Lancet
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Randomized Controlled Trial Comparative Study Clinical Trial
Randomised trial of intravenous streptokinase, oral aspirin, both, or neither among 17,187 cases of suspected acute myocardial infarction: ISIS-2. ISIS-2 (Second International Study of Infarct Survival) Collaborative Group.
17,187 patients entering 417 hospitals up to 24 hours (median 5 hours) after the onset of suspected acute myocardial infarction were randomised, with placebo control, between: (i) a 1-hour intravenous infusion of 1.5 MU of streptokinase; (ii) one month of 160 mg/day enteric-coated aspirin; (iii) both active treatments; or (iv) neither. Streptokinase alone and aspirin alone each produced a highly significant reduction in 5-week vascular mortality: 791/8592 (9.2%) among patients allocated streptokinase infusion vs 1029/8595 (12.0%) among those allocated placebo infusion (odds reduction: 25% SD 4; 2p less than 0.00001); 804/8587 (9.4%) vascular deaths among patients allocated aspirin tablets vs 1016/8600 (11.8%) among those allocated placebo tablets (odds reduction: 23% SD 4; 2p less than 0.00001). The combination of streptokinase and aspirin was significantly (2p less than 0.0001) better than either agent alone. ⋯ An excess of non-fatal reinfarction was reported when streptokinase was used alone, but this appeared to be entirely avoided by the addition of aspirin. Those allocated the combination of streptokinase and aspirin had significantly fewer reinfarctions (1.8% vs 2.9%), strokes (0.6% vs 1.1%), and deaths (8.0% vs 13.2%) than those allocated neither. The differences in vascular and in all-cause mortality produced by streptokinase and by aspirin remain highly significant (2p less than 0.001 for each) after the median of 15 months of follow-up thus far available.