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)x10(-2), P<0.001), Petersen's elastic modulus (1.77 (0.69) vs 1.19 (0.63) mmHg x 10(3), 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 Petersen's elastic modulus (5.94 (4.98) vs 3.64 (3.27) mmHg x 10(3), 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.


CONCLUSIONS
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 clinician's decision to intervene with therapy.
Cardiovascular Haemodynamic Unit, University Department of Surgery, Royal Free and University College Medical School, University College London and The Royal Free Hospital, Pond Street, NW3 2QG, London, UK.
Koon-Sung
KS
Cheng
Alok
A
Tiwari
Cara R
CR
Baker
Richard
R
Morris
George
G
Hamilton
Alexander M
AM
Seifalian
D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008297:Male; D015588:Observer Variation; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D017539:Tunica Intima / Q000473:pathology*; D017540:Tunica Media / Q000473:pathology*; D018616:Ultrasonography, Doppler, Duplex