Survival of patients with the automatic implantable cardioverter defibrillator

Between May 1982 and May 1988, 37 patients (28 males and 9 females, mean age 57.6, range 16-76 years) of approximately 600 evaluated for sustained ventricular tachycardia and/or fibrillation (VT/VF) were treated with an automatic implantable cardioverter defibrillator (AICD). Twenty-eight of the patients had coronary artery disease, 7 had nonischemic cardiomyopathy, 1 had amyloid heart disease, and 1 had rheumatic heart disease. The mean ejection fraction was 32.2 +/- 12.9% (range, 9-64%). Eleven patients have died at a mean of 16.7 months after implantation. The cumulative survival rate was 81% at 1 year, 77% at 2 years, 68% at 3 years, and 53% at 4, 5, and 6 years. Considering only sudden deaths, the survival was 97% at 1 and 2 years, 90% at 3 years, and 80% at 4, 5, and 6 years. Twenty-one of the 37 patients received spontaneous shocks. If the first shock marks the time to death in the absence of an AICD, the cumulative survival rate would have been 56% at 1 year, 42% at 2 years, 29% at 3 years, and 14% at 4, 5, and 6 years. The maximum amount of time to a first appropriate shock was 39.7 months. Thirty-nine devices have been explanted: 28 for battery depletion; 5 for infections; 3 for improper sensing; 2 for electronic failure; and 1 at the time of cardiac transplantation. The average time to failure of the 28 units removed for battery depletion was 19.8 +/- 6.9 months.(ABSTRACT TRUNCATED AT 250 WORDS)