The Effects of Lower Intensity Anticoagulation Therapy on Coagulation System in Patients With Mechanical Prosthetic Valves

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The effects of lower intensity anticoagulation therapy on coagulation system in patients with mechanical prosthetic valves

Summary  To evaluate the effect of lower intensity anticoagulation therapy in patients with mechanical prosthetic valves, laboratory-based hematological assays including prothrombin time (PT), activity of factor X, antithrombinI (ATI), D-dimer, fibrinogen (Fg) and platel et al pha-granular membrane protein (GMP-140) were performed in 65 patients who had been on warfarin treatment for over one month. The patients were assigned to 3 groups on the basis of their International Normalized Ratios (INR), ranging from 2.00 to 2.50; 2.51 to 3.00; 3.01 to 4.50, respectively. The results showed that the D-dimer, Fg, GMP-140 levels were higher after mechanical valve replacement than those before operation, indicating, the activation of coagulation and fibrinolysis system and the damage of platelets. Lower intensity anticoagulation therapy (INR 2.00 to 2.50) could effectively inhibit the activity of factor X and increase the level of ATI. There were no appreciable differences among D-dimer, Fg, GMP-140 and ATI in the 3 anticoagulation intensity groups. These results suggest that in patients with new generation mechanical prosthetic valves, target anticoagulation level (INR 2.00 to 2.50) may result in good protection from thrombo-embolism.