Short-term infarct vessel patency with aspirin and dipyridamole started 24 to 36 hours after intravenous streptokinase.

The duration of intravenous heparin therapy required to maintain patency of the infarct-related artery after intravenous streptokinase is uncertain. Twenty-eight patients were prospectively treated with 1.5 million units of intravenous streptokinase within 4 hours of onset of chest pain. Intravenous heparin was begun after the streptokinase infusion was complete and was discontinued within 36 hours. Aspirin, 325 mg daily, and dipyridamole, 75 mg three times a day, was begun before the heparin was discontinued. Coronary angiography was performed both at 2 hours after completion of the streptokinase infusion and again at a mean of 8.7 (+/- 3.2) days after the initial catheterization. One patient died after treatment with streptokinase but before early angiography. In 21 of 27 patients (78%), Thrombolysis in Myocardial Infarction trial (TIMI) grade 2 or 3 perfusion in the infarct vessel was observed on initial angiography. Repeat angiograms were available in 17 of the 21 patients with initially patent vessels. Continued patency (TIMI grade 2 or 3) was found in 15 of the 17 patients (88%). Two of the four patients who did not undergo repeat angiography died, and the remaining two patients required coronary artery bypass grafting for unstable angina. Bleeding complications occurred in 6 of 27 patients (22%), with two (7%) requiring surgical evacuation of a groin hematoma. There were no instances of intracerebral bleeding and only two patients required transfusions. Thus, the combination of aspirin and dipyridamole following 36 hours of systemic heparinization after intravenous streptokinase infusion is associated with a reocclusion rate comparable to that which has been reported for more prolonged systemic anticoagulation with fewer hemorrhagic complications.