Background: In 2015 guidelines regarding endovascular treatment (ET) of Large Vessel Occlusion (LVO) in acute ischemic stroke (AIS) were changed, leading to more patients being transferred to comprehensive stroke centers (CSC) for ET in selected patients, sometimes bypassing primary stroke centers. In the era of ET, there is a need for a simple yet sensitive pre-hospital tool to triage appropriate patients to CSCs. Many prehospital stroke scales predicting LVO are not in widespread clinical use because they are complex and not reliable. A recently published Denmark study demonstrated the PASS tool (Score range 0-3) for detecting LVO where a score of ≥2 was considered to be optimal in predicting LVO with sensitivity of 0.66.
Methods: A retrospective analysis of AIS patients with confirmed anterior circulation LVO by catheter-based cerebral angiography between January 2015 and June 2016 was conducted. PASS scores were calculated and correlated with NIHSS to assess for severity of the stroke.
Results: Fifty-four patients received ET during the study period. Those who had posterior circulation LVO were excluded, leaving 44 patients for final analysis. Only 5 (11.4%) patients had PASS score of <2 while 39 patients (88.6 %) had a score of ≥2 showing sensitivity of 0.89 for those patients with LVO. Average NIHSS scores were 11 (95% CI 6.6-15) for PASS <2 and 20 (95% CI 18.5-22.5) for PASS ≥2 (p value 0.005).
Conclusion: The PASS tool is simple, quick, and easy to perform and has high sensitivity in AIS patients with LVO. To assess its value and efficacy in real time it should be implemented into EMS systems and be performed in the pre-hospital setting.