The Effect of Secondary Transfer Distance on Outcomes for Patients with Acute Ischemic Stroke: A Retrospective Cohort Study

Objective: The efficacy of mechanical thrombectomy (MT) and intravenous thrombolytic therapy (IVT) in patients with acute ischemic stroke (AIS) is time dependent. In this study, we investigated the effect of interhospital distance on outcomes for patients who received secondary transfer and were treated with MT and IVT to a comprehensive stroke center (CSC).
Material and Methods: We included patients with AIS who were secondarily transferred by road to our center, which is considered a CSC, between January 7, 2023, and January 7, 2024. We compared patients based on their distance from the treatment facility: those who were closer or further than 30 km and those who were closer or further than 90 km, in terms of the treatment they received (MT/IVT), three-month mortality, intracranial hemorrhage within 36 hours, and good neurological outcome.
Results: The study included 259 patients who were secondarily transferred from 29 different hospitals. In the <30 km group, the number of patients who received at least one MT/IVT therapy was at least one MT/IVT therapy in the ≥30 km group, 11 patients (7.6%) received at least one MT/IVT therapy (p=0.005). In multivariate analysis, patients transferred within 30 km were twice as likely to receive IVT/MT, compared to those transferred from longer distances.
Conclusion: The need to travel greater distances in the secondary transfer of patients with AIS decreases the chance of these patients receiving MT/IVT. Although three-month mortality, intracranial hemorrhage within 36 hours, and a good neurological outcome did not differ between near and far patients, increasing the number of CSC centers will increase the number of stroke patients who can access MT/IVT treatment options.

Keywords: Acute ischemic stroke, thrombectomy, thrombolytic therapy, emergency medicine