Abstract TP74: Aspects Scoring Applied to CTA Source Images is Predictive of Final Infarct Volume and Good Functional Outcome

Abstract

Introduction: CTP and MRI are increasingly used to assess endovascular thrombectomy (EVT) candidacy in large vessel occlusion stroke. Unfortunately, availability of these advanced neuroimaging techniques is not widespread and this can lead to over-triage to EVT-capable centers. Hypothesis: ASPECTS scoring applied to computed tomography angiography source images (CTA-SI) will be predictive of final infarct volume (FIV) and functional outcome. Methods: We reviewed data from consecutive patients undergoing EVT at our institution for anterior circulation occlusion between 01/14 - 01/19. We recorded demographics, comorbidities, NIHSS, treatment time parameters, and outcomes as defined by mRS (0-2 = good outcome). Cerebrovascular images were assessed by outcome-blinded raters and collateral score, TICI score, FIV, and both CT and CTA-SI ASPECTS scores were noted. Patients were grouped by ASPECTS score into low (0-4), intermediate (5-7), and high (8-10) for some analyses. FIV was predicted using a linear regression with NIHSS, good reperfusion (TICI 2b/3), collateral score, CT to groin puncture, CT and CTA-SI ASPECTS as independent variables. After excluding those with baseline mRS≥2, a binary logistic regression was performed including covariates of age, NIHSS, good reperfusion, and diabetes (factors significant at p<0.05 on univariate analysis) to assess the impact of CTA-SI ASPECTS group on outcome. Results: Analysis included 137 patients for FIV and 102 for outcome analysis (35 excluded for baseline mRS≥ 2). Linear regression found CTA-SI ASPECTS (Beta -10.8, p=0.002), collateral score (Beta -42.9, p=0.001) and good reperfusion (Beta 72.605, p=0.000) were independent predictors of FIV. Relative to the low CTA-SI ASPECTS group, the high CTA-SI ASPECTS group was more likely to have good outcome (OR 3.75 [95% CI 1.05-13.3]; p=0.41). CT ASPECTS was not predictive of FIV or good outcome. Outcomes: In those undergoing EVT for anterior circulation occlusion, CTA-SI ASPECTS is predictive of both FIV and functional outcome, while CT ASPECTS predicts neither. CTA-SI ASPECTS holds promise as a lower-cost, more widely available option for triage of patients with large vessel occlusion. Further study is needed comparing CTA-SI ASPECTS to CTP parameters.