Abstract Body: Background: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the most common hereditary stroke disorder due to pathogenic variants in the NOTCH3 gene on chromosome 19. Characteristics of CADASIL patients hospitalized with acute ischemic stroke (AIS) have not been widely reported.

Methods: We identified all adult hospitalizations in the National Inpatient Sample (NIS) from 2018-2020 with diagnosis codes for acute ischemic stroke (ICD-10 I63) and the newly available code as of October 2018 for CADASIL (I67.850) using weighted sampling. Descriptive statistics evaluated demographic and clinical characteristics among AIS patients with and without CADASIL.

Results: Of a total 1,918,920 weighted AIS hospitalizations, there were 300 patients with CADASIL. The prevalence of CADASIL among AIS patients increased from 0.2% in 2018 to 2.8% in 2020. AIS patients with CADASIL were similar in sex and more likely to be younger (55.8 ± 25.2 vs 69.7 ± 31.4 years, p<0.001), White (70.0% vs 65.4%, p=0.03), and Asian/Pacific Islander (6.7% vs 3.1%, p<0.001) compared to those without CADASIL. CADASIL patients had lower rates of hypertension, diabetes, and coronary artery disease (55.0% vs 82.4%, p<0.001; 21.7% vs 38.9%, p<0.001; 3.3% vs 10.6%, p=0.004). There was no difference in the rate of dyslipidemia (43.3% vs 49.8%, p=0.31), obesity (15.0% vs 8.9%, p=0.19) and smoking (23.3% vs 18.5%, p=0.38) in patients with CADASIL vs those without. There was no difference in the rate of administration of IV thrombolysis (5.0% vs 8.3%, p=0.25), however CADASIL patients were less likely to undergo endovascular thrombectomy (EVT) (0.0% vs 4.1%, p<0.001). CADASIL patients had lower rates of in-hospital mortality and were more likely to be discharged home (0.0% vs 6.5%, 53.3% vs 33.3%, all p-values <0.001).

Conclusions: CADASIL was rare in our NIS population with a prevalence of 2.8% in 2020. Patients with CADASIL, in general, carried a lower burden of vascular risk factors. They received IV thrombolysis at an equal rate but EVT at a lower rate, likely due to the small vessel pathology of CADASIL. While less likely to experience in-hospital mortality, nearly two-thirds were not independent enough to be discharged home. Our findings highlight the need for targeted therapies addressing the pathophysiology of CADASIL to prevent AIS in these patients with an otherwise low burden of vascular risk factors.