Assessment of Arterial Stiffness with Pulse Wave Velocity or Augmentation Index: Which Method is the Best?: Scientific Letter

Abstract

Assesment of large arterial stiffness is increasingly used in clinal settings. Although there are several invasive and non-invasive methods such as carotid-femoral pulse wave velocity (PWV) and augmentation index (AI), researchers and clinicians still face problems in selecting the best methodology for their specific use. PWV, which is defined as the velocity of the arterial pulse for moving along the vessel wall, plays an important clinical role in defining patients under high cardiovascular risk and it is inversely correlated with arterial elasticity and relative arterial compliance. PWV along the aorta can be measured by using two ultrasound or pressure sensitive transducers fixed transcutaneously over the course of a pair of arteries separated by a known distance: the femoral and right common carotid arteries. PWV is calculated from measurements of pulse transit time and the distance, according to the following formula: PWV (m/s)= distance (m)/transit time (s). AI is defined as Dp/pp (where Dp is the difference between the late systolic peak and the mid-systolic peak and pp is the amplitude of the pulse pressure wave). Central blood pressure and pulse pressure, the AI and PWV, which are often used incorrectly as interchangeable indexes of arterial stiffness, increase with age, hypertension, diabetes mellitus and hyperlipidemia, and are associated with target organ damage such as left ventricular hypertrophy, microalbuminuria, carotid intima-media thickness and endothelial dysfunction. Althouhg the carotid-femoral (aortic) PWV is the gold standard test for assessing central arterial stiffness, the AI reflects stiffness of the systemic arterial tree. This paper summaries the advantages and disadvantages of PWV and AI in the assessment of arterial stiffness.