on behalf of the catalan stroke code and reperfusion consortium (cat-scr) Ischemic Stroke To cite: carrera D, gorchs M, Querol M, et al. J NeuroIntervent Surg epub ahead of print: [please include Day Month Year].AbSTrACT background and purpose Our aim was to revalidate the race scale, a prehospital tool that aims to identify patients with large vessel occlusion (lVO), after its region-wide implementation in catalonia, and to analyze geographical differences in access to endovascular treatment (eVT). Methods We used data from the prospective cicaT registry (stroke code catalan registry) that includes all stroke code activations. The race score evaluated by emergency medical services, time metrics, final diagnosis, presence of lVO, and type of revascularization treatment were registered. sensitivity, specificity, and area under the curve (aUc) for the race cut-off value ≥5 for identification of both lVO and eligibility for eVT were calculated. We compared the rate of eVT and time to eVT of patients transferred from referral centers compared with those directly presenting to comprehensive stroke centers (csc). results The race scale was evaluated in the field in 1822 patients, showing a strong correlation with the subsequent in-hospital evaluation of the national institute of health stroke scale evaluated at hospital (r=0.74, P<0.001). a race score ≥5 detected lVO with a sensitivity 0.79 and specificity 0.62 (aUc 0.76). Patients with race ≥5 harbored a lVO and received eVT more frequently than race <5 patients (lVO 35% vs 6%; eVT 20% vs 6%; all P<0.001). Direct admission at a csc was independently associated with higher odds of receiving eVT compared with admission at a referral center (Or 2.40; 95% ci 1.66 to 3.46), and symtoms onset to groin puncture was 133 min shorter. Conclusions This large validation study confirms race accuracy to identify stroke patients eligible for eVT, and provides evidence of geographical imbalances in the access to eVT to the detriment of patients located in remote areas. MeThodS Study setting

The studied biomarkers were not sufficient for an accurate differential diagnosis of stroke in the hyperacute setting. Additional discovery of new biomarkers and improvement on laboratory techniques seem necessary for achieving a molecular diagnosis of stroke.