Abstract W P375: Prior Antithrombotic Therapy, Initial Neurological Severity And 3-month Outcome In Acute Ischemic Stroke Patients With Non-valvular Atrial Fibrillation: The Samurai-nvaf Study

Background and Purpose: We aimed to assess whether prior antithrombotic therapy affects initial neurological severity and functional outcome in acute ischemic stroke patients with non-valvular atrial fibrillation (NVAF). Methods: Patients with NVAF who were admitted within 7 days after ischemic stroke onset from 2011 to 2014 were enrolled from the register of a prospective, multicenter, observational study (the SAMURAI-NVAF study). Patients receiving novel oral anticoagulants at onset were excluded from the study. They were classified into 3 groups: the non-WF group, patients without prior warfarin; the iWF group, those on warfarin with initial PT-INR below the target range; the sWF group, those on warfarin with initial PT-INR within or above the target range. They were also divided into patients without prior antiplatelet agents (the non-AP group) and those with (the AP group). Initial neurological severity was measured by NIHSS score. Poor functional outcome was defined by mRS 3-6 at 3 months of onset. Results: Of 1000 patients studied, 713, 221 and 66 were assigned to the non-WF group, the iWF group and the sWF group, respectively. Of all, 245 were assigned to the AP group, mainly taking aspirin (202 patients). On multivariate analysis, the sWF group (vs. the non-WF group) (standardized regression coefficient [β], -0.23; p Conclusions: Prior sufficient warfarinization was associated with mild neurological severity and favorable outcome in acute ischemic stroke patients with NVAF, whereas prior insufficient warfarinization and prior antiplatelet therapy were not.