Experience with the wearable cardioverter-defibrillator in older patients: Results from the Prospective Registry of Patients Using the Wearable Cardioverter-Defibrillator

Background: Use of the wearable cardioverter-defibrillator (WCD) in older patients has not been described previously. Objective: The purpose of this study was to assess WCD wear time, risk of arrhythmic events during WCD use, and implantable cardioverter-defibrillator (ICD) implantation rates after the end of WCD use in patients with age ≥65 years vs <65 years. Methods: We stratified 1732 patients with ischemic and nonischemic cardiomyopathy from the Prospective Registry of Patients Using the Wearable Defibrillator Registry into 2 subgroups by age: those with age ≥65 years and those with age <65 years. Wear time, arrhythmic events, and end-of-use decisions, specifically ICD implantation or improvement in ejection fraction, were evaluated for each age group. Results: There were 722 patients with age ≥65 years (41.7%) and 1010 patients with age <65 years (58.3%). Daily WCD wear time was longer in the older population (median 22.8 h/d (IQR 21.5 - 23.2) vs 22.3 h/d (IQR 19.5 - 23.0); P <.001). Patients with age ≥65 years experienced higher event rates, per 100 patient-years, for any sustained ventricular tachycardia/ventricular fibrillation (31.95 vs 9.82; P =.027) and ventricular tachycardia/ventricular fibrillation treated with WCD shock (6.92 vs 2.37; P =.034), particularly with ischemic cardiomyopathy. Younger patients experienced a trend toward a higher event rate for atrial arrhythmias with nonischemic cardiomyopathy (150.07 vs 74.86; P =.055). At the end of WCD use, ICD implantation was more frequent in older patients (41.8% vs 36.5%; P =.034). Conclusion: Older patients had good compliance with the WCD, presented with more frequent ventricular arrhythmias, and were more likely to receive an ICD at the end of WCD use. The WCD may play a role in risk stratification of the older population.