RESUMO
OBJECTIVE:To discuss the correlation between Interntion Normalized Ratio(INR)with concentration of warfarin enantiomer and dose density after cardiac valve replacement. METHODS:The plasma concentration of R-warfarin or S-warfarin, dose of unit weight and INR of 176 patients with anticoagulation after cardiac valve replacement in each time point were moni-tored,and the correlation of INR and warfarin plasma concentration or dose was observed. RESULTS:Doses of all patients in 24-288 h were significantly higher than 0 h,the differences were statistically significant(P0.05). Average plasma concentration of R-warfarin or S-warfarin had consistent trend,plasma concentration of enantiomers was fluctuated within a certain range after 108 h,there were no significant differences(P>0.05). Compared with 0 h,there was no significant difference when INR was 12 h (P>0.05),it increased significantly in 36 h and had been increasing,then fluctuated within a certain range after 108 h,compared with 108 h,there were no significant differences(P>0.05). The correlation coefficient between INR and unit weight dose of warfa-rin in 60 h>36 h>12 h,it showed correlation(P<0.001). There was certain correlation between plasma concentration of warfarin and dose density in 12,36 and 60 h. CONCLUSIONS:The correlation between plasma concentration of warfarin and unit weight dose is stronger than the correlation between INR and unit weight dose. When combined with other coagulation,it may help to man-age warfarin dose.