical limitations in the clinical practice at present. This review highlighted the importance of right ventricular strain in the diagnosis of RHF preoperatively and revealed that RVLS might have a crucial clinical measurement for the selection and management of LVAD patients in the future with the more extensive multicenter studies.

Mitral Valve Regurgitation with a Rotary Left Ventricular Assist Device: The Haemodynamic Effect of Inlet Cannulation Site and Speed Modulation

Mitral valve regurgitation (MVR) is common in patients receiving left ventricular assist device (LVAD) support, however the haemodynamic effect of MVR is not entirely clear. This study evaluated the haemodynamic effect of MVR with LVAD support and the influence of inflow cannulation site and LVAD speed modulation. Left atrial (LAC) and ventricular (LVC) cannulation was evaluated in a mock circulation loop with no, mild, moderate and severe MVR with constant speed and speed modulation (±600 RPM) modes. The use of an LVAD relieved pulmonary congestion during severe MVR, by reducing left atrial pressure from 20.5 to 10.8 (LAC) and 11.5 (LVC) mmHg. However, LAC resulted in decreased left ventricular stroke work (-0.08 J), ejection fraction (-7.9%) and higher MVR volume (+12.7 mL) and pump speed (+100 RPM) compared to LVC. This suggests that LVC, in addition to reducing MVR severity, also improves ventricular washout over LAC. LVAD speed modulation in synchrony with ventricular systole reduced MVR volume and increased ejection fraction with LAC and LVC, thus demonstrating the potential benefits of this mode, despite a reduction in cardiac output.

Right ventricular afterload sensitivity dramatically increases after left ventricular assist device implantation: A multi-center hemodynamic analysis

BACKGROUND

Right ventricular (RV) failure is a source of morbidity and mortality after left ventricular assist device (LVAD) implantation. In this study we sought to define hemodynamic changes in afterload and RV adaptation to afterload both early after implantation and with prolonged LVAD support.

METHODS

We reviewed right heart catheterization (RHC) data from participants who underwent continuous-flow LVAD implantation at our institutions (n = 244), excluding those on inotropic or vasopressor agents, pulmonary vasodilators or additional mechanical support at any RHC assessment. Hemodynamic data were assessed at 5 time intervals: (1) pre-LVAD (within 6 months); (2) early post-LVAD (0 to 6 months); (3) 7 to 12 months; (4) 13 to 18 months; and (5) very late post-LVAD (18 to 36 months).

RESULTS

Sixty participants met the inclusion criteria. All measures of right ventricular load (effective arterial elastance, pulmonary vascular compliance and pulmonary vascular resistance) improved between the pre- and early post-LVAD time periods. Despite decreasing load and pulmonary artery wedge pressure (PAWP), RAP remained unchanged and the RAP:PAWP ratio worsened early post-LVAD (0.44 [0.38, 0.63] vs 0.77 [0.59, 1.0], p < 0.001), suggesting a worsening of RV adaptation to load. With continued LVAD support, both RV load and RAP:PAWP decreased in a steep, linear and dependent manner.

CONCLUSIONS

Despite reducing RV load, LVAD implantation leads to worsened RV adaptation. With continued LVAD support, both RV afterload and RV adaptation improve, and their relationship remains constant over time post-LVAD. These findings suggest the RV afterload sensitivity increases after LVAD implantation, which has major clinical implications for patients struggling with RV failure.

Left ventricular assist device implantation strategies and outcomes

Over the past 15 years, the field of mechanical circulatory support has developed significantly. Currently, there are a multitude of options for both short and long term cardiac support. Choosing the appropriate device for each patient depends on the amount of support needed and the goals of care. This article focuses on long term, implantable devices for both bridge to transplantation and destination therapy indications. Implantation strategies, including the appropriate concomitant surgeries are discussed as well as expected long term outcomes. As device technology continues to improve, long term mechanical circulatory support may become a viable alternative to transplantation.

