Implantable cardioverter-defibrillators and survival in advanced heart failure patients with continuous-flow left ventricular assist devices: a systematic review and meta-analysis

AIMS: Implantable cardioverter-defibrillators (ICDs) implantation in heart failure (HF) patients with reduced ejection fraction improves survival by reducing mortality secondary to arrhythmic events. Whether advanced HF patients treated with continuous-flow left ventricular assist devices (CF-LVADs) derive similar benefit is controversial. METHODS AND RESULTS: We searched PubMed, Cochrane Central Register of Controlled Trials, Embase, and Scopus from inception through November 2018 for studies examining the association between ICD implantation and all-cause mortality in patients with advanced HF and CF-LVADs. Analyses were performed using a random-effects model. Hazard ratios (HRs) were calculated with 95% confidence intervals (CIs). Heterogeneity and publication bias were formally assessed, using I2 and funnel plots, respectively. Eight observational studies with a total of 6416 patients (ICD group = 3450, no ICD group = 2966) met inclusion criteria. The majority of patients (84.6%) came from the two largest observational studies. There was no difference in mortality in the ICD and no ICD groups (HR 0.96, 95% CI 0.73-1.27, P = 0.79, I2 = 42%), and ICD implantation post-CF-LVAD was not associated with an improvement in mortality (HR 0.87, 95% CI 0.48-1.57, P = 0.64, I2 = 0%). Additionally, there was no significant difference in the likelihood of transplantation (HR 1.10, 95% CI 0.93-1.30, P = 0.28, I2 = 26%) or non-mortality adverse events between the two groups. CONCLUSION: Implantable cardioverter-defibrillator use was not associated with improved survival in advanced HF patients with CF-LVADs. These findings underscore the need to formally study the efficacy of ICDs in this population in a dedicated randomized controlled study.