title: Human coronary plaque wall thickness correlated positively with flow shear stress and negatively with plaque wall stress: an IVUS-based fluid-structure interaction multi-patient study.
abstract: BACKGROUND
  Atherosclerotic plaque progression and rupture are believed to be associated with mechanical stress conditions. In this paper, patient-specific in vivo intravascular ultrasound (IVUS) coronary plaque image data were used to construct computational models with fluid-structure interaction (FSI) and cyclic bending to investigate correlations between plaque wall thickness and both flow shear stress and plaque wall stress conditions.
  
  
  METHODS
  IVUS data were acquired from 10 patients after voluntary informed consent. The X-ray angiogram was obtained prior to the pullback of the IVUS catheter to determine the location of the coronary artery stenosis, vessel curvature and cardiac motion. Cyclic bending was specified in the model representing the effect by heart contraction. 3D anisotropic FSI models were constructed and solved to obtain flow shear stress (FSS) and plaque wall stress (PWS) values. FSS and PWS values were obtained for statistical analysis. Correlations with p < 0.05 were deemed significant.
  
  
  RESULTS
  Nine out of the 10 patients showed positive correlation between wall thickness and flow shear stress. The mean Pearson correlation r-value was 0.278 ± 0.181. Similarly, 9 out of the 10 patients showed negative correlation between wall thickness and plaque wall stress. The mean Pearson correlation r-value was -0.530 ± 0.210.
  
  
  CONCLUSIONS
  Our results showed that plaque vessel wall thickness correlated positively with FSS and negatively with PWS. The patient-specific IVUS-based modeling approach has the potential to be used to investigate and identify possible mechanisms governing plaque progression and rupture and assist in diagnosis and intervention procedures. This represents a new direction of research. Further investigations using more patient follow-up data are warranted.
authors.forename: Rui
authors.initials: R
authors.lastname: Fan
authors.affiliation: School of Biological Science and Medical Engineering, Southeast University, Nanjing, China. dtang@wpi.edu.
authors.forename: Dalin
authors.initials: D
authors.lastname: Tang
authors.forename: Chun
authors.initials: C
authors.lastname: Yang
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.forename: Richard
authors.initials: R
authors.lastname: Bach
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.forename: David
authors.initials: D
authors.lastname: Muccigrosso
authors.forename: Kristen
authors.initials: K
authors.lastname: Billiar
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.forename: Genshan
authors.initials: G
authors.lastname: Ma
authors.forename: Akiko
authors.initials: A
authors.lastname: Maehara
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
mesh_terms: D000368:Aged; D000465:Algorithms; D016880:Anisotropy; D003198:Computer Simulation; D003331:Coronary Vessels / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology*; D033081:Shear Strength; D012815:Signal Processing, Computer-Assisted; D013314:Stress, Mechanical; D014463:Ultrasonography