Abstract WMP101: Potential Causes Of Anticoagulant Underuse In Patients With Atrial Fibrillation Presenting With Ischemic Strokes

Background: Underuse of FDA-approved stroke prevention methods in atrial fibrillation (AF) remains a major problem. We aimed to explore the potential causes of oral anticoagulant (OAC) non-use and compare the frequency of these factors between AF patients with acute ischemic stroke (AIS) off and on oral anticoagulant (OAC). Methods: The Neuro-AFib study is a multicenter observational study aiming to clarify the causes of different stroke types in a contemporary AF cohort. Potential causes of OAC non-use were systematically collected from all enrolled patients based on the exclusion criteria of the Direct OAC (DOAC) studies. The frequency of potential causes of OAC non-use (AIS-off-OAC) are explored in AF patients consecutively admitted to 22 US academic stroke centers with an AIS between 1/2018-12/2019, and these rates are compared to AIS-on-OAC. Results: Among 4898 patients with known AF who had IS, 2694 (55%) were not using any OAC, and 45% were AIS-on-OAC. CHA2DS2-VASc <2, the cutoff representing low embolic risk until late 2019, was found in 7% of AIS-off-OAC group compared to 3.8% in AIS-on-OAC (p<0.0001). The most common factor in OAC non-use group was history of falls (26%) vs 18% in AIS-on-OAC group (p=0.004). History of bleeding [intracranial (2.3%) and extracranial (18.5%)] was found in 20.8% of AIS-off-OAC vs 10.4% of AIS-on-OAC group (p<0.0001). 82.6% of these hemorrhages were classified as major bleeds. Pre-stroke cognitive impairment was also common in AIS-off-OAC (21.7%). Renal failure (creatinine >2mg/dl) was found in 13% of AIS-off-OAC. Gait problems leading to limited mobility (10%) and excessive alcohol use (3.8%) were other potential factors for OAC non-use. Among OAC non-users, 64% had at least one risk factor defined above. Conclusions: In a large multicenter contemporary IS cohort with known AF, 55% of patients were not on OAC, and about two thirds of them had a reason that would exclude them from the phase 3 DOAC studies. Other than improving the accuracy of risk prediction algorithms, research should focus on identifying optimal management approaches for this large AF population who present challenges to lifelong OAC use. FDA-approved left atrial appendage closure procedures can be considered in such AF patients.