Impact of Previous Stroke on Clinical Outcome in Elderly Patients with Nonvalvular Atrial Fibrillation: ANAFIE Registry

Abstract

Background: We determined the long-term event incidence among elderly patients with nonvalvular atrial fibrillation in terms of history of stroke/transient ischemic attack (TIA) and oral anticoagulation. Methods: Patients aged ≥75 years with documented nonvalvular atrial fibrillation enrolled in the prospective, multicenter, observational All Nippon Atrial Fibrillation in the Elderly Registry between October 2016 and January 2018 were divided into 2 groups according to history of stroke/TIA. The primary end point was the occurrence of stroke/systemic embolism within 2 years, and secondary end points were major bleeding and all-cause death within 2 years. Cox models were used to determine whether there was a difference in the hazard of each end point in patients with/without history of stroke/TIA, and in ischemic stroke/TIA survivors taking direct oral anticoagulants versus those taking warfarin. Results: Of 32 275 evaluable patients (13 793 women [42.7%]; median age, 81.0 years), 7304 (22.6%) had a history of stroke/TIA. The patients with previous stroke/TIA were more likely to be male and older and had higher hazard rates of stroke/systemic embolism (adjusted hazard ratio, 2.25 [95% CI, 1.97-2.58]), major bleeding (1.25, 1.05-1.49), and all-cause death (1.13, 1.02-1.24) than the other groups. Of 6446 patients with prior ischemic stroke/TIA, 4393 (68.2%) were taking direct oral anticoagulants and 1668 (25.9%) were taking warfarin at enrollment. The risk of stroke/systemic embolism was comparable between these 2 groups (adjusted hazard ratio, 0.90 [95% CI, 0.71-1.14]), while the risk of major bleeding (0.67, 0.48-0.94), intracranial hemorrhage (0.57, 0.39-0.85), and cardiovascular death (0.71, 0.51-0.99) was lower among those taking direct oral anticoagulants. Conclusions: Patients aged ≥75 years with nonvalvular atrial fibrillation and previous stroke/TIA more commonly had subsequent ischemic and hemorrhagic events than those without previous stroke/TIA. Among patients with previous ischemic stroke/TIA, the risk of hemorrhagic events was lower in patients taking direct oral anticoagulants compared with warfarin. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: UMIN000024006.