A database of virtual healthy subjects to assess the accuracy of foot-to-foot pulse wave velocities for estimation of aortic stiffness

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 309; no. 4; pp. H663 - H675
• Main Authors: Willemet, Marie, Chowienczyk, Phil, Alastruey, Jordi
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 15.08.2015
• Subjects: Adult; Aged; Algorithms; Aorta - physiology; Coronary vessels; Datasets as Topic; Female; Geometry; Healthy Volunteers; Humans; Integrative Cardiovascular Physiology and Pathophysiology; Male; Middle Aged; Physiology; Pulse Wave Analysis - methods; Pulse Wave Analysis - standards; Signal-To-Noise Ratio; Vascular Stiffness; Velocity; numerical 1D model; aortic stiffness; brachial-ankle PWV; database of virtual subjects; carotid-femoral PWV
• ISSN: 0363-6135; 1522-1539; 1522-1539
• DOI: 10.1152/ajpheart.00175.2015

While central (carotid-femoral) foot-to-foot pulse wave velocity (PWV) is considered to be the gold standard for the estimation of aortic arterial stiffness, peripheral foot-to-foot PWV (brachial-ankle, femoral-ankle, and carotid-radial) are being studied as substitutes of this central measurement. We present a novel methodology to assess theoretically these computed indexes and the hemodynamics mechanisms relating them. We created a database of 3,325 virtual healthy adult subjects using a validated one-dimensional model of the arterial hemodynamics, with cardiac and arterial parameters varied within physiological healthy ranges. For each virtual subject, foot-to-foot PWV was computed from numerical pressure waveforms at the same locations where clinical measurements are commonly taken. Our numerical results confirm clinical observations: 1) carotid-femoral PWV is a good indicator of aortic stiffness and correlates well with aortic PWV; 2) brachial-ankle PWV overestimates aortic PWV and is related to the stiffness and geometry of both elastic and muscular arteries; and 3) muscular PWV (carotid-radial, femoral-ankle) does not capture the stiffening of the aorta and should therefore not be used as a surrogate for aortic stiffness. In addition, our analysis highlights that the foot-to-foot PWV algorithm is sensitive to the presence of reflected waves in late diastole, which introduce errors in the PWV estimates. In this study, we have created a database of virtual healthy subjects, which can be used to assess theoretically the efficiency of physiological indexes based on pulse wave analysis.