Abstract 9424: Coronary Artery Disease-Related Death May Be Associated With Higher Critical Plaque Wall Stress: A Multi-Patient 3D Fluid-Structure Interaction Study Comparing Plaque Wall Stress, Flow Shear Stress, and Plaque Burden as Risk Indicators

Abstract

Introduction: Plaque burden has been used to predict cardiovascular events. However, many patients without flow-limiting atherosclerosis and without prior symptomatology develop catastrophic syndromes including stroke, or sudden cardiac death. We hypothesized that plaque wall stresses play an important role in vulnerable plaque rupture and may serve as a risk factor for cardiovascular event. The objective of this study was to compare plaque wall stress, flow shear stress, and plaque burden and identify their possible association with coronary artery disease (CAD)-related death. Methods: Ex vivo MRI data of coronary plaques from 12 patients (6 died from CAD cause and 6 died from non-CAD cause, based on autopsy reports) were used to construct 3D fluid-structure interaction models. Plaque wall stress and flow shear stress were extracted from all nodal points on the lumen surface of each 3D plaque model for analysis. The maxima of plaque wall stress and flow shear stress from all local maxima (excluding those on healthy sites) of each plaque were defined as the 3D critical plaque wall stress (CPWS) and 3D critical flow shear stress (CFSS), respectively. Plaque burden was calculated as plaque+media area/total vessel area bounded by the out-boundary. Two-sided Student t-test was used to compare the difference of CPWS, CFSS and plaque burden between the CAD and non-CAD groups. Results: Table 1 shows that mean 3D CPWS from CAD Group was 94.3% higher than that from non-CAD Group (265.6 vs. 136.7 kPa, P=0.0029). No difference was found for 3D CFSS values (p=0.851) and plaque burden (p=0.552) between the two groups. Conclusion: The results showed that plaques from the CAD group were associated with higher critical plaque wall stresses compared with plaques from the non-CAD group, suggesting that CPWS may serve to predict event risk, and may provide more accurate plaque vulnerability assessment. Prospective and large-scale studies are needed to further validate our findings.