Long-term follow-up of patients with nonischemic dilated cardiomyopathy and ventricular tachyarrhythmias treated with implantable cardioverter defibrillators.

We analyzed our 10-year cumulative experience of 40 consecutive patients with idiopathic dilated cardiomyopathy and associated ventricular tachyarrhythmias, treated with implantable cardioverter defibrillators. Dilated cardiomyopathy was defined as left ventricular ejection fraction (EF) less than or equal to 50% with no defineable etiology. Patient characteristics included: 24 male, mean age 52 years, mean EF = 33%, New York Heart Association Class I-III, presenting syndrome--cardiac arrest (n = 28), syncope/near syncope (n = 12). At 2.5 years mean follow-up, there were 16 deaths: one operative, three sudden, two incessant ventricular tachycardia/ventricular fibrillation (VT/VF), six heart failure, and four noncardiac. The actuarial mortality at 1 and 4 years was 0% and 14% for sudden death, 11% and 34% for cardiac death. The projected mortality was 52% and 78% for same time intervals (P less than 0.01). No useful baseline variable predicted who would or would not receive an ICD shock in follow-up. ICD therapy appears effective in reducing sudden death mortality in this high risk population.