Abstract A011: SymptomatiC stratificatiOn based on moRphological fEatures of carotid WEB (SCORE-WEB)

Introduction: Carotid web (CaW) is an underrecognized cause of cryptogenic stroke, though many cases are incidentally detected. Morphologic determinants of symptomatic presentation remain unclear. Hypothesis: We hypothesized that selected morphologic features could distinguish symptomatic from incidental CaWs and be combined into a practical risk score. Methods: We conducted a cross-sectional analysis of patients with CaW diagnosed at a comprehensive stroke center (2014–2024). CaWs were deemed symptomatic if associated with ipsilateral ischemic events without competing etiologies. High-resolution computed tomography angiography with thin-slice reconstructions was used for morphologic assessment. Five parameters, i) pre-web angle, ii) pocket area, iii) lesion length, iv) bulb caliber, and v) distal caliber, were selected based on physiologic plausibility and prior evidence. A simplified morphological risk score (SCORE-CAW) ( Table 1 ) was derived. Each variable was discretized into one to five strata. Cutoffs were defined at points where symptomatic rates shifted meaningfully (0.1 mm for size, 0.5 mm2 for area, 1° for angle), then consolidated into clinically practical thresholds. Adjacent intervals were merged to preserve monotonicity. SCORE-CAW ranges from 5–16 points, with higher scores reflecting greater symptomatic risk. Discrimination was assessed using area under the receiver operating characteristic curve (AUC). Results: Among 110 patients (80 symptomatic, 30 asymptomatic; median age 50, 69% women), symptomatic CaWs showed smaller pre-web angles, larger pocket areas, longer lesion length, smaller bulb calibers, and larger distal calibers. The multivariable model achieved an AUC of 0.803 ( Figure 1 ). The simplified SCORE-CAW preserved accuracy (AUC 0.824), with monotonic increases in symptomatic risk across strata ( Figure 2 ). A threshold ≥12 points yielded sensitivity 0.54, while ≤7 points reliably excluded symptomatic cases (sensitivity 0.99). Conclusions: SCORE-CAW, based on five reproducible morphologic features, accurately discriminates symptomatic from incidental CaWs. This pragmatic tool offers a standardized framework for risk stratification and may guide patient selection for preventive interventions. Multicenter validation is warranted.