Initial Severity And Functional Outcomes Of Acute Ischemic Stroke With Atrial Fibrillation On Direct Oral Anticoagulants(DOACs): Japan Stroke Data Bank

Purpose: The purpose of this study was to examine the associations between oral anticoagulants (OACs) at onset and outcomes in acute ischemic stroke (AIS) patients with atrial fibrillation. Methods: AIS patients with comorbidity of atrial fibrillation (aged ≥18 years, pre-stroke modified Rankin Scale [mRS] 0-2) admitted within 24 hours after onset from January 2017 to December 2020 were examined from a long-lasting nationwide hospital-based multicenter prospective registry, the Japan Stroke Data Bank. Patients were classified into 3 groups according to anticoagulants at onset: no-anticoagulant group, warfarin group and DOAC group. The co-primary outcomes were the National Institutes of Stroke Scale (NIHSS) on admission and favorable outcome at discharge, corresponding to the mRS of 0-2. Mixed effects logistic regression was performed to examine the association between antithrombotic agents and these outcomes. Results: Of a total of 6,838 patients, 4,249 (62.1 %) patients were classified into the no-anticoagulant group, 907 (13.3 %) into warfarin group and 1,682 (24.6 %) into DOACs group. Median NIHSS score on admission was 7 [interquartile range: 2-19] in the warfarin group and 5 [2-15] in the DOAC group, versus 9 [3-20] in the no-anticoagulant group. Both warfarin and DOAC groups had lower NIHSS scores as compared to no-antithrombotic group (adjusted incidence rate ratio 0.96 [95% confidence interval 0.94-0.99] and 0.81 [0.79-0.83], respectively) after adjustment by age, sex, hypertension (HT), dyslipidemia (DL), diabetes mellitus (DM) and history of stroke. The rate of favorable outcome at discharge was 41.5 % in no-anticoagulant group, 42.0% in warfarin group and 48.1 % in DOACs group. In multivariable analysis, sex, NIHSS on admission, HT, DL, DM, history of stroke and intravenous thrombolysis and mechanical thrombectomy, DOACs group more frequently had favorable outcome (odds ratio 1.20 [95% CI 1.03-1.40]) than no-anticoagulant group, but warfarin group did not (1.05 [0.86-1.27]). Conclusion: Taking DOACs prior to onset appears associated with milder stroke severity and a more favorable outcome following acute ischemic stroke in patients with atrial fibrillation.