Impact of Left Ventricular Ejection Fraction on Recurrent Ventricular Tachyarrhythmias in Recipients of Implantable Cardioverter Defibrillators

OBJECTIVE: This study evaluates the impact of left ventricular ejection fraction (LVEF) on recurrences of ventricular tachyarrhythmias in recipients of implantable cardioverter defibrillator (ICD). BACKGROUND: Data regarding recurrences of ventricular tachyarrhythmias in ICD recipients according to LVEF is limited. METHODS: A large retrospective registry was used, including all consecutive ICD recipients with episodes of ventricular tachycardia (VT) or fibrillation (VF) from 2002 to 2016. Patients with LVEF <35% were compared to patients with LVEF ≥35%. The primary end point was first recurrences of ventricular tachyarrhythmias at 5 years. Secondary end points were ICD-related therapies, rehospitalization, and all-cause mortality at 5 years. Cox regression, Kaplan Meier, and propensity score matching analyses were applied. RESULTS: A total of 528 consecutive ICD recipients were included (51% with LVEF ≥35% and 49% with LVEF <35%). LVEF <35% was associated with reduced freedom from recurrent ventricular tachyarrhythmias (40 vs. 49%, log rank p = 0.014; hazard ratio [HR] = 1.381; 95% confidence interval [CI] 1.066-1.788; p = 0.034), mainly attributed to recurrent sustained VT in primary preventive ICD recipients. Accordingly, LVEF <35% was associated with reduced freedom from first appropriate ICD therapies (28 vs. 41%, log rank p = 0.001; HR = 1.810; 95% CI 1.185-2.766; p = 0.001). Finally, LVEF <35% was associated with a higher rate of rehospitalization (23 vs. 34%; p = 0.005) and all-cause mortality at 5 years (13 vs. 29%; p = 0.001). CONCLUSION: LVEF <35% was associated with reduced freedom from recurrent ventricular tachyarrhythmias, appropriate device therapies, rehospitalization and all-cause mortality secondary to index ventricular tachyarrhythmias.