Levels of plasminogen activator inhibitor in patients with angina pectoris.

Levels of plasminogen activator inhibitor type 1 (PAI) were measured in 180 patients with angina pectoris (148 males and 32 females, age range 29 to 70 years). An age-matched normal population served as a control. PAI was determined by a functional titration assay, its activity was expressed as arbitrary units (AU). PAI levels were significantly (P less than 0.005) higher in patients with angina (24.3 +/- 10.3 AU/ml) than in normals (20.4 +/- 4.6 AU/ml). PAI levels were unrelated to sex or age in both the patient and the control groups. Plasma triglyceride levels were correlated to PAI in patients and in normals. Patients with a history of previous myocardial infarction (n = 114) had similar PAI levels as patients without infarction (24.2 +/- 11.1 AU/ml as compared to 24.4 +/- AU/ml). It is concluded that PAI levels are elevated in patients with coronary heart disease, whether myocardial infarction has taken place or not.