Carotid Duplex-Derived Markers Across Angiographic Coronary Artery Disease Burden: A Pandemic-Era Real-World Cohort...

Background: Carotid atherosclerosis is a recognised manifestation of systemic vascular disease, and its association with coronary artery disease (CAD) has been well described. However, previous studies have largely been conducted under conventional diagnostic conditions and have focused on carotid plaque, intima-media thickness, or simple present-versus-absent stenosis classifications, rather than duplex-derived haemodynamic markers across the spectrum of angiographic CAD burden. The COVID-19 pandemic and post-pandemic period changed referral patterns and created more variable cardiovascular presentations, including symptoms that could resemble or mask obstructive CAD. Therefore, we investigated whether the established association between carotid stenosis severity and CAD burden remains detectable in a diagnostically heterogeneous real-world cohort, and whether routinely available carotid duplex haemodynamic parameters provide a clinically relevant signal in this setting. Methods: This single-centre, cross-sectional study was performed as a carotid-focused secondary analysis of the BG Study cohort. We included 902 consecutive patients who underwent invasive coronary angiography between 2021 and 2023 and carotid duplex ultrasonography during the same hospitalisation. CAD burden was defined according to the number of major coronary vessels with ≥70% diameter stenosis and classified as no CAD, one-vessel, two-vessel, or three-vessel disease. Carotid duplex parameters included peak systolic velocities of the common, internal, and external carotid arteries, as well as ICA stenosis severity graded according to NASCET criteria. Associations with CAD burden were assessed using a staged statistical approach combining χ² tests, Kruskal-Wallis tests with post hoc pairwise comparisons, Spearman correlation, inverse probability weighting, and ordered logistic regression. Results: The prevalence of measured ICA stenosis of any grade and severe ICA stenosis increased with greater CAD burden (both p < 0.001). Median PSV values of the bilateral ICAs and ECAs differed significantly across CAD groups on global intergroup testing. Post hoc pairwise analyses showed that significant corrected differences were concentrated between patients without CAD and those with multivessel or three-vessel CAD, particularly for ICA stenosis measures and bilateral ECA PSV. Spearman analysis demonstrated weak but statistically significant correlations between carotid parameters and CAD burden (ρ = 0.085-0.134). After inverse probability weighting, covariate balance was achieved, with all post-IPW standardised mean differences being <0.01. In ordered logistic regression (OLR) analysis, patient-reported history of carotid stenosis (OR 2.25, 95% CI 1.38-3.67; p < 0.001), right external carotid artery PSV per 10 cm/s (OR 1.31, 95% CI 1.09-1.57; p = 0.004), left ICA PSV per 10 cm/s (OR 1.17, 95% CI 1.01-1.36; p = 0.034), and left ICA stenosis per 10% (OR 1.24, 95% CI 1.11-1.39; p < 0.001) were independently associated with higher CAD burden. Exploratory ratio-based analyses showed that the ECA/CCA PSV ratio was associated with CAD presence and higher CAD burden, whereas the ICA/CCA ratio showed weaker associations; neither ratio-based index outperformed absolute ECA PSV. Conclusions: In this carotid-focused secondary analysis of a pandemic-era angiography cohort, carotid stenosis severity and duplex-derived haemodynamic parameters were independently but modestly associated with increasing angiographic CAD burden. These findings support carotid duplex markers as adjunctive indicators of systemic atherosclerotic burden rather than standalone tools for CAD detection or treatment decision-making. Future validation in vascular surgery populations is warranted to determine whether routinely available carotid duplex parameters can contribute to targeted cardiovascular risk recognition before major vascular procedures.