Double-blind randomised trial of intravenous tissue-type plasminogen activator versus placebo in acute myocardial infarction.

In a double-blind randomised trial 129 patients with first myocardial infarction of less than 6 h duration were allocated to treatment with human recombinant tissue-type plasminogen activator (rt-PA) given intravenously over 90 min, or to placebo infusion. Coronary angiography at the end of this infusion showed that the infarct-related vessel was patent in 61% of 62 assessable coronary angiograms in the rt-PA-treated group compared with 21% in the control group. Treatment with rt-PA was not accompanied by any major complications. In the rt-PA group the circulating fibrinogen level at the end of the catheterisation was 52 +/- 29% (mean +/- SD) of the starting value.