Cardiac resynchronization therapy with a defibrillator in non‐ischemic and ischemic patients for primary and secondary prevention of sudden cardiac death: Analysis of the Japan cardiac device treatment registry database

BACKGROUND: Panoramic studies in patients with cardiac resynchronization therapy with a defibrillator (CRT‐D) focusing on the etiology and indication are scarce. Besides, a controversy exists regarding requirement of a defibrillator in non‐ischemic patients for primary prevention with CRT. METHODS: Annual trends of de novo CRT‐D implantations from 2011 to 2020 and outcomes of those between January 2011 and August 2015 were analyzed from the Japan cardiac device treatment registry (JCDTR) and New JCDTR database. RESULTS: From 2011 to 2020, 8062 CRT‐D recipients were registered, whose dominant indication was primary prevention of sudden cardiac death with a steady rate of about 70%. There was no significant temporal change of the proportion of non‐ischemic patients being about 70% and 65% for primary and secondary prevention, respectively. Non‐ischemic patients for primary prevention were associated with increased odds of appropriate ICD therapy [adjusted hazard ratio (aHR): 1.66; 95% confidence interval (CI): 1.01–2.75; p = .047] and reduced odds of any death (aHR: 0.66; 95% CI: 0.44–0.99; p = .046) as compared to ischemic patients. CONCLUSIONS: Proportion of non‐ischemic etiology was much higher than that of ischemic one in the CRT‐D cohort. Based on the higher odds of appropriate ICD therapy, non‐ischemic patients for primary prevention appear to be prudently selected in Japan.