Abstract 160: Etiologies Of Intracerebral Hemorrhage In Patients With Atrial Fibrillation On Or Off Oral Anticoagulants: The Neuro-Afib Study

Background: Intracerebral hemorrhage (ICH) is the most feared complication of oral anticoagulants (OAC) used to prevent ischemic strokes (IS) in patients with atrial fibrillation (AF). As different ICH etiologic factors correspond to different ICH risks, we aimed to present the causes of ICH in AF patients who were or were not using OAC, based on data from a multicenter contemporary cohort. Methods: The Neuro-AFib study is a multicenter effort to elucidate the current causes and consequences of IS and ICH in AF patients. Detailed clinical, laboratory and multimodal imaging data were collected from consecutive patients with AF admitted to 15 US stroke centers with an IS or ICH between 1/2018-12/2019. Etiologic factors of AF patients who were admitted with ICH on OAC (OAC-ICH) and off OAC (nonOAC-ICH) will be compared. Results: A total of 868 patients presented with ICH and had a diagnosis of AF, either previously known (88%) or diagnosed during admission (12%). 571 patients (66%) were on OAC at the time of their ICH of whom 58% were on direct OAC (DOAC), 40% on warfarin and 2% on heparin. OAC-ICH patients were older than nonOAC-ICH (76.6±10 vs 74.4±13, p=0.006) while sex distribution was the same in both groups (43% female). CHA 2 DS 2 -VASC was higher in OAC-ICH (4.3±1.6 vs 3.9±1.9, p=0.001) but HAS-BLED score was the same in both groups (2.7±1.1). Cerebral amyloid angiopathy (CAA) was diagnosed in 42.5% of the ICH patients based on modified Boston criteria while hypertensive cerebral small vessel disease (HTN-cSVD) in 57.5%. HTN-cSVD was the more common ICH etiology among OAC-ICH (65%) compared to nonOAC-ICH (49%). Among OAC-ICHs, DOAC-related ICHs tended to be more commonly of hypertensive etiology when compared to warfarin-ICH (p=0.09). Conclusions: Our study is the first to report the etiologic mechanisms of ICH in AF patients on or off OAC. CAA is known to be a major cause of OAC-ICH with exceedingly high recurrence rates. Despite this fact, HTN-cSVD was more common among OAC-ICH (especially DOAC-ICH) patients, supporting the view that the presence/absence of HTN-cSVD risk markers such as deep microbleeds are as important as CAA-markers in determining the optimal stroke prevention method in AF patients (left atrial appendage closure vs lifelong OAC).