P1025Wearable cardioverter-defibrillator therapy for the prevention of sudden cardiac death: a systematic review and meta-analysis

Abstract

Background: The wearable cardioverter-defibrillator (WCD) was approved in 2001 for prevention of sudden cardiac death (SCD) in patients not suitable for permanent defibrillator implant. Subsequent published studies have provided conflicting data, leading to significant variation in WCD use and practice patterns. To help clarify this uncertainty, we synthesized available evidence on the use of WCDs and a wide range of clinical outcomes. Method(s): We searched PubMed, EMBASE, Google Scholar, and references of the included articles for relevant studies from 1/1/2001 through 11/30/2017. All studies reporting on the outcomes of patients using WCD were included. The main outcomes were the pooled incidence rates of appropriate and inappropriate WCD therapies. Secondary outcomes included pooled incidence of death while wearing a WCD, and pooled rates of appropriate WCD therapies in subgroups of ischemic and non-ischemic cardiomyopathy. Summary estimates were derived using DerSimonian and Laird's method. Heterogeneity was explored using subgroup analyses and meta-regression. Result(s): Twenty-seven observational (21 retrospective, 6 prospective) studies enrolling 30,902 patients were included in meta-analysis. Twenty-one studies either used data provided by the WCD manufacturer or had financial disclosures involving the WCD manufacturer. The pooled incidence of receiving appropriate WCD therapy was 5 per 100 persons over 3 months (95% CI 3.0, 7.0; I2=93.1%) and inappropriate therapy was 2 per 100 persons over 3 months (95% CI 2.0 4.0; I2=90.3%). Mortality while wearing the WCD was rare; the pooled incidence was 0.4 per 100 persons over 3 months (95% CI 0.0, 1.0, I2=60.7%). In subgroup analysis, the pooled incidence rates of appropriately WCD therapies in patients with ischemic cardiomyopathy and non-ischemic cardiomyopathy were 11 per 100 persons over 3 months (95% CI 6.0, 20.0) and 6 per 100 persons over 3 months (95% CI 3.0, 12.0), respectively. There was significant heterogeneity across the studies that was in part explained by type of cardiomyopathy (ischemic vs. other) and by mean ejection fraction. Conclusion(s): The rate of appropriate WCD therapy over 3 months of follow-up was substantial. All studies were observational, and majority had mixed indications. Randomized clinical trials are needed to address the safety, efficacy, and cost-effectiveness of WCD. (Figure Presented).