Imaging in patients after cardiac transplantation and in patients with ventricular assist devices

The field of cardiac imaging and the management of patients with severe heart failure have advanced substantially during the past 10 years. Cardiac transplantation offers the best long-term survival with high quality of life for the patients with end stage heart failure. However, acute cardiac rejection and cardiac allograft vasculopathy (CAV) can occur post cardiac transplantation and these problems necessitate regular surveillance. The short-term success of mechanical circulatory support devices (MCSD), such as ventricular assist devices (VADs), in improving survival and quality of life has led to a dramatic growth of the patient population with these devices. The development of optimal imaging techniques and algorithms to evaluate these advanced heart failure patients is evolving and multimodality non-invasive imaging approaches and invasive techniques are commonly employed. Most of the published studies done in the transplant and VAD population are small, and biased based on the strength of the particular program, and there is a relative lack of published protocols to evaluate these patient groups. Moreover, the techniques of echocardiography, computed tomography (CT), magnetic resonance imaging, and nuclear cardiology have all progressed rapidly in recent years. There is thus a knowledge gap for cardiologists, radiologists, and clinicians, especially regarding surveillance for CAV and ideal imaging approaches for patients with VADs. The purpose of this review article is to provide an overview of different noninvasive imaging modalities used to evaluate patients after cardiac transplantation and for patients with VADs. The review focuses on the role of echocardiography, CT, and nuclear imaging in surveillance for CAV and rejection and on the assessment of ventricular structure and function, myocardial remodeling and complications for VAD patients.

Minimally invasive delivery of a novel direct epicardial assist device in a porcine heart failure model

OBJECTIVE

Despite advances in design, modern ventricular assist device placement involves median sternotomy and cardiopulmonary bypass and is associated with infectious/embolic complications. In this study, we examine the feasibility and function of a novel minimally invasive, non-blood-contacting epicardial assist device in a porcine ischemic cardiomyopathy model.

METHODS

Feasibility was first tested in an ex vivo thoracoscopic trainer box with slaughterhouse hearts. Five male Yorkshire swine underwent selective ligation of the circumflex artery to create a posterolateral infarct Twelve weeks after infarct, all animals underwent left minithoracotomy. A custom inflatable bladder was positioned over the epicardial surface of the infarct and firmly secured to the surrounding border zone myocardium with polypropylene mesh and minimally invasive mesh tacks. An external gas pulsation system actively inflated and deflated the bladder in synchrony with the cardiac cycle. All animals then underwent cardiac magnetic resonance imaging to assess ventricular function.

RESULTS

All subjects successfully underwent off-pump placement of the epicardial assist device via minithoracotomy. Ejection fraction significantly improved from 29.1% ± 4.8% to 39.6% ± 4.23% (P < 0.001) when compared with pretreatment. End-systolic volume decreased (76.6 ± 13.3 mL vs 62.4 ± 12.0 mL, P < 0.001) and stroke volume increased (28.6 ± 3.4 mL vs 37.9 ± 3.1 mL, P < 0.05) when assisted. No change was noted in end-diastolic volume (105.1 ± 11.4 vs 100.3 ± 12.7). On postmortem examination, mesh fixation and device position were excellent in all cases. No adverse events were encountered.

CONCLUSIONS

Directed epicardial assistance improves ventricular function in a porcine ischemic cardiomyopathy model and may provide a safe alternative to currently available ventricular assist device therapies. Further, the technique used for device positioning and fixation suggests that an entirely thoracoscopic approach is possible.

