Implementation and Validation of Field Assessment Stroke Triage for Emergency Destination (FAST-ED) in a Rural EMS Region.

Abstract

Objectives: Prehospital identification of large vessel occlusion (LVO) stroke patients is crucial for timely mechanical thrombectomy (MT). The Field Assessment Stroke Triage for Emergency Destination (FAST-ED) score effectively predicts LVOs, but its utility in rural, multi-state emergency medical services (EMS) systems remains unexplored.

Methods: This prospective cohort study included ground prehospital stroke alerts in Vermont, New Hampshire, and Maine from July 2021 to December 2022. Patients with a prehospital FAST-ED score recorded were enrolled. LVO was confirmed by CT angiography. Our primary outcome was the accuracy of LVO identification with FAST-ED scores. Secondary outcomes included the predictiveness of the prehospital FAST-ED score for Thrombectomy Capable Center (TCC) appropriateness, MT, and 30-day mortality.

Results: This study included 370 patients. The overall LVO prevalence was 23.2% (n = 86). A positive FAST-ED score demonstrated a sensitivity of 73% (95% CI, 63%-82%) and specificity of 61% (95% CI, 55%-66%) for presence of LVO. The PPV was 36% (95% CI, 29%-44%) and the NPV was 88% (95% CI, 83%-92%). Positive FAST-ED scores were associated with significantly higher rates of TCC appropriateness (46% vs 10%, p < 0.0001), mechanical thrombectomy (19% vs 6%, p < 0.001) and 30-day mortality (24% vs 6%, p < 0.001).

Conclusions: The FAST-ED score can be implemented by prehospital personnel to triage patients to a TCC when faced with options for hospital destination in a rural setting. This study supports incorporating FAST-ED scoring in rural protocols for potential diversions to TCCs. Further research should be done to better characterize the effects of prehospital diversion on time to thrombectomy, functional outcomes, and mortality.