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

Background: Data regarding the prognostic impact of age in implantable cardioverter defibrillator (ICD) recipients is limited.

Objective: The study sought to assess the impact of age on recurrences of ventricular tachyarrhythmias in ICD recipients.

Methods: This "secondary prevention" study is based on a large retrospective registry including consecutive ICD recipients with documented ventricular tachyarrhythmias from 2002 to 2016. Patients < 75 years of age were compared to patients ≥ 75 years. The primary endpoint was first recurrence of ventricular tachyarrhythmias at 5 years. Secondary endpoints were ICD-related therapies, rehospitalization, and all-cause mortality at 5 years. Statistics comprised Kaplan-Meier survival curves, multivariable Cox regression analyses, and propensity-score matching.

Results: A total of 592 consecutive ICD recipients with index ventricular tachyarrhythmias was included (< 75 years: 78%; ≥ 75 years 22%). Age ≥ 75 years 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 ≥ 75 years 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).

Conclusion: Elderly ICD recipients aged ≥ 75 years are at increased risk of recurrent ventricular tachyarrhythmias, appropriate ICD therapies, and all-cause mortality at 5 years.