The t-PA/PAI-1 complex is a good indicator of the release of fibrinolysis activators and inhibitors from the vascular wall, but its clinical significance in chronic ischemic heart disease is unclear. The plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), and the t-PA/PAI-1 complex (including various coagulation factors) were assayed in 72 patients with coronary artery disease (CAD) and 29 control (C) subjects. The CAD patients were subdivided into 3 groups: single-vessel disease (G1, n=30), double-vessel disease (G2, n=20), and triple-vessel disease (G3, n=22). The patients with triple-vessel disease had higher fibrinogen values (G3: 318±75mg/dl, C: 263±56), factor VII activity (G3: 143±36%, C: 123±14), and t-PA antigen levels (G3: 4.7±0.8ng/ml, C: 3.3±0.7) than controls. Patients with double- and triple-vessel disease also showed higher levels of factor VIII, vWF antigen, thrombin-antithrombin III complex (G1: 2.3±0.6ng/ml, G2: 2.7±0.5, G3: 3.1±0.5, C: 2.0±0.5), and t-PA/PAI-1 complex (G1: 13.9±6.1ng/ml, G2: 16.4±4.6, G3: 18.2±5.9, C: 10.7±4.9) than control subjects. The t-PA/PAI-1 complex levels were correlated significantly with the activities of factors VII and VIII and the thrombin-antithrombin III complex. These findings suggest that patients with CAD have greater blood coagulability than controls, and that this difference is related to the severity of the disease. Since there was a significant correlation between coagulation factors and t-PA/PAI-1 complexes, higher t-PA/PAI-1 complex levels may be a vascular endothelial response to higher blood coagulability in multivessel disease.