Assessment of superficial coronary vessel wall deformation and stress: validation of in silico models and human coronary arteries in vivo

Abstract

Cyclic biomechanical stress at the lumen-intima interface plays a crucial role in the rupture of coronary plaque. We performed a comprehensive assessment of a novel angiography-based method for four-dimensional (4D) dynamic assessment of superficial wall stress (SWS) and deformation with a total of 32 analyses in virtual stenosis models with equal lumen dimensions and 16 analyses in human coronary arteries in vivo. The in silico model analyses demonstrated that the SWS, derived by the proposed global displacement method without knowledge of plaque components or blood pressure, was comparable with the result calculated by traditional finite element method. Cardiac contraction-induced vessel deformation increased SWS. Softer plaque and positive arterial remodeling, associated with a greater plaque burden, showed more variation in mean lumen diameter within the cardiac cycle and resulted in higher SWS. In vivo patient analyses confirmed the accuracy of computed superficial wall deformation. The centerlines predicted by our method at random selected time instant matched well with the actual one in angiograms by Procrustes analysis (scaling: 0.995 ± 0.018; dissimilarity: 0.007 ± 0.014). Over 50% of the maximum SWS occurred at proximal plaque shoulders. This novel 4D approach could be successfully to predict superficial wall deformation of coronary artery in vivo. The dynamic SWS might be more realistic to evaluate the risk of plaque rupture.

Angiography-Based 4-Dimensional Superficial Wall Strain and Stress: A New Diagnostic Tool in the Catheterization Laboratory

“…In silico and in vivo studies have revealed that angiographybased assessment of dynamic coronary artery deformation allows computation of superficial wall strain and stress, as reported by Wu et al (10,11,14). Lipid-rich plaque models had numerically higher wall stress than calcified and fibrous plaques, and wall stress increased with plaque burden.…”

“…Coronary angiograms with minimal vessel image overlap and foreshortening are selected (13). Several key time-points during the cardiac cycle are identified from the electrocardiogram or according to the different stages of vessel motion during heart contraction and relaxation (Figure 2) (14). The number of frames for cardiac cycle can be determined from one QRS wave to the next on the electrocardiogram, when available.…”

“…The calculation of wall stress was first validated on in silico stenosis models (n = 32) (14). The idealized virtual stenosis models were designed with lumen dimensions identical to human coronary arteries (normal lumen diameter of 3 mm).…”

Can the Wall Shear Stress Values of Left Internal Mammary Artery Grafts during the Perioperative Period Reflect the One-Year Patency?

“…We performed calculations to determine the volume flow rate of native coronary arteries that were not measured during surgery based on the previous research of Gould et al 21 With appropriate setting of boundary conditions, WSS values were calculated following an equivalent form, τ ¼ 4 μQ/πR 3 , where τ and μ are WSS value and dynamic blood viscosity, respectively, and R and Q represent the inner vessel radius and volume flow rate, respectively. For postprocessing, the lumen of the LIMA was divided into 3mm length pieces and a bin-angle of 30 degrees, similar to Wu et al 22 The mean WSS values were calculated within every portion for statistical analyses.…”

“…For postprocessing, the lumen of the LIMA was divided into 3-mm length pieces and a bin-angle of 30 degrees, similar to Wu et al 22 The mean WSS values were calculated within every portion for statistical analyses.…”