ISIS-2 trial

17187 patients entering 417 hospitals a median of 5 hours after the onset of the symptoms of acute myocardial infarction were randomised with placebo control to:

• a 1 hr i.v. infusion of 1.5 MU of streptokinase
• one month of 160 mg/day enteric-coated aspirin
• both of the above
• none of the above

Both streptokinase and aspirin reduce mortality when compared to placebo:

• streptokinase alone: 9.2% vs. 12.0% (2p < 0.00001)
• aspirin alone: 9.4% vs. 11.8% (2p < 0.00001)

The use of both agents together gave a synergistic reduction in mortality:

• aspirin + streptokinase: mortality = 8.0%
• placebo: mortality = 13.2%
• this represents an odds reduction for death of 42%

There was no significant increase in serious side-effects such as intracranial haemorrhage or bleeds requiring transfusion.

Reference:

• Randomised trial of intravenous streptokinase, oral aspirin, both, or neither among 17187 cases of suspected acute myocardial infarction: ISIS-2. (1988). Lancet, 2, 349-60.