Methodologic study and clinical significance of anticoagulation monitoring following mechanical heart valve replacement

Objective: To investigate the possibility of quantitative test of plasma prothrombin and warfarin in anticoagulation monitoring following mechanical heart valve replacement. Methods: Plasma concentrations of prothrombin and warfarin, activity of coagulation factor VII (F VII), international normalized ratio(INR), oral dosage of warfarin and anticoagulation complications were measured and analyzed in 65 anticoagulation patients following mechanical heart valve replacement. Results: Plasma concentration of prothrombin in bleeding group [(81 45±41 27)mg/L] was significanlty lower than that in control group [(128 55±31 58)mg/L] (P0 01) . The warfarin concentration in bleeding group [(546 93±148 18)ng/ml] was significanlty higher than in control group [(339 47±107 28)ng/ml](P0 05). There was no difference in INR, F VII activity and dosage of oral warfarin between these two groups(P0 05). The plasma concentrations of prothrombin and warfarin were more stable than INR valve. There were close correlation between plasma prothrombin and warfarin (r=0 849,P0 01), INR and F VII(r=-0 781,P0 01). Conclusion: The quantitative measurement of plasma concentrations of prothrombin and warfarin will be helpful in monitoring anticoagulation therapy following mechanical heart valve replacement.