The Impact of Rapid Transfer on the Prognosis of Aneurysmal Subarachnoid Hemorrhage: A Multi-center Cohort Study

BACKGROUND: Aneurysmal subarachnoid hemorrhage (aSAH) carries high mortality and disability. Existing studies largely focus on in-hospital treatment timing, whereas evidence on the prehospital window from symptom onset to arrival at an endovascular-capable hospital remains scarce, with multicenter data from China particularly lacking. This study investigated the association between prehospital transfer time (PTT) and clinical outcomes. METHODS: This retrospective multicenter cohort study enrolled 726 adult aSAH patients from 7 comprehensive stroke centers in China. Patients were categorized into a rapid transfer group (PTT ≤8 h) and a delayed transfer group (PTT >8 h). Multivariable logistic regression models, adjusting for age, Hunt-Hess grade, modified Fisher grade and other confounders, were used to evaluate the independent effect of PTT on 6-month functional prognosis (poor outcome defined as modified Rankin Scale score >2), 12-month all-cause mortality, and in-hospital complications. RESULTS: After multivariable adjustment, delayed transfer was independently associated with a higher risk of 6-month poor functional outcome (adjusted OR 5.306, 95% CI 3.175-9.170, P < 0.001) and increased 12-month all-cause mortality (adjusted OR 2.558, 95% CI 1.321-5.121, P = 0.006). Delayed transfer also significantly increased the risk of in-hospital complications, including brain herniation, hydrocephalus, ischemic stroke, and aneurysmal rebleeding. CONCLUSIONS: Arrival at an endovascular-capable hospital within 8 hours of symptom onset is independently associated with better functional outcomes, lower mortality, and fewer severe complications in aSAH patients. Optimizing prehospital transfer to achieve the 8-hour treatment window should be a priority goal in regional stroke network construction.