CORONARY THROMBOLYSIS WITH RECOMBINANT HUMAN TISSUE-TYPE PLASMINOGEN-ACTIVATOR - A PROSPECTIVE, RANDOMIZED, PLACEBO-CONTROLLED TRIAL

Patients (45) with acute transmural myocardial infarction and angiographically confirmed complete coronary occlusion were prospectively randomized, 2 for 1, to treatment of acute coronary thrombosis with i.v. recombinant human tissue-type plasminogen activator (rt-PA) or placebo. Each of 5 additional consecutive patients was treated with a high dose of rt-PA for 2 h. Twenty-five of 33 patients (75%) receiving 0.5 to 0.75 mg/kg of rt-PA over 30 to 120 min had angiographically proven recanalization within 90 min of initiation of therapy. Only 1 of 14 patients given placebo had spontaneous recanalization within 45 min (P < 0.001). Thirteen placebo-treated patients were crossed over to the intracoronary rt-PA group. Nine (69%) exhibited subsequent recanalization within 45 min. Levels of circulating fibrinogen decreased after treatment with rt-PA by an average of only 8% of baseline values. None of the patients manifested a depletion of fibrinogen level to below 100 mg/dl. Six patients who were completely unresponsive to rt-PA were subsequently treated with intracoronary streptokinase and none responded. Thus, either i.v. or intracoronary rt-PA induced coronary thrombolysis without eliciting clinically significant fibrinogenolysis in patients with evolving myocardial infarction due to thrombotic coronary occlusion.