Abstract 073: ASPECTS decay during interfacility transfers in patients with large vessel occlusion

Background Some patients with large vessel occlusion (LVO) are first evaluated at primary stroke centers (PSCs) before transfer to a comprehensive stroke center (CSC) for Endovascular thrombectomy (EVT). A subgroup of those patients experiences rapid infarction growth during transfer limiting the benefit from intervention. We evaluated the incidence, predictors, and outcomes of imaging decay of patients with LVO transferred for EVT. Methods A retrospective analysis of all patients with anterior circulation LVO transferred for EVT. ASPECTS decay was defined as 2 ASPECTS points decrement at CSC compared to PSC. Primary outcome was 90 day home time. Results 182 (44.5% female) patients met the inclusion criteria. Median (IQR) time between baseline and follow up CTs was 250.5 (163‐324.25) minutes. Out of the 182 patients, 66 patients (36%) had ASPECTS decay, and 32/66 patients (48%) underwent EVT. Collateral score was strongly associated with the ASPECTS decay (OR= 0.29, [0.19‐0.46], p<0.001) in multivariate logistic regression. Patients with ASEPCTS decay have a significant lower rate of 90‐day home‐time (P<0.001) and higher risk of 90‐day mortality (P<0.001), and in hospital death (P=0.03). In patients with ASPECTS decay, performing EVT was not associated with improved 90‐day home time ( β = 0.19, [‐3.2 ‐27.8], p=0.12). Conclusions For patients with LVO transferred for thrombectomy, a third of our patients developed ASPECTS decay. Collateral blood flow was the main determinant of ASPECTS decay during inter‐facility transfers. Decay is strongly associated with poor functional outcomes.