Monitoring Of Plasma Concentrations Of Warfarin Enantiomers And Its Clinical Significance For Early Anticoagulation Therapy Of Patients Following Mechanical Heart Valve Replacement

[Objective] To study variation of plasma concentrations of warfarin enantiomers and its clinical significance for early anticoagulantion monitoring of patients following mechanical heart valve replacement.[ Methods ] Twenty-three inpatients following mechanical valve replacement in HuaXi hospital of Sichuan university from November 2004 to February 2005 were chosen. The total plasma warfarin concentration,the plasma concentrations of S-warfarin (S-W) and R-warfarin (R-W) and international normalized ratio(INR) were determined respectively at six time-points: before taking warfarin,after taking warfarin 24 -hour, 48 -hour, 72^th-hour,120^th-hour,144^th-hour. Changes and correlationships of all the above indexes were compared before and after taking warfarin. At the same time, the clinical complications,such as hemorrhage, thromboembolism and death were observed.[Results] (1)There were no hemorrhage,thromboembolism and death in our group; (2)S-Warfarin concentration increased significantly after 24 hours after initial dose administration of warfarin and tended to remain constant after 120 hours, S-Warfarin concentration was lower than S-Warfarinconcentration significantly in steady state; (3)There were significant relationships between concentrations of S-warfarin and factor W in 144 hours. There were significant relationships between concentrations of S-warfarin and fjaptor II after 72 hours. (4)There were not significant relationships between S-Warfarin concentration and INR in 120 hours, There were significant relationships between S-warfarin concentration and INR after 120 hours.[Conclusion] The S-warfarin concentration was a precise index in early anticoagulation monitoring of patients following mechanical heart valve replacement, Further study will be necessary to evaluate its clinical application in anticoagulation monitoring.