Abstract WP102: Side-to-side Relative Reduction In End-diastolic Velocity Of The Common Carotid Artery For Emergent Discrimination Of Anterior Circulation Large Vessel Occlusion

Abstract

Introduction: Side-to-side relative reduction in end-diastolic velocity (EDV) of the common carotid artery (CCA) may discriminate ipsilateral anterior circulation large vessel occlusion (LVO), which will contribute faster patient triage for reperfusion therapy. We evaluated the discriminative accuracy of this simple sonographic index for anterior circulation LVO in acute stroke population, including intracerebral hemorrhage (ICH). Methods: Among patients with acute stroke admitted to our institute between 2016-2018, those who underwent both carotid ultrasonography and head MRA or CTA within 24 hours after last known normal time were reviewed. Relative EDV reduction was calculated as a ratio by dividing the CCA EDV lower side by the EDV higher side. Anterior circulation LVO was defined as occlusion of the internal carotid artery (ICA) or M1 segment of the middle cerebral artery on the lower EDV side. Discriminative performance of relative EDV reduction for anterior circulation LVO was assessed by receiver operating characteristics analysis. Results: A total of 688 patients (411 males; median age 77 years; 87 with anterior circulation LVO) were analyzed. When compared to no occlusion, value of relative EDV reduction was remarkably lower in ICA occlusion, followed by that in M1 occlusion (Figure). Area under the curve (AUC) of relative EDV reduction for ICA occlusion was 0.96 (95% confidence interval [CI] 0.94-0.99) with an appropriate cut-off value of 0.50 (sensitivity 94%, specificity 94%). When the discrimination target was set to anterior circulation LVO, the AUC was 0.78 (95% CI 0.72-0.85) with an appropriate cut-off value of 0.67 (sensitivity 69%, specificity 83%). At this cut-point, 51% of patients with M1 occlusion was classified as false negative. Conclusions: The discriminative performance of the relative CCA EDV reduction in acute stroke population was excellent for ICA occlusion and acceptable for anterior circulation LVO.