The study was a randomized trial of myocardial reperfusion in acute myocardial infarction by selective intracoronary infusion of nitroglycerin and/or intracoronary infusion of streptokinase. The trial was single-blinded as to the interventional therapy; it was double-blinded as to the drug infused. The primary endpoint was the ejection fraction on the 10th day of intervention. Patients were assigned to one of four treatment arms: an intracoronary infusion of streptokinase; an intracoronary infusion of nitroglycerin; combined infusions of nitroglycerin and streptokinase; a control group receiving conventional therapy without acute catheterization. All patients underwent anticoagulant therapy with intravenous heparin followed by warfarin for three months. Patients were followed for a minimum of two years.