Abstract WP75: Ischemic Core Volume Modifies the Association Between ASPECT Score and Clinical Outcome

Background: While CT ASPECT scores predict clinical outcomes, the association between the scores and ischemic lesion volume is not linear as the subcortical regions involve small volumes while the cortical areas often involve large volumes. We evaluated whether ASPECTS and CTP ischemic core volume, modify each other’s association with clinical outcome in patients undergoing endovascular thrombectomy (EVT). Methods: In a prospective multicenter cohort study of imaging selection (SELECT), anterior circulation large vessel occlusion patients up to 24 hours from last known well were enrolled at 9 centers. All patients received a unified imaging profile (NCCT, CTA, and CTP with ischemic core volume [rCBF Results: Of 445 enrolled, 284 received EVT and are included in this analysis. Median (IQR) ASPECTS was 8 (7-9), median (IQR) ischemic core volume 10 ml (0-33). Both ASPECTS and ischemic core volume independently correlated with good outcome after EVT. For ASPECTS, the probability of good outcome decreased by 14% per point (aOR 1.18, 95% CI 1.01-1.38, p=0.03). For CTP mRS 0-2 probability dropped by 25% for each 10 ml increase in core volume (aOR 0.75, 95% CI 0.67-0.84, P Conclusion: ASPECTS association with clinical outcome after EVT was strongly modified by ischemic core volumes. Favorable outcomes were achieved in patients with small ischemic core volume despite low ASPECTS.