Residual coronary stenosis after thrombolysis with rt-PA or streptokinase: acute results and 3 weeks follow-up.

Ninety-one patients with acute myocardial infarction were assigned to intravenous treatment with streptokinase or rt-PA as part of the randomized trial carried out by the European Study Group for Recombinant Tissue-Type Plasminogen Activator (rt-PA). A patent coronary artery was found in 37 of 45 (82%) patients treated with rt-PA and in 27 of 46 (59%) patients treated with streptokinase 75-90 minutes after start of infusion. Patients were subsequently anticoagulated with heparin or dicoumarol up to a repeat angiography 3 weeks after the infarction. Of the 64 patients with successful reperfusion, 3 died and 3 suffered reocclusion of the vessel. Quantitative analysis of the coronary stenosis both immediately after thrombolysis and at 3 weeks follow-up was possible in 33 cases. Residual stenosis (percentage narrowing of diameter) decreased from 74 +/- 14% to 56 +/- 17% (P less than 0.05). No difference was observed between the groups of patients treated with streptokinase (74 +/- 9% to 57 +/- 12%, N = 17) and with rt-PA (74 +/- 17% to 56 +/- 21%, N = 16). Despite the significant regression, a coronary stenosis of more than 50% of the diameter persisted in 82% of the patients three weeks after the infarction.