Analysis of the hemodynamic impact of coronary plaque morphology in mild coronary artery stenosis.

As is well known, plaque morphology plays an important role in the hemodynamics of stenotic coronary arteries, thus their clinic outcomes. However, so far, there has been no research on how the cross-sectional shape of a stenotic lumen affects its hemodynamics. Therefore, this study aims to explore the impact of plaque cross-sectional shape on coronary hemodynamics under mild or moderate stenosis conditions (diameter stenosis degree ≤50 %). A three-dimensional model of the coronary tree was established using CT images of a subject without coronary stenosis. Based on real CT images of patients, six types of plaque cross-sectional morphologies were created at the same location in one main left coronary artery model, controlling for 50 % and 25 % diameter stenosis, respectively. Computational fluid dynamics (CFD) simulations were performed on the six stenosed coronary models and one normal control model under the same boundary conditions. The differences in hemodynamic results among the models were compared. (1) Type III plaque caused the largest disturbance in the flow field. (2) In type IV plaque, the area with an oscillatory shear index (OSI) >0.1 accounted for 11.18 %. (3) Type V plaque exhibited the most prominent vortex flow lines. (4) Hemodynamic parameters within type VI plaques were most similar to those of normal coronary arteries. (5) Area stenosis better reflects the severity of coronary stenosis. Different cross-sectional morphologies can lead to abnormalities in different hemodynamic parameters, leading to different clinical outcomes. Especially, type III plaques are most likely to cause vascular wall damage, while type V plaques warrant caution due to the risk of complications such as thrombosis. Considering plaque cross-sectional morphology can provide doctors with more information and theoretical support for diagnosis.