November 29, 2010Circulation
Dabigatran and Warfarin in Vitamin K Antagonist–Naive and –Experienced Cohorts With Atrial Fibrillation
Why the study?
Does dabigatran reduce stroke and systemic embolism compared to warfarin in VKA-naive and VKA-experienced patients with atrial fibrillation?
Population
18,113 patients with atrial fibrillation, divided into vitamin K antagonist-naive and VKA-experienced cohorts.
Comparison
Dabigatran 110 mg twice daily or 150 mg twice… vs Warfarin (target INR 2.0 to 3.0)
Design
RCT
Authors
Discussion
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Implication
Dabigatran 150 mg BID reduces stroke/systemic embolism vs warfarin irrespective of prior VKA exposure; confirms consistent superiority across both AF subgroups.
Key Points
- To evaluate whether previous exposure to vitamin K antagonists influences the relative efficacy and safety of dabigatran compared to warfarin in patients with atrial fibrillation.
- Randomized trial (NCT00262600) comparing dabigatran 110 mg BID, dabigatran 150 mg BID, and warfarin in 18,113 patients with atrial fibrillation.
- Patients were stratified into VKA-naive (≤62 days lifetime VKA exposure, including 33% never prescribed a VKA) and VKA-experienced cohorts.
- Outcomes evaluated included annual rates of stroke/systemic embolism, major bleeding, and intracranial bleeding.
- In VKA-naive patients, annual stroke/systemic embolism rates were 1.57% for dabigatran 110 mg (P=0.65 vs warfarin), 1.07% for dabigatran 150 mg (P=0.005 for superiority vs warfarin), and 1.69% for warfarin; intracranial bleeding was 0.19% (P<0.001) and 0.33% (P=0.005) versus 0.73% for warfarin.
- In VKA-experienced patients, annual stroke/systemic embolism rates were 1.51% for dabigatran 110 mg (P=0.32 vs warfarin), 1.15% for dabigatran 150 mg (P=0.007 for superiority vs warfarin), and 1.74% for warfarin.
- In VKA-experienced patients, major bleeding occurred at 2.66% per year with dabigatran 110 mg (P=0.003 vs warfarin) and 3.30% with dabigatran 150 mg (P=0.41 vs warfarin) compared to 3.57% with warfarin, with intracranial bleeding significantly reduced in both dabigatran arms (0.26% and 0.32% vs 0.79%, P<0.001 for both).
Structured PICO
Does dabigatran reduce stroke and systemic embolism compared to warfarin in VKA-naive and VKA-experienced patients with atrial fibrillation?
P
Population
18,113 patients with atrial fibrillation, divided into vitamin K antagonist (VKA)-naive (≤62 days of lifetime VKA exposure, with 33% never prescribed a VKA) and VKA-experienced cohorts.
I
Intervention
Dabigatran 110 mg twice daily or 150 mg twice daily
C
Comparator
Warfarin (target INR 2.0 to 3.0)
O
Outcome
Stroke and systemic embolismhard clinical
Previous vitamin K antagonist exposure does not influence the relative benefits of dabigatran over warfarin for stroke prevention in patients with atrial fibrillation.
Cite This Study
Ezekowitz et al. (2010) studied this question.