Pretreatment plasminogen activator inhibitor-1 (PAI-1) levels and the outcome of thrombolysis with streptokinase in patients with acute myocardial infarction.

Background: The risk for reinfarctions and delays in reperfusion after streptokinase therapy may be caused by the antifibrinolytic effect of platelet-derived type 1 plasminogen activator inhibitor (PAI-1). This study aims to show the relation of pretreatment PAI-1 levels of patients with acute myocardial infarction treated with streptokinase therapy and the outcome of fibrinolysis, with the emphasis on reperfusion and reinfarction.

Methods: Pretreatment PAI-1 levels of 60 patients with acute myocardial infarction, treated with streptokinase, were determined by the chromogenic method. Failure of thrombolysis with streptokinase was present when reperfusion was delayed as assessed by noninvasive reperfusion criteria, or reinfarctions developed.

Results: Mean pretreatment PAI-1 level of patients was 6.3+/-1.2 U/ml; span 1.2 U/ml to 34.0 U/ml. Thrombolysis with streptokinse failed significantly in patients with pretreatment PAI-1 levels >4.0 U/ml (p < 0.05), mainly because of significant occurrence of reinfarction (p < 0.05), but less to delayed reperfusion (p > 0.05).

Conclusion: Failure of thrombolysis with streptokinase is significantly associated with pretreatment PAI-1 levels of >4.0 U/ml.