Abstract 26: Timing The Optimal Transfer Modality For Suspected Large-vessel Stroke Patients: A Post-hoc Analysis Of The Racecat Trial

Abstract

Introduction: Current recommendations for regional stroke destination suggest that patients with an acute severe stroke should be triaged based on estimated time to arrival to a thrombectomy-capable center. We aimed to evaluate which time period available at the time that patient is triaged is able to discriminate which transfer modality should be chosen. Methods: We built and ordered logistic regression model adjusted for multiple comparisons with the RACECAT trial population using time periods available during triage: time from onset to emergency medical services (EMS) evaluation, estimated time of arrival to the thrombectomy-capable center and between centers distance. Estimated times were computed using a distance matrix API. Primary outcome was disability at 90 days, as assessed by the shift analysis on the modified Rankin score. Results: Of the 1369 patients evaluated, median time from onset to EMS evaluation, estimated time to arrival to the thrombectomy-capable center and between centers distances were 65 minutes (interquartile ratio (IQR) 43 to 138), 61 minutes (IQR 36 to 80) and 62 minutes (IQR 36 to 73), respectively. In patients transferred to local stroke centers, delay in EMS evaluation was associated with higher degrees of disability (for each 30 minutes delay, adjusted common odds ratio (acOR) 1.035, 97.5% confidence interval (CI) 1.005 to 1.066), with no influence in patients directly transferred to thrombectomy-capable centers (for each 30 minutes delay, acOR 0.999, 97.5% CI 0.981 to 1.018) (p interaction =0.048). In patients evaluated by EMS above 120 minutes after stroke onset, direct transfer to a thrombectomy-capable center was associated with lower degrees of disability (acOR 1.494, 95% CI 1.026 to 2.174). Conclusion: In the RACECAT trial, delay in EMS evaluation was associated with higher degrees of disability in patients transferred to local stroke centers and may serve as a potential biomarker for prehospital triage optimization.