Prior Direct Oral Anticoagulant Therapy is Related to Small Infarct Volume and No Major Artery Occlusion in Patients With Stroke and Non‐Valvular Atrial Fibrillation

BACKGROUND: The aims of the present study were to investigate the relationships between prior direct oral anticoagulant (DOAC) therapy and infarct volume and the site of arterial occlusion in patients with acute ischemic stroke and non‐valvular atrial fibrillation. METHODS AND RESULTS: From March 2011 through November 2016, consecutive patients with acute ischemic stroke in the middle cerebral artery territory and non‐valvular atrial fibrillation were recruited. The infarct volume was assessed semi‐automatically using initial diffusion‐weighted imaging, and the arterial occlusion site was evaluated on magnetic resonance angiography. The effect of prior DOAC treatment on the site of arterial occlusion was assessed by multivariate ordinal logistic regression analysis. A total of 330 patients (149 women; median age 79 [quartiles 71–86] years; median National Institutes of Health Stroke Scale score 11 [4–21]) were enrolled. Of these, 239 were on no anticoagulant, 40 were undertreated with a vitamin K antagonist (VKA), 22 were sufficiently treated with VKA (PT‐INR ≥1.6), and 29 were on a DOAC before the acute ischemic stroke. The infarct volume on admission differed among the groups (median 14.5 [2.0–59.8] cm(3) in patients with no anticoagulation, 24.8 [2.1–63.0] in undertreated VKA, 1.3 [0.3–13.5] in sufficient VKA, and 2.3 [0.5–21.0] in DOAC, P=0.001). Multivariate analysis showed that prior DOAC treatment was independently and negatively associated with more proximal artery occlusion (odds ratio [OR] 0.34, P=0.015), compared with no anticoagulant. CONCLUSIONS: DOAC treatment before the event was associated with smaller infarct volume and decreased risk of greater proximal artery occlusion in acute ischemic stroke patients with non‐valvular atrial fibrillation, compared with no anticoagulation.