Therapeutic Monitoring Anticoagulation of Warfarin in Patients with Prosthetic Heart Valve Replacement

Objective To evaluate some methods to monitor anticoagulation therapy of warfarin.Methods 126 Cases of prosthetic heart valve replacement were collected from June 2005 to May 2006.Follow-up visit ended on 31st of December 2006 and recorded complications、INR value and warfarin dosage.18 out-patient cases from our hospital were adopted HPLC to measure plasma concentrations of warfarin during September 2006.Results ①126 cases were visited,up for seven to nineteen months.Six cases(4.16%)died,ten cases(7.94%)were hemorrhage relating to anticoagulation,and three cases(2.38%)were thromboembolism.②After anticoagulation measured INR value is 2.39±1.27,daily dose of warfarin is(3.19±1.43)mg.③Eighteen cases of plasma concentrations of warfain were measured,the observed INR values are as follows: three of them are smaller than 1.8(Group A),ten are larger than 1.8 and samller than 2.5(Group B),the rest five are larger than 2.5(Group C).The average warfarin plasma concentrations of Group C is higher than that of Group B(P0.000 5).④There is no obvious linear correlation between INR value and plasma concentrations(r=0.65,P0.1),and there is also no obvious linear correlation between INR value and the amount of daily warfarin dose taken(r=0.26,P0.2).Conclusions ①Bleeding and thromboembolism which are relative to warfarin anticoagulation are the main complications after prosthetic heart valve replacement.The rate of bleeding is higher than that of thromboembolism.②Plasma concentrations of warfarin is an index of anticoagulation monitoring,which can give clinicians advice to adjust the dosage of warfarin safely and effectively.