Dabigatran Etexilate vs. Warfarin in Different Types of Atrial Fibrillation
NEW ORLEANS, LA—A subgroup analysis from the RE-LY trial has demonstrated that in patients with atrial fibrillation (AF), twice-daily dabigatran etexilate has better efficacy and lower rates of major bleeding when compared with warfarin, as reported at ACC.11, the American College of Cardiology's 60th Annual Scientific Session. The RE-LY trial randomized 18,113 patients with atrial fibrillation and at least one risk factor for stroke to dabigatran etexilate (110mg or 150mg twice daily) or dose-adjusted warfarin. Investigators noted that the data also support the concept that anticoagulation should be provided based on clinical risk factors rather than type of AF.
Greg Flaker, MD from the University of Missouri, Columbia, and colleagues categorized patients into different types of AF. Of the 18,107 patients with AF, 5,943 had paroxysmal AF, 5,789 had persistent AF, and 6,375 had permanent AF. The rates of stroke or systemic embolism (%/year) in patients with permanent AF were 1.78, 1.11, and 1.58%/year with dabigatran etexilate 110mg twice daily, dabigatran 150mg twice daily, and warfarin, respectively.
Dabigatran etexilate 150mg twice daily was more effective than warfarin across AF types (paroxysmal AF: HR=0.61 [0.42–0.90]; persistent AF: HR=0.64 [0.43–0.93]; and permanent AF: HR=0.70 [0.48–1.01]. The P-value for the interaction was 0.88. Dabigatran etexilate 110mg twice daily showed similar efficacy to warfarin (paroxysmal AF: HR=0.60 [0.41–0.89]; persistent AF: HR=0.96 [0.69–1.35] and permanent AF: HR=1.13 [0.81–1.57]; the P-value for the interaction was 0.05).
Rates for major bleeding episodes (MBE) in permanent AF were 2.74, 3.07 and 2.96% per year with dabigatran etexilate 110mg twice daily, 150mg twice daily, and warfarin, respectively. In paroxysmal AF, rates were 3.05%, 3.74% and 3.91% per year, respectively; and for persistent AF, MBE rates were 2.87%, 3.14% and 3.88%/year, respectively. The P-value for interaction was not significant (P=0.58).
Consistent with the overall RE-LY trial results, dabigatran etexilate 150mg twice daily offers improved efficacy compared with warfarin for the prevention of stroke or systemic embolism and dabigatran etexilate 110mg twice daily demonstrated lower major bleeding, irrespective of the type of AF.