title: Relationship among coronary plaque compliance, coronary risk factors and tissue characteristics evaluated by integrated backscatter intravascular ultrasound.
abstract: BACKGROUND
  The purpose of the present study was to evaluate the mechanical properties of coronary plaques and plaque behavior, and to elucidate the relationship among tissue characteristics of coronary plaques, mechanical properties and coronary risk factors using integrated backscatter intravascular ultrasound (IB-IVUS).
  
  
  METHODS
  Non-targeted plaques with moderate stenosis (plaque burden at the minimal lumen site: 50-70%) located proximal to the site of the percutaneous coronary intervention target lesions were evaluated by IB-IVUS. Thirty-six plaques (less calcified group: an arc of calcification ≤10°) in 36 patients and 22 plaques (moderately calcified group: 10° < an arc of calcification ≤60°) in 22 patients were evaluated. External elastic membrane volume (EEMV) compliance, lumen volume (LV) compliance, plaque volume (PV) response (difference between PV in systole and diastole), EEM area stiffness index were measured at the minimal lumen site. Relative lipid volume (lipid volume/internal elastic membrane volume) was calculated by IB-IVUS.
  
  
  RESULTS
  In the less calcified group, there was a significant correlation between EEMV compliance and the relative lipid volume (r = 0.456, p = 0.005). There was a significant inverse correlation between EEM area stiffness index and the relative lipid volume (p = 0.032, r = -0.358). The LV compliance and EEM area stiffness index were significantly different in the diabetes mellitus (DM) group than in the non-DM group (1.32 ± 1.49 vs. 2.47 ± 1.79%/10 mmHg, p =0.014 and 28.3 ± 26.0 vs. 15.7 ± 17.2, p =0.020). The EEMV compliance and EEM area stiffness index were significantly different in the hypertension (HTN) group than in the non-HTN group (0.77 ± 0.68 vs. 1.57 ± 0.95%/10 mmHg, p =0.012 and 26.5 ± 24.3 vs. 13.0 ± 16.7, p =0.020). These relationships were not seen in the moderately calcified group.
  
  
  CONCLUSIONS
  The present study provided new findings that there was a significant correlation between mechanical properties and tissue characteristics of coronary arteries. In addition, our results suggested that the EEMV compliance and the LV compliance were independent and the compliance was significantly impaired in the patients with DM and/or HTN. Assessment of coronary mechanical properties during PCI may provide us with useful information regarding the risk stratification of patients with coronary heart disease.
authors: Department of Cardiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan. masanori@ya2.so-net.ne.jp
authors: Yoshiyuki
authors: Y
authors: Ishihara
authors: Masanori
authors: M
authors: Kawasaki
authors: Arihiro
authors: A
authors: Hattori
authors: Hajime
authors: H
authors: Imai
authors: Shigekiyo
authors: S
authors: Takahashi
authors: Hironobu
authors: H
authors: Sato
authors: Tomoki
authors: T
authors: Kubota
authors: Munenori
authors: M
authors: Okubo
authors: Shinsuke
authors: S
authors: Ojio
authors: Kazuhiko
authors: K