Increased thrombogenesity in patients with cyanotic congenital heart disease

Abstract

Background: The basic mechanisms of thromboembolism in cyanotic congenital heart disease (CCHD) have not been well clarified. P-selectin on the platelets reflects platelet activation. Thrombomodulin is a critical cofactor for thrombin-mediated activation of protein C and reflects the anticoagulant activity of the endothelium. The present study was performed to evaluate whether platelet activation exists in patients with CCHD. Methods and Results: Platelet P-selectin as a marker of platelet activation, plasma thrombomodulin level and protein C activity as markers of anticoagulant activity of the endothelium and thrombin - antithrombin complex III (TAT) were examined in 35 patients with CCHD. Plasma thrombomodulin level (1.1±0.9 vs 2.2±0.3 FU/ml) and protein C activity (71.1±29.8 vs 117.8±24.8%) were significantly lower in patients with CCHD as compared with the control subjects. The levels of plasma TAT (255±811 vs 1.9±0.9 ng/ml) and P-selectin on platelets (6.3±4.5 vs 3.3±0.3 mean fluorescence intensity) were significantly higher in the patients with CCHD than in the controls. Four of the CCHD patients who experienced thromboembolic events had elevated levels of platelet Pselectin (p=0.02) compared with CCHD patients without thromboembolic events. Conclusion: Platelet activation exists in patients with CCHD and it may play an important role in the thromboembolic events in CCHD.