A donor age of less than 35 years has long been considered crucial for heart transplantation. Because of limited donor heart supply and increasing demand for cardiac transplants, we attempted to expand the donor pool by using hearts from older individuals. This study was designed to determine if older donor hearts adversely affected cardiac transplant patient prognosis by predisposing them to graft failure from coronary artery disease, ventricular dysfunction, or death. Since 1982, 314 heart transplants have been performed at our institutions. Potential donors were deemed fit if there was no history of heart disease, the chest x-ray film was normal, the electrocardiogram showed nonspecific changes only, and blood pressure was maintained without major pharmacological support. In 47 (15%), donor age was 35 years or greater (group 1: mean age, 39 years; range, 35-49 years). In 267 (85%), donor age was less than 35 years (group 2: mean age, 23 years; range, 2-34 years). Mean group 1 recipient age was 55 years (range, 39-68 years) compared with 46 years (range, 0.7-66 years) in group 2 (p less than 0.01). Pretransplant inotropic support, mechanical support, or both were required in 15 (33%) group 1 patients and in 41 (16%) group 2 patients (p less than 0.01). Group 1 and 2 follow-up intervals were 1.1 +/- 1.0 and 1.8 +/- 1.4 years (mean +/- SD), respectively (p less than 0.0001). Overall survival was 64% versus 65%, group 1 versus group 2, and life table analysis showed no significant difference between the groups. There were three of 17 (18%) deaths due to coronary artery disease in group 1 and 20 of 87 (23%) in group 2 (p = NS). Seven patients in group 2 and none in group 1 required retransplant because of coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)