Clinical utility of the RACE score for differentiating stroke from stroke mimics in the emergency department

Objective Rapid differentiation of true stroke from stroke mimics remains a major challenge during emergency department stroke evaluations. This study aimed to evaluate the clinical utility of the Rapid Arterial Occlusion Evaluation (RACE) score in distinguishing stroke from stroke mimics and identifying large vessel occlusion (LVO) in patients evaluated through an emergency department stroke activation workflow. Materials and methods This retrospective observational study analyzed routinely collected clinical data from consecutive adult patients evaluated through an emergency department stroke activation pathway. The RACE score was calculated at bedside as part of routine stroke workflow, and final diagnoses were established by vascular neurologists based on clinical evaluation and neuroimaging findings. Patients were classified as stroke or stroke mimic cases. The diagnostic performance of the RACE score for identifying LVO was assessed using receiver operating characteristic (ROC) curve analysis, and logistic regression was used to evaluate the association between RACE score and LVO. Results A total of 303 patients were included in the final analysis, of whom 133 (43.9%) were diagnosed with stroke and 170 (56.1%) were classified as stroke mimics. Patients with stroke were significantly older than those with stroke mimics (69.13 ± 12.59 vs. 61.67 ± 17.72 years, p = 0.001). The mean RACE score was significantly higher in stroke patients than in stroke mimics (3.15 ± 2.62 vs. 1.64 ± 1.91, p 0.001), and RACE scores ≥5 were more frequent in stroke cases (30.8% vs. 8.8%, p 0.001). LVO was identified in 46 patients (15.4%). Patients with LVO had significantly higher RACE scores than those without LVO (4.59 ± 2.63 vs. 1.85 ± 2.03, p 0.001), and 56.5% of LVO cases had RACE scores ≥5. Logistic regression analysis showed that higher RACE scores were significantly associated with the presence of LVO odds ratio (OR) 1.59, 95% Confidence Interval (CI) 1.38–1.83, p 0.001. Conclusion The RACE score may provide clinically useful information for differentiating stroke from stroke mimics during emergency department evaluations. Higher RACE scores were associated with confirmed stroke and the presence of LVO, suggesting that the RACE score may serve as a practical adjunct to bedside neurological assessment within acute stroke workflows.