Abstract Number: Esoc2026a2107 Diagnostic Accuracy of the Turkish Version of the Race Score for Large Vessel Occlusion Triage and Differentiation of Stroke Mimics

Abstract Background and aims Delayed recognition of large vessel occlusion (LVO) prolongs access to therapy and worsens outcomes. This study evaluated the adaptability of the Turkish version of the Rapid Arterial Occlusion Evaluation (RACE) score for LVO triage and its ability to differentiate stroke mimics in a hospital emergency medical services (EMS) setting. Methods This single-center study at a comprehensive stroke center serving five to six million people integrated the translated RACE score into clinical practice. A total of 355 patients presenting with suspected stroke were enrolled. Senior medical students applied the score during acute stroke workflows. RACE assessments were compared with neuroimaging-confirmed diagnoses. Diagnostic performance—sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV)—was evaluated at multiple thresholds. Results At a RACE cut-off value of ≥5, sensitivity, specificity, positive predictive value, and negative predictive value were 62.1%, 87.2%, 52.6%, and 91.0%, respectively. A total of 170 stroke mimic cases were classified into four main subgroups based on clinical severity and etiology: critical non-neurological disease (CNND), non-critical non-neurological disease (NCNND), critical neurological disease (CND), and non-critical neurological disease (NCND). RACE scores in the NCNND group were predominantly clustered between 0 and 1. Notably, 42.9% of patients with intracerebral hemorrhage (ICH) had RACE scores ≥5. Conclusions The RACE score assists in rapid LVO triage and exclusion of non-stroke conditions during hospital EMS workflows. Although higher false-positive rates in ICH patients limit prehospital bypass strategies, this finding may facilitate expedited intrahospital diagnostic workup. Conflict of interest "Name of author: nothing to disclose". Figure 1 - belongs to Results