Background

Wearable cardioverter defibrillators (WCD) are important to avoid immediate implantable cardioverter defibrillator (ICD) implantation in patients, who are at temporary high risk of sudden cardiac death (SCD). Several factors should be taken into consideration e. g. patient selection, compliance and optimal drug treatment, when WCD is prescribed. We aimed to present real world data from 7 centers from Germany and Switzerland according to age differences regarding outcome, prognosis, WCD data and compliance.

Material and Methods

Between 04/2012 and 03/2021, 1105 patients were included in this registry. Outcome data according to age-differences (old≥45 compared to young<45 years) were analyzed. At young age WCDs were more often prescribed due to congenital heart disease and myocarditis. On the other hand, ischemic cardiomyopathy (ICM) were more present in older patients. Wear days of WCD were similar between both groups (p=0.115). In addition, during the WCD use documented arrhythmic life-threatening events were comparable (sustained ventricular tachycardia: 5.8% versus 7.7%, ventricular fibrillation (VF) 0.5% versus 0.6%) and consequently the rate of appropriate shocks was similar between both groups. Left ventricular ejection fraction improvement was documented over follow-up with a better improvement in younger patients as compared to older patients (77% versus 63%, p=0.002). At baseline the rate of left bundle branch block, the QTc duration, and the PQ duration were longer in older patients as compared to younger patients. In addition, at baseline the rate of atrial fibrillation was significantly higher in older the group (23% versus 8%; p=0.001). The rate of permanent cardiac implantable electronic device implantation (CiED) was significantly lower in the younger group (25% versus 36%, p=0.05). The compliance rate defined as wearing WCD at least 20 hours per day was significantly lower in young patients compared to old patients (68,9% versus 80,9%, p<0.001). During follow-up no significant difference regarding all-cause mortality or arrhythmic death was documented in both groups. A low compliance rate of wearing WCD is predicted by young patients and patients suffering from NICM.

Conclusion

Regardless of the lower compliance rate in younger patients, the clinical events were similar and more ICD implantation could be avoided compared to older patients.