Arterial stiffness

Abstract

Measurements of biomechanical properties of arteries have become an important surrogate outcome used in epidemiological and interventional cardiovascular research. Structural and functional differences of vessels in the arterial tree result in a dampening of pulsatility and smoothing of blood flow as it progresses to capillary level. A loss of arterial elastic properties results a range of linked pathophysiological changes within the circulation including increased pulse pressure, left ventricular hypertrophy, subendocardial ischaemia, vessel endothelial dysfunction and cardiac fibrosis. With increased arterial stiffness, the microvasculature of brain and kidneys are exposed to wider pressure fluctuations and may lead to increased risk of stroke and renal failure. Stiffening of the aorta, as measured by the gold-standard technique of aortic Pulse Wave Velocity (aPWV), is independently associated with adverse cardiovascular outcomes across many different patient groups and in the general population. Therefore, use of aPWV has been proposed for early detection of vascular damage and individual cardiovascular risk evaluation and it seems certain that measurement of arterial stiffness will become increasingly important in future clinical care. In this review we will consider some of the pathophysiological processes that result from arterial stiffening, how it is measured and factors that may drive it as well as potential avenues for therapy. In the face of an ageing population where mortality from atheromatous cardiovascular disease is falling, pathology associated with arterial stiffening will assume ever greater importance. Therefore, understanding these concepts for all clinicians involved in care of patients with cardiovascular disease will become vital.

Figure 1

Left hand panel: Sagittal image of the aorta from the aortic root to the level of the bifurcation. L1 through L5 indicate the level of cine phase contrast magnetic resonance imaging image acquisition, and R1 through R4 indicate the region of pulse wave velocity measurement. Right hand panel: Association between age and regional aortic PWV in regions A-R1, B-R2, C-R3, D-R4. Reprinted from Hickson SS, Butlin M, Graves M, et al. The relationship of age with regional aortic stiffness and diameter. JACC Cardiovasc Imaging 2010;3:1247–55, with permission from Elsevier