Safety of High-Dose Dabigatran in Elderly and Younger Patients with a Low Bleeding Risk: A Prospective Observational Study

Introduction: In patients with atrial fibrillation (AF) at risk for stroke, dabigatran 150 mg twice a day (DE150) is superior to warfarin for stroke prevention. However, there is paucity of data with respect to bleeding risk at this dose in elderly patients (≥75 years). We aimed to evaluate the safety of DE150 in comparison to warfarin in a real-world population with AF and low bleeding risk (HAS-BLED score ≤2). Methods: In this prospective observational study, 754 consecutive patients with AF and HAS-BLED score ≤2 were included. We compared outcome of elderly patients (age ≥75 tears) to younger patients (age <75 years). The primary end point was the combined incidence of all-cause mortality, stroke, systemic emboli, and major bleeding event during a mean follow-up of 1 year. Results: There were 230 (30%) elderly patients, 151 patients were treated with warfarin, and 79 were treated with DE150. Fifty-two patients experienced the primary endpoint during the 1-year follow-up. Among the elderly, at 1-year of follow-up, the cumulative event rate of the combined endpoint in the DE150 and warfarin was 8.9 and 15.9% respectively (p = 0.14). After adjustment for age and gender, patients who were treated with DE150 had a nonsignificant difference in the risk for the combined end point as patients treated with warfarin both among the elderly and among the younger population (HR 0.58, 95% C.I = 0.25-1.39 and HR = 1.12, 95% C.I 0.62-2.00, respectively [p for age-group-by-treatment interaction = 0.83). Conclusions: Our results suggest that Dabigatran 150 mg twice a day can be safely used among elderly AF patients with low bleeding risk.