A prospective placebo-controlled double-blind multicenter trial of intravenous streptokinase in acute myocardial infarction (ISAM): long-term mortality and morbidity.

Long-term mortality and morbidity of 1,741 patients with acute myocardial infarction, treated with intravenous streptokinase (1.5 million IU/h) or placebo, was assessed in a double-blind placebo-controlled trial (ISAM). At the 7 month follow-up, 94 (10.9%) of the 859 patients in the streptokinase group and 98 (11.1%) of the 882 patients in the placebo group had died; at an average follow-up of 21 months, 14.4% of the streptokinase group and 16.1% of the placebo group had died. The differences were not statistically significant. Long-term mortality was slightly higher in patients with anterior myocardial infarction and streptokinase treatment (20.1 versus 18.4%) and lower in patients with inferior myocardial infarction (10.2 versus 14.2%). Patients with previous myocardial infarction had a higher long-term mortality rate with streptokinase (34.9 versus 21.5% with placebo, p = 0.03). At 7 months, there were significantly more cases of reinfarction in the streptokinase group (7.2 versus 4.5%, p = 0.02). It is concluded that despite a significant limitation of infarct size by intravenous streptokinase, long-term mortality is only slightly reduced and reinfarction is significantly more frequent. Both findings suggest the need for complementary therapy such as revascularization procedures after thrombolysis.