VKORC1 and atrial fibrillation: ANCOVA was used to select variables from the potential independent factors.Based on these criteria, 13 primary input variables were chosen from the initialfactors for subsequent construction of the model (Table 2), namely sex, age, BSA,height, weight, smoke, digoxin, AF, TC, LDL, Cox-Maze, VKORC1, andCYP2C9.