Associations between systemic vasculitis and hospitalization outcomes in adults with acute ischemic stroke: An analysis of the US National Inpatient Sample, 2006–2020

Objective: Systemic vasculitis is a multisystem inflammatory disorder that may exacerbate cerebrovascular injury and complicate the clinical course of acute ischemic stroke (AIS). This study aimed to assess the associations between systemic vasculitis and hospitalization outcomes in adults admitted for AIS. Methods: Adults hospitalized with a principal diagnosis of acute ischemic stroke were identified from the US Nationwide Inpatient Sample (2006–2020). After exclusions, patients with systemic vasculitis were matched 1:4 to those without vasculitis using propensity score matching. Survey-weighted logistic and linear regression models were used to evaluate in-hospital outcomes, complications, length of stay, and total hospital charges, with stratified analyses by chronic kidney disease, heart failure, and systemic autoimmune disease status. Results: Among 1,283,209 eligible AIS hospitalizations, 2,594 patients with systemic vasculitis were matched to 10,376 patients without vasculitis. After adjustment, systemic vasculitis was associated with higher risks of in-hospital mortality (aOR = 1.24, 95% CI: 1.01–1.51), any complication (aOR = 1.13, 95% CI: 1.03–1.24), venous thomboembolism (aOR = 1.66, 95% CI: 1.29–2.14), sepsis/shock (aOR = 1.54, 95% CI: 1.30–1.83), acute kidney injury (aOR = 1.15, 95% CI: 1.01–1.30), and delirium or altered mental status (aOR = 2.26, 95% CI: 1.53–3.32). Systemic vasculitis was also associated with longer LOS (adjusted β = 1.38 days, 95% CI: 1.15–1.60) and higher total hospital charges (adjusted β = 19.91 thousand USD, 95% CI: 14.73–25.09). Stratified analyses showed generally consistent associations for LOS and hospital charges, although individual complications varied across subgroups. Conclusion: Systemic vasculitis is independently associated with worse in-hospital outcomes among adults hospitalized for AIS, including higher mortality, greater risks of major complications, longer hospitalization, and higher hospital charges. These findings highlight the need for careful inpatient monitoring and individualized management in this high-risk population.