Association between CYP2C9, VORC1, VDR, and APOE genotypes on warfarin maintenance and response during initial anticoagulation for Chinese patients with heart valve replacement

To the,Editor:For patients with mechanical and bioprosthetic heart valve replacement,vitamin K antagonist(VKA)therapy is recommended according to guidelines.Effective and safe therapywith warfarin requires continuous monitoring of prothrombin time and international normalized ratio(INR)levels to adjust the dose of warfarin.