OBJECTIVE: To compare the predictive accuracy of currently used warfarin dose prediction algorithm in the elderly aged ≥60 years in an area of Xinjiang. METHODS: The elderly aged ≥60 years who had reached the standard of warfarin administration for atrial fibrillation in People’s Hospital of Xinjiang Uygur Autonomous Region from Oct. 2018 to Oct. 2020 were enrolled to detect the important warfarin drug metabolism genes CYP2 C9 and VKORC1. Basic information of patients was collected

and the accuracy of each model was evaluated by percentage prediction and mean absolute error. RESULTS: A total of 61 patients were enrolled

among which CYP2 C9*1/*1

CYP2 C9*1/*3 and CYP2 C9*3/*3 genotype patients accounted for 88.52%（54 cases）

8.20%（5 cases） and 3.28%（2 cases）

respectively. VKORC1-1639 AA

AG and GG genotype patients accounted for 68.85%（42 cases）

22.95%（14 cases） and 8.20%（5 cases）

respectively. Patients with CYP2 C9*1/*1 combined with VKORC1-1639 GG genotype had the highest target dose of warfarin at（6.51±0.96） mg/d; followed by patients with CYP2 C9*1/*1 combined with VKORC1-1639 AG genotype at target dose of warfarin of（4.26±1.14） mg/d. The target dose of warfarin of CYP2 C9*1/*3 combined with VKORC1-1639 GG genotype was（3.28±1.45） mg/d

slightly higher than（3.13±0.83） mg/d of CYP2 C9*1/*1 combined with VKORC1-1639 AA genotype

both were higher than（2.07±1.32） mg/d of CYP2 C9*1/*3 combined with VKORC1-1639 AA genotype. The target doses of warfarin in patients with CYP2 C9*1/*3 combined with VKORC1-1639 AG

CYP2 C9*3/*3 combined with VKORC1-1639 AA and CYP2 C9*3/*3 combined with VKORC1-1639 AG genotype were <1 mg/d. The models with better prediction results included the International Warfarin Pharmacogenetics Consortium（IWPC） model（ideal predicted dose in 35 cases

57.38%）

Technical Guidance for Genetic Detection of Drug Metabolism Enzymes and Drug Action Targets（Trial）（2015）（referred to as “guideline model”）（ideal predicted dose in 40 cases

65.57%）

the mean absolute errors were 0.70 mg/d（95%CI=0.56-0.84） and 0.87 mg/d（95%CI=0.56-1.89）

respectively. CONCLUSIONS: Based on the influence of CYP2 C9 and VKORC1 gene polymorphisms on the stable dose of warfarin in patients with atrial fibrillation in this area of Xinjiang

the IWPC model and the guideline model are more suitable for people aged ≥60 years in this area of Xinjiang.