Influence of CYP2C9 and VKORC1 on Warfarin Dose, Anticoagulation Attainment and Maintenance Among European–Americans and African–Americans
Key result
CYP2C9 and VKORC1 variants explained up to 30% of warfarin dose variability in European-Americans and 10% in African-Americans, and increased over-anticoagulation risk in European-Americans (p<0.01).
Why the study?
Do CYP2C9 and VKORC1 polymorphisms influence warfarin dose and anticoagulation outcomes differently among European-Americans and African-Americans?
Population
575 patients receiving warfarin, comprising 302 European-Americans and 273 African-Americans
Design
Cohort
Authors
Discussion
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Member takes
Implication
Ancestry-specific genetic effects on warfarin dosing should not yet alter practice; leaves open prospective validation of risk prediction across groups.
Study Design
Type
Observational (n=575)
Structured PICO
Do CYP2C9 and VKORC1 polymorphisms influence warfarin dose and anticoagulation outcomes differently among European-Americans and African-Americans?
P
Population
575 European-American and African-American patients receiving warfarin.
E
Exposure
Assessment of common CYP2C9 and VKORC1 polymorphisms
O
Outcome
Warfarin dose, time to target International Normalized Ratio (INR), time to stabilization, and risk of over-anticoagulation (INR: > 4)surrogate
Main Result
p-value: p=<0.01
CYP2C9 and VKORC1 polymorphisms explain a significant portion of warfarin dose variability, particularly in European-Americans, but their ability to predict over-anticoagulation risk is inconsistent across racial groups.
Cite This Study
Limdi et al. (2008) conducted an observational in Patients receiving warfarin (n=575). CYP2C9 and VKORC1 polymorphisms vs. Wild-type genotypes was evaluated on Warfarin dose, time to target INR, time to stabilization, and risk of over-anticoagulation (INR > 4) (p=<0.01). CYP2C9 and VKORC1 variants explained up to 30% of warfarin dose variability in European-Americans and 10% in African-Americans, and increased over-anticoagulation risk in European-Americans (p<0.01).