Evaluating the hemodynamical response of a cardiovascular system under support of a continuous flow left ventricular assist device via numerical modeling and simulations

Dilated cardiomyopathy is the most common type of the heart failure which can be characterized by impaired ventricular contractility. Mechanical circulatory support devices were introduced into practice for the heart failure patients to bridge the time between the decision to transplant and the actual transplantation which is not sufficient due to the state of donor organ supply. In this study, the hemodynamic response of a cardiovascular system that includes a dilated cardiomyopathic heart under support of a newly developed continuous flow left ventricular assist device—Heart Turcica Axial—was evaluated employing computer simulations. For the evaluation, a numerical model which describes the pressure-flow rate relations of Heart Turcica Axial, a cardiovascular system model describing the healthy and pathological hemodynamics, and a baroreflex model regulating the heart rate were used. Heart Turcica Axial was operated between 8000 rpm and 11000 rpm speeds with 1000 rpm increments for assessing the pump performance and response of the cardiovascular system. The results also give an insight about the range of the possible operating speeds of Heart Turcica Axial in a clinical application. Based on the findings, operating speed of Heart Turcica Axial should be between 10000 rpm and 11000 rpm.

In vitro evaluation of aortic insufficiency with a rotary left ventricular assist device

Aortic insufficiency (AI) is usually repaired prior to rotary blood pump (RBP) implantation but can develop during support due, in part, to the sustained RBP-induced high pressure gradient across the aortic valve. Repair of the aortic valve before or during RBP support predisposes these critically ill patients to even higher risks. This study used an in vitro mock circulation loop to identify the severity of AI and/or left heart failure (LHF) that might benefit from valve repair while investigating RBP operating strategies to reduce the hemodynamic influence of AI. Reproduction of AI with RBP-supported LHF reduced device efficiency, particularly in the more severe cases of AI and LHF. The requirement for repair or closure of the aortic valve was demonstrated in all conditions other than those with only mild AI. When a sinusoidal RBP speed pulse was induced, small changes in systemic flow rate and regurgitant volume were observed with all degrees of AI. Variation of the pulse phase delay only resulted in minor changes to systemic flow rate, with a maximum difference of 0.17 L/min. Although the clinical implications of these small changes may be insignificant, changes in systemic flow rate and transvalvular pressure were shown when the sinusoidal RBP speed pulse was applied with no AI. In these cases, transvalvular pressure was reduced by up to 8% through sinusoidal copulsation of the RBP, which may prevent or delay the onset of AI. This in vitro study suggests that surgical intervention is required with moderate or worse AI and that RBP operating strategies should be further explored to delay the onset and reduce the harmful effects of AI.

Significance of postoperative acute renal failure after continuous-flow left ventricular assist device implantation

BACKGROUND

Deteriorating renal function is common in patients with advanced heart failure and is associated with poor outcomes. The relationship between renal function and left ventricular assist device (LVAD) implantation is complex and has been explored in multiple studies with contradictory results. The aim of our study is to examine the significance of postoperative renal failure after implantation of a continuous-flow LVAD and its relationship to outcomes.

METHODS

From March 2006 to July 2011, 100 patients underwent implantation of a HeartMate II (Thoratec Corp, Pleasanton, CA) or HeartWare (Heart International, Inc, Framingham, MA) LVAD at our institution. Patients were stratified based on postoperative development of acute renal failure (ARF). Variables were compared using 2-sided t tests, χ(2) tests, Cox proportional hazards models, and log-rank tests to determine whether there was a difference between the 2 groups and whether postoperative renal failure was a significant independent predictor of outcome.

RESULTS

We identified 28 patients (28%) with postoperative ARF and 72 patients (72%) without postoperative ARF. The 2 groups were similar with regard to demographics and comorbidities. The patients with ARF were more likely to be intubated preoperatively (14.3% versus 1.4%; p = 0.021) and had higher preoperative central venous pressure (CVP) (14.3 mm Hg versus 10.7 mm Hg; p = 0.015). Postoperatively patients with ARF had a longer hospital stay (32.4 versus 18.7; p = 0.05), were more likely to experience right ventricular (RV) failure (25% versus 5.6%; p = 0.01) and ventilator-dependent respiratory failure (VDRF) (28.6% versus 6.9%; p = 0.007). There was a significant difference when comparing the ARF and non-ARF groups for 30-day (17.9% versus 0%; p < 0.001), 180-day (28.6% versus 2.8%; p < 0.001), and 360-day mortality (28.6% versus 6.9%; p = 0.012).

