Tissue plasminogen activator release and plasminogen activator inhibitor levels in coronary artery disease.

Unstable angina and Q wave myocardial infarction are associated with intraluminal coronary thrombosis, a process to which impaired fibrinolysis may contribute. The authors examined the extrinsic fibrinolytic system, including tissue plasminogen activator antigen, plasminogen activator inhibitor activity and antigen, and euglobulin clot lysis time before and after venous occlusion in 56 patients undergoing coronary angiography for chest pain syndromes and in 16 healthy controls. Fibrinolysis variables were similar (with greater than 95% confidence) in the patients with thrombus-associated coronary syndromes as compared with those with chest pain syndromes not due to coronary thrombosis. These fibrinolytic variables were also similar to those in patients without coronary artery disease and in healthy controls. Their data suggest that defective fibrinolysis is not involved, at least systemically, in the pathogenesis of thrombus-associated coronary artery syndromes.