Importance of modulating balance of procoagulant and fibrinolytic activity to success of antithrombotic therapy.

T hrombosis is a dynamic process in which procoagulant activity, which promotes platelet activation and fibrin deposition, is balanced by physiologic anticoagulant and fibrinolytic activity. Historically, the treatment of thrombosis has been based on the use of agents that either inhibit procoagulant activity (i.e., anticoagulants) or induce fibrinolytic activity (i.e., plasminogen activators). However, recent data suggest that the success of antithrombotic interventions requires both inhibition of factors that promote thrombosis and induction of clot lysis. Thus, even when intense fibrinolytic activity is induced in patients with myocardial infarction, increases in procoagulant activity appear to be an important determinant of recurrent thrombosis.1-3 Results of recent clinical trials are consistent with the importance of conjunctive therapy with aspirin and heparin in patients given fibrinolytic agents.4-9 These