Real-world effectiveness and the safety of anticoagulant treatment in elderly non-valvular atrial fibrillation in the ANAFIE registry, the largest real-world elderly AF registry

Abstract

Abstract Background The optimal anticoagulant regimen for elderly AF has not been well elucidated, because this population, especially the very elderly (≥85 years), have not been sufficiently represented in most randomized controlled clinical trials for stroke prevention in non-valvular AF (NVAF). Purpose The ANAFIE registry was designed to evaluate the real-world anticoagulant treatment status of elderly (≥75 years) NVAF patients including >8,000 very elderly patients. In this main analysis of the ANAFIE, the incidence of stroke or systemic embolic events (stroke/SEE), and major bleeding were compared between warfarin (WF) and direct oral anticoagulants (DOACs). Methods A total of 33,018 NVAF patients aged ≥75 years was enrolled in the ANAFIE, and followed for 2 years. The incidence of stroke/SEE and major bleeding by type of anticoagulants (WF and all DOACs) was estimated using Kaplan-Meier method. Hazard ratio (HR) and 95% confidence interval (95% CI) were calculated by Cox proportional hazard model. Results In the analysis set of 32,099 patients, the mean age was 81.5 years. 23,738 (74%) were <85 years and 8,361 (26.0%) were ≥85 years. 92.5% of the whole population used anticoagulants including WF (27.6%) or DOACs (72.3%). The ratio of each DOAC was dabigatran 7.8%, rivaroxaban 21.5%, apixaban 26.9% and edoxaban 16.1%. Stroke/SEE and major bleeding was observed in 396 patients (1.24/100 patient-years [py]) and 279 patients (0.87/100py). The time in therapeutic range for patients <85 years and ≥85 years in the WF group was 76.7% and 72.2%, respectively. The incidence of stroke/SEE was numerically lower in patients taking any DOAC vs. WF regardless of age group (<85 years [HR 0.83] and ≥85 years [HR 0.71]). Major bleeding was also lower vs. WF in both age groups (<85 years [HR 0.60] and ≥85 years [HR 0.65]). Conclusion In elderly NVAF patients enrolled in the ANAFIE registry, the incidence of stroke/SEE and major bleeding was lower in patients taking a DOAC compared with WF for all patients ≥75 years, even for very elderly patients. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Daiichi Sankyo Co., Ltd.