Plasma thrombomodulin levels in coronary sinus blood in patients with coronary artery disease.

Plasma thrombomodulin (TM) levels in coronary sinus blood were measured in 15 patients with coronary artery disease who underwent elective PTCA (group A). TM was also measured in eight patients with coronary artery disease (group B) and six patients without coronary artery disease (group C), who only underwent diagnostic coronary angiography. The baseline level was 21.6 +/- 3.4 U/ml in group A, and 21.0 +/- 4.9 in group B, and both levels were slightly higher (P < 0.05) than those in group C (15.1 +/- 3.3). In group A, the level increased to 27.5 +/- 8.3 (P < 0.01) immediately after PTCA and then returned to 22.2 +/- 5.1 by 24 h. In groups B and C, levels showed no change immediately after angiography. In group A, the percentage increase in the TM level immediately after PTCA from that before the procedure correlated with the number of balloon inflations (r = 0.76, P < 0.01). In conclusion, the plasma TM level in coronary sinus blood might indicate endothelial damage due to atherosclerotic coronary artery disease and an increase in the level after PTCA might directly indicate vascular injury by balloon inflation.