CONCLUSIONS

Patients in whom ARF developed after LVAD implantation had a higher rate of VDRF and RV failure and a longer length of stay (LOS). Postoperative ARF was associated with higher mortality at the 30-day, 180-day, and 360-day intervals. ARF after LVAD may be an early marker of poor outcome, particularly RV failure, and may be an opportunity for early intervention and rescue.

Long-term continuous flow left ventricular assist device support and end-organ function: prospects for destination therapy

Pulsatile flow left ventricular assist devices (PF-LVADs) have successfully supported patients with severe heart failure for bridge-to-transplant (BTT) and destination therapy (DT). End-organ dysfunction is often reversed, optimizing the patient's condition to enhance survival, and quality of life. Questions have been raised regarding the potential for continuous flow LVADs (CF-LVADs) to provide the same quality of circulatory support. Prior research showing that PF is superior to continuous, non-PF does not appear to be relevant with CF-LVADs for BTT and DT. Under most clinical conditions, arterial pulsatility is present during CF-LVAD support, and this type of support should not be termed "nonpulsatile." Clinical studies have shown that renal, hepatic, and neurocognitive function is either maintained within a normal range, or is significantly improved, during CF-LVAD support for durations up to 15 months. Results of the randomized clinical trial between the CF HeartMate II and the pulsatile HeartMate XVE (both by Thoratec Corp, Pleasanton, CA, USA) are pending final US Food and Drug Administration (FDA) review and are not yet published. Studies of microcirculation during CF-LVAD support indicate that capillary blood flow is adequate to support cellular function. There are anecdotal cases of patients being supported with a CF-LVAD for over seven years with preserved end-organ function. Presently, there are no clinical reports indicating that end-organ function is not well maintained. Current clinical evidence indicates that end-organ perfusion and function can be well maintained for extended durations of support with a CF-LVAD.

Inhaled nitric oxide after left ventricular assist device implantation: a prospective, randomized, double-blind, multicenter, placebo-controlled trial

BACKGROUND

Used frequently for right ventricular dysfunction (RVD), the clinical benefit of inhaled nitric oxide (iNO) is still unclear. We conducted a randomized, double-blind, controlled trial to determine the effect of iNO on post-operative outcomes in the setting of left ventricular assist device (LVAD) placement.

METHODS

Included were 150 patients undergoing LVAD placement with pulmonary vascular resistance ≥ 200 dyne/sec/cm(-5). Patients received iNO (40 ppm) or placebo (an equivalent concentration of nitrogen) until 48 hours after separation from cardiopulmonary bypass, extubation, or upon meeting study-defined RVD. For ethical reasons, crossover to open-label iNO was allowed during the 48-hour treatment period if RVD criteria were met.

RESULTS

RVD criteria were met by 7 of 73 patients (9.6%; 95% confidence interval, 2.8-16.3) in the iNO group compared with 12 of 77 (15.6%; 95% confidence interval, 7.5-23.7) who received placebo (p = 0.330). Time on mechanical ventilation decreased in the iNO group (median days, 2.0 vs 3.0; p = 0.077), and fewer patients in the iNO group required an RVAD (5.6% vs 10%; p = 0.468); however, these trends did not meet statistical boundaries of significance. Hospital stay, intensive care unit stay, and 28-day mortality rates were similar between groups, as were adverse events. Thirty-five patients crossed over to open-label iNO (iNO, n = 15; placebo, n = 20). Eighteen patients (iNO, n = 9; placebo, n = 9) crossed over before RVD criteria were met.

CONCLUSIONS

Use of iNO at 40 ppm in the perioperative phase of LVAD implantation did not achieve significance for the primary end point of reduction in RVD. Similarly, secondary end points of time on mechanical ventilation, hospital or intensive care unit stay, and the need for RVAD support after LVAD placement were not significantly improved.

