Gorog Thrombosis Test: analysis of factors influencing occlusive thrombus formation.

We used the Gorog Thrombosis Test to analyze the factors influencing the occlusion time, which represents platelet activation and subsequent occlusive thrombus formation, in 132 healthy Japanese volunteers (116 men, 16 women; mean age, 45.0 +/- 12.0 years). The Gorog Thrombosis Test was designed to evaluate platelet aggregation and thrombolytic activity under a high shear stress condition (175 dynes/cm) in a native blood sample in vitro. The mean +/- SD occlusion time was 154.8 +/- 64.7 s (men, 153.4 +/- 64.2 s and women, 165.4 +/- 56.5 s). The occlusion time was inversely correlated with von Willebrand factor ristocetin cofactor activity (VWF:Rco) (r = -0.242, P = 0.0055) and von Willebrand factor antigen (r = -0.230, P = 0.0080). The mean occlusion time in the group with VWF:Rco of at least 170% (137 s) was significantly shorter than that in the group with VWF:Rco less than 170% (156 s, P < 0.05). Platelet counts, other coagulation markers and smoking showed no significant correlations with occlusion time. Red blood cells (r = -0.177, P = 0.0365), hemoglobin (r = -0.191, P = 0.0245) and hematocrit (r = -0.182, P = 0.0329) also showed inverse correlations with the occlusion time. This report is the first to clearly demonstrate the role of von Willebrand factor in the formation of occlusive thrombi in the Gorog Thrombosis Test.