Supplementary Material for: Ethnic-Associated Phenotype Variations in Moyamoya Cerebrovascular Outcomes

Introduction: Moyamoya has been extensively described in East Asian populations, and despite its accepted clinical presentation and course, it is fundamental to describe major cerebrovascular complications in other ethnically diverse samples. Hence, we sought to determine if distinct ethnic groups are at higher risk of developing stroke using the National Inpatient Sample (NIS) database. Methods: We included all moyamoya patients admitted from January 2013 until December 2018 in the NIS database. Multivariate regression analysis was used to determine the risk of developing stroke and poor outcomes in different races compared to white patients. Results: Out of the 6093 admissions with diagnosis of moyamoya disease that were captured, 2,520 were white (41.6%), 2,078 were African American (AA) (34.1%), 721 were Hispanic (11.8%), and 496 were Asian (8.14%). For arterial ischemic stroke (AIS), we found that AA race had a significantly reduced risk of AIS compared to white patients (odds ratio = 0.8, 95% confidence interval: 0.7–0.9, p = 0.031). While being Hispanic or Asian significantly increased 1.5 and 2-fold the risk of hemorrhagic stroke. Conclusion: This study highlights the unique features and phenotypes of moyamoya cases among different ethnicities. While possibly AA are protected from developing AIS due to underlying causes of moyamoya such as sickle cell disease, Asians seems to be more susceptible to hemorrhagic stroke