Atrial fibrillation increases the risk of recurrent ventricular tachyarrhythmias in implantable cardioverter defibrillator recipients

Summary Background Data regarding recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator (ICD) recipients according to atrial fibrillation is limited. Objective To assess the prognostic impact of atrial fibrillation on recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator recipients. Methods A large retrospective registry was used, including all ICD recipients with episodes of ventricular tachycardia or fibrillation from 2002 to 2016. Patients with atrial fibrillation were compared to those without atrial fibrillation. The primary endpoint was first recurrence of ventricular tachyarrhythmias at 5 years. Secondary endpoints comprised recurrences of ICD-related therapies, first cardiac rehospitalization and all-cause mortality at 5 years. Cox regression, Kaplan-Meier and propensity score-matching analyses were applied. Results A total of 592 consecutive ICD recipients were included (33% with atrial fibrillation). Atrial fibrillation was associated with reduced freedom from recurrent ventricular tachyarrhythmias (42% vs. 50%, log-rank P = 0.004; hazard ratio 1.445, 95% confidence interval 1.124–1.858), mainly attributable to recurrent ventricular fibrillation in secondary-preventive ICD recipients. Accordingly, atrial fibrillation was associated with reduced freedom from first appropriate ICD therapies (31% vs. 42%, log-rank P = 0.001; hazard ratio 1.598, 95% confidence interval 1.206–2.118). Notably, the primary endpoint of freedom from first episode of recurrent ventricular tachyarrhythmias was still reduced in those with atrial fibrillation compared to those without atrial fibrillation after propensity score matching. Regarding secondary endpoints, patients with atrial fibrillation still showed a trend towards reduced freedom from appropriate ICD therapies. Conclusions Atrial fibrillation was associated with increased rates of recurrent ventricular tachyarrhythmias and appropriate device therapies in ICD recipients with ventricular tachyarrhythmias.