title: Morphological and Stress Vulnerability Indices for Human Coronary Plaques and Their Correlations with Cap Thickness and Lipid Percent: An IVUS-Based Fluid-Structure Interaction Multi-patient Study.
abstract: Plaque vulnerability, defined as the likelihood that a plaque would rupture, is difficult to quantify due to lack of in vivo plaque rupture data. Morphological and stress-based plaque vulnerability indices were introduced as alternatives to obtain quantitative vulnerability assessment. Correlations between these indices and key plaque features were investigated. In vivo intravascular ultrasound (IVUS) data were acquired from 14 patients and IVUS-based 3D fluid-structure interaction (FSI) coronary plaque models with cyclic bending were constructed to obtain plaque wall stress/strain and flow shear stress for analysis. For the 617 slices from the 14 patients, lipid percentage, min cap thickness, critical plaque wall stress (CPWS), strain (CPWSn) and flow shear stress (CFSS) were recorded, and cap index, lipid index and morphological index were assigned to each slice using methods consistent with American Heart Association (AHA) plaque classification schemes. A stress index was introduced based on CPWS. Linear Mixed-Effects (LME) models were used to analyze the correlations between the mechanical and morphological indices and key morphological factors associated with plaque rupture. Our results indicated that for all 617 slices, CPWS correlated with min cap thickness, cap index, morphological index with r = -0.6414, 0.7852, and 0.7411 respectively (p<0.0001). The correlation between CPWS and lipid percentage, lipid index were weaker (r = 0.2445, r = 0.2338, p<0.0001). Stress index correlated with cap index, lipid index, morphological index positively with r = 0.8185, 0.3067, and 0.7715, respectively, all with p<0.0001. For all 617 slices, the stress index has 66.77% agreement with morphological index. Morphological and stress indices may serve as quantitative plaque vulnerability assessment supported by their strong correlations with morphological features associated with plaque rupture. Differences between the two indices may lead to better plaque assessment schemes when both indices were jointly used with further validations from clinical studies.
authors.affiliation: Mathematical Sciences Department, Worcester Polytechnic Institute, Massachusetts, United States of America.
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri, United States of America.
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.affiliation: The Cardiovascular Research Foundation, New York, New York, United States of America.
authors.forename: Akiko
authors.initials: A
authors.lastname: Maehara
authors.affiliation: Mathematical Sciences Department, Worcester Polytechnic Institute, Massachusetts, United States of America.|Network Technology Research Institute, China United Network Communications Co., Ltd., Beijing, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Yang
authors.affiliation: Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America.
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Billiar
authors.affiliation: Mathematical Sciences Department, Worcester Polytechnic Institute, Massachusetts, United States of America.
authors.forename: Zheyang
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, United States of America.
authors.forename: Richard
authors.initials: R
authors.lastname: Bach
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: Muccigrosso
authors.affiliation: The Cardiovascular Research Foundation, New York, New York, United States of America.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.affiliation: Mathematical Sciences Department, Worcester Polytechnic Institute, Massachusetts, United States of America.|School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
authors.forename: Dalin
authors.initials: D
authors.lastname: Tang