Difference in carotid artery elasticity in subjects with different brachial artery kinetic of vasodilatation

Abstract

Increased carotid stiffness and impaired brachial artery flow-mediated dilatation (FMD) associate with cardiovascular events. We have previously reported three FMD patterns based on the time of maximal dilatation. The aim of the present study was to verify whether different FMD patterns associate with carotid artery stiffness. In all, 133 subjects were enrolled. All participants underwent complete clinical examination, blood sampling and ultrasound study. FMD was used as a measure of endothelial function. Based on the maximal brachial artery FMD, subjects were divided into Early dilators (peak FMD at 50 s), Late dilators (peak FMD over 50 s) and No dilators. Echo-Doppler evaluation of carotid arteries was performed in order to calculate elastic indexes (strain, β-stiffness index and distensibility). In all, 64 subjects were classified as Early FMD, 36 as Late FMD and 33 as No dilators. Age, gender and cardiovascular risk factors were comparable among three groups. Early FMD had higher values of strain compared with both Late and no Dilators (P<0.001). Furthermore, Early dilators showed a significantly lower stiffness and higher distensibility compared with Late and No dilators. No significant differences between Late FMD and No Dilators were detected. Our results demonstrate that common carotid artery elasticity indexes significantly differ among Early, Late and No dilators. Subjects with delayed or absent brachial artery dilatation have stiffer common carotid arteries compared with subjects with early dilatation. In conclusion, our research suggests that the assessment of the kinetics of FMD in a clinical setting might represent a useful screening tool to improve the cardiovascular risk stratification.