Pathologic shear and lesion morphology in human coronary arteries

Introduction: Although individual effects of lesion characteristics—including stenosis severity, eccentricity and lesion length—on coronary haemodynamics is known, their relative importance and whether they interact remains poorly understood. This study aimed to address this. Methods: Computational fluid dynamics simulations were performed in three-dimensional (3D) models of 104 coronary arteries reconstructed from 3D quantitative coronary angiography. Shear stress at the site of maximal stenosis and size of poststenotic areas with low shear stress (<1 Pa) were quantified. Results: With increasing stenosis severity, peak shear increased in a mono-exponential manner (Figure 1, first row), whereas size of low shear areas demonstrated a threshold effect, with a steep increase when diameter stenosis was > 40% and subsequently followed a sigmoidal curve (Figure 1, second row). Two-way ANCOVA analysis revealed that stenosis severity and lesion length were both independent predictors of peak shear and size of low shear areas. Conclusion: This study showed that stenosis severity and lesion length are independent predictors of pathogenic physiological processes, whereas lesion eccentricity is not.