Clinical management of continuous-flow left ventricular assist devices in advanced heart failure

Continuous-flow left ventricular assist devices (LVAD) have emerged as the standard of care for advanced heart failure patients requiring long-term mechanical circulatory support. Evidence-based clinical management of LVAD-supported patients is becoming increasingly important for optimizing outcomes. In this state-of-art review, we propose key elements in managing patients supported with the new continuous-flow LVADs. Although most of the presented information is largely based on investigator experience during the 1,300-patient HeartMate II clinical trial, many of the discussed principles can be applied to other emerging devices as well. Patient selection, pre-operative preparation, and the timing of LVAD implant are some of the most important elements critical to successful circulatory support and are principles universal to all devices. In addition, proper nutrition management and avoidance of infectious complications can significantly affect morbidity and mortality during LVAD support. Optimizing intraoperative and peri-operative care, and the monitoring and treatment of other organ system dysfunction as it relates to LVAD support, are discussed. A multidisciplinary heart failure team must be organized and charged with providing comprehensive care from initial referral until support is terminated. Preparing for hospital discharge requires detailed education for the patient and family or friends, with provisions for emergencies and routine care. Implantation techniques, troubleshooting device problems, and algorithms for outpatient management, including the diagnosis and treatment of related problems associated with the HeartMate II, are discussed as an example of a specific continuous-flow LVAD. Ongoing trials with other continuous-flow devices may produce additional information in the future for improving clinical management of patients with these devices.

Long-term Mechanical Circulatory Support System reliability recommendation by the National Clinical Trial Initiative subcommittee

The Long-Term Mechanical Circulatory Support (MCS) System Reliability Recommendation was published in the American Society for Artificial Internal Organs (ASAIO) Journal and the Annals of Thoracic Surgery in 1998. At that time, it was stated that the document would be periodically reviewed to assess its timeliness and appropriateness within 5 years. Given the wealth of clinical experience in MCS systems, a new recommendation has been drafted by consensus of a group of representatives from the medical community, academia, industry, and government. The new recommendation describes a reliability test methodology and provides detailed reliability recommendations. In addition, the new recommendation provides additional information and clinical data in appendices that are intended to assist the reliability test engineer in the development of a reliability test that is expected to give improved predictions of clinical reliability compared with past test methods. The appendices are available for download at the ASAIO journal web site at www.asaiojournal.com.

Role of a percutaneous ventricular assist device in decision making for a cardiac transplant program

BACKGROUND

The role of a percutaneous ventricular assist device (VAD) for left heart support in the management of patients in cardiogenic shock is not well defined.

METHODS

All patients who received LV support using the percutaneous TandemHeart (percTH) ventricular support device (Cardiac Assist, Pittsburgh, PA) were retrospectively reviewed. Indications for insertion included bridge to decision (BTD) or "salvage" and bridge to transplant (BTT).

RESULTS

Between April 2005 and December 2008, 22 percTH devices were successfully implanted in patients (13 men) with isolated left heart failure. Mean duration of support was 6.8 +/- 9.4 days (median, 4; maximum, 45 days). Of patients requiring percTH support for at least 3 days, mean pump flows were 3.77 +/- 1.10, 4.22 +/- 0.69, and 4.04 +/- 0.41 L/min on at days 1, 2, and 3. Mean serum aspartate aminotransferase levels were 455 +/- 994 mg/dL before percTH, 551 +/- 1046 mg/dL at day 1, and 231 +/- 225 mg/dL at day 3 after percTH. No mechanical device failure, device-related infections, or cerebrovascular accidents occurred. Ten of 11 BTT patients were successfully bridged. Support was withdrawn in 7 of 11 BTD patients. The percTHs were successfully explanted in 4 BTD patients: 1 as recovery, 1 direct to transplant, and 2 to VAD.

CONCLUSIONS

The percTH was reliable, with no mechanical device failures and minimal associated adverse events. We support the use of the percTH in the BTD mode, allowing time for a more complete evaluation of neurologic and end-organ status without the added expense and morbidity of a long-term VAD.

