Experience With the Wearable Cardioverter-Defibrillator in Patients at High Risk for Sudden Cardiac Death

BACKGROUND This study evaluated the wearable cardioverter-defibrillator (WCD) for use and effectiveness in preventing sudden death caused by ventricular tachyarrhythmia or fibrillation. METHODS From April 2010 through October 2013, 6043 German WCD patients (median age, 57 years; male, 78.5%) were recruited from 404 German centers. Deidentified German patient data were used for a retrospective, nonrandomized analysis. RESULTS Ninety-four patients (1.6%) were treated by the WCD in response to ventricular tachyarrhythmia/fibrillation. The incidence rate was 8.4 (95% confidence interval, 6.8-10.2) per 100 patient-years. Patients with implantable cardioverter-defibrillator explantation had an incidence rate of 19.3 (95% confidence interval, 12.2-29.0) per 100 patient-years. In contrast, an incidence rate of 8.2 (95% confidence interval, 6.4-10.3) was observed in the remaining cardiac diagnosis groups, including dilated cardiomyopathy, myocarditis, and ischemic and nonischemic cardiomyopathies. Among 120 shocked patients, 112 (93%) survived 24 hours after treatment, whereas asystole was observed in 2 patients (0.03%) with 1 resulting death. CONCLUSIONS This large cohort represents the first nationwide evaluation of WCD use in patients outside the US healthcare system and confirms the overall value of the WCD in German treatment pathways.