Prediction of Acenocoumarol Dose from CYP2C9, VKORC1 Gene Variants and Patient Characteristics in Vietnamese Heart Valve Replacement Patients

Acenocoumarol is a vitamin K anticoagulant that is commonly used in patients after mechanical heart valve replacement in Vietnam. The purpose of the study is to develop an algorithm for predicting acenocoumarol treatment dose based on genetic and clinical characteristics in Vietnamese patients. A total of 284 patients after mechanical valve replacement who were taking acenocoumarol were enrolled in this study. The Sanger’s Sequencing technique was performed to identify the polymorphisms of CYP2C9 * 3 and VKORC1-1639G> A, 1173C> T. The result showed that patients with variants of gene CYP2C9 * 3, VKORC1-1639G> A and 1173C> T need a lower dose of acenocoumarol than normal to achieve anticoagulant effect. Polymorphisms of CYP2C9 *3, VKORC1-1639G> A, 1173C> T, age and BMI explained 36.9% of variability acenocoumarol dose. The algorithm for predicting acenocoumarol dose has been developed in Vietnamese patients after mechanical valve replacement: Log (mg/week) =1.315 – 0.138 (VKORC1-1639G>A) – 0.051 (VKORC1 1173C>T) – 0.091 (CYP2C9*3) – 0.003 (year) + 0.011 (BMI).