Stroke prevention using dabigatran in elderly Chinese patients with atrial fibrillation.

BACKGROUND: Little is known about the clinical benefit of a non-vitamin K antagonist oral anticoagulant compared with warfarin in elderly Chinese patients with atrial fibrillation (AF).

OBJECTIVE: The purpose of this study was to evaluate the clinical benefit of dabigatran in elderly (age ≥80 years) Chinese patients with nonvalvular AF with regard to the risk of ischemic stroke and intracranial hemorrhage (ICH).

METHODS: This was an observational study.

RESULTS: We studied 571 Chinese patients (mean age 84.8 ± 4.0 years; 58.1% women) with nonvalvular AF. The primary outcome was hospital admission for ischemic stroke, and the secondary outcome was admission for ICH. The mean CHA2DS2-VASc (congestive heart failure [1 point], hypertension [1 point], age 65-74 years [1 point] and age ≥75 years [2 points], diabetes mellitus [1 point], prior stroke or transient ischemic attack [2 points], vascular disease [1 point], sex category [female] [1 point]) and HAS-BLED (hypertension [1 point], abnormal renal/liver function [1 point], stroke [1 point], bleeding history [1 point] or predisposition [1 point], labile international normalized ratio [1 point], elderly [age >65 years] [1 point], drugs/alcohol concomitantly [1 point]) scores were 4.8 ± 1.6 and 2.4 ± 0.8, respectively. Of 571 patients, 129 (22.6%) were taking dabigatran 110 mg twice daily and the remaining were on warfarin. After a mean follow-up of 2.6 years (a total of 1471 patient-years), ischemic stroke occurred in 83 patients on warfarin (6.9% per year) compared with 4 patients on dabigatran (1.4% per year) (hazard ratio 0.22; 95% confidence interval 0.23-0.67). There were 8 incidences of ICH: 7 in patients on warfarin (0.59% per year) and 1 patient on dabigatran (0.35% per year). Dabigatran was associated with a substantially lower ischemic stroke risk (1.4% per year vs 5.4% per year) and similar ICH risk (0.35% per year vs 0.36% per year) as compared with warfarin with time in therapeutic range (TTR) ≥55%.

CONCLUSION: In elderly Chinese patients with AF, this study suggested that dabigatran achieved superior stroke risk reduction and similar risk of ICH compared with warfarin with TTR ≥55%. Dabigatran may be preferable to warfarin in elderly patients with AF for stroke prevention, particularly in those with poor TTR.