How does the stiffness of blood vessel walls and deposited plaques impact coronary artery diseases?

Coronary artery disease (CAD) is a condition where the coronary arteries, which supply blood to the heart muscle, become narrowed or blocked. The most common cause of CAD is atherosclerosis, which is a condition in which plaque builds up inside the arteries, causing them to harden and narrow. These are critical conditions due to their high prevalence, adverse impact on health and quality of life, and potential for severe complications. Early detection, prevention, and effective management are essential to mitigate their effects, which delves critically on the understanding of blood flow dynamics (hemodynamics) in these arteries. While fluid dynamics simulations incorporating the deformability of blood vessels have proven to be immensely useful in this context, their outcomes remain far from being amenable for clinical decision making in real-life medical practice because of their limitations in capturing the implications of certain key physiological features such as the stiffnesses of the artery walls and the plaque deposits formed therein. In an effort to circumvent these deficits, here we report the development and deployment of a fluid–structure interaction model that unveils the sensitive dependence of the clinically relevant hemodynamic parameters on the arterial wall and plaque stiffness, bringing in explicit quantitative assessment of the pathophysiology of arterial disease progression. Our results enable direct quantification of the time-averaged wall shear stress, offering clinical insights into the biomechanical environment and the endothelial response that are critical in the initiation and progression of atherosclerotic plaques. In addition, our results pinpoint the alterations in the fractional flow reserve due to changes in the deformability of the arterial walls and plaques, providing a functional assessment of the impact of these plaques on coronary blood flow. Our simulation platform thus helps in a comprehensive assessment of cardiovascular risk, enabling better prediction, prevention, and treatment of atherosclerosis-related conditions—a paradigm that has remained to be elusive in clinical practices thus far.