Carotid intima-media thickness (IMT) in patients with severe familial and non-familial hypercholesterolemia: The effect of measurement site on the IMT correlation with traditional cardiovascular risk factors and calcium scores.

Abstract

The carotid intima-media thickness (IMT) measurement may be carried out proximally (pIMT) or distally (dIMT) in relation to the bulb of the common carotid artery which has significant implications on the results and correlation with risk factors. The aim of the study was to compare the pIMT and dIMT in patients with familial hypercholesterolemia confirmed by genetic testing (FH group) and patients with severe non-familial hypercholesterolemia, with negative results of genetic testing (NFH group) and to determine the correlation of results with traditional atherosclerotic risk factors and calcium scores. A total of 86 FH and 50 NFH patients underwent pIMT and dIMT measurements of both carotid arteries as well as computed tomography (CT) with coronary and thoracic aorta calcium scoring. The meanpIMT of both right and left common carotid artery were significantly higher in patients with FH compared to the NFH group (meanpRIMT 0.721 ± 0.152 vs. 0.644 ± 0.156, p < 0.01, meanpLIMT 0.758 ± 0.173 vs. 0.670 ± 0.110, p < 0.01). Patient age, pre-treatment lowdensity lipoprotein (LDL) cholesterol levels (LDLmax) at baseline and systolic blood pressure were independent predictors of pIMT increases in both carotid arteries. Smoking history, age and LDLmax were independent predictors of dIMT increase. There was a significant correlation between the calcium scores of the ascending aorta, coronary artery and aortic valve and all IMT parameters. The IMT measured proximally better between patients with familial and non-familial hypercholesterolemia. The association between IMT and traditional cardiovascular risk factors varies between measurement sites. IMT values correlate CT calcium scores in all patients with hypercholesterolaemia regardless of genetic etiology.