VKORC1-1639A allele influences warfarin maintenance dosage among Blacks receiving warfarin anticoagulation: A retrospective cohort study

• Authors: Fatima Donia Mili, Centers for Disease Control and Prevention; Tenecia Allen, Emory University; Paula Weinstein Wadell, Centers for Disease Control and Prevention; W. Craig Hooper, Centers for Disease Control and Prevention; Christine De Staercke, Centers for Disease Control and Prevention; Christopher J. Bean, Centers for Disease Control and Prevention; Cathy Lally, Emory University; Harland Austin, Emory University; Nanette K Wenger, Emory University
• Journal Title: Future Cardiology
• Volume: Volume 14, Number 1
• Publisher: Future Medicine | 2018-01-01, Pages 15-26
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.2217/fca-2017-0025
• Subjects: Health Sciences, Epidemiology; Health Sciences, Pharmacology
• Keywords: Blacks; CYP2C9; VKORC1; VKORC1-1639G>A warfarin; anticoagulation; pharmacogenetics; thromboembolism; African Americans; Alleles; Anticoagulants; Dose-Response Relationship, Drug; Female; Follow-Up Studies; Genotype; Georgia; Humans; Incidence; Male; Middle Aged; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Retrospective Studies; Thrombosis; Time Factors; Vitamin K Epoxide Reductases; Warfarin

Abstract

Aim: The study objectives were to investigate the association between selected CYP2C9 and VKORC1 single nucleotide polymorphisms with serious bleeding or thrombotic risk, and to estimate mean daily maintenance dose of warfarin and international normalized ratio measurements among Blacks receiving warfarin anticoagulation. Methods: We conducted a retrospective cohort study among 230 Black adults receiving warfarin for a minimum of three consecutive months with a confirmed date of first dosage. Results: A lower mean daily maintenance dosage of warfarin was required to maintain an international normalized ratio measurement within the therapeutic range among Blacks with the VKORC1-1639G>A variant alleles ([G/A vs G/G, p = 0.02], [A/A vs G/A, p = 0.008] and [A/A vs G/G, p = 0.001]). Conclusion: Data indicated that VKORC1-1639A variant allele influenced warfarin daily maintenance dosage among our small, likely admixed Black patient population.