Abstract 283: Readmission Rates and Etiologies among Patients with Primary Angiitis of the Central Nervous System

Abstract

Introduction Primary Angiitis of the Central Nervous System (PACNS) is a rare, relapsing inflammatory disorder of blood vessels in the brain and spinal cord presenting clinically with a spectrum of manifestations including strokes, seizures, and neurologic deficits. Limited data are available on the modifiable and nonmodifiable predictors of readmissions for patients diagnosed with PACNS, which hinders the ability of healthcare systems to risk‐stratify patients based on their specific demographics, comorbidities, and hospital status. Methods We identified patients with PACNS (ICD‐10 code: I67.7) admitted from 2016‐2019 using the Nationwide Readmission Database (NRD). The difference in days between the index admission and the readmission was used to identify patients who were readmitted within 30 and 90 days. The primary diagnosis of the readmission was used to identify the etiology of readmission. Data was weighted to allow for representative nationwide estimates. Results We identified 1,398 patients admitted with a primary diagnosis of PACNS between 2016 and 2019. The mean age was 52.81 years, with 59.20% (n=828) being female. The 30‐day readmission rate was 10.52% (n=147) and the 90‐day readmission rate was 19.60% (n=274). Nearly half of 90‐day readmissions occurred within the first 30 days. Annual variations in readmission rates were insignificant. Age and sex distribution were not statistically different between patients not requiring readmission, those readmitted within 30 days, and those readmitted within 90 days. Compared to those not requiring readmission, patients readmitted within 30 days had a higher prevalence of diabetes (38.07% vs 29.06%; p=0.023) and hypertension (65.66% vs 56.88%; p=0.035), while those readmitted within 90 days had a higher prevalence of diabetes (41.56% vs 27.19%, p<0.001), dyslipidemia (48.49% vs 39.77%, p=0.009), obstructive sleep apnea (10.79% vs 6.73%, p=0.028), and ischemic stroke (32.56% vs 25.18%, p=0.013). The most common etiologies of 30‐ and 90‐day readmissions were cardiovascular (47.05% and 47.81%), neurological (26.80% and 20.61%), and infectious (9.07% and 7.58%). Conclusion The rates of 30‐ and 90‐day readmissions among patients with PACNS have remained stable between 2016 and 2019. Patients with PACNS requiring readmission had a higher incidence of vascular risk factors. Cardiovascular, neurological, and infectious conditions were the most common etiologies for 30‐ and 90‐day readmissions. While our analysis suggests a role for vascular risk factor modification to prevent readmissions in patients diagnosed with PACNS, further research is required to validate this hypothesis and identify other modifiable risk factors.