Coronary artery atherectomy reduces plaque shear strains: an endovascular elastography imaging study.
Mechanical response and properties of the arterial wall can be used to identify the biomechanical instability of plaques and predict their vulnerability to rupture. Shear strain elastography (SSE) is proposed to identify vulnerable plaque features attributed to mechanical structural heterogeneities. The aims of this study were: 1) to report on the potential of SSE to identify atherosclerotic plaques; and 2) to use SSE maps to highlight biomechanical changes in lesion characteristics after directional coronary atherectomy (DCA) interventions. For this purpose, SSE was imaged using in vivo intravascular ultrasound (IVUS) radio-frequency data collected from 12 atherosclerotic patients before and after DCA intervention. Coronary atherosclerotic plaques (pre-DCA) showed high SSE magnitudes with large affected areas. There were good correlations between SSE levels and soft plaque content (i.e., cellular fibrosis, thrombosis and fibrin) (mean |SSE| vs. soft plaque content: r = 0.82, p < 0.01). Significant differences were noticed between SSE images before and after DCA. Stable arteries (post-DCA) exhibited lower values than pre-DCA vessels (e.g., pre-DCA: mean |SSE| = 3.9 ± 0.2% vs. 1.1 ± 0.2% post-DCA, p < 0.001). Furthermore, SSE magnitude was statistically higher in plaques with a high level of inflammation (e.g., mean |SSE| had values of 4.8 ± 0.4% in plaques with high inflammation, whereas it was reduced to 1.8 ± 0.2% with no inflammation, p < 0.01). This study demonstrates the potential of the IVUS-based SSE technique to detect vulnerable plaques in vivo.
Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada.
Zahra
Z
Keshavarz-Motamed
Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan; Department of Cardiology, Tohoku University, Sendai, Japan.
Yoshifumi
Y
Saijo
Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada.
Younes
Y
Majdouline
INSERM, UMR_S 1039, Bioclinical Radiopharmaceutic, Faculty of Medicine, University Joseph-Fourier, Grenoble, France.
Laurent
L
Riou
Laboratory TIMC-IMAG/DyCTiM, University Joseph-Fourier, CNRS UMR 5525, Grenoble, France; University of Savoie, Polytech Annecy-Chambery, Le Bourget du Lac, France.
Jacques
J
Ohayon
Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada; Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, University of Montreal, Montréal, Québec, Canada. Electronic address: guy.cloutier@umontreal.ca.
Guy
G
Cloutier
D000465:Algorithms; D017073:Atherectomy; D003094:Collagen / Q000737:chemistry; D003331:Coronary Vessels / Q000601:surgery*; D054459:Elasticity Imaging Techniques; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007249:Inflammation; D016018:Least-Squares Analysis; D009038:Motion; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000601:surgery*; D012421:Rupture; D033081:Shear Strength; D013314:Stress, Mechanical; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
D003094:Collagen
Human study; Image processing; Intravascular ultrasound; Shear strain imaging; Vascular elastography; Vulnerable coronary atherosclerotic plaques