Correlation of Plaque-RADS with Luminal Stenosis and Ankle-Brachial Index in CLTI Patients

Introduction. This cross-sectional study analyzed 260 carotid arteries in 130 consecutive patients with CLTI undergoing preoperative duplex ultrasonography at a tertiary vascular center between January 2021 and December 2023. To correlate quantitative carotid stenosis with qualitative Plaque-RADS categories using duplex ultrasonography in patients with chronic limb-threatening ischemia (CLTI), and to evaluate whether plaque phenotype is associated with systemic markers of disease severity, specifically the Ankle-Brachial Index (ABI) and TASC II classification. Methods. Stenosis was graded according to NASCET criteria. Plaque morphology was classified using the Plaque-RADS system (Types 1–4c). The Ankle-Brachial Index (ABI) and anatomical complexity of lower-extremity disease (TASC II classification) were recorded. Statistical analyses included the chi-squared test and Fisher's exact test as appropriate. Results. The mean patient age was 75.4 years. Stable plaque phenotypes (Plaque-RADS types 1, 2, and 3a) were overwhelmingly associated with stenosis <70% (90%, 100%, and 85.7% of cases, respectively; P <.001). Patients with ABI >0.3 more frequently harbored lower-risk plaque types (P = .038). Higher anatomical complexity (TASC C/D) was associated with a significantly greater prevalence of high-risk plaque types 3a, 3b, 4a, and 4b (50%, 66.7%, 75%, and 100%, respectively; P=.004–.005). Conclusion. While stenosis severity largely correlates with plaque morphological risk, a subset of patients with non-obstructive lesions harbors high-risk plaque phenotypes that would be missed by hemodynamic criteria alone. Plaque-RADS should be integrated as a complementary stratification tool alongside luminal grading in patients with systemic atherosclerosis.