Simulation of Coronary Blood Flow Based on Biomedical Imaging

Abstract

Cardiovascular diseases (CVDs), specifically coronary artery diseases and stroke, are the leading causes of global mortality, affecting approximately 17.9 million people each year. CVDs are a collection of abnormalities in coronary arteries and heart and blood vessels that include coronary heart and vascular diseases. In 2019, the World Health Organization (WHO) reported that more than 34 people died per minute from CVDs. This represents 31.2% of global deaths; 7.43 million people died owing to coronary heart disease whereas 6.71 million people died owing to brain stroke. Atherosclerosis is one of the most common and non-communicable chronic and cumulative complex cardiovascular diseases. Computed tomography coronary angiography (CCTA) image-based non-invasive virtual fractional flow reserve (vFFR) is a potential clinical method for determining the physiological parameters of coronary lesions. Computational hemodynamic (CHD) factors are important for the initiation and progression of atherosclerotic plaques in the main coronary arteries. Under normal and hypertension pressure conditions, we investigated the hemodynamic significance of various degrees of coronary area of stenosis (AS), including multiple sequential stenoses (MSS). MSS in a single-branch coronary artery presents difficulties when it comes to conducting the physiological evaluation of commonly used invasive interventions. Each stenosis in a single branch of an MSS coronary artery has an influence on the hemodynamic parameters due to possible additional stenoses in the area. We demonstrate significant CHD characteristics in patient-based right coronary artery (RCA) models of MSS using pulsatile heart flow simulations. The hemodynamic factors in coronary blood flow simulations of different degrees of AS indicate a relationship between proximal moderate stenosis and distal severe stenosis models. The results show the physical effects of different hemodynamic factors, including velocity magnitude (VM), mean pressure difference (MPD), wall shear stress (WSS), and vFFR, which allow for predicting the physiological computation under severity conditions of MSS arteries. In this study, we identify the fundamental physics of coronary plaques with MSS and report on the impact of these factors on vFFR measurements. We also investigated the lesion severity of the main coronary arteries using one-dimensional (1D) hemodynamic factors compared to three-dimensional (3D) heart flow computational models because the computational load of 3D hemodynamic simulations is an important drawback in most clinical cases. We observed that vFFR3D (vFFR in 3D) and v vFFR1D results did not differ significantly as a function of stenosis length, type (concentric or eccentric), or location in the coronary artery. The Pearson product moment was found to be r = 0.9661, p  0.0001, implying a strong correlation between vFFR1D and vFFR3D. We describe central hemodynamic features with various coronary luminal areas using the fluid-structure interaction (FSI) method based on the coupled momentum method (CMM). A computational procedure for solving the FSI along with the CMM problem is presented to determine patientbased cardiovascular flows. Open-source tools and techniques were used for CCTA image segmentation, 3D reconstruction, grid generation, and CHD simulations. The results yielded different hemodynamic parameters, allowing for the prediction and assessment of lumen area severity in MSS coronaries. These findings provide insight and improvement in the pathophysiological assessment of MSS. The CHD results allow a medical expert to estimate the severity of coronary lesions and stenosis physiological blood-flow conditions in a non-invasive manner.