Survival benefit of implantable cardioverter-defibrillators in left ventricular assist device-supported heart failure patients.

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) reduce mortality in heart failure (HF). In patients requiring a ventricular assist device (VAD), the benefit from ICD therapy is not well established. The aim of this study was to define the impact of ICD on outcomes in VAD-supported patients. METHODS AND RESULTS: We reviewed data for consecutive adult HF patients receiving VAD as a bridge to transplantation from 1996 to 2003. The primary outcome was survival to transplantation. A total of 144 VADs were implanted [85 left ventricular (LVAD), 59 biventricular (BIVAD), mean age 50 ± 12 years, 77% male, left ventricular ejection fraction 18 ± 9%, 54% ischemic]. Mean length of support was 119 days (range 1-670); 103 patients (72%) survived to transplantation. Forty-five patients had an ICD (33 LVAD, 12 BIVAD). More LVAD patients had an appropriate ICD shock before implantation than after (16 vs 7; P = .02). There was a trend toward higher shock frequency before LVAD implant than after (3.3 ± 5.2 vs 1.1 ± 3.8 shocks/y; P = .06). Mean time to first shock after VAD implant was 129 ± 109 days. LVAD-supported patients with an ICD were significantly more likely to survive to transplantation [1-y actuarial survival to transplantation: LVAD: 91% with ICD vs 57% without ICD (log-rank P = .01); BIVAD: 54% vs 47% (log-rank P = NS)]. An ICD was associated with significantly increased survival in a multivariate model controlling for confounding variables (odds ratio 2.54, 95% confidence interval 1.04-6.21; P = .04). CONCLUSIONS: Shock frequency decreases after VAD implantation, likely owing to ventricular unloading, but appropriate ICD shocks still occur in 21% of patients. An ICD is associated with improved survival in LVAD-supported HF patients.

Early adverse events as predictors of 1-year mortality during mechanical circulatory support.

BACKGROUND: Ventricular assist devices (VADs) provide effective treatment for end-stage heart failure; however, most patients experience > or =1 major adverse events (AEs) while on VAD support. Although early, non-fatal AEs may increase the risk of later death during VAD support, this relationship has not been established. Therefore, we sought to determine the impact on 1-year mortality of AEs occurring during the first 60 days of VAD support. METHODS: A retrospective analysis was performed using prospectively collected data from a single-site database for patients aged > or =18 years receiving left ventricular or biventricular support during 1996 to 2008 and who survived >60 days on VAD support. Fourteen major classes of AEs occurring during this 60-day period were examined. One-year survival rates of patients with and without each major AE were compared. RESULTS: The study included 163 patients (80% men; mean age, 49.5 years), of whom 87% were European American, 72% had left ventricular support, and 83% were bridge to transplant. The occurrence of renal failure, respiratory failure, bleeding events, and reoperations during the first 60 days after implantation significantly increased the risk of 1-year mortality. After controlling for gender, age, VAD type, and intention to treat, renal failure was the only major AE significantly associated with later mortality (hazard ratio, 2.96; p = .023). CONCLUSIONS: Specific AEs, including renal failure, respiratory and bleeding events, and reoperations, significantly decrease longer-term survival. Renal failure conferred a 3-fold increased risk of 1-year mortality. Peri-operative management should focus on strategies to mitigate risk for renal failure in order to maximize later outcomes.

Incidence and patterns of adverse event onset during the first 60 days after ventricular assist device implantation.

