Abstract 030: Novel CT‐based Biomarkers for Patients with Anterior Circulation Stroke and Large Infarct Core

IntroductionPatients with acute ischemic stroke (AIS) due to anterior circulation large vessel occlusion (LVO) can benefit from endovascular therapy (EVT) regardless of the Alberta Stroke Program Early CT Score (ASPECTS). Net water uptake (NWU) is a novel biomarker that measures edema and tissue injury from the degree of hypoattenuation on non‐contrast CT (NCCT). Using our recently developed algorithm for automated NWU calculations, and a newly proposed Visual Hypodensity Score (VHS, Table 1), we evaluated whether these new biomarkers perform better than ASPECTS to distinguish which patients with large core will have functional independence at 90 days.MethodsFrom a prospectively collected registry of patients with LVO AIS, we included only subjects with initial NCCT ASPECTS 0‐5. We compared the baseline characteristics of the cohort. The primary outcome was the association between each biomarker and 90‐day modified Rankin Scale (mRS) 0 to 3, statistically evaluated using multivariable logistic regression. We also determined the interrater reliability of the VHS between two raters, one vascular neurologist and one neurointerventionalist.ResultsAmong 64 patients with anterior circulation LVO AIS and large infarct core, median age was 70 years [IQR 57‐76], 51.6% were female, median NIHSS was 21 [17‐25], median ASPECTS was 4 [3‐5], and 48.4% underwent EVT (Table 2). The interrater reliability of the VHS was moderate (kappa = 0.478) when evaluating individual brain regions. However, reliability was very good when evaluating whether the total VHS was within 5 points of each other (kappa = 0.806, Table 4 for details). Both the VHS and Average NWU showed a significant association with 90‐day mRS 0‐3 in multivariable logistic regression (Table 4). ASPECTS was not significantly associated. The VHS was significantly associated with NWU in linear regression (beta coefficient 0.723, p < 0.001).ConclusionThe new radiological scoring system, the Visual Hypodensity Score, and the novel automated NCCT net water uptake were both significantly associated with 90‐day mRS outcome for patients with LVO AIS and large infarct core. As previously suspected, ASPECTS was not associated. The VHS showed moderate interrater reliability here, which can be further investigated in a larger study with pre‐training for raters. NWU is another promising biomarker from NCCT, and our algorithm is the first open‐access application for this purpose. These new markers could serve as better tools t