Reassessment of Clinical Variables in Cardiac Resynchronization Defibrillator Patients at Time of First Replacement: DARC (Death After Replacement of CRT) score.

Background Cardiac resynchronization defibrillator (CRT-D) as primary prevention is known to reduce mortality. At time of replacement, higher age and comorbidities may attenuate the benefit of implantable defibrillator (ICD) therapy. The purpose of this study was to evaluate the progression of comorbidities after implantation and their association with mortality following CRT-D generator replacement. In addition, a risk score was developed to identify patients at high risk for mortality after replacement. Methods and results We identified patients implanted with a primary prevention CRT-D (n=648) who subsequently underwent elective generator replacement (n=218) from 2 prospective ICD registries. The cohort consisted of 218 patients (median age 70 years, male gender 73%, mean LVEF 36 ± 11% at replacement). Median follow-up after replacement was 4.2 years during which 64 patients (29%) died and 11 patients (5%) received appropriate ICD shocks. An increase in comorbidities was observed in 77 patients (35%). The 5-year mortality rate was 41% in patients with ≥ 2 comorbidities at time of replacement. A risk score incorporating age, gender, LVEF, atrial fibrillation, anemia, chronic kidney disease, and history of appropriate ICD shocks at time of replacement accurately predicted 5-year mortality (C-statistic 0.829). Patients with a risk score of >2.5 had excess mortality at 5-year post replacement compared with patients with a risk score Conclusion A simple risk score accurately predicts 5-year mortality after replacement in CRT-D patients, as patients with a risk score of >2.5 are at high risk of dying despite ICD protection. This article is protected by copyright. All rights reserved.