Abstract TP425: Prevalence and Predictors of Cortical Superficial Siderosis Among African Americans with Ischemic Stroke and Transient Ischemic Attack

Abstract

Background: Cortical Superficial Siderosis (cSS) detected on brain MRI affects 0.7% of the general population. In studies of predominantly White individuals, cSS is considered a sensitive marker of cerebral amyloid angiopathy (CAA) associated with increased risk of intracerebral hemorrhage. However, its prevalence and predictors in ischemic stroke (IS) —particularly in African Americans (AA)—has not been well studied. We sought to characterize the prevalence and vascular risks associated with cSS in AA with IS and transient ischemic attack (TIA). Methods: We included 2001 consecutive (year 2009-2018) IS and TIA patients, wherein 1048 patients (52%) were AA with available T2*gradient-echo MRI sequence. cSS rating was performed according to standardized guidelines. Race was determined by self-report based on U.S. census procedures, categorized as White, AA or Other racial groups (ORG). Vascular risk factors included age, diabetes, hypertension, systolic blood pressure (SBP), dyslipidemia, BMI, smoking, prior stroke, coronary artery disease; and illicit drug use (IDU). Differences in associations with cSS were assessed using univariate analyses. Results: We observed cSS in 1.15% (n=23) of AA, 0.4% (n=9) Whites and 0.6% (n=12) ORG patients. Compared to Whites with cSS, AA were younger (63 vs. 69 years), had higher proportion of men (70 vs 56%), hypertension (83 vs 78%), IDU (22 vs 11%), higher SBP (166±33 vs 162±15mmHg), and lower CAD prevalence (13 vs 33%), although differences did not reach statistical significance. Compared to AA without cSS, AA with cSS had higher proportion of men (69.6 vs 49.7%), prior stroke (39.1 vs 29.7%), IDU (21.7 vs 12.9%), and higher SBP (166±33 vs 153±37mmHg), the latter being the only statistically significant (p=0.038). The remaining vascular risk factors did not differ in patients with and without cSS, or between racial groups. Conclusion: The prevalence of cSS in AA with IS/TIA at our urban center is higher than in the general population and higher than in Whites. The vascular risk factor profile seems to differ between AA and White patients with and without cSS. Our results may be relevant in studies of cSS in AA wtih IS/TIA patients as the underlying angiopathy may not represent CAA, but require replication in larger samples.