Aortic pulse wave velocity, elasticity, and composition in a nonhuman primate model of atherosclerosis.

Abstract

SUMMARY Aortic pulse wave velocity was determined in Macaca fascicularis monkeys fed either atherogenic or control diets for 36 months. The foot-to-foot velocity and apparent phase velocities of the second through seventh Fourier harmonics at a given diastolic pressure in the atherosclerotic monkeys were 1.5 to 2.0 times the values for the control animals. More than 80% of the aortic intimal surface of the atherosclerotic monkeys was covered with fibrous or fatty plaque, which approximately doubled wall thickness and wall thickness to radius ratio. Angiochemical evaluations showed no difference in collagen or elastin concentration (as a fraction of lipid and mineral-free dried aorta), but the atherosclerotic aortas were 1.5 to 2.0 times that of control in collagen and elastin content (defined as the absolute quantity beneath a square centimeter of intimal surface). Total cholesterol and calcium concentrations in the atherosclerotic aortas were more than 10 times the values for the control aortas. The static circumferential distensibility of the excised atherosclerotic aortas was significantly less than control, but there was no difference in incremental (Young's) modulus of elasticity. The in vitro pressure-strain elastic modulus of the atherosclerotic aortas was more than twice that of control, which was predicted from the enhanced wave velocity. The significantly increased stiffness of the atherosclerotic arteries appeared to be due mainly to the increased wall thickness caused by the atherosclerotic plaques rather than to material changes described by Young's modulus. Extensive medial damage, however, also was present and could have had a major influence on stiffness. Atherosclerosis therefore can result in increased aortic stiffening, detectable by pulse wave velocity, even if there is no change in the overall Young's modulus of elasticity.

Risk factors for changes in aorto-iliac arterial compliance in healthy men.

“…Gosling 3 used pulse wave velocity to show reduced compliance with advancing age. Others have showed this relationship using techniques that measure arterial wall movement 9 or aortic distension. 13 The present study suggests that this relationship is a reflection of aging rather than of concomitant changes of blood pressure or lipid status.…”

“…Animal studies 9 have shown that atherosclerosis causes reduced compliance in large elastic arteries. Farrar et al 10 also showed that producing regression of atherosclerosis in monkeys causes an increase in arterial compliance.…”

Ventricular–vascular coupling in hypertension

“…Atherosclerosis may modify pressure wave propagation and reflection along the arterial tree. Animal studies 95,96 have shown an increase of pulse wave velocity after induction of atherosclerosis with lipid-rich diet. Large population studies, however, did not show a significant impact of dyslipidemia on pulse wave velocity Ventricular-vascular coupling in different conditions.…”

Effects of atorvastatin on aortic pulse wave velocity in patients with hypertension and hypercholesterolaemia: a preliminary study

“…Studies in monkeys [24][25][26][27] have previously shown that a diet regimen rich in cholesterol is associated in the long term with a significant pressureindependent increase of aortic PWV, and that following a chronic hypolipidaemic diet, the regimen is associated with a further transient increase of PWV, in relation with the reduction of the lipid vascular content, a biomaterial usually considered as soft. After this early phase, the increase in PWV tends to disappear and is even reversed as a consequence of the remodelling of the vascular wall.…”