Establishment of a Han Chinese-specific pharmacogenetic-guided warfarin dosing algorithm

Area of Science:

• Pharmacogenomics
• Clinical Pharmacology
• Cardiovascular Medicine

Background:

• Warfarin is a common oral anticoagulant with a narrow therapeutic range, posing challenges in dosing due to interindividual variability and bleeding risk.
• Existing ethnic-specific algorithms for warfarin dosing may not adequately perform for Han Chinese populations.
• Accurate prediction of warfarin maintenance dose is crucial for patient safety and treatment efficacy, especially in patients with heart valve replacements.

Purpose of the Study:

• To establish a precise and effective Han Chinese-specific pharmacogenetic-guided algorithm for predicting warfarin maintenance dosage.
• To evaluate the performance of the newly developed algorithm against other existing warfarin dosing algorithms.

Main Methods:

• Recruited 361 Han Chinese patients with heart valve replacements undergoing warfarin therapy.
• Genotyped 38 single nucleotide polymorphisms (SNPs) in 13 candidate genes using MassARRAY.
• Developed a multiple linear regression model in a derivation cohort and validated its accuracy in a separate cohort, comparing it with five other algorithms.

Main Results:

• A Han Chinese-specific pharmacogenetic-guided warfarin dosing algorithm was established, explaining 58.3% of the variance in warfarin doses.
• The developed algorithm demonstrated superior accuracy with a mean absolute error of 0.74 mg/day and a mean percentage error of 26.9%.
• The algorithm outperformed five other algorithms, including those based on other ethnicities, in predicting warfarin maintenance doses.

Conclusions:

• Physicians should utilize race-specific algorithms for warfarin dosing, as algorithms from other ethnicities may not be directly applicable.
• The newly established Han Chinese-specific algorithm has the potential to significantly assist clinicians in determining appropriate warfarin maintenance doses.
• This pharmacogenetic approach enhances the safety and efficacy of warfarin therapy in the target patient population.