The Clinical Predictive Score for Prehospital Large Vessel Occlusion Stroke: A Retrospective Cohort Study in the Asian Country.

Background: Large vessel occlusive (LVO) stroke causes severe disabilities and occurs in more than 37% of strokes. Reperfusion therapy is the gold standard of treatment. Studies proved that endovascular thrombectomy (EVT) is more beneficial and decreases mortality. This study aimed to evaluate the factor associated with LVO stroke in an Asian population and to develop the scores to predict LVO in a prehospital setting. The score will hugely contribute to the future of stroke care in prehospital settings in the aspect of transferal suspected LVO stroke patients to appropriate EVT-capable stroke centers.

Methods: This study was a retrospective cohort study using an exploratory model at the emergency department of Ramathibodi Hospital, Bangkok, Thailand, between January 2018 and December 2020. We included the stroke patients aged >18 who visit ED and an available radiologic report representing LVO. Those whose stroke onset was >24 hours and no radiologic report were excluded. Multivariable logistic regression analysis developed the prediction model and score for LVO stroke.

Results: A total of 252 patients met the inclusion criteria; 61 cases (24%) had LVO stroke. Six independent factors were significantly predictive: comorbidity with atrial fibrillation, clinical hemineglect, gaze deviation, facial palsy, aphasia, and cerebellar sign abnormality. The predicted score had an accuracy of 92.5%. The LVO risk score was categorized into three groups: low risk (LVO score <3), moderate risk (LVO score 3-6), and high risk (LVO score >6). The positive likelihood ratio to predicting LVO stroke were 0.12 (95% CI 0.06-0.26), 2.33 (95% CI 1.53-3.53) and 45.40 (95% CI 11.16-184.78), respectively.

Conclusion: The Large Vessel Occlusion (LVO) Risk Score provides a screening tool for predicting LVO stroke. A clinical predictive score of ≥3 appears to be associated with LVO stroke.