The investigation of the relationship between carotid intima-media thickness and vascular compliance in patients with coronary artery disease

Carotid artery intima-media thickness (IMT) is used as an indicator of atherosclerosis and a risk predictor for stroke and cardiovascular diseases. In macroscopic view, the atherosclerotic process constitutes changes in structure and mechanical function of vessels. The aim of this study was to investigate the relationship between carotid IMT and elastic property, or compliance, of the vessel. Eighteen patients (10 males, 8 females, mean age: 65.5+/-12.2) who received coronary angiography due to coronary artery disease (CAD) were enrolled in this study. The IMT was measured at left carotid artery 5 cm below bifurcation. The blood pressure was measured through a catheter placed in aortic arch and continuous pressure change was recorded simultaneously during performing of carotid sonography. A sequence of cross section images of carotid sonogram was recorded. An image analysis algorithm is developed for serial luminal area measurements. Then the estimation of compliance was computed according to Windkessel model. Regression analysis shows negative correlation (r=-0.704) between IMT and vascular compliance. The results correlate the elastic property and structural change of carotid artery during the process of atherosclerosis. This finding further support that IMT is a good parameter for evaluation of the severity of atherosclerosis.