The Effect of Frailty on Mortality and Defibrillator Implantation in Older Recipients of Cardiac Resynchronization Therapy

Background Cardiac resynchronization therapy guidelines do not distinguish between defibrillators (CRT-D) and pacemakers (CRT-P). Drivers of CRT device choice remain uncertain but may be influenced by comorbidities and frailty, particularly in older recipients. Purpose We sought to evaluate the effect of frailty, measured as deficit accumulation, on mortality and CRT device choice in older (age≥75 yrs) heart failure patients. Methods In 502 consecutive older CRT recipients with EF≤35% implanted between 2002 and 2014 (age 81±4 yrs; 71% men; 19% CRT-P), we retrospectively collected 36 dichotomous variables each reflecting the presence or absence of a deficit and summed these to create a frailty score which has been previously validated in the primary care setting as a predictor of mortality. We divided the score into quartiles of fit, mild, moderate, and severe frailty and tested its association with survival from time of device implant (Cox regression) and type of CRT device implanted (chi-square). Results Over a median follow up of 4.7 yrs, 414 (82%) patients died. Frailty quartile predicted mortality in unadjusted analysis (Figure) and similarly after adjustment for device type, ejection fraction, and age at time of device implant. The 1-, 3-, and 7-year cumulative survival between fit and severely frail recipients were 98% vs. 71% (p=0.02), 86% vs. 51% (p Conclusion A frailty score predicts mortality in older CRT recipients and tracks physician tendency towards CRT-P implantation among the frail relative to the fit. Yet, even among the severely frail, CRT-D remained the norm in our sample despite its lack of known benefit on survival compared to CRT-P. As a result, type of device implanted did not predict survival, indicating that physician intuition may be limited regarding frailty assessment and patient outcome. Use of a frailty score may assist in CRT device choice by helping physicians identify patient frailty extent and providing individualized risk assessment.