Introduction
It is well known that an implantable cardioverter-defibrillator (ICD) improves survival and reduces the mortality rate due to ventricular tachyarrhythmias [1-3]. The Danish Cardiac Arrest Registry showed the superiority of early implantation of ICD in patients surviving myocardial infarction (MI) with cardiac arrest [4]. However, some patients do not meet the criteria for ICD implantation or are unable to receive an implantable device such as patients in the acute phase of MI or myocarditis. The wearable cardioverter defibrillator (WCD) may be considered to protect these patients against malignant ventricular tachyarrhythmias and as a bridge to decision for ICD implantation [5]. However, compliance is impaired due to comfort issues [6]. Poor compliance and obesity decreased the efficacy of WCD therapy [7]. In addition, the VEST trial showed no reduction of arrhythmic death as the primary endpoint in recent MI patients with reduced left ventricular ejection fraction (LVEF < 35%) [8].
One cohort study on sudden cardiac death (SCD) reported that WCD treatment is effective in females with a first shock success rate of 95% [9]. WEARIT-II-Registry presented a higher rate of ventricular and atrial arrhythmic events in females as compared to males [10]. However, randomized controlled trials and further data on gender differences are lacking. Therefore, we analyzed in a multicenter setting a consecutive patient cohort wearing WCD to explore gender differences regarding compliance, rate of appropriate WCD shocks, and mortality.