OBJECTIVE: The prevalence of atrial fibrillation (AF) and the risk of stroke and bleeding vary according to age. To estimate effects of dabigatran, compared with warfarin, on stroke, bleeding and mortality in patients with AF in the Randomized Evaluation of Long-Term Anticoagulant Therapy (RE-LY) trial according to age, we analysed treatment effects using age as a continuous variable and using age categories.
METHODS: RE-LY included 10 855 (59.9%) patients aged <75years, 4231 patients (23.4%) aged 75–79 years, 2305 (12.7%)aged 80–84 years and 722 (4.0%)aged ≥85years at baseline.
RESULTS: Benefits of dabigatran versus warfarin regarding stroke (HR range 0.63 (95%CI 0.46 to 0.86) to 0.70 (0.31 to 1.57) for dabigatran 150mg twice daily), HR range 0.52 (0.21 to 1.29) to 1.08 (0.73 to 1.60) for dabigatran 110mg twice daily) and intracranial bleeding were maintained across all age groups (interaction p values all not significant). There was a highly significant interaction (p value interaction <0.001) between age and treatment for extracranial major bleeding, with lower rates with both doses of dabigatran compared with warfarin in younger patients (HR 0.78 (0.62 to 0.97) for 150mg twice daily, HR 0.72 (0.57 to 0.90) for 110mg twice daily) but similar (HR 1.50 (1.03 to 2.18) for 110mg twice daily) or higher rates (HR 1.68 (1.18 to 2.41) for 150mg twice daily) in older patients (≥80years).
CONCLUSIONS: Both once-daily regimens of edoxaban were noninferior to warfarin with respect to the prevention of stroke or systemic embolism and were associated with significantly lower rates of bleeding and death from cardiovascular causes. (Funded by Daiichi Sankyo Pharma Development; ENGAGE AF-TIMI 48 ClinicalTrials.gov number, NCT00781391.)