Evaluation of Bleeding Events Requiring Hospitalization in Patients With Atrial Fibrillation Receiving Dabigatran, Warfarin, or Antiplatelet Therapy.

Objective: To determine the incidence and severity of bleeding events requiring hospitalization among patients with atrial fibrillation (AF) receiving anticoagulants (dabigatran or warfarin) or antiplatelet agents (eg, aspirin and clopidogrel).

Methods: This was a single-center, retrospective cohort study involving 1494 patients with AF hospitalized from November 1, 2010, to November 1, 2011, with prior warfarin, dabigatran, or antiplatelet therapy.

Results: Overall bleeding events in the dabigatran group compared to the warfarin group were 24% and 12%, respectively ( P = .004). Of these events, individually, there were no significant differences in major (56% vs 58%, P = .88), life-threatening (25% vs 36%, P = .38), or minor bleeding (44% vs 42%, P = .06). Gastrointestinal (GI) bleeding occurred more in the dabigatran group compared to the warfarin group ( P = .02). Intracranial bleeding occurred in 15% of patients in the warfarin group and did not occur at all in the dabigatran group. Warfarin patients had significantly more overall bleeding events compared to antiplatelet therapy ( P < .001), with an increasing trend seen in major bleeding ( P = .06). GI bleeding, however, favored the warfarin group over the antiplatelet group (48% vs 73%, P = .04).

Conclusion: Anticoagulation with dabigatran was associated with an overall increased occurrence of bleeding requiring hospital admission compared to warfarin. GI bleeding was more prevalent with dabigatran and antiplatelets than with warfarin. There were more intracranial hemorrhages seen in the warfarin group.