Effects of Intracoronary Streptokinase and Intracoronary Nitroglycerin Infusion on Coronary Angiographic Patterns and Mortality in Patients with Acute Myocardial Infarction

We randomly assigned patients with a clinical diagnosis of acute myocardial infarction to one of four treatment groups: intracoronary streptokinase, intracoronary nitroglycerin, intracoronary streptokinase and intracoronary nitroglycerin, or conventional therapy without initial angiography. Of 124 patients 122 sustained acute myocardial infarction. Initial angiography revealed total occlusion of the coronary artery responsible for infarction in 67 per cent (61 of 91). Acute recanalization occurred in 74 per cent (32 of 43) of patients receiving streptokinase but in only 6 per cent (1 of 18) of patients treated with nitroglycerin alone (P less than 0.01). At angiography of all four groups on Day 10 to 14 the vessel responsible for acute myocardial infarction was patent in 77 per cent (71 of 92) of patients; there was no difference among groups, indicating gradual, endogenous thrombolysis in patients not treated with streptokinase. Patients with subtotal obstruction initially had significant improvement in left ventricular function, significantly lower peak creatine kinase levels, and a trend toward lower mortality than patients with total occlusion initially. Mortality at six months in patients receiving streptokinase (21 per cent, 13 of 62) did not differ significantly from that in patients not treated with streptokinase (10 per cent, 6 of 61). Additional studies will be necessary to assess treatment effects in the angiographic subsets identified by this trial.