Abstract WP51: Neurological Severity and Infarct Size in Patients With Acute Ischemic Stroke During DOAC Treatment for Nonvalvular Atrial Fibrillation

Background and purpose: Less severe and smaller infarct are features in acute stroke patients treated with warfarin within a therapeutic range of PT-INR than in those without. But it remains unclear the severity and size of infarct in acute stroke patients treated with direct oral anticoagulants [DOAC]. We investigated the features of acute stroke in patients treated with DOAC, warfarin or without. Methods: We enrolled consecutive 190 non-valvular atrial fibrillation patients (mean age 78; 63% male) who developed acute ischemic stroke and classified them into 4 groups, 109 patients with no anticoagulant therapy [Control group], 25 patients with DOAC therapy [DOAC group], 19 patients treated with warfarin within a therapeutic range of PT-INR [>= 1.6 in patients aged 70 years old or older, >= 2.0 in those aged younger than 70 years old, Warfarin well controlled group], and 37 patients treated with warfarin with subtherapeutic PT-INR values [Warfarin not controlled group]. Infarcts sizes were defined as the maximum diameter of infarct, using the brain MRI diffusion-weighted image. Stroke severity on admission were assessed by the National Institutes of Health Stroke Scale[NIHSS].We compared them among the groups. Results: There were no significant differences in preadmission CHADS2 score among the 4 groups. The median infarct size were 31mm (interquartile (IQR) 13-59) in the control group, 10mm (IQR 7.4-38) in the DOAC group, 12mm (IQR 8.0-45) in the warfarin well controlled group, and 24mm (IQR 13-67) in the warfarin not controlled group. The size of infarct was significantly smaller in the DOAC group than the control group (P=0.01). The NIHSS on admission was 4 ([IQR] 2-15) in the control group, 2 (1-6) in the DOAC group, 4 (1-17) in the warfarin well controlled group and 5 (3-17) in e warfarin not controlled group. Stroke severity on admission was also more favorable in the DOAC group when compared with the control group (P=0.03) Conclusions: Smaller and less severe infarct may be feature of acute ischemic stroke during DOAC therapy when compared to that without any anticoagulant therapy.