The influence of peripheral vascular disease on the carotid and femoral wall mechanics in subjects with abdominal aortic aneurysm

Abstract

Aim: Aortic and carotid stiffness is elevated in patients with abdominal aortic aneurysm (AAA). Peripheral vascular disease (PVD) frequently coexists with AAA and may further impair the arterial wall mechanics and increase the cardiovascular load. We therefore studied the elastic carotid and muscular femoral biomechanical properties and intima-media thickness (IMT) in this group of patients. Methods: The elastic indices and IMTs of the common carotid and common femoral arteries were determined in 30 patients with AAA (15 with PVD) with a duplex scanner coupled with a wall tracking system. Fasting plasma creatinine level, glucose and lipid concentrations, and their physiologic variables known to influence the arterial wall mechanics were also assessed. Results: Patients with AAA and PVD have significantly stiffer carotid (Petersen's elastic modulus, 2207 ± 905 mm Hg versus 1268 ± 432 mm Hg; P = .001; stiffness index, 22.73 ± 9.63 versus 12.60 ± 4.24; P = .001] and femoral (Petersen's elastic modulus, 4906 ± 4057 ]mm Hg versus 2599 ± mm Hg; P = .043; stiffness index, 49.02 ± 40.04 versus 26.07 ± 13.22; P = .044) arteries than subjects with AAA alone. Although patients with PVD have thicker carotid and femoral IMTs, no statistical difference was seen between the two groups. The subjects were matched for age, body mass index, heart rate, systolic and diastolic blood pressures, total vascular risk score, plasma creatinine level, and fasting lipid and glucose concentrations. Conclusion: Subjects with PVD and AAA have significantly stiffer carotid and femoral arteries, which may indicate increased cardiovascular load and may account for the highest mortality rate seen in these patients in the UK Small Aneurysm Trial. Therefore, treatment of associated cardiovascular risk factors is important and may have to be tailored on an individual basis according to the findings of the arterial wall mechanics.