Low Carotid Artery Wall Shear Stress is Associated with Significant Coronary Artery Disease in Patients with Chest Pain

Aim: To investigate the relationships among carotid wall shear stress (WSS), carotid intima-media thickness (IMT), and total plaque area (TPA) using ultrasound (US) in the common carotid artery (CCA) in patients with suspected coronary artery disease (CAD). Methods: Carotid artery US was performed in 950 patients with suspected CAD, and mean IMT, TPA, and hemodynamic parameters of CCA, including peak and mean WSS, were measured. We analyzed the carotid parameters according to the presence of CAD and the predictive values of WSS and TPA for the presence of significant CAD. Results: Compared with patients without CAD (n 667), patients with CAD (n 283) demonstrated significantly higher mean IMT (0.66 vs. 0.74 mm, p < 0.001), TPA (0.13 vs. 0.20 cm(2), p = 0.002), and beta stiffness index (5.12 vs. 5.60, p = 0.045) and lower mean WSS (2.59 vs. 2.23 dyne/cm(2), p < 0.001). Mean WSS revealed significant negative correlations with the beta stiffness index (r = -0.116, p < 0.001), mean IMT (r = -0.193, p = 0.007), and TPA (r = -0.296, p < 0.001). Mean WSS, mean IMT and TPA revealed significant difference with respect to CAD severity (for all p < 0.001). Age [OR, 1.038 (95% CI, 1.010 - 1.066), p = 0.007], diabetes mellitus [1.606 (1.194 - 1.807), p = 0.011], smoking [1.758 (1.564-1.866), p < 0.001], carotid TPA [2.615 (1.320-5.183), p = 0.006], and mean WSS [0.554 (0.371 - 0.838), p = 0.005] were significant CAD predictors. Conclusions: In patients with chest pain, low local shear stress and high plaque burden in the carotid arteries were significant CAD predictors. These findings indicate that carotid WSS has a role as an index of atherosclerosis and serves as a predictor of significant coronary atherosclerosis.