IntroductionIntracranial artery calcification (ICAC) is a common finding on computed tomography (CT) in patients presenting with large vessel occlusion acute ischemic stroke (LVO-AIS) and could serve as a useful biomarker of intracranial atherosclerosis and altered intracranial vessel pliability in patients undergoing endovascular thrombectomy (EVT). MethodsThis was a retrospective cohort study analyzing consecutive patients undergoing CT head prior to EVT between 2016 and 2020. Extent of ICAC proximal to the target vessel was scored using a validated grading scale examining thickness and circumferential extent of calcifications. The relationship between 3 levels of ICAC burden and procedural, clinical, and safety outcomes was analyzed. ResultsAmong 86 patients meeting inclusion criteria, ICAC of any degree was present in 72.1%. Median ICAC score was 3 [IQR 0-4]. There was a U-shaped association between ICAC score and successful reperfusion: 90.9%, 65.7%, and 94.4% in the low, intermediate, and high ICAC score groups, respectively (p = 0.008). Use of rescue intervention, most often angioplasty and stenting, was greatest in the high ICAC score group: 3.0% vs. 5.7% vs. 22.2% (p = 0.05). Functional independence at 90 days did not differ significantly among groups (41.7% vs. 31.0% vs. 15.4%, p = 0.26), nor did rates of symptomatic intracranial hemorrhage (15.2% vs. 14.3% vs. 16.7%, p = 0.97). ConclusionsICAC is seen on CT in nearly three-quarters of patients with LVO-AIS. Extent of ICAC has a U-shaped association with successful reperfusion, in part due to more frequent use of rescue interventions in patients with extensive ICAC.