Ninety-three patients with acute anterior myocardial infarction were treated with emergency percutaneous transluminal coronary angioplasty (PTCA). All were found to have a high-grade obstruction in the left anterior descending (LAD) vessel or the bypass graft to this vessel; 64 patients had a total occlusion. A completely successful PTCA, defined as a residual lesion of less than or equal to 50%, was achieved in 73 (78%) patients. A partially successful PTCA, with a residual lesion of 51% to 99%, was achieved in 12 (13%) patients. PTCA was unsuccessful in eight (9%) patients. Hospital mortality was 14%. Three parameters viewed separately each predicted hospital mortality: presence of shock, a proximal location of the LAD vessel occlusion, and the residual stenosis after PTCA. Reocclusion was found in only 11% of patients but 34% had evidence of restenosis on restudy.