Abstract 157: Ischemic Strokes In Patients With Atrial Fibrillation On Oral Anticoagulant: The Neuro-AFib Study

Abstract

Background: Ischemic stroke (IS) admissions in patients with atrial fibrillation (AF) using either direct oral anticoagulants (DOAC) or Vitamin K antagonists (VKA) are commonly seen in stroke units but data on their prevalence and causes are scarce. Understanding the frequency/causes of failures of current FDA-approved preventive methods in patients with AF is important to reduce stroke risk and related death/disability. Methods: The Neuro-AFib study is a multicenter effort geared toward elucidating the causes and consequences of IS and hemorrhagic stroke in a contemporary AF cohort. Detailed clinical, laboratory and multimodal neuro- and cardiac imaging data from known AF patients consecutively admitted to 22 US academic stroke centers with an IS between 1/2018-12/2019 were used to compare characteristics of IS on vs off oral anticoagulants. Results: Out of 6443 IS patients with AF, 4898 (76%) had known AF prior to the acute stroke. Among these patients with known AF, 2204 (45%) were using oral anticoagulants [OAC= DOAC (59.3%) or VKA (40.7%)]. Patients who had IS on OAC were younger (76.8 + 11 vs 78 + 12, p=0.001), had higher mean CHA 2 DS 2 -VASc scores (4.17 + 1.5 vs 3.9 + 1.5, p<0.0001), and more likely to have a past history of IS/TIA when compared to non-OAC group (35% vs 23%, p<0.0001). In a multivariable logistic regression model, history of IS/TIA, diabetes, hyperlipidemia, heart failure, prosthetic heart valve, sleep apnea, permanent atrial fibrillation, left atrial dilation and ischemic arterial disease were all independently associated with IS on OAC (all p<0.05). Imaging data were complete in 15% of the cohort and IS on OAC group had more acute lacunar infarcts, and extracranial and intracranial atherosclerotic disease causing 50% or more ipsilateral stenosis compared to patients with IS off OAC (all p<0.05). Conclusions: Based on a large multicenter contemporary cohort of IS patients with known AF, the numbers of patients who failed OACs (and especially DOACs) are high. These patients have severe vascular risk factor loads, concurrent etiologies, and they are more likely to have recurrent ischemic events. Further detailed data focused on imaging and IS mechanisms from this contemporary cohort will be ready to be presented during ISC 2022.