Abstract:

Objective To assess the effects of genotype⁃guided warfarin anticoagulation in Chinese elderly patients with nonvalvular atrial fibrillation（AF）. Methods All the nonvalvular AF patients were assigned into two group shaving their warfarin dose determined by an algorithm using genetic and clinical factors（genetic group）or the same algorithm using clinical factors only（control group）. For those in the genetic group，we also included genotypes for CYP2C9 and VKORC1.Genomic DNA was extracted from peripheral blood samplefor patients from genetic group using standard protocols. In the control group，the physicians and pharmacists determining the initial doses used the warfarin dosing algorithm to determine patients′ initial warfarin doses. Further dose adjustments in both groups used INR measurements and standard protocols. Results The incidence of over ⁃anticoagulant and under ⁃ anticoagulant events in genetic group was lower than that in control group（P < 0.05）. The percentage of INR value in the the rapeutic range（TTR）in the first 1 month and 3 months of the genome was significantly higher than that in the control group. The cumulative incidence of ischemic stroke events occurred in the genetic group was significantly lower than that in the control group. Conclusion Genotype⁃guided dosing could improve the average TTR，improve the safety of treatment，increase the average TTR and the TTR can reach a higher level in the early stage of anticoagulation and resulted in a lower risk of ischemic stroke events significantly.

Key words:

atrial fibrillation, warfarin, genetype?guided