Genotype-based anticoagulant therapy with warfarin for atrial fibrillation

Objective: To investigate the efficacy and safety of genotype-based anticoagulant therapy with warfarin in patients with atrial fibrillation. Methods: A total of 66 patients with non-valvular atrial fibrillation treated admitted to our hospital from December 2014 to May 2015 were enrolled in this study. The patients were randomly allocated to the control group (n=33) and the intervention group (n=33). Patients in the intervention group were given genotypebased (including VKORC1, CYP4F2, GGCX, and CYP2C9) anticoagulant therapy with warfarin, whereas patients in the control group received routine warfarin therapy according to the clinical practice. After 6 months of follow-up, the adjusted dose of warfarin, the time to achieve stable dose and International Normalized Ratio (INR) standard level, and the incidences of bleeding and thrombosis in both groups were recorded and compared. Results: Overall, 57 patients completed the follow-up, with 28 patients in the intervention group, and 29 patients in the control group. The intervention group received a daily dose of warfarin at 2.8 mg/d, which was lower than that of the empirical dose (3 mg/d). And the actual dose of warfarin used was not consistent with the empirical dose in 24 (85.7%) patients. What’s more, there were 18 (64.3%) patients in the intervention group without dose adjustment, which was significantly more than that of the control group (10/34.5%). The time to stable dose and to the INR standard level in the intervention group were (15.1±5.1) d and (6.8±3.9) d, respectively, significantly shorter as compared to (27.6±6.6) d and (12.9±5.6) d, respectively in the control group. In addition, during the treatment and follow-up, the rate of bleeding and thrombosis was 0 in the intervention group and 5 (17.2%) in the control group, indicating that the adverse reactions in the intervention group was significantly lower than that of the control group (P=0.022). Conclusion: Genotype-based anticoagulant therapy with warfarin is safe and effective in the treatment of non-valvular atrial fibrillation, which can shorten the latency to achieve stable dose and to the INR standard level, reduce the risk of bleeding/thrombosis, and improve clinical prognosis.