Abstract WP223: Race-ethnic Differences in the Impact of Antithrombotic Use on Inpatient Mortality Among Intracerebral Hemorrhage Patients in the Florida Stroke Registry (2013–2024)

Background: The use of anticoagulants and antiplatelets in patients at risk for intracerebral hemorrhage (ICH) is growing. Still, the extent to which their associated mortality risk varies by race-ethnicity remains poorly understood. The objective is to examine the association between race-ethnicity and type of antithrombotic use on inpatient mortality among ICH patients in the Florida Stroke Registry (FSR). Methods: We analyzed 32,036 ICH patients in the FSR (2013–2024). Antithrombotic exposure was categorized as anticoagulant-associated ICH (AA ICH), antiplatelet-only ICH (AP ICH), or non-antithrombotic ICH (NA ICH). Multivariable logistic regression models with hospital-level random effects examined the interaction between race-ethnicity and antithrombotic type on inpatient mortality, adjusted for demographics, clinical severity, and comorbidities. Results: Mean age was 69 years, and 54% were male, 60% were Non-Hispanic (NH) White, 18% NH Black, 16% Hispanic, and 6% Other. AA ICH occurred in 17%, AP ICH in 25%, and NA ICH in 58%. Overall, inpatient mortality was 16% with an unadjusted downward trend observed across all three groups from 2013 to 2024. Throughout the years, inpatient mortality occurred in 20%, 16%, and 16% of AA, AP, and NA ICH, respectively. AA ICH carried the highest adjusted inpatient mortality versus NA ICH among NH Black patients (AOR= 2.01; 95% CI 1.51-2.69). Inpatient mortality for AP ICHs versus NA ICH was also significantly highest among NH Black patients (AOR=1.37; 95% 1.11-1.68). Significant race-antithrombotic interactions were observed across crude and adjusted models (p-interaction <0.0001), with ROC values improving from 0.63 to 0.76 after adjustment. Conclusion: The effect of antithrombotic use on the inpatient mortality of ICH patients in Florida between 2013 and 2024 was not uniform for the race/ethnicity groups. These findings underscore the need for further research to elucidate the underlying biological, socioeconomic, and healthcare system factors contributing to these differences, ultimately aiming to improve outcomes for all ICH patients.