Since 1984, the Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA project) has studied progress in acute coronary artery disease (CAD) in defined geographic areas. This study, based in a French MONICA center in Southwestern France, assessed acute myocardial infarction (AMI) frequency, prognosis, and treatment between 1985 and 1990. The age-standardized AMI attack rate showed a slight decrease in men (218.3 of 100,000 in 1985 and 200.1 of 100,000 in 1990, p < 0.05). In men, the AMI age-standardized 28-day case fatality rate decreased from 38% in 1985 to 27% in 1990 (p < 0.001), with a dramatic reduction in the age-standardized in-hospital case fatality rate (21% in 1985 and 11% in 1990, p < 0.001). Furthermore, the in-hospital 28-day case fatality decreased exclusively in male patients with a history of CAD (33% in 1986 and 19% in 1990, p < 0.01). AMI treatment improved between 1986 and 1990 with increased use of antiplatelets (40.7% in 1986, 73.6% in 1989, and 84.8% in 1990, p < 0.001), beta-blockers (29.5% in 1986, 45.7% in 1989, and 57.7% in 1990, p < 0.001), and thrombolytic therapy (23.6% in 1986, 45.3% in 1989, and 39.5% in 1990, p < 0.001). Invasive cardiology technique utilization increased dramatically between 1986 and 1990 with the generalized use of coronary angiography (68.2% in 1986, 89.3% in 1989, and 87.3% in 1990, p < 0.001) and percutaneous transluminal coronary angioplasty (17.7% in 1986, 49.6% in 1989, and 55.3% in 1990, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)