Objective:To derive a scale to improve pre-hospital detection of large vessel occlusion (LVO).
Background:There is a need to rapidly identify patients with acute ischemic stroke (AIS) due to LVO to improve access to endovascular therapy. Methods:We conducted a retrospective review of consecutive AIS patents enrolled in our prospective CSC registry (2008-2013). Patients were excluded if they were <18 years, non-ambulatory, or did not have MRA or CTA. Demographic and clinical
characteristics were compared between patients with and without LVO, defined as occlusion of the intracranial internal carotid artery, basilar artery, or middle cerebral artery. We compared our LVO Scale (LVOS) to the Cincinnati Prehospital Stroke Severity Scale (CPSSS) using ROC curves and determining their area under the curve (AUC). Results:A total of 1,663 patients were identified (mean age 62 years, SD 14, 45.6[percnt] women, 66.8[percnt] Black). LVO was present in 171 patients (10.3[percnt]). LVOS is a 6-point scale derived from NIHSS that includes 2 points for abnormal speech or language (NIHSS ≥1 for either), 1 point for gaze preference, (NIHSS ≥1), 1 point for facial asymmetry (NIHSS ≥1), 1 point for asymmetrical arm drift (RUE ≠ LUE), and 1 point for asymmetrical leg drift (RLE≠LLE). The LVOS had an AUC=0.688 (95[percnt] CI 0.736-0.640), compared to 0.646 (95[percnt] CI 0.693-0.598) for the CPSSS, and 0.678 (95[percnt] CI 0.0.723-0.633) for the NIHSS. A LVOS score ≥3 was 75.4[percnt] sensitive (95[percnt] CI 68.5-81.4) and 50.3[percnt] specific, positive likelihood ratio of 1.517 and negative likelihood ratio of 0.162 in predicting LVO. A CPSSS score ≥2 was 46.8[percnt] sensitive (95[percnt] CI 39.7-54.0) and 90.0[percnt] specific, positive likelihood ratio of 2.870 and negative likelihood ratio of 0.238 in predicting LVO.Conclusions:The LVOS compares favorably to the CPSSS in its ability to identify patients with LVO. Prospective prehospital validation is needed. Disclosure: Dr. Gropen has nothing to disclose. Dr. Boehme has nothing to disclose. Dr. Martin-Schild has received personal compensation for activities with Genentech. Dr. Albright has nothing to disclose. Dr. Perrin has nothing to disclose. Dr. Samai has nothing to disclose. Dr. Pishanidar has nothing to disclose. Dr. Janjua has nothing to disclose. Dr. Levine has nothing to disclose. Dr. Brandler has nothing to disclose. Dr. Rosenbaum has nothing to disclose.