Introduction The diagnosis of large vessel occlusion (LVO) with underlying intracranial atherosclerotic disease (ICAD) before endovascular treatment (EVT) continues to be a challenge.

Aim We aimed to analyze baseline clinical-radiological variables associated with ICAD-LVO before EVT.

Methods Retrospective study of consecutive patients with stroke treated with EVT from January-2020 to April-2022. We included anterior intracranial LVO (ICA, MCA-M1,2) and analyzed baseline clinico-radiological variables associated with ICAD-LVO. We evaluated the diagnostic value of a multivariate regression model and a weighted scale to diagnose ICAD-LVO before EVT. ICAD-LVO was defined as the presence of angiographic residual stenosis or a trend to re-occlusion during EVT.

Results Of 338 patients included, 28 patients (8.3%) presented with ICAD-LVO. After adjusting for confounders, absence of atrial fibrillation (OR 10.19, 95%CI 1.12–86.6; p=0.033), lower hypoperfusion intensity ratio (HIR [Tmax>10s/Tmax>6s ratio], OR 0.02, 95%CI 0.00–0.41; p=0.013), presence of symptomatic intracranial artery calcification (IAC, OR 6.94, 95%CI 1.69–28.45, p=0.007), presence of a more proximal occlusion (ICA, MCA-M1: OR 3.16, 95%CI 1.03–9.67; p=0.044) and smoking (OR 3.26, 95%CI 1.21–8.75; p=0.019) were associated with ICAD-LVO. A weighted scale based on the covariates such as HIR (3points), absence of AF (2p), IAC (1p), occlusion location (1p) and smoking (1p) predicted ICAD-LVO with good accuracy (AUC=0.88, 95%CI 0.83–0.94; p<0.001).

Conclusion A combination of clinical and radiological variables available before EVT can accurately predict the presence of an ICAD-LVO. The ICAD-Scale could be useful to perform a rapid assessment of underlying etiology and suggest specific pathophysiology-based measures (adjunctive pharmacological treatment, angioplasty and/or intracranial stenting).

Disclosure of Interest Dr Molina reported receiving personal fees from AstraZeneca for consultant services outside the submitted work. Dr Tomasello reported receiving personal fees from Anaconda Biomed, Balt, Medtronic, Perflow, and Stryker outside the submitted work. Dr Ribo reported receiving personal fees from Anaconda Biomed, AptaTargets, Cerenovus, Medtronic, Methinks, Philips, Sanofi, Stryker, Balt, and Rapid AI outside the submitted work; he has a modest ownership of NoraHealth. The other authors report no conflicts. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.