Long-Term Follow-Up of Prophylactic Implantable Cardioverter-Defibrillator-Only Therapy: Comparison of Ischemic and Nonischemic Heart Disease

Background: The benefits of primary prophylactic implantable cardioverter-defibrillators (ICDs) are actually debated, as some drawbacks become more apparent and as the natural history of cardiac disease seems to improve. Therefore, contemporary follow-up data of non-trial populations treated according to current guidelines remain necessary. The aim of this study was to evaluate mortality and the occurrence of ICD interventions in patients with coronary artery disease (CAD) and dilated cardiomyopathy (DCM) who received in the recent era a primary prophylactic ICD without resynchronization therapy. Hypothesis: Survival and event-free rates from appropriate ICD therapy are different between ischemic and nonischemic ICD patients. Methods: Prospective cohort study of 427 consecutive primary prevention ICD patients with ischemic or nonischemic heart disease, excluding patients with resynchronization. Results: Ischemic heart disease was present in 290 patients (68%), nonischemic heart disease in 137 patients (32%). During a median follow-up of 31 months (interquartile range [IQR] 15-45 months), 30 patients (7%) died. Mortality was not different in both disease categories. The incidence of appropriate ICD interventions was similar in CAD and DCM (23% vs 21%). Appropriate ICD intervention occurred more frequently in patients with atrial fibrillation (29% vs 19%). Inappropriate ICD intervention occurred in 11% of patients. Conclusions: The clinical course of ischemic and nonischemic heart disease patients treated with a primary prophylactic ICD is similar with respect to mortality and to appropriate and inappropriate ICD interventions, in spite of a younger age at baseline of the DCM patients.