Assessing technological change in cardiothoracic surgery

Technological innovation--broadly defined as the development and introduction of new drugs, devices, and procedures--has played a major role in advancing the field of cardiothoracic surgery. It has generated new forms of care for patients and improved treatment options. Innovation, however, comes at a price. Total national health care expenditures now exceed $2 trillion per year in the United States and all current estimates indicate that this number will continue to rise. As we continue to seek the most innovative medical treatments for cardiovascular disease, the spiraling cost of these technologies comes to the forefront. In this article, we address 3 challenges in managing the health and economic impact of new and emerging technologies in cardiothoracic surgery: (1) challenges associated with the dynamics of technological growth itself; (2) challenges associated with methods of analysis; and (3) the ways in which value judgments and political factors shape the translation of evidence into policy. We conclude by discussing changes in the analytical, financial, and institutional realms that can improve evidence-based decision-making in cardiac surgery.

Conventional radiography and computed tomography of cardiac assist devices

Patients intended for circulatory support by cardiac assist devices (CAD) usually suffer from end-stage acute or chronic heart failure. Since the introduction of CAD in 1963 by DeBakey and coworkers, the systems have gone through a substantial evolution and have been increasingly used in the intervening decades. The spectrum of CAD includes a variety of systems serving to assist the systolic function of the left ventricle, the right ventricle, or both. Conventional radiography and multislice spiral computed tomography (CT) are the most commonly used radiological techniques for imaging patients with a CAD. CT is very useful for evaluating CAD systems by using both two- and three-dimensional reconstructions of the volumetric data sets. The two techniques together allow for the comprehensive assessment of patients with devices by imaging the in- and outflow cannulae, the anastomoses, the position of the pump, as well as associated complications. A close collaboration with cardiac surgeons with expertise in the field of circulatory support is deemed necessary for adequate image interpretation. This article describes the technical diversity of the currently available CAD systems. The imaging characteristics on conventional radiography and multislice spiral CT as well as the typical complications of their use are demonstrated.

Renal function and outcome after continuous flow left ventricular assist device implantation

BACKGROUND

Renal dysfunction as a risk factor with the use of left ventricular assist devices (LVAD) is controversial. We determined the effect of renal function on outcomes after continuous flow LVAD implantation.

METHODS

Eighty-six patients with advanced heart failure undergoing continuous flow LVAD implantation as bridge to transplantation from November 1998 to July 2007 were retrospectively analyzed. Renal function was assessed using the Modification of Diet in Renal Disease study-derived glomerular filtration rates (GFR [mL x min(-1) x 1.73 m(-2)]). Patients were categorized into two groups based on pre-LVAD GFR: those with normal renal function (GFR > 60, n = 46), and those with renal dysfunction (GFR < 60, n = 40).

RESULTS

Post-LVAD survival at 1, 3, and 6 months for GFR greater than 60 was 91.3%, 79.9%, 72.6%, respectively, and for GFR less than 60, it was 92.5%, 66.5%, 47.9%, respectively (p = 0.038). Bridge-to-transplant rate was lower for GFR less than 60 than for GFR greater than 60 (40.0% versus 63.0%, p = 0.033). For GFR less than 60, GFR improved on LVAD support: implant to month 6, 41.7 +/- 11.5 to 62.7 +/- 25.0 (p = 0.021). Post-LVAD survival was improved in GFR less than 60 patients who after LVAD implantation recovered renal function to GFR greater than 60 (p < 0.001). Patients with post-LVAD renal failure had significantly lower post-LVAD survival regardless of pre-LVAD renal function (p < 0.001).

CONCLUSIONS

Patients with renal dysfunction have poorer outcomes after continuous flow LVAD implantation. However, renal function improves after LVAD implantation and is associated with improved survival. Our data underscore the importance of end-organ function in patient selection for LVAD therapy.