Abstract WP257: Prevalence of Co-Morbid Ischemic Stroke and Antiphospholipid Syndrome and Characteristics of Patients: Analysis of the National Inpatient Sample

Abstract

Background: Antiphospholipid syndrome (APLS) is an acquired thrombophilia that is a known cause of ischemic stroke (IS). However, there is a paucity of population-based studies of the prevalence and effects of APLS diagnosis on patients hospitalized with IS. Here we use the National Inpatient Sample (NIS) to evaluate the characteristics of patients admitted to the hospital for IS with a diagnosis of APLS. Methods: Adult patients in the NIS from 2016-20 with non-elective admissions and a primary discharge diagnosis of IS (ICD-10 I63*) were included. The study exposure was APLS, defined in ICD-10 codes D68.61-62. We excluded individuals with ICD codes for other thrombophilia conditions (D6*). The primary outcomes were in-hospital death vs good outcome (discharge home/self care). We fit logistic regression models adjusted for age, race/ethnicity, Charlson index, household income by ZIP code, administration of IV thrombolysis or thrombectomy (EVT), hospital teaching status, census region, and bedsize. Results: We included 434,463 IS discharges, of which 1,407 had APLS. Discharges with APLS were younger, more likely to be female, non-white, lower income, less vascular comorbidities, and less likely to receive IV thrombolysis but more likely to receive EVT (Table 1). In the multivariable logistic regression model, those with APLS were more likely to have in-hospital death (OR 1.49, 95% CI 1.12-1.98, p=0.006) and less likely to have discharge home (OR 0.70, 955 CI 0.62-0.78, p<0.001). In a subset of this cohort (n=175,428), the NIH Stroke Scale (NIHSS) was available and not significantly different (p=0.768) between patients with and without APLS. Conclusion: IS with APLS happens in younger individuals with fewer vascular risk factors but worse outcomes and higher odds of in-hospital death. The NIHSS findings suggested that stroke severity alone does not account for the observed differences in outcome. Further research is needed to understand these findings and their causes. .