Coronary atheroma develop in local sites that are widely variable among patients and are considerably variable in their vulnerability for rupture. This talk will present a topical review of studies conducted by our international consortium on predictive biomechanical modeling of coronary plaque that investigate site of development, morphologic features that determine stability, and emerging in vivo models of rupture probability. Biomechanical, in conjunction with hemodynamic factors that influence the actual site of development of plaques have been studied. Plaque vulnerability, in vivo, is more challenging to assess. Important steps have been made in defining the biomechanical factors that are predictive of plaque rupture and the likelihood of this occurring if characteristic features are known. A critical key in defining plaque vulnerability is the accurate quantification of both the morphology and the mechanical properties of the diseased arteries. Recently, an early IVUS based palpography technique developed to assess local strain, elasticity and mechanical instabilities has been successfully revisited and improved to account for complex plaque geometries. This is based on an initial best estimation of the plaque components’ contours, allowing subsequent iteration for elastic modulus assessment as a basis for plaque stability determination. The improved method has also been preliminarily evaluated in patients with successful histologic correlation. Further clinical evaluation and refinement are on the horizon.
Bibliographie
Deleaval F, Bouvier A, Finet G, Cloutier G, Yazdani SK, Le Floc’h S, Clarysse P, Pettigrew RI, Ohayon J. The intravascular ultrasound elasticity-palpography technique revisited : A reliable tool for the in vivo detection of vulnerable coronary atherosclerotic plaques. Ultrasound in Medicine and Biology, (in press), 2013.Bouvier A, Deleaval F, Doyley MM, Yazdani SK, Finet G, Le Floc’h S, Cloutier G, Pettigrew RI, Ohayon J. A Direct Vulnerable Atherosclerotic Plaque Elasticity Reconstruction Method Based on an Original Material-Finite Element Formulation : Theoretical Framework. Phys. Med. Biol., (in press), 2013.
Le Floc’h S, Cloutier G, Saijo Y, Finet G, Yazdani SK, Deleaval F, Rioufol G, Pettigrew RI and Ohayon J. A Four-Criterion Selection Procedure for Atherosclerotic Plaque Elasticity Reconstruction based on in Vivo Coronary Intravascular Ultrasound Radial Strain Sequences. Ultrasound in Medicine and Biology, 38(12):2084-97, 2012.
Ohayon J, Mesnier N, Broisat A, Toczek J, Riou L, Tracqui P. Elucidating atherosclertic vulnerable plaque rupture by modeling cross substitution of ApoE-/- mouse and human plaque component stiffnesses. Biomechanics and Modeling in Mechanobiology, 11(6):801-13, 2012.
Ohayon J, Gharib AM, Garcia A, Heroux J, Yazdani SK, Malvè M, Tracqui P, Martinez MA, Doblare M, Finet G, Pettigrew RI. Is arterial wall-strain stiffening and additional process responsible for atherosclerosis in coronary bifurcations ? in vivo Study Based on Dynamic CT and MRI. Am J Physiol Heart Circ Physiol. 301:H1097-106, 2011.
