title: The effects of plaque morphology and material properties on peak cap stress in human coronary arteries.
abstract: Heart attacks are often caused by rupture of caps of atherosclerotic plaques in coronary arteries. Cap rupture occurs when cap stress exceeds cap strength. We investigated the effects of plaque morphology and material properties on cap stress. Histological data from 77 coronary lesions were obtained and segmented. In these patient-specific cross sections, peak cap stresses were computed by using finite element analyses. The finite element analyses were 2D, assumed isotropic material behavior, and ignored residual stresses. To represent the wide spread in material properties, we applied soft and stiff material models for the intima. Measures of geometric plaque features for all lesions were determined and their relations to peak cap stress were examined using regression analyses. Patient-specific geometrical plaque features greatly influence peak cap stresses. Especially, local irregularities in lumen and necrotic core shape as well as a thin intima layer near the shoulder of the plaque induce local stress maxima. For stiff models, cap stress increased with decreasing cap thickness and increasing lumen radius (R = 0.79). For soft models, this relationship changed: increasing lumen radius and increasing lumen curvature were associated with increased cap stress (R = 0.66). The results of this study imply that not only accurate assessment of plaque geometry, but also of intima properties is essential for cap stress analyses in atherosclerotic plaques in human coronary arteries.
authors.affiliation: a Department of Biomedical Engineering , Thoraxcenter, Erasmus Medical Center , Rotterdam , The Netherlands.
authors.forename: Ali C
authors.initials: AC
authors.lastname: Akyildiz
authors.affiliation: a Department of Biomedical Engineering , Thoraxcenter, Erasmus Medical Center , Rotterdam , The Netherlands.|b Interuniversity Cardiology Institute of the Netherlands (ICIN) , Utrecht , The Netherlands.
authors.forename: Lambert
authors.initials: L
authors.lastname: Speelman
authors.affiliation: a Department of Biomedical Engineering , Thoraxcenter, Erasmus Medical Center , Rotterdam , The Netherlands.
authors.forename: Harm A
authors.initials: HA
authors.lastname: Nieuwstadt
authors.affiliation: c Department of Mechanical Engineering , Eindhoven University of Technology , Eindhoven , The Netherlands.|d Department of Mathematics and Computer Science , Eindhoven University of Technology , Eindhoven , The Netherlands.
authors.forename: Harald
authors.initials: H
authors.lastname: van Brummelen
authors.affiliation: e CVPath Institute, Inc. , Gaithersburg , MD , USA.
authors.forename: Renu
authors.initials: R
authors.lastname: Virmani
authors.affiliation: f Department of Radiology , Erasmus Medical Center , Rotterdam , The Netherlands.
authors.forename: Aad
authors.initials: A
authors.lastname: van der Lugt
authors.affiliation: a Department of Biomedical Engineering , Thoraxcenter, Erasmus Medical Center , Rotterdam , The Netherlands.|g Department of Applied Sciences , Delft University of Technology, Delft , , The Netherlands.
authors.forename: Anton F W
authors.initials: AF
authors.lastname: van der Steen
authors.affiliation: a Department of Biomedical Engineering , Thoraxcenter, Erasmus Medical Center , Rotterdam , The Netherlands.
authors.forename: Jolanda J
authors.initials: JJ
authors.lastname: Wentzel
authors.affiliation: a Department of Biomedical Engineering , Thoraxcenter, Erasmus Medical Center , Rotterdam , The Netherlands.
authors.forename: Frank J H
authors.initials: FJ
authors.lastname: Gijsen
mesh_terms: D003331:Coronary Vessels / Q000473:pathology*; D020342:Finite Element Analysis; D006801:Humans; D008955:Models, Cardiovascular; D009203:Myocardial Infarction / Q000473:pathology; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D013314:Stress, Mechanical; D017539:Tunica Intima / Q000473:pathology
keywords: atherosclerosis; cap stress; finite element models; plaque morphology; plaque properties