Non-Invasive Vascular Function Tests:

Abstract

Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp he clustering of conventional risk factors for cardiovascular disease (CVD) is associated with exaggerated vascular damage and poorer outcomes. 1 Therefore, clinical medicine and public health policies place significant emphasis on the modification of conventional risk factors and lifestyle behaviors to reduce the epidemic of CVD. 2 Although the population-attributable risk of major vascular risk factors is substantial, it is often difficult to distinguish those individuals with a moderate baseline risk who might benefit from aggressive risk reduction strategies. Furthermore, some studies have reported that the traditional cardiovascular risk factors account for "only 50%" of those who go on to develop coronary heart disease. 3 Therefore, additional tests to assist in the prediction of the cardiovascular risk in these individuals may be warranted. 4,5 Ultrasound examination of the carotid artery is increasingly being used as a surrogate marker of atherosclerosis and is a strong predictor of future vascular events. 6 However, evaluation of the regression of subclinical atherosclerosis by carotid arterial ultrasound examination following treatment of risk factors takes time (ie, more than 1 year is required in most cases to confirm such regression), 7 and therefore more sensitive markers to assess the effect of treatment of risk factors on vascular damage are proposed.Risk factors for CVD cause not only structural, but also functional vascular damage. Several non-invasive methods are currently used to assess functional vascular damage, including measurement of flow-mediated vasodilatation (FMD) of the brachial artery induced by reactive hyperemia, pulse wave velocity (PWV), augmentation index (AI), central blood pressure (BP), etc and these vascular function tests have attracted attention as new tools for determining CVD risk. [8][9][10][11][12][13][14][15] In this review, we describe the pathophysiology of vascular functions, the non-invasive methods of evaluating vascular functions and the clinical applicability of these tests for CVD risk stratification. Functions of ArteriesThe arterial wall has 3 layers (ie, the intima, including the endothelium, the media, and the adventitia) and each of these layers has a role in systemic circulation. Functions of the EndotheliumEndothelium regulates vascular tone, hemostasis and/or vascular permeability. 16 To exert these functions, endothelial cells biosynthesize several vasoactive substances, 17 and of these, nitric oxide (NO) in particular has a pivotal role in protecting against the initiation/progression of atherosclerosis via its vasodilatory activity and its inhibitory activity against vascular smooth muscle cell growth, nuclear transcription of cell adhesion molecules, platelet aggregation and The arterial wall has 3 layers (ie, the intima, including the endothelium, the media, and the adventitia); each of these layers has individual roles in systemic circulation. The ...

Effect of Wave Reflection and Arterial Stiffness on the Risk of Development of Hypertension in Japanese Men

“…In addition, MML analyses also revealed longitudinal associations of rAI and SBP2 with baPWV. Apart from arterial stiffness, as mentioned, increased peripheral reflectance related to peripheral vascular damage may also worsen pressure wave reflection, which could functionally increase arterial stiffness via elevation of central blood pressure 7, 8, 9. Consequently, arterial stiffness and pressure wave reflection may be additively associated with the development of hypertension.…”

“…Wave reflection has also been reported as a risk factor for the development of hypertension 3, 5, 16. In addition to arterial stiffness, which increases the speed of propagation of the pressure wave originating from the left ventricle along the arterial wall, peripheral wave reflectance also affects the wave reflection; thus, arterial stiffness and wave reflection may reflect partially different facets of damage in the arterial tree 7, 8, 9. The findings of the present study suggest that both baPWV, a marker of arterial stiffness, and rAI, a marker of wave reflection, are independent predictors of the risk of development of hypertension.…”

“…Alternatively, microvascular damage in the arterial tree has also been proposed as an important factor for the development of hypertension 6, 7. In the arterial tree, abnormal wave reflection is caused not only by the increased pressure wave propagation speed on the arterial wall, derived from increased arterial stiffness, but also by elevation of the amplitude of the reflected wave secondary to increased peripheral reflectance, derived from peripheral vascular damage 8, 9. Consequently, it is possible that wave reflection acts additively or synergistically with arterial stiffness to increase the risk of development of hypertension.…”

Endothelial Dysfunction, Increased Arterial Stiffness, and Cardiovascular Risk Prediction in Patients With Coronary Artery Disease: FMD‐J (Flow‐Mediated Dilation Japan) Study A

“…Noninvasive vascular function tests have been developed and performed for assessment of functional vascular damage and severity of atherosclerosis 7, 8, 9. Impairment of vascular function, such as endothelial dysfunction and increased arterial stiffness, is closely associated with the development and maintenance of atherosclerotic conditions, leading to target organ damage and cardiovascular complications 10.…”

CAVI vs. pressure and stiffness gradients in the arterial tree

“…1,2 The plausible underlying mechanisms of this increased cardiovascular risk are increased cardiac afterload, impaired coronary blood flow, atherogenesis and/or endorgan damage. 2 Abnormal pressure and stiffness gradients are considered to have some causal role in these mechanisms.…”