Frailty and Risk of Death Without Device Therapy Among Patients with Primary Prophylaxis Implantable Cardioverter-Defibrillators: The CERTITUDE Registry

BACKGROUND Frailty is common among patients with heart failure and is associated with non-arrhythmic morbidity and mortality. Whether frailty assessment can be used to improve risk stratification among patients undergoing primary prevention implantable cardioverter-defibrillator (ICD) placement is unknown. OBJECTIVE This study examined the association between frailty and death without ICD therapy following ICD implantation among patients with heart failure. METHODS We used data from the Biotronik CERTITUDE Registry linked to Medicare claims to identify adults aged ≥66 years with heart failure who underwent primary prevention ICD implantation between 1/1/2015 and 12/22/2022. Frailty was assessed using the validated Claims-Based Frailty Index (CFI) and stratified into robust (CFI <0.15), pre-frail (CFI 0.15-0.25), and frail (CFI ≥0.25) groups. RESULTS Among 1060 adults with heart failure who underwent primary prevention ICD implantation, 12.1% (128) were identified as frail. The primary outcome of death without ICD therapy for up to 5-years increased stepwise across frailty groups (16.5% in robust, 26.3% in pre-frail, 45.3% in frail; p<0.001), with a similar pattern observed for all-cause mortality (26.3%, 37.3%, 55.5%, respectively; p<0.001). After adjusting for age, sex, and comorbidities, frailty remained associated with death without ICD therapy (frail vs. robust; HR 1.92, 95% CI 1.12-3.29) and mortality (frail vs. robust; HR 1.66, 95% CI 1.07-2.58). The frailty threshold (CFI=0.20) identified the point where predicted 5-year risk of death without ICD therapy exceeded risk of ICD therapy. CONCLUSION Frailty is associated with higher risks of death without ICD therapy and all-cause mortality among patients undergoing primary prevention ICD.