Comparing Carotid and Brachial Artery Stiffness: A First Step Toward Mechanical Mapping of the Arterial Tree

Abstract

Arterial stiffness is a predictor of cardiovascular mortality. It increases with age and is accelerated by hypertension and other cardiovascular risk factors. In addition to the disease state, arterial stiffness increases from the proximal to the distal arterial compartments. Concurrent assessment of various vessels from the same subjects is unavailable in the literature. The aim of this work was to quantify an intrinsic mechanical feature, namely, wall stiffness, of the common carotid artery (CCA) and brachial artery (BA). CCAs and BAs of healthy adolescents were investigated. Cine loops of CCA and BA B-mode data were digitally recorded at the same clinical examination, and arterial elastic moduli were estimated off-line with our proprietary non-invasive Imaging-based BioMarker (ImBioMark) algorithm. The 11 study subjects were 14.4 ± 1.2 years old, with normal body habitus and blood pressures 112.3 ± 10.6/63.6 ± 5.7 mm Hg. BAs had a higher elastic modulus than CCAs (arterial elastic moduli: 129.73 ± 25.67 kPa vs. 49.55 ± 14.75 kPa, p < 0.001). There was a positive correlation between the BA and CCA (slope = 0.36, intercept = 111.62 kPa, R2 = 0.045). This article documents, for the first time, a correlation between the CCA and BA of the same subject, under the same conditions. We previously reported preliminary data for the aorta and documented the effect of aging on the CCA; we now intend to study the femoral artery as well and include age stratification to pursue our investigations. The results reported here can be seen as the first step toward mechanical mapping of the arterial tree.