Sex-Differences in Arrhythmic Burden with the Wearable Cardioverter Defibrillator.

BACKGROUND: Data on the arrhythmic burden of women at-risk for sudden cardiac death are very limited, especially in patients using the wearable cardioverter defibrillator (WCD).

OBJECTIVE: We aimed to characterize WCD compliance, atrial and ventricular arrhythmic burden, and WCD outcomes by sex, in patients enrolled in the WEARIT-II U.S. Registry.

METHODS: In WEARIT-II, we stratified 2,000 patients by sex into women (n=598), and men (n=1402). WCD wear time, ventricular and atrial arrhythmia events during WCD use, and ICD implantation rates at the end of WCD use were evaluated.

RESULTS: WCD mean wear time was similar in women and men (94 vs. 90 days, p=0.145), with longer daily use in women (21.4 vs. 20.7 hour/day, p=001). Burden of ventricular tachycardia (VT) or ventricular fibrillation (VF) was higher in females with 30 events per 100 patient-years compared to 18 events per 100 patient-years in men (p=0.017), with similar findings for treated, and non-treated VT/VF. Recurrent atrial arrhythmias/SVT were also more frequent in women than in men (167 vs. 73 events per 100 patient-years, p=0.042). However, ICD implantation rate at the end of WCD use was similar in both women and men (41% vs. 39%, p=0.448).

CONCLUSIONS: In WEARIT-II, we have shown a higher burden of ventricular and atrial arrhythmia events in women as compared to men. ICD implantation rates at the end of WCD use were similar. Our findings warrant monitoring women at risk for sudden cardiac death who have a high burden of atrial and ventricular arrhythmias while using the WCD.