Abstract 18: External Validation of the RACE Scale After Its Implementation in the Stroke Code Protocol in Catalonia

Abstract

Introduction: We aimed to revalidate the RACE scale as a pre-hospital tool to identify patients with large vessel occlusion (LVO) and patients receiving endovascular treatment (EVT) after its implementation in the Stroke Code protocol of Catalonia (7.5 M inhabitants). Methods: We used data from the CICAT registry (Feb to Jun 2016), a government-mandated, prospective, hospital-based dataset that includes all Stroke Code activations. CICAT is linked to the EMS database to capture information about the pre-hospital care. RACE score, pre-hospital and in-hospital delays, final diagnostic, presence of LVO (TICA, MCA M1 or M2, tandem or basilar occlusion) and revascularization treatment were registered. Sensitivity, specificity and area under the curve (AUC) to identify LVO and patients receiving EVT were calculated for the pre-established cut off RACE≥5. Results: From the 1600 stroke code activations we included in the study the 962 patients in which the RACE scale was available (60%). The RACE scale showed a strong correlation with the NIHSS evaluated at hospital arrival (r=0.74, p<0.001). Distribution of final diagnosis and median RACE scores were: ischemic with LVO (22.1%), RACE 7 [5-8], ischemic without LVO (29.3%), RACE 3 [2-5], hemorrhagic(17.8%), RACE 6 [4-7], mimic(21.0%), RACE 2 [1-4] and transient ischemic attack(9.7%), RACE 3 [1-5]. A RACE cut-off score ≥5 showed sensitivity 0.80 and specificity 0.63 to detect LVO (AUC 0.78, Youden index 0.45), similar to results obtained in the validation study. In patients with RACE≥5 the rates of LVO (42% Vs 9%;p<0.001) and EVT (21% Vs 6%;p<0.001) were significantly higher than in patients with RACE<5. Conclusion: This large validation study performed after implementation of the RACE scale in the real clinical practice in the region of Catalonia confirms RACE accuracy to identify candidates to EVT. A RACE score ≥5 detected 77% of patients that finally underwent EVT confirming the scale as a valuable tool at the prehospital level.