Increasing age is associated with recurrent ventricular tachyarrhythmias and appropriate ICD therapies secondary to documented index ventricular tachyarrhythmias.

Abstract

Data regarding theprognostic impact of age in implantable cardioverter defibrillator (ICD) recipients is limited. The study sought to assess the impact of age on recurrences of ventricular tachyarrhythmias in ICD recipients. This "secondary prevention" study is based on a large retrospective registry including consecutive ICD recipients with documented ventricular tachyarrhythmias from 2002 to 2016. Patients < 75years of age were compared to patients ≥ 75years. The primary endpoint was first recurrence of ventricular tachyarrhythmias at 5years. Secondary endpoints were ICD-related therapies, rehospitalization, and all-cause mortality at 5years. Statistics comprised Kaplan-Meier survival curves, multivariable Cox regression analyses, and propensity-score matching. A total of 592 consecutive ICD recipients with index ventricular tachyarrhythmias was included (< 75years: 78%; ≥ 75years 22%). Age ≥ 75years was associated with the primary endpoint of first recurrence of ventricular tachyarrhythmias (49% vs. 43%, log-rank p = 0.015; HR 1.418; 95% CI 1.070-1.881; p = 0.015), and with the secondary endpoint of first appropriate ICD therapy (78% vs. 22%, log-rank p = 0.011) even within multivariable Cox regression analyses. After propensity-score matching, age ≥ 75years was still associated with the primary endpoint of first recurrence of ventricular tachyarrhythmias (49% vs. 42%, log-rank p = 0.045; HR 1.482; 95% CI 1.007-2.182; p=0.046). Elderly ICD recipients aged ≥ 75years are at increased risk of recurrent ventricular tachyarrhythmias, appropriate ICD therapies, and all-cause mortality at 5years.