Risk of Bleeding With Dabigatran in Atrial Fibrillation | Journal Scan

Study Questions:

Is there an increased risk of bleeding among atrial fibrillation (AF) patients treated with dabigatran as compared to warfarin?


Using pharmacy and medical claims between 2010 and 2011, a sample of newly diagnosed AF patients who initiated dabigatran or warfarin was identified. Bleeding events were categorized as major or minor based on anatomic site, and a propensity score was developed to compare dabigatran users to warfarin users.


Dabigatran was associated with a higher risk of bleeding relative to warfarin for any bleeding (hazard ratio [HR], 1.30; 95% confidence interval [CI], 1.20-1.41), major bleeding (HR, 1.58; 95% CI, 1.36-1.83), and gastrointestinal bleeding (HR, 1.85; 95% CI, 1.64-2.07). The risk of intracranial hemorrhage was lower among dabigatran users compared to warfarin users (HR, 0.32; 95% CI, 0.20-0.50). The risk of major bleeding associated with dabigatran was notably elevated among African Americans and patients with chronic kidney disease.


The authors concluded that dabigatran, as compared to warfarin, was associated with a higher incidence of major bleeding and gastrointestinal bleeding, but a lower risk of intracranial bleeding in AF patients.


This study adds evidence from ‘real-world’ patients that dabigatran use is associated with an increased risk of gastrointestinal bleeding among AF patients. The investigators also demonstrated a higher rate of major bleeding among dabigatran patients, a finding not seen in the randomized RE-LY trial. However, similarly to the patients in the RE-LY trial, the Medicare patients prescribed dabigatran experienced a lower risk of intracranial hemorrhage, the most feared complication of any oral anticoagulant. While this analysis adjusted for many bleeding risk factors, the authors were not able to account for inappropriate use of dabigatran. Importantly, they were not able to assess for drug choice or dosing relative to renal function, which was shown to be a cause for significant bleeding during early adoption of dabigatran therapy for AF (NEJM 2012;366:864-6). Clinicians should proceed carefully when prescribing any oral anticoagulant, ensuring that patients are given a safe dose and all modifiable risk factors for bleeding are addressed.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Anticoagulation Management and Atrial Fibrillation, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: African Americans, Anticoagulants, Atrial Fibrillation, beta-Alanine, Intracranial Hemorrhages, Medicare, Renal Insufficiency, Chronic, Risk Factors, Warfarin

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