title: Effect of tissue properties, shape and orientation of microcalcifications on vulnerable cap stability using different hyperelastic constitutive models.
abstract: Approximately half of all cardiovascular deaths associated with acute coronary syndrome occur when the thin fibrous cap tissue overlying the necrotic core in a coronary vessel is torn, ripped or fissured under the action of high blood pressure. From a biomechanics point of view, the rupture of an atheroma is due to increased mechanical stresses in the lesion, in which the ultimate stress (i.e. peak circumferential stress (PCS) at failure) of the tissue is exceeded. Several factors including the cap thickness, morphology, residual stresses and tissue composition of the atheroma have been shown to affect the PCS. Also important, we recently demonstrated that microcalcifications (μCalcs>5 µm are a common feature in human atheroma caps, which behave as local stress concentrators, increasing the local tissue stress by at least a factor of two surpassing the ultimate stress threshold for cap tissue rupture. In the present study, we used both idealized µCalcs with spherical shape and actual µCalcs from human coronary atherosclerotic caps, to determine their effect on increasing the circumferential stress in the fibroatheroma cap using different hyperelastic constitutive models. We have found that the stress concentration factor (SCF) produced by μCalcs in the fibroatheroma cap is affected by the material tissue properties, μCalcs spacing, aspect ratio and their alignment relative to the tensile axis of the cap.
authors: Department of Biomedical Engineering, The City College of The City University of New York, New York, USA; The Graduate Center of The City University of New York, New York, NY, USA.
authors: Luis
authors: L
authors: Cardoso
authors: Department of Biomedical Engineering, The City College of The City University of New York, New York, USA.
authors: Adreanne
authors: A
authors: Kelly-Arnold
authors: Department of Biomedical Engineering, The City College of The City University of New York, New York, USA.
authors: Natalia
authors: N
authors: Maldonado
authors: Department of Biomedical Engineering, The City College of The City University of New York, New York, USA.
authors: Damien
authors: D
authors: Laudier
authors: Department of Biomedical Engineering, The City College of The City University of New York, New York, USA; The Graduate Center of The City University of New York, New York, NY, USA. Electronic address: Weinbaum@ccny.cuny.edu.
authors: Sheldon
authors: S
authors: Weinbaum
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003331:Coronary Vessels / Q000473:pathology; D004548:Elasticity / Q000502:physiology; D020342:Finite Element Analysis; D006801:Humans; D008955:Models, Cardiovascular; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012422:Rupture, Spontaneous / Q000000981:diagnostic imaging / Q000503:physiopathology; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000503:physiopathology*; D055114:X-Ray Microtomography
keywords: Fibrous cap rupture; Micro computed tomography; Microcalcifications; Vulnerable plaque