Haematological effects of anisoylated plasminogen streptokinase activator complex and streptokinase in patients with acute myocardial infarction. Interim report of the IRS II Study.

86 patients with a first myocardial infarction presenting within 6 hours of the onset of symptoms were randomly allocated to treatment with intravenous streptokinase or anisoylated plasminogen streptokinase activator complex (APSAC). Plasma concentrations of fibrinogen, plasminogen, alpha 2-antiplasmin and fibrinogen degradation products and thrombin and prothrombin times, were measured before the injection of the thrombolytic drug and every 3 hours during the first 24 hours. APSAC and streptokinase produced identical and important systemic effects. APSAC produced a slightly smaller decrease in fibrinogen concentrations. The duration of this systemic activity was about the same for the 2 drugs (congruent to 24 hours).