Most reports of the decrease in age-adjusted coronary heart disease (CHD) are based on databases with upper age cut-offs that exclude approximately half of the events. We report changes in rates of acute myocardial infarction (AMI) and of out-of-hospital coronary death between 1986 and 1996 among New Jersey residents > or =15 years old. Data on patients discharged with the diagnosis of AMI from nonfederal acute care hospitals in the state (n = 270,091) and all records in the New Jersey death registration files with CHD (n = 172,175) listed as the cause of death from 1986 to 1996 (total study n = 442,266) were analyzed. The rate of hospitalized AMI cases in the state remained essentially unchanged during these 11 years, whereas in-hospital and 30-day case fatality among all age groups and both sexes declined. Age-adjusted CHD rates showed a decrease in fatal events, a smaller decrease in total events, and a slight increase in nonfatal events. The proportion of fatal CHD events occurring out-of-hospital decreased especially among men. The median age at occurrence of events increased by 1 year. Despite a decrease in CHD mortality, the rate of nonfatal events increased, especially among persons > or =75 years old. Thus, the decrease in age-adjusted CHD mortality is not all due to treatment and true prevention of CHD, but the disease simply occurs at an older age.