ABSTRACT NUMBER: ESOC2026OT17 PREHOSPITAL BIOMARKER AND PHONE CALL-BASED DETECTION FOR ISCHAEMIC STROKE THROMBECTOMY (PRONTO): WORK IN PROGRESS

Abstract Background and aims Large vessel occlusion (LVO) stroke is effectively treated by time-critical thrombectomy but procedures are only available at regional comprehensive stroke centres. Many eligible patients need interhospital transfer which creates delays. Direct admission to comprehensive centres may improve outcomes but no accurate triage tool exists. Methods This pre-hospital project is evaluating whether lateral flow biomarker tests combined with specific clinical information communicated from ambulance practitioners to stroke teams can detect LVO stroke and those LVO patients which are potentially suitable for thrombectomy. Results Study design: Prospective observational cohort study. Study setting: Ambulance services and hospital stroke units. Study population: Adults with at least one FAST symptom presenting to an ambulance service within 6 hours of onset. Study processes: Two portable lateral flow assays use fingerprick capillary blood to detect D-dimer and Glial Fibrillary Acidic Protein (Upfront diagnostics). Ambulance practitioners communicate the lateral flow result and specific clinical information during a routine pre-alert call to the nearest stroke team. Standard rules assign outcomes of LVO/non-LVO and suitable/not suitable for direct comprehensive centre admission. Reference standards: Independently adjudicated standard CT brain +/- CT/MR angiography plus expert clinician opinion establishes the presence of LVO or non-LVO condition. Suitability for direct comprehensive centre admission is pre-specified as: confirmed LVO stroke, NIHSS ≥ 6, pre-stroke mRS scale 0-2 and no pre-existing brain tumour, dementia or advanced cancer diagnosis. Main analyses: Sensitivity, specificity, negative and positive predictive values for identification of LVO stroke and suitable for direct comprehensive centre admission. Sample size: 496 participants. Conflict of interest