Impaired carotid and femoral viscoelastic properties and elevated intima–media thickness in peripheral vascular disease

Background: We undertook a study to determine whether peripheral vascular disease of the lower extremity (PVD) per se affects the arterial viscoelastic properties and intima–media thickness (IMT) of the carotid and femoral arteries. Methods: Thirty-five patients with PVD, 35 age- and gender-matched control subjects were examined with ultrasound scan wall tracking system, with the simultaneous measurement of blood pressure for carotid and femoral IMT and viscoelastic properties. Results: Subjects with PVD have significantly impaired carotid elastic properties including compliance (mean (SD): 6.50 (2.39) vs 9.93 (4.07) %mmHg−1×10−2, P<0.001), Petersenʹs elastic modulus (1.77 (0.69) vs 1.19 (0.63) mmHg×103, P=0.001) and stiffness index (17.92 (7.21) vs 12.10 (6.17), P=0.001) when compared to non-PVD controls. They also have significantly altered femoral elastic properties including Petersenʹs elastic modulus (5.94 (4.98) vs 3.64 (3.27) mmHg×103, P=0.025) and stiffness index (58.42 (47.76) vs 36.96 (33.43), P=0.033). The carotid (0.85 (0.35) vs 0.59 (0.23) mm, P<0.001) and femoral (1.05 (0.39) vs 0.69 (0.31) mm, P<0.001) IMTs are also significantly elevated in PVD patients. After adjustment for the presumed cardiovascular load assessed on the basis of a cumulative total vascular risk score, as well as age, systolic and diastolic pressure, the carotid viscoelastic indices and the carotid and femoral IMTs remained highly significant. However, the difference in femoral elastic variables was no longer evident. Conclusion: PVD per se affects the femoral and carotid wall mechanics and morphology similarly to other cardiovascular risk factors and events. These parameters may provide further information for cardiovascular risk assessment in addition to the classical risk factors and the Framingham equation. Indeed, some guidelines have suggested that additional factors such as the carotid scan may influence the clinicianʹs decision to intervene with therapy.