Age-Related differences in compliance and wearing time of wearable cardioverter defibrillators: a monocentric retrospective observational study

The wearable cardioverter defibrillator (WCD) is used for temporary protection of patients deemed to be at high risk for sudden death (SCD) not yet meeting indications for an implantable defibrillator (ICD). Adherence and wearing time are crucial for the effectiveness of WCD, as the device can only detect and treat arrhythmias when worn. The ideal wearing time is approximately 23 hours per day, allowing for personal hygiene. This study examines the impact of age on WCD wearing time in a monocentric cohort of patients.

This study aimed to evaluate the impact of age on adherence to WCD to develop strategies to improve device effectiveness, particularly for younger patients at high risk of sudden cardiac death.

We conducted a monocentric retrospective observational study, including 110 consecutive patients who were prescribed a WCD between 2020 and 2024 either for primary or secondary prophylaxis. Adherence und wearing time events were evaluated by two investigators using the Zoll Life Vest network database.

The cohort's mean age was 64 years, with a mean left ventricular ejection fraction (LVEF) of 34%. The mean wearing duration time was 53 days, and the average wearing time was 21.7 hours per day. Gender distribution was 103 men (78%) and 29 women (22%) with a lower women representation as comparable to other study cohorts (such as the one from the WEAR IT registry). Our analysis found no significant difference in wearing time between males and females or among patients of different weight categories. However, a significant difference was observed when comparing younger patients (≤50 years old) to older patients (>50 years old). In our study cohort, younger patients showed a lower mean wearing time of 18.7 hours/day, while older patients had a mean wearing time of 21.8 hours/day, which was significantly different when compared using an independent samples T-test (one-sided p = 0.004, two-sided p = 0.009). Further reinforcing our hypothesis, a bivariate correlation analysis showed a significant correlation between age and wearing time (2-significance = 0.014).

Our observational real-life study indicates that younger patients exhibit significantly lower compliance with WCD wearing time compared to older patients. This suggests a need for more careful follow-up and monitoring of younger patients to encourage consistent use of the WCD, ensuring compliance and reducing their arrhythmic risk for sudden cardiac death. Given that the highest risk of arrhythmias occurs within the first three months following an HFrEF diagnosis, younger patients may benefit from closer follow-up during this period due to their lower adherence to wearing the device compared to older patients. This approach aligns with evidence suggesting that a longer follow-up period can improve recovery of left ventricular function, as demonstrated in the HF-Opt study