Abstract TP142: Perfusion Profiles to Identify Acute Extracranial Internal Carotid Artery Atherosclerosis-Related Stroke Prior to Endovascular Therapy

Abstract

Introduction: Perfusion imaging has been used to assess collateral status in patients with acute ischemic stroke secondary to anterior large-vessel occlusion. We aimed to evaluate the hypoperfusion intensity ratio (HIR), a surrogate of collateral status, in acute stroke secondary to extracranial atherosclerosis disease (AD) compared with extracranial non-AD etiologies prior to EVT. Methods: We retrospectively reviewed the data of consecutive EVT stroke patients in our prospectively collected registry from January 2019 to December 2022. Inclusion criteria: patients with anterior circulation stroke with concomitant extracranial internal carotid artery (ICA) disease with 70-100% stenosis per NASCET criteria and patients who underwent computed tomography perfusion (CTP) before EVT. Patients were divided into those with extracranial AD and non-AD based on clinical and radiological characteristics. HIR was calculated as the volume of ischemic brain tissue with a Tmax>10s divided by a Tmax>6s. A relative CBF<30% was also obtained. Multivariable regression was used to identify the HIR independently associated with extracranial ICA AD-related stroke; adjusted odds ratio with 95%CIs were calculated using the non-AD group as a reference. Results: Among all 624 EVT patients, 79 met inclusion criteria. Of these patients (21 women [36.2%]; median age 67 [60-75] years), 58 (72.5%) had extracranial ICA AD. Patients in the AD group had significantly lower CBF<30% (median 8ml [0-17] vs 19ml [9-36]), lower Tmax>10s (median 29ml [11-69] vs 68ml [38-117]), and lower HIR (median 0.27 [0.13-0.45] vs 0.49 [0.42-0.59]). There was no significant difference in time from last know well to CTP between groups. Lower HIR was independently associated with AD after adjusting for variables related to AD (Figure1). Conclusions: Low HIR values was a predictor of stroke secondary to extracranial ICA AD and could be helpful to differentiate from other non-AD etiologies prior to EVT.