Takahiro Shimizu, Yasuhiro Hasegawa, Yoshifumi Tsuboi, Toshihiro Ueda, Jinichi Sasanuma, Atsushi Tsuchiya, Ririko Takeda, Yohichi Imaizumi, Hajime Ono, Satoshi Inoue, Hiroyuki Nozaki, Takehiko Nagao, Hajime Nakanishi, Shojiro Kawaguchi, Kengo Yokomine, Hisanao Akiyama, Yoshihisa Yamano
Incorporating LVO-related items into prehospital stroke assessment substantially improved diagnostic precision for LVO, with MPSS+4 scale outperforming all other tools. The strong association between MPSS+4 scale scores and subsequent EVT implementation suggests that MPSS+4 scale may serve as a practical, clinically meaningful instrument for emergency medical technicians in prehospital triage of suspected acute stroke and identification of EVT candidates.
INTRODUCTION: Timely identification and transfer of patients with large vessel occlusion (LVO) to thrombectomy-capable stroke centers (TSCs) for endovascular thrombectomy (EVT) remains a major challenge in prehospital stroke care. This study evaluated the clinimetric performance of the Cincinnati Prehospital Stroke Scale (CPSS), the Maria Prehospital Stroke Scale (MPSS) and novel large vessel occlusion (LVO) screening scales created by integrating four LVO-related items into these established prehospital assessments.
METHODS: Using prehospital electronic records linked with hospital data across Kawasaki City from April 2023 to March 2024, we retrospectively analyzed whether the addition of aphasia, unilateral spatial neglect (USN), conjugate eye deviation, and atrial fibrillation (via ambulance ECG) improved prehospital LVO detection. These items were incorporated into the MPSS (MPSS+4 scale) and CPSS (CPSS+4 scale), and the predictive performance of four tools: CPSS, CPSS+4 scale, MPSS, and MPSS+4 scale was compared.
RESULTS: Among 1,653 transported patients, 207 (12.5%) had LVO. MPSS+4 scale demonstrated the highest predictive performance for LVO (AUROC 0.768). The addition of the four LVO-related items significantly improved LVO prediction for both MPSS and CPSS (p < 0.001 for each). Higher MPSS+4 scale scores were strongly and progressively associated with the likelihood of receiving endovascular therapy (EVT) after hospital arrival. Adjusted odds ratios increased from 2.97 to 100.59 for scores 2-9 compared with a score of 1.
CONCLUSION: Incorporating LVO-related items into prehospital stroke assessment substantially improved diagnostic precision for LVO, with MPSS+4 scale outperforming all other tools. The strong association between MPSS+4 scale scores and subsequent EVT implementation suggests that MPSS+4 scale may serve as a practical, clinically meaningful instrument for emergency medical technicians in prehospital triage of suspected acute stroke and identification of EVT candidates.