Abstract WP093: Prevalence, Trends, and Outcomes of Posterior Circulation Ischemic Stroke in the United States

Background: Posterior circulation ischemic stroke has been previously studied in single center and multicenter registries. The prevalence, trends, and outcomes of posterior circulation ischemic stroke at a national level are not known. Methods: We identified patients admitted with posterior circulation ischemic stroke using the Nationwide Inpatient Sample from 2016 to 2022. We compared the rates of intravenous thrombolysis, thrombectomy, stent placement, in-hospital mortality, routine discharge without palliative care (based on discharge disposition), and length and costs of hospitalization in patients admitted with posterior circulation ischemic stroke with those admitted with carotid ischemic stroke. Results: A total of 381,170 (23.5%) and 1,235,780 (76.5%) patients were admitted with posterior circulation and anterior circulation ischemic strokes, respectively over a 7-year period. There was a trend towards an increase in the proportion of patients admitted with posterior circulation ischemic strokes from 41,540 in 2016 to 73,110 in 2022 (p trend p<0.001). Patients with posterior circulation ischemic stroke were more likely to have diabetes mellitus and less likely to have heart failure and atrial fibrillation. The proportion of patients with NIHSS score 0-9 was significantly higher in patients with posterior circulation ischemic stroke (81.8% versus 56.5%). The utilization of IV thrombolysis (6.1% versus 13.3%), thrombectomy (4.0% versus 16.3%) and stent placement or endarterectomy (0.9% versus 5.5%) were significantly lower (p<0.001) in patients with posterior circulation ischemic stroke compared with those with anterior circulation ischemic stroke. The in-hospital mortality was significantly higher (odds ratio 1.18, 95% confidence interval 1.09-1.28) in patients with posterior circulation ischemic stroke after adjusting for potential confounders. Conclusions: Over 20% of acute ischemic stroke patients have posterior circulation ischemic stroke in the United States. Patients with posterior circulation ischemic stroke are less likely to receive acute stroke treatment compared with those with anterior circulation ischemic stroke.