Carotid Bifurcation Angle as a Marker for Intracranial Atherosclerosis Risk

Introduction The geometric configuration of the carotid bifurcation may influence local hemodynamics, plaque deposition, and vascular remodeling. While conventional risk factors for intracranial atherosclerotic disease (ICAD) are well established, the role of carotid bifurcation angle has been underexplored. Methods We retrospectively analyzed patients undergoing diagnostic cerebral angiography for carotid artery disease or stenting between 2024‐2025. Carotid bifurcation angles were measured bilaterally from angiographic images using standardized outer‐wall landmarks by a single blinded reviewer. ICAD was defined as ≥50% stenosis in any intracranial vessel arising from the carotid circulation. Patients were stratified by ICAD status, and carotid angles were compared using t‐testing and logistic regression adjusted for conventional vascular risk factors. Results A total of 124 patients were included (mean age 72 years, 69% male); 22 (17.7%) had ICAD. Mean carotid bifurcation angle was significantly greater in ICAD‐positive patients (103° ± 16.3) compared to ICAD‐negative patients (41° ± 23.0, p<0.0001). NIHSS at presentation was higher in the ICAD group (4.5 vs 2.1, p=0.04). Coronary artery disease was paradoxically more frequent in the non‐ICAD group (72.5% vs 31.8%, p<0.001). Conclusions In this single‐center cohort, wider carotid bifurcation angles were strongly associated with the presence of ICAD, independent of conventional vascular risk factors. These findings suggest that carotid bifurcation angle may represent a novel anatomical marker of ICAD risk. Validation in larger, prospective multicenter studies is warranted to determine its potential role in risk stratification and prevention strategies.