In this study, 70 patients ≥70 years of age admitted to the coronary care unit with non-Q-wave acute myocardial infarction (AMI) were followed prospectively for 1 year, and the clinical course in these patients was compared with that in 61 patients <70 years with non-Q-wave AMI and 56 patients ≥70 years with Q-wave AMI. Compared with the younger patients with non-Q-wave AMI, older patients were more likely to develop atrial fibrillation (23% vs 8%, p < 0.05) and congestive heart failure (53% vs 30%; p < 0.01), and less likely to receive thrombolytic therapy (9% vs 28%; p < 0.01), cardiac catheterization (41 % vs 72%; p < 0.01), and coronary angioplasty (20% vs 39%;p < 0.05). Hospital mortality did not differ significantly between older and younger non-Q-wave AMI patients (10% vs 3%), but 1-year mortality was higher in the elderly (36% vs 16%; p = 0.02). Elderly patients with Q-wave AN had more in-hospital complications, including death (25% vs 10%, p < 0.05), than elderly patients with non-Q-wave AMI. In contrast, postdischarge mortality was higher in elderly patients with non-Q-wave AMI, so that total mortality at 1 year was similar in the 2 groups. Overall, elderly patients with non-Q-wave AMI accounted for 62% of all deaths occurring during the first year after discharge (relative risk 2.6 compared with other groups; p < 0.01). Thus, elderly patients with non-Q-wave AMI have a significantly increased mortality risk during the year after hospital discharge compared with other patients with AMI, suggesting that an aggressive diagnostic and therapeutic approach may be of particular benefit in these patients.