Abstract TP160: Increased Prevalence of Intracranial Atherosclerotic Disease Among Asian Ischemic Stroke Patients in an Urban US Cohort

Introduction: Race-ethnic disparities have been documented across ischemic stroke subtypes. East Asian cohorts consistently show a higher burden of intracranial atherosclerotic disease (ICAD), but few U.S.-based studies have examined stroke etiologies among Asian Americans (AA). This study compared ischemic stroke subtypes between AA and non-Hispanic White (NHW) patients. Methods: Using our local Get With The Guidelines® registry, we conducted a cross-sectional study of adults admitted to Rush University Medical Center with ischemic stroke from January 1, 2016, to December 31, 2023. Stroke etiology was classified using TOAST criteria. For large-artery atherosclerosis, neurologists adjudicated intracranial vs. extracranial involvement. Only the first stroke admission was included per patient. We compared characteristics and subtype prevalence between AAs and NHWs and used logistic regression adjusting for demographics and vascular risk factors. Results: Among 1,055 patients (mean age 66.6±14.8 years; 43.0% female; 9.1% AA), 17.4% had large-artery atherosclerosis (7.8% ICAD), 34.3% cardioembolism, 9.7% small-vessel occlusion (SVO), and 26.7% cryptogenic stroke. Compared to NHWs, AAs had a higher prevalence of ICAD (13.4% vs. 7.2%, p = 0.04) and SVO (16.5% vs. 9.0%, p = 0.03). In age- and sex-adjusted models, AAs had approximately two-fold greater odds of ICAD (OR 2.01, 95% CI 1.06–3.80) and SVO (OR 2.00, 95% CI 1.12–3.57); associations were attenuated after adjusting for vascular risk factors. No differences were observed in extracranial atherosclerosis or cardioembolic stroke. Conclusions: In this single-center study, AAs had significantly higher age- and sex-adjusted odds of stroke due to ICAD and SVO compared to NHWs. These differences attenuated after adjusting for risk factors, suggesting a role for vascular health in subtype disparities. Unlike East Asians, among whom ICAD accounts for up to half of strokes, AAs exhibited a more heterogeneous pattern. Limitations include the cross-sectional design and small AA sample, limiting subgroup analysis. Larger studies are needed to examine stroke etiologies across AA subgroups and drivers of observed disparities.