Significance of soluble thrombomodulin in the coronary circulation of patients with coronary artery disease

OBJECTIVES: The relationship between plasma levels of soluble thrombomodulin, a probable marker for endothelial damage, and the severity of coronary atherosclerosis was investigated. METHODS: Plasma soluble thrombomodulin levels were evaluated in 160 patients(mean age 62 +/- 11 years) who underwent coronary angiography. Blood samples were obtained from the peripheral vein, ostium of the left coronary artery and coronary sinus. The levels of plasma thrombomodulin were measured by enzyme-linked immunosorbent assay. The change of thrombomodulin level in the coronary circulation (delta TM) was calculated as the coronary sino-arterial difference. Patients were classified into four groups according to the number of diseased vessels, and the severity of coronary atherosclerosis was evaluated with the modified Gensini score. RESULTS: Coronary sinus levels of thrombomodulin were significantly higher in the two or more vessel disease(VD) groups than in the no or one VD groups(p < 0.05). delta TM were significantly higher in the 2VD than in the 0VD groups(p < 0.05), and higher in the 3VD than in the 0VD or 1VD groups(p < 0.05). delta TM showed positive correlation with Gensini score for left coronary arteries(r = 0.347, p < 0.0001). CONCLUSIONS: The increment of thrombomodulin across the coronary circulation was significantly correlated with the severity of coronary atherosclerosis, suggesting a close association between the progression of coronary atherosclerotic stenosis and damage to the endothelial surface.