From June 1988 to March 1991, an unselected cohort of 150 consecutive patients with acute myocardial infarction (AMI) (less than 6 hours) was managed according to a strategy designed to ensure early patency of the infarct-related artery in the maximum number of patients. The following procedures were used: (1) intravenous thrombolysis, which was the usual treatment (n = 103), followed in 98 cases by emergency coronary angiography 90 minutes after the beginning of thrombolysis. This identified 31 thrombolysis failures (32%) and led to 19 rescue angioplasties (18 successes). All patients were then scheduled for predischarge angiography. (2) Direct angioplasty, which was performed in 40 patients because of contraindications to thrombolysis (n = 23), cardiogenic shock (n = 3), diagnostic doubt (n = 7) or "ideal" conditions for direct angioplasty (n = 7). Success (defined as Thrombolysis in Myocardial Infarction [TIMI] flow greater than 1, with a residual stenosis less than 50% in the infarct-related artery) was achieved in 36 of 40 patients (90%). (3) The 7 remaining patients were given conventional medical treatment because of advanced age, contraindications to thrombolysis and angioplasty, or spontaneous reperfusion (confirmed by emergency angiography). In all, emergency angioplasty was performed in the acute phase in 39% of the 150 patients in this nonselected cohort.(ABSTRACT TRUNCATED AT 250 WORDS)