Comparison of Mortality and Readmission in Non-ischemic vs Ischemic Cardiomyopathy After Implantable Cardioverter-Defibrillator Implantation

Abstract Data is lacking on the contemporary risk of death and readmission following implantable cardioverter-defibrillator (ICD) implantation in patients with non-ischemic cardiomyopathies (NIC) compared with ischemic cardiomyopathies (IC) in a large nationally representative cohort. We performed a retrospective cohort study using the National Cardiovascular Data Registry (NCDR) ICD Registry linked with Medicare claims from April 1, 2010 to December 31, 2013. We established a cohort of NIC and IC patients with a left ventricular ejection fraction ≤35% who received a de novo, primary prevention ICD. We compared mortality and readmission using Kaplan-Meier curves and Cox proportional hazard regressions models. We also evaluated temporal trends in mortality. Among 31,044 NIC and 68,458 IC patients with a median follow up of 2.4 years, 1-year mortality was significantly higher in IC patients (12.3%) compared with NIC (7.9%, p