A Pharmacogenetic Study of Warfarin Dosing, "The COUMA-GEN Study"
Status:
Completed
Trial end date:
2007-11-01
Target enrollment:
Participant gender:
Summary
Anticoagulation with warfarin is a common and potentially hazardous therapeutic intervention.
It is a leading cause of iatrogenic bleeding events and, hence, of malpractice claims. There
are no good alternatives presently for warfarin anticoagulation, and even when alternatives
become available (i.e., ximelagatran), cost, labeling, and experience (outcomes-related)
issues will continue to favor an extensive and ongoing use of warfarin. If the present study
is able to confirm an advantage for a genotype-driven algorithm, in terms of improved
efficiency, therapeutic efficacy, and, especially, safety, then a pharmacogenetics approach
to warfarin dosing can be recommended as the basis for an Intermountain Health Care
(IHC)-wide quality improvement initiative that should improve patient outcomes, reduce
resource use (costs of achieving safe and therapeutic anticoagulation), and reduce adverse
clinical events. COUMA-GEN is a prospective, randomized study of patients who are to begin
chronic warfarin therapy for specific, qualifying clinical reasons (i.e., atrial fibrillation
(AF), deep vein thrombosis (DVT), or post-orthopedic surgery prophylaxis). Qualifying
patients will be consented and randomized to an individualized, genotype-based
warfarin-dosing regimen or to standard care (without knowledge of genotype). In each study
arm, a predicted maintenance dose will be determined. All patients will receive a baseline
International Normalized Ratio (INR). For patients in all 3 entry strata, a starting dose of
warfarin that is twice the assigned daily maintenance dose (according to the specific
treatment arm) will be prescribed on the first and second days, and then the dose will revert
to the assigned maintenance dose.
Phase:
N/A
Details
Lead Sponsor:
Intermountain Health Care, Inc.
Collaborators:
Deseret Foundation LDS Hospital Cardiovascular Research