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Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
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CYP2C9 Polymorphism and Unstable Anticoagulation with Warfarin in Patients Within the First 3 Months Following Heart

Ewa Wypasek1, Marek Cieśla2, Bogdan Suder2

  • 1John Paul II Hospital, Institute of Cardiology, Jagiellonian University School of Medicine, Kraków, Poland.

Advances in Clinical and Experimental Medicine : Official Organ Wroclaw Medical University
|October 16, 2015
PubMed

Insights

Patients with CYP2C9*2 or *3 genetic variants require lower warfarin doses and experience less stable anticoagulation after heart valve replacement. These CYP2C9 variants are linked to unstable warfarin treatment, irrespective of monitoring methods.

Area of Science:

  • Pharmacogenomics
  • Cardiovascular Surgery
  • Clinical Pharmacology

Background:

  • Warfarin dosing is influenced by genetic variations in VKORC1 and CYP2C9.
  • CYP2C9 gene polymorphisms are key determinants of warfarin metabolism and efficacy.

Purpose of the Study:

  • To evaluate the impact of CYP2C9 allelic variants on anticoagulation stability in patients undergoing heart valve replacement.
  • To assess the influence of CYP2C9 genotypes on warfarin dose requirements and therapeutic range achievement post-surgery.

Main Methods:

  • A case-control study compared CYP2C9*2/*3 carriers with wild-type CYP2C9*1/*1 individuals.
  • Warfarin dose and time in therapeutic range (TTR) were assessed in the first 3 months post-heart valve replacement.
  • Patients were monitored using coagulometers or local outpatient clinics; drug interactions were excluded.

Main Results:

  • CYP2C9*2/*3 carriers required significantly lower warfarin doses (estimated and actual) compared to wild-type.
  • Carriers exhibited lower TTR values and a longer time above the therapeutic INR range.
  • No significant differences in warfarin doses, TTR, or adverse events were observed between self-testing and standard-care subgroups.

Conclusions:

  • Presence of CYP2C9*2 or *3 genotypes is associated with unstable warfarin treatment post-heart valve replacement.
  • The observed instability is independent of the international normalized ratio (INR) testing method used.
Abstract

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