The relationship between mechanical properties of carotid artery and coronary artery disease

Carotid intima-media thickness (CIMT) is a useful indicator of coronary artery disease (CAD). The relation between functional changes of the common carotid artery (CCA) and CAD is unclear. This study investigated the relationship between CCA strain and CIMT in the assessment of CAD.

Within a 1-month period, 121 patients underwent coronary angiography and ultrasonography of the CCA. Circumferential strain and strain rate were measured in the left CCA by 2D ultrasonography with a speckle tracking method and CIMT was measured using standard techniques. Adequate images were obtained in 104 patients (59 ± 11 years, 39 females), of which 46 had CAD. Strain and strain rate were negatively correlated with CIMT and were positively correlated with the number of risk factors. CIMT was significantly higher, and strain and strain rate were significantly lower in the CAD group (OR, 95% CI, P-value, CIMT: 23.23, 2.03-265.30, 0.011; strain: 0.51, 0.31-0.82, 0.006; strain rate: 0.01, 0.00-0.13, 0.001). However, after adjustment for cardiovascular risk factors, only strain and strain rate were significantly associated with CAD (OR, 95% CI, P-value, CIMT: 5.28, 0.28-99.84, 0.267; strain: 0.51, 0.30-0.88, 0.014; strain rate: 0.01, 0.00-0.42, 0.014). CAD severity, assessed by the number of stenosed coronary arteries, was also significantly correlated with strain and strain rate, but was not significantly correlated with CIMT.

Both CIMT and CCA strain were associated with CAD. CAD severity and extent were correlated with strain and strain rate, but were not correlated with CIMT. The evaluation of mechanical properties of CCA by ultrasonographic 2D strain imaging could therefore be more effective than that by CIMT for the assessment of CAD.