Abstract WP368: Thromboelastography for Risk Stratification in Embolic Stroke of Undetermined Source: A Pilot Study

Background: Embolic Stroke of Undetermined Source (ESUS) has diverse potential mechanisms, including occult atrial fibrillation (AF) and hypercoagulable states. Thromboelastography (TEG) is a viscoelastic assay that provides real-time assessment of coagulation and may identify hypercoagulability in stroke patients. This study evaluated the potential role of TEG in detecting hypercoagulable state in ESUS Methods: The study was conducted at 2 academic medical centers in the United States. Adult ESUS patients underwent TEG as part of outpatient post-discharge evaluation. Hypercoagulability was defined using TEG by any of the following: shortened clot initiation time (R time 32 mm),or elevated citrated rapid TEG maximum amplitude (CRT MA >70 mm). All patients were on antiplatelet (AP) therapy prior to testing and were followed through in-person or virtual visits. The primary objective was to assess TEG and its association with recurrent stroke or death Results: Of 64 patients (median age 61; 52% female), 23% had a patent foramen ovale, 20% with history of or active malignancy, 3% COVID-19 positive test, and 7.8% developed AF during a median 9-month (IQR 6-12) follow-up. Median time from stroke to TEG testing was 2 months (IQR 1-3). Abnormal TEG profiles were detected in 21 patients (33%). Recurrent strokes and deaths each occurred in 3 (4.6%) patients with two patients suffering both stroke and death; all patients with stroke or death had abnormal TEG. All recurrent stroke events occurred in patients with elevated both CFF MA and CRT MA, including two who additionally had shortened R-time. No recurrent strokes occurred in patients with