Benefits of Implantable Cardioverter–Defibrillator for Secondary Prevention in Patients With Organic Heart Disease

ABSTRACT Background Implantable cardioverter‐defibrillators (ICD) are first‐line treatment to prevent sudden cardiac death due to recurrent ventricular tachycardia and fibrillation (VT/VF). However, some patients with organic heart disease (OHD) die without ever receiving appropriate ICD therapy. This study aimed to identify predictors of death without appropriate ICD therapy in patients with OHD who received ICD or cardiac resynchronization therapy with a defibrillator (CRT‐D) for secondary prevention. Methods We analyzed consecutive patients who received ICD/CRT‐D for secondary prevention between 2000 and 2022. Patients without OHD or those alive without appropriate ICD therapy were excluded. The “no‐benefit group” included patients who died or developed severe disability without appropriate ICD therapy or those who died within 1 year after their first appropriate therapy. The “benefit group” included patients who survived > 1 year after appropriate therapy. Clinical characteristics were compared between the groups. Results Of the 170 patients analyzed (median follow‐up: 9.1 years), 43 (25%) were classified into the no‐benefit group (30 died without appropriate therapy, 10 died within 1 year of first appropriate therapy, and 3 developed severe disability without appropriate therapy). Multivariate analyses identified age > 70 years and history of VF as independent predictors of “no benefit.” Among patients with VF aged ≥ 70 years, 71% were classified into the no‐benefit group. Conclusions Although 75% of patients benefited from ICD therapy for secondary prevention, elderly patients with VF may gain limited benefits from ICD implantation.