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Keywords:

Antiplasmin, Blood Coagulation, Factor V, Fibrinogen, Fibrinolysis, Humans, Infusions, Parenteral, Myocardial Infarction, Recombinant Proteins, Streptokinase, Tissue Plasminogen Activator, Science & Technology, Life Sciences & Biomedicine, Cardiac & Cardiovascular Systems, Peripheral Vascular Disease, Cardiovascular System & Cardiology, alpha-2-Antiplasmin, 1102 Cardiorespiratory Medicine and Haematology, 1103 Clinical Sciences, 1117 Public Health and Health Services, Cardiovascular System & Hematology, 3201 Cardiovascular medicine and haematology, 3202 Clinical sciences, 4207 Sports science and exercise

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 between 30% and 45% in the rt-PA group but significantly more in the streptokinase group (to between 15% and 25%). Thus rt-PA induced much less systemic fibrinolytic activation than streptokinase. In the patients who received rt-PA, a weak correlation (r = .21, n = 89, .1 greater than p greater than .05) was found between the extent of fibrinogen breakdown at 90 min and the plasma rt-PA concentration.(ABSTRACT TRUNCATED AT 250 WORDS)