Abstract WP82: Evaluation of Infarct Core Determination in Patients With Large Vessel Occlusion

Abstract

Introduction: Estimation of infarct core (IC) is a critical component in the evaluation of patients with large vessel occlusion (LVO) for endovascular stroke therapy (EST), but the optimal method to determine IC is uncertain. Methods: From our prospectively maintained institutional registry, we identified acute ischemic stroke (AIS) patients with LVO between 1/2018 and 2/2019. Patients were included if they underwent consecutively and technically adequate non-contrast CT, CT angiography (CTA), and CT Perfusion (CTP). ASPECTS was assessed by an experienced neuroradiologist. CTP IC was determined using RAPID. Final infarct volume (FIV) was determined by manual volume segmentation on DWI sequences from 24h MRI, but this analysis was limited to patients who underwent EST with TICI 2b/3 reperfusion within 120 minutes of presentation CT imaging, to minimize IC growth affecting the results. Correlation between IC measurements was calculated using Spearman p. Results are provided as median [IQR]. Results: Among 772 patients with LVO, 199 patients met inclusion criteria. Median age was 69 [59-79], 47% were female and 57% were white. Median NIHSS was 15 [9-21], the most common occlusion site was M1 MCA (55%). Median CT ASPECTS was 7 [6-9], median CTA ASPECTS was 6 [5-7], and median CTP-RAPID IC volume was 11 [0-47]. Presentation CT ASPECTS correlated with CTP-RAPID IC (Fig. 1A, r=-0.57; p<0.0001), as did CTA ASPECTS (Fig. 1B, r=-0.61; p<0.0001). Presentation CTA ASPECTS correlated with CTP-RAPID IC in patients presenting 0-6 hrs (CTA r=-0.69; p<0.0001) and 6-24 hrs (r=-0.58; p<0.0001). Among 90 patients with EST and TICI 2b/3, presentation CTA ASPECTS correlated better with FIV (r=-0.65; p<0.0001) compared to presentation CTP-RAPID (r=0.61; p<0.0001). Conclusions: In patients with LVO in the anterior circulation, CTA ASPECTS correlated well with CTP-RAPID IC in the early and late time windows, and was more reflective of 24h MRI findings in patients who received EST.