Abstract TP77: Impact of Time and Aspects on Clinical Core Mismatch in Large Vessel Occlusion Strokes

Abstract

Introduction: Patient selection for endovascular thrombectomy (EVT) for anterior circulation large vessel occlusion (LVO) strokes in the 6-24-hour time window is dependent on delineating clinical core mismatch (CCM) as defined by DAWN trial criteria. In contrast, patient selection in the early window (0-6 hours) can be performed using ASPECTS on CT head. We aim to determine the prevalence of DAWN-CCM in LVO strokes and the impact of time and ASPECTS. Methods: Retrospective analysis of large vessel occlusion [internal carotid and middle cerebral artery-M1] strokes at a CSC. Consecutive patients who underwent CT perfusion or MRI within 120 minutes of CT head were included in the study (treated and untreated). Ischemic core volume was assessed using RAPID [IschemaView] and ASPECTS using automated ASPECTS [Brainomix]. CCM was defined using DAWN trial criteria [DAWN-CCM: NIHSS ≥10 and core <31 ml, NIHSS ≥20 and core <51 ml]. Results: A total of 116 patients were included. Mean age was 71 ±14 and 62% were females. Mean ischemic core volume and median ASPECTS were 46 ±65 ml and 8 (6-9), respectively. In patients with NIHSS score ≥10 (98), 57% had DAWN-CCM in the 0-24-hour window. Proportion of patients with DAWN-CCM in 6-24-hour window was 70% (6-12 hours), 50% (12-18 hours), and 50% (18-24 hours) [p=0.35]. Proportion of patients with DAWN-CCM by ASPECTS group was 88% (ASPECTS 9-10), 64% (ASPECTS 6-8) and 13% (ASPECTS 0-5) [p=<0.01] (Figure 1). Probability of DAWN-CCM declines by 7% for every 2 hours increase in TLKW to imaging, and by 13% for every 1-point decrease in ASPECTS. Conclusion: Approximately 57% of LVO strokes have clinical core mismatch. LVO strokes with DAWN-CCM decline with increasing time and decreasing ASPECTS. ASPECTS alone may be sufficient to identify patients with DAWN-CCM in a resource limited setting and avoid time consuming advanced imaging.