Real-World Meta-Analysis of Dabigatran vs. Warfarin for Atrial Fibrillation

Study Questions:

What are the real-world outcomes associated with dabigatran versus warfarin use for stroke prevention in atrial fibrillation (AF)?


The authors conducted a systematic search of published literature from the first availability of dabigatran through March 10, 2015 for longitudinal, observational studies comparing dabigatran to warfarin for stroke prevention in nonvalvular AF. Hazard ratios were extracted and pooled for ischemic stroke, gastrointestinal bleeding, and intracranial bleeding between dabigatran- and warfarin-treated cohorts.


Seven retrospective cohort studies met the inclusion criteria, consisting of 348,750 patients and a mean follow-up of 2.2 years. Dabigatran 150 mg was not superior to warfarin for stroke prevention (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.84-1.01), had a lower hazard of intracranial hemorrhage (HR, 0.44; 95% CI, 0.34-0.59), and had a higher hazard of gastrointestinal bleeding (HR, 1.23; 95% CI, 1.01-1.50). The hazard for gastrointestinal bleeding was potentiated in studies of elderly populations (mean/median age ≥75 years) as compared to younger populations (<75 years). Dabigatran 110 mg was not superior to warfarin for stroke prevention (HR, 0.95; 95% CI, 0.72-1.18), had a lower hazard for intracranial hemorrhage (HR, 0.49; 95% CI, 0.34-0.72), but had a similar hazard for gastrointestinal bleeding (HR, 0.91; 95% CI, 0.55-1.51).


The authors concluded that dabigatran is comparable to warfarin for stroke prevention in nonvalvular AF in real-world populations. They also concluded that dabigatran is associated with a lower risk of intracranial hemorrhage, but a greater risk of gastrointestinal bleeding, especially in the elderly.


The authors concluded that in an unselected real-world population, dabigatran is not superior to warfarin for ischemic stroke prevention in nonvalvular AF, which differs from the RE-LY trial results. However, both doses of dabigatran were associated with a lower risk of intracranial hemorrhage. Importantly, elderly patients taking the higher dose of dabigatran (150 mg) were at higher risk for gastrointestinal bleeding as compared to warfarin-treated patients. Further studies may need to explore the difference in patient selection or anticoagulant care delivery and monitoring to understand the difference in ischemic stroke risk reduction between the randomized RE-LY study and the real-world meta-analysis data. In the mean time, clinicians should carefully consider the comorbidities and expected medication compliance whenever starting a patient on any of the direct oral anticoagulants, including dabigatran.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Anticoagulants, Antithrombins, Arrhythmias, Cardiac, Atrial Fibrillation, Gastrointestinal Hemorrhage, Intracranial Hemorrhages, Primary Prevention, Risk Reduction Behavior, Stroke, Warfarin, Vascular Diseases

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