We performed this study to elucidate whether there were significant correlations 1) between intima-media thickness (IMT) of carotid artery and the extent of coronary atherosclerosis and 2) between carotid IMT and risk factors of atherosclerosis in patients with coronary atherosclerosis.

All study subjects (n=326, 200 males, 59±10 years) had chest pain and underwent coronary angiography. IMT was measured in the far wall of the internal and common carotid arteries and the carotid bulb using high-resolution ultrasound with a 3-11 MHz linear probe. We also evaluated the presence of plaque in the carotid artery. The extent of coronary atherosclerosis was divided into 4 groups (0, 1, 2, and 3) according to the number of coronary arteries narrowed more than 50% of the diameter.

In patients with one or more diseased coronary vessels, IMT of the common carotid artery was thicker (0.81±0.15 mm vs. 0.91±0.28 mm, p<0.05) and plaques were more frequently found (16% vs. 40%, p<0.05). There was also a significant correlation between the extent of coronary artery atherosclerosis and IMT of the common carotid artery (r=0.217, p<0.001) and the internal carotid artery (r=0.177, p<0.01). Multiple regression analysis revealed hypertension and smoking, among the atherosclerosis risk factors, as independent factors in the IMT of the common carotid artery and carotid bulb.

We concluded that there was a significant correlation between the extent of coronary artery disease and IMT of the carotid artery;and that hypertension and smoking, of all atherosclerosis risk factors, were independent factors in the IMT of the carotid artery.