Abstract TP298: Early and Extended Time Window Prehospital Large Vessel Occlusion Scale Application: A Retrospective Analysis

Abstract

Introduction: Multiple trials have validated thrombectomy as a viable option in acute stroke patients with Anterior Large Vessel Occlusion (LVO). As a consequence, there has been a dire need for proper routing of patients. Currently, there are established prehospital scales but limited evidence for late window LVO screening. Methods: We assessed 748 patients, from June 2016 to June 2018, who presented within a 24 hour last known well time (LKWT) and were assessed with RAPID neuroimaging and CT angiography. An analysis was completed of patients with LVOs versus those without a LVO. Patient’s medical records were reviewed to obtain their baseline presenting NIHSS, which was used to derive 14 corresponding LVO stroke scale values. Patients excluded had absent NIHSS values and unknown LKWT. LVO stroke scales excluded evaluated history of seizures, seizure at onset, grip strength, or age > 45 as criteria. Results: A total of 748 consecutive patients (67 years, 51% male, 49% African American) were analyzed with 110 confirmed anterior LVO, 476 patients in the 0-6-hour (hr) window, and 272 in the 6-24-hr window. In the 0-6-hr window, the top three scales in sensitivity were ranked in order of C-STAT (0.83) > MaPSS (0.81) > VAN (0.80). In the 6-24-hr window, the top three scales that ranked equally in sensitivity were MaPSS (0.75), VAN (0.75), and C-STAT (0.75). In the 0-6-hr window, the top three scales in specificity were ranked in order of 3-ISS (0.88) > MiPSS (0.76) > FPSS (0.72) = sNIHSS-8 (0.72). In the 6-24-hr window, the top three scales in specificity were ranked in order of 3-ISS (0.90) > MiPSS (0.84) > FPSS (0.83). (See Table 1). Conclusion: To correctly identify as many patients as possible in the pre-hospital setting with the available scales, the data suggests that C-STAT, VAN, and MaPSS are effective within the early and late windows. To reduce routing of incorrect prehospital LVO identification, the data suggests that 3-ISS, MiPSS, and FPSS are effective in the early and late windows