Vitamin K antagonists and children with heart diseases

Posted by Chantel M. Contributed by US National Library of Medicine National Institutes of Health

In the study of "Vitamin K antagonists in children with heart diseases: height and VKORC1 genotype are the main determinants of the warfarin dose requirement" by Moreau C, Bajolle F, Siguret V, Lasne D, Golmard JL, Elie C, Beaune P, Cheurfi R, Bonnet D, Loriot MA., posted in US National Library of Medicine National Institutes of Health, found that height, target INR, VKORC1 and CYP2C9 genotypes were the main determinants of warfarin dose requirement, accounting for 48.1%, 4.4%, 18.2% and 2.0%, respectively, and explaining 69.7% of the variability. Our model predicted the warfarin dose within 7mg/week in 86.7% of patients. None of the covariates were associated with the time spent above or below the INR range. Whether this model predicts accurately the effective maintenance dose is currently investigated.