2403Experience with the wearable cardioverter-defibrillator by disease etiology: results from the wearit-II registry

Abstract

Abstract Background The use of the wearable cardioverter-defibrillator (WCD) in patients with non-ischemic cardiomyopathy has been less characterized. Objective We aimed to characterize WCD use and outcomes for patients with ischemic or non-ischemic cardiomyopathy, enrolled in the WEARIT-II Registry. Methods In WEARIT-II, we stratified 1,732 patients into ischemic (n=805) and non-ischemic etiology (n=927). WCD wear time, arrhythmia events during WCD use, and implantable cardioverter-defibrillator (ICD) implantation rates, or ejection fraction (EF) improvement at the end of WCD were evaluated for etiology subgroups. Results The WCD median wear time was higher in patients with non-ischemic cardiomyopathy (93 vs. 87 days, p=0.003), however daily use was similar (22.4 vs. 22.6 hours, p=0.07). There were 24 ischemic patients (3%) with sustained VT/VF events compared to 10 patients (1%) with non-ischemic cardiomyopathy (p=0.013). About 2/3 of these events were treated with WCD shock in ischemic patients, half of them in the non-ischemic group (1.9% vs. 0.4%). Atrial arrhythmias were frequent in both groups (3.1% vs. 3.1%, p=0.06). At the end of WCD use, 36% of the non-ischemic patients were implanted with an ICD compared to 42% in ischemic (p=0.01), likely due to the lower rate of sustained ventricular arrhythmias (Figure). Figure 1 Conclusions In WEARIT-II, patients with non-ischemic cardiomyopathy had longer WCD use than ischemic patients with good compliance. The rate of sustained ventricular arrhythmia events was lower in non-ischemic patients avoiding the need for an ICD implantation in more patients compared to ischemic, following a time period of risk stratification. Acknowledgement/Funding WEARIT-II was funded by an unrestricted research grant from ZOLL Inc.