Racial and Ethnic Differences in the Risk of Ischemic Stroke After Nontraumatic Intracerebral Hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) is associated with an increased risk of ischemic stroke. Whether there are racial and ethnic disparities in the risk of ischemic stroke after ICH is poorly understood. We therefore aimed to test the hypothesis that non-Hispanic Black and Hispanic ICH patients have a higher risk of ischemic stroke compared with non-Hispanic White ICH patients. METHODS: We performed a retrospective cohort study using the Healthcare Cost and Utilization Project (HCUP) on all hospitalizations at all nonfederal hospitals in Florida from 2005 to 2018 and New York from 2006 to 2016. Race and ethnicity were coded as a single variable in HCUP. We included patients with an ICH, and without a prior or concomitant diagnosis of ischemic stroke, ascertained using validated International Classification of Diseases-Clinical Modification-9 and 10 diagnosis codes. Using Cox proportional hazard models, we studied the relationship between race and risk of ischemic stroke starting from the time of discharge from ICH hospitalization, after adjustment of demographics and vascular comorbidities. RESULTS: We included 91 342 patients with ICH-62% non-Hispanic White, 18% non-Hispanic Black, and 12% Hispanic patients. Non-Hispanic Black and Hispanic patients were younger and had a higher prevalence of cardiovascular comorbidities; however, atrial fibrillation was more prevalent among non-Hispanic White patients. During a median follow-up period of 4.4 years (interquartile range, 1.5-8.1), an incident ischemic stroke occurred in 3377 (6%) non-Hispanic White, 1323 (8%) non-Hispanic Black, and 844 (8%) Hispanic patients. In adjusted Cox models, the risk of an ischemic stroke was significantly higher among non-Hispanic Black patients (hazard ratio, 1.6 [95% CI, 1.5-1.8]) and Hispanic patients (hazard ratio, 1.4 [95% CI, 1.3-1.5]), compared with non-Hispanic White patients. Similar results were obtained in sensitivity analyses when using death as a competing risk and after excluding patients with atrial fibrillation and valvular heart disease. CONCLUSIONS: In a large heterogeneous cohort of patients with ICH, we found that non-Hispanic Black and Hispanic patients had a significantly higher risk of ischemic stroke compared with non-Hispanic White patients.