The Impact of the Right Coronary Artery Geometric Parameters on Hemodynamic Performance.

PURPOSE: Coronary artery geometry can have a significant impact in the hemodynamic behavior of coronary blood flow, influencing atherosclerotic plaque formation. The present work focuses on, through a statistical study, the connection between several geometric parameters of the right coronary artery-ostium cross-sectional area, angles between the common trunk and the side-branches, tortuosity, curvature and cross-sectional area in each side-branch-and their influence on hemodynamic descriptors. Parameters such as low wall shear stress and local disturbed flow, which are associated with atherosclerosis formation, were analysed. METHODS: Computed tomography images of ten healthy individuals were selected to reconstruct in vivo three-dimensional models of right coronary arteries. Blood flow was simulated through a compliant model with realistic boundary conditions. Calculated hemodynamic descriptors values were correlated with the geometric parameters using the Pearson correlation coefficient (r) and the p value. RESULTS: The strongest correlations were found in the middle and distal segments of the right coronary artery. A decrease in the ostium area promotes a decrease in the WSS magnitude from the proximal to the distal segment (r = 0.82). Very strong correlations (r > 0.90) were achieved between geometric parameters (cross-sectional area, angle, tortuosity) of the right-ventricular branch and the wall shear stress magnitude in the middle and distal segments. CONCLUSIONS: Low values of tortuosity, smaller cross-sectional area and higher angle of the right-ventricular branch leads to a hemodynamic behavior more propitious to atherosclerosis formation, within the study cases. The right-ventricular branch seems to have the highest influence in the hemodynamic behavior of the right coronary artery.

Correlation between geometric parameters of the left coronary artery and hemodynamic descriptors of atherosclerosis: FSI and statistical study.

The hemodynamics conditioned by coronary geometry may play an important role in the creation of a pro-atherogenic environment in specific locations of the coronary tree. The aim of this study is to identify how several geometric parameters of the left coronary artery - cross-section areas, proximal left anterior descending artery length, angles between the branches and the septum, curvature and tortuosity - can be related with hemodynamic descriptors, using a computational fluid-structure interaction method. It is widely accepted that the hemodynamic indicators play an important role in identifying possible pro-atherogenic locations. A statistical study, using Pearson correlation coefficient and P value, was performed for a population study of 8 normal human left coronary arteries presenting right-dominant circulation. Within the study cases, arteries with high caliber (r = 0.88), high angles LMS-LAD (r = 0.49), LAD-LCx (r = 0.57) and LAD-Septum (r = 0.52), and high tortuosity LMS-LCx (r = 0.63) were correlated with a hemodynamic behavior propitious to plaque formation in the left anterior descending artery. In contrast, high proximal left anterior descending artery length (r = -0.41), high angle LMS-LCx (r = -0.59), high tortuosity LMS-LAD (r = -0.56) and LAD-LCx (r = -0.55) and high curvature of LMS (r = -0.60) and LCx (r = -0.56) can lead to non-favorable hemodynamic conditions for atheroma formation. Graphical abstract.