Does antiplatelet therapy enhance myocardial salvage after coronary reperfusion?

The aim of this study was to test the hypothesis that either the cyclooxygenase inhibitor aspirin or the thromboxane A2 receptor antagonist sulotroban exerts a direct myocardial effect that enhances myocardial salvage afforded by reperfusion. Accordingly, 21 anesthetized dogs underwent suture occlusion of the left anterior descending coronary artery. At 2.5 h after occlusion, all dogs received intravenous streptokinase (20,000 U/kg body weight over 30 min) and were randomized to the following groups: group I (n = 7) received no additional treatment, group II (n = 7) received aspirin (5 mg/kg intravenously) and group III (n = 7) received sulotroban (10 mg/kg followed by 10 mg/kg per h intravenously). At 3 h after occlusion, the dogs underwent coronary reperfusion for the next 3 h. Myocardial infarct size as a percent of the hypoperfused zone was similar among dogs in group I (42 +/- 8%), group II (41 +/- 10%) and group III (45 +/- 11%). The incidence and the extent of myocardial hemorrhage were similar in all three study groups. Infarct size as a percent of the hypoperfused zone was significantly smaller in dogs without hemorrhage irrespective of treatment (35 +/- 9% versus 63 +/- 5%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)