Outcomes among patients with primary angiitis of the CNS: A Nationwide United States analysis.

BACKGROUND: Primary angiitis of the central nervous system (PACNS) is a relapsing-remitting disease with a heterogeneous course. Case series have delineated the long-term disease course but not acute outcomes or their determinants. The national United States hospital burden of PACNS has not been quantified. METHODS: Analysis of the United States Nationwide Readmissions Database (2016-2018) to characterize the frequency of PACNS hospitalizations, demographic features, inpatient mortality, and discharge outcomes. RESULTS: During the 3-year study period, unweighted 1843 (weighted 3409) patients with PACNS were admitted to the 1078 Healthcare Cost and Utilization Project HCUP participating hospitals; with weighting, this value indicates that 1136 patients were admitted each year to US hospitals, representing yearly 0.01 cases per 100 000 national hospitalizations. The majority of patients were hospitalized in metropolitan teaching hospitals (81.6%). The median age at admission was 54.9 (IQR: 44.0-66.5) years and 59.4% were women. Neurologic manifestations included ischemic stroke in 38.2%, transient ischemic attack in 20.2%, seizure disorder in 22.8%, and intracranial hemorrhage in 13.0%. Overall, 60.0% of patients were discharged home, 35.0% discharged to a rehabilitation facility or nursing home and 5.0% died before discharge. Patient features independently associated with the discharge to another facility or death included older age (odds ratio [OR], 1.03 [95% CI, [1.03-1.04]]), male sex (OR, 1.22 [1.04-1.43]), intraparenchymal hemorrhage (OR, 1.41 [1.08-1.84]), ischemic stroke (OR, 2.79 [2.38-3.28]), and seizure disorder (OR, 1.57 [1.31-1.89]). CONCLUSION: Our study showed PACNS is still a rare inflammatory disorder of the blood vessels of the central nervous system suggesting an annual hospitalization of 5.1 cases per 1,000,000 person-years in the more diverse and contemporary US population. Overall, 4 in 10 had unfavorable discharge outcome, being unable to be discharged home, and 1 in 20 died before discharge.