Acronym: International Study of Infarct Survival
Purpose: To evaluate the use of the thrombolytic drug streptokinase versus aspirin versus the combination of both for the treatment of acute myocardial infarction.
Format: Randomized, double blind, multicenter, two-by-two factorial placebo controlled trial
Treatment Group: Streptokinase OR the combination of streptokinase and aspirin
Control Group: Placebo
Number of Patients: 17,187
Suspected acute myocardial infarction within 24 hours of symptom onset
No contraindication for streptokinase or aspirin
Prior GI bleed or peptic ulcer disease
Severe refractory hypertension
Recent arterial procedure
Allergy to streptokinase or aspirin
Follow-up: Initially 5 weeks, but most recent publication followed for 10 years
Primary Endpoint: Cardiovascular mortality at 5 weeks
Non-fatal reinfarction or stroke
Major bleeding requiring blood transfusion
Randomized acute MI patients to aspirin alone, streptokinase alone or both combined. The combination of the two was better than either agent alone. Aspirin reduced non-fatal reinfarction without increasing bleeding risk. Streptokinase alone increased bleeding requiring transfusion, intracranial hemorrhage and non-fatal re-infarction if used alone. Survival benefit of combination of aspirin and streptokinase extended out at least 10 years.
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