Pulse wave analysis measurements: important, underestimated and undervalued parameters in cardiovascular health problems

The aim of the current investigation was to test the hypothesis that age-related changes in augmentation index (AIx) are more prominent in younger individuals ( 50 years). Aging exerts a number of deleterious changes in the cardiovascular system, and, in particular, on the large arteries. Previous studies have suggested that AIx and pulse wave velocity (PWV) increase linearly with age, yet epidemiological data concerning pulse pressure suggest that large artery stiffening predominantly occurs later in life. Peripheral and central blood pressure, augmentation pressure (AP), and AIx were determined in 4,001 healthy, normotensive individuals, aged 18 to 90 years. Aortic and brachial PWV were also determined in a subset of 998 subjects. Peripheral and central pulse pressure, AP, AIx, and aortic and brachial PWV all increased significantly with age; however, the age-related changes in AIx and aortic PWV were non-linear, with AIx increasing more in younger individuals, whereas the changes in PWV were more prominent in older individuals. These data suggest that AIx might be a more sensitive marker of arterial stiffening and risk in younger individuals but aortic PWV is likely to be a better measure in older individuals.

Early detection of subclinical atherosclerosis is important to reduce patients' cardiovascular risk. However, current diagnostic strategy focusing on traditional risk factors or using risk scoring is not satisfactory. Non-invasive imaging tools also have limitations such as cost, time, radiation hazard, renal toxicity, and requirement for specialized techniques or instruments. There is a close interaction between arterial stiffness and atherosclerosis. Increased luminal pressure and shear stress by arterial stiffening causes endothelial dysfunction, accelerates the formation of atheroma, and stimulates excessive collagen production and deposition in the arterial wall, leading to the progression of atherosclerosis. Pulse wave velocity (PWV), the most widely used measure of arterial stiffness, has emerged as a useful tool for the diagnosis and risk stratification of cardiovascular disease (CVD). The measurement of PWV is simple, non-invasive, and reproducible. There have been many clinical studies and meta-analyses showing the association between PWV and coronary/cerebral/carotid atherosclerosis. More importantly, longitudinal studies have shown that PWV is a significant risk factor for future CVD independent of well-known cardiovascular risk factors. The measurement of PWV may be a useful tool to select subjects at high risk of developing subclinical atherosclerosis or CVD especially in mass screening.