A review on the biomechanics of coronary arteries

Globally, cardiovascular diseases are seen as one of the largest economic burdens on society and the single largest cause of death, with atherosclerosis the leading cause of myocardial infarction (heart attack). Due to the complex interactions in the coronary vasculature, medical imaging technology is unable to recognise correlations between artery and fluid mechanics and disease initiation and progression, hence, biomechanical analysis of coronary arteries in patient-specific models is necessary to provide critical information in clinical settings; large variability in modelling approaches, parameters and results still, however, hamper accurate and reliable model development. This review aims to assist in filling that gap by presenting an overview of research efforts to date, from both theoretical and experimental perspectives, to assist in addressing the challenge of developing a reliable and accurate biomechanical model of human coronary arteries. Studies have been categorised primarily on their approach, either purely theoretical, purely experimental/clinical or a combined theoretical and experimental/clinical approach as well as then divided into structural, fluid, and fluid-structure interaction (FSI) analysis. From research efforts to date it is clear that the development of FSI models to incorporate the effects of shear-thinning, non-Newtonian flows in viscoelastic, realistic artery and plaque morphologies developed from in vivo, high resolution imaging is critical for accurate determination of disease initiation/progression, including atherosclerosis, plaque formation, and failure mechanisms. The inclusion of micro-constituents such as micro-calcification, endothelial cell layer, collagen cross-linking, vascular smooth muscle cell contractility and constitutive blood equations also affects stress magnitude, distribution and failure mechanisms and should be adequately accounted for. A set of appendices are also provided where studies are summarised and assessed based on their approach to modelling and are categorised by considering the imaging modality used, methodology, material and blood properties, type of coronary artery, approach to the study (theoretical, experimental, in vitro & in vivo), number of patients/specimens and a general description. It is hoped this review will assist in furthering the field of coronary artery biomechanics and contribute to developing accurate and reliable patient-specific models capable of improving our understanding of cardiovascular biomechanics and hence, the initiation/progression of related diseases to address the growing global morbidity, mortality and economic challenge of cardiovascular disease and myocardial infarction. (C) 2019 Elsevier Ltd. All rights reserved.