Abstract WP239: Potential Impact of C-STAT for Prehospital Stroke Triage up to 24 Hours on a Regional Comprehensive Stroke Center

Abstract

Introduction: Thrombectomy may be beneficial up to 24 hours since last normal. We previously reported the feasibility of the Cincinnati Stroke Triage Assessment Tool (C-STAT) for prehospital triage. We estimated the potential impact of the expanded thrombectomy time window on overtriage to our comprehensive stroke center (CSC). Methods: From June-November, 2015, Cincinnati Fire Department (CFD) providers performed C-STAT after a positive prehospital “FAST: face, arm, speech, time” stroke screen in suspected stroke/TIA patients. Preferential triage was not employed at that time. Final diagnoses and presence/absence of large vessel occlusion (LVO) was ascertained via chart review. Impact on triage volumes by positive C-STAT up to 24 hours from last seen normal was estimated. Results: Of 158 patients with prehospital suspicion for stroke/TIA, 105 were FAST positive, within 24 hours of onset, and had complete C-STAT and clinical data available. The Table shows the characteristics of enrolled subjects. Forty six percent (17/37) of C-STAT+ patients were non-strokes. C-STAT sensitivity and specificity for LVO were: 71% (36, 92) and 69% (55, 80). Within six hours of symptom onset, 57% (12/21) of C-STAT+ prehospital suspected stroke patients were not triaged to the CSC. From 6-24 hours, 62% (10/16) C-STAT+ patients were not triaged to the CSC. Overall, preferential triage using C-STAT would increase transport of prehospital suspected stroke cases to the CSC by 11% (12/105) within six hours and 21% (22/105) within 24 hours. Conclusions: Within CFD, preferential triage using C-STAT would increase transport of prehospital suspected stroke cases to the CSC by 11% within six hours and an additional 10% within 24 hours. Almost half of prehospital C-STAT+ cases were non-strokes. More stringent criteria for CSC triage (e.g., exclusion of seizure/hypoglycemia) may improve performance. Acceptable overtriage rates for prehospital suspected stroke should be established.