Analysis of coagulation and fibrinolysis during intravenous infusion of recombinant human tissue-type plasminogen activator in patients with acute myocardial infarction.

Abstract

Coagulation and fibrinolysis were studied in patients with acute myocardial infarction during intravenous infusion of recombinant human tissue-type plasminogen activator (rt-PA) (0.75 mg/kg over 90 min, n = 101), streptokinase (1,500,000 IU over 60 min, n = 61), or placebo (n = 40). In the rt-PA group, the plasma level of rt-PA antigen was 1.2 +/- 0.6 micrograms/ml (mean +/- SD) and the euglobulin fibrinolytic activity (EFA) was 910 +/- 735 IU t-PA/ml. In the streptokinase group, the EFA was equivalent to 430 +/- 435 IU t-PA/ml. At the end of the infusion, the plasma fibrinogen level measured with a coagulation rate assay was decreased to 57 +/- 33% of the preinfusion value in the rt-PA group, to 7 +/- 10% in the streptokinase group, and remained unchanged in the placebo group. Fibrinogen-fibrin degradation products increased to 0.75 +/- 0.54 mg/ml in the streptokinase group but to only 0.10 +/- 0.13 mg/ml in the rt-PA group. The plasma levels of alpha 2-antiplasmin, plasminogen, and factor V decreased to...