BACKGROUND: Although ventricular assist devices (VADs) provide effective treatment for end-stage heart failure, VAD support remains associated with significant risk for adverse events (AEs). To date there has been no detailed assessment of the incidence of a full range of AEs using standardized event definitions. We sought to characterize the frequency and timing of AE onset during the first 60 days of VAD support, a period during which clinical observation suggests the risk of incident AEs is high. METHODS: A retrospective analysis was performed utilizing prospectively collected data from a single-site clinical database including 195 patients aged 18 or greater receiving VADs between 1996 and 2006. Adverse events were coded using standardized criteria. Cumulative incidence rates were determined, controlling for competing risks (death, transplantation, recovery-wean). RESULTS: During the first 60 days after implantation, the most common AEs were bleeding, infection, and arrhythmias (cumulative incidence rates, 36% to 48%), followed by tamponade, respiratory events, reoperations, and neurologic events (24% to 31%). Other events (eg, hemolysis, renal, hepatic events) were less common (rates <15%). Some events (eg, bleeding, arrhythmias) showed steep onset rates early after implantation. Others (eg, infections, neurologic events) had gradual onsets during the 60-day period. Incidence of most events did not vary by implant era (1996 to 2000 vs 2001 to 2006) or by left ventricular versus biventricular support. CONCLUSIONS: Understanding differential temporal patterns of AE onset will allow preventive strategies to be targeted to the time periods when specific AE risks are greatest. The AE incidence rates provide benchmarks against which future studies of VAD-related risks may be compared.

Ventricular arrhythmias during left ventricular assist device support.

Left ventricular assist devices (LVADs) have been used effectively as a "bridge" to cardiac transplantation and as destination therapy in patients with advanced heart failure. Ventricular arrhythmias (VAs) have been reported to occur in LVAD-supported patients, although their incidence, risk factors, and clinical significance have not been characterized. In this study, 111 patients who received LVAD support as a bridge to cardiac transplantation at the University of Pittsburgh Medical Center from January 1987 to June 2001 were evaluated. Clinically significant VA was defined as ventricular fibrillation, sustained ventricular tachycardia, or nonsustained ventricular tachycardia with symptoms requiring antiarrhythmic therapy. Patients were grouped on the basis of the presence or absence of VAs. VAs occurred in 24 patients (22%) during device support. Ischemic heart disease was the cause of heart failure in 71% of patients (17 of 24) in the VA group and 45% of patients (39 of 87) in the group without VAs (p <0.05). The mortality rate was significantly higher (p <0.001) during LVAD support in the group with VAs (33%) compared with the group without VAs (18%). In the group with VAs, the early (1 week) occurrence (9%). In conclusion, although clinically significant VAs occur in patients with heart failure receiving LVAD support, the overall incidence is low. VAs are more frequent in patients with ischemic heart failure, and their occurrence is associated with greater mortality. The occurrence of VAs early after LVAD implantation, in particular, predicts a higher mortality rate.

Differential exercise performance on ventricular assist device support.

BACKGROUND: Ventricular assist devices (VADs) are approved for destination therapy because they improve survival in end-stage heart failure (HF). VADs are powered pneumatically or electrically. Pneumatic and electric left ventricular assist devices (LVADs) and biventricular assist devices (BiVADs) provide excellent hemodynamic support at rest, but differences in their effects on exercise tolerance are unclear. We sought to evaluate the effect of devices with varying operating parameters on exercise capacity. METHODS: Exercise physiology data obtained during maximal exercise with on-line gas-exchange analysis were collected for 38 consecutive VAD-implanted HF patients referred for exercise testing. RESULTS: Electric LVADs were implanted in 18 patients, and pneumatic LVADs in 10 patients. Percent of predicted peak exercise oxygen consumption (VO2%) was significantly greater in pneumatic LVAD patients (52.1 +/- 11.1% vs 38.2 +/- 11.3%, p < 0.05). The 10 patients implanted with a pneumatically powered LVAD were compared to 10 patients implanted with a pneumatically powered BiVAD. LVAD-supported patients had a higher VO2% (52.1 +/- 11.1% vs 36.5 +/- 17.7%, p < 0.05). CONCLUSIONS: HF patients supported with a pneumatic LVAD appear to have better exercise tolerance than those receiving an electric LVAD. Patients on LVAD support have better exercise tolerance than BiVAD-supported patients. This highlights the importance of right ventricular function to exercise tolerance in HF patients, and may have implications for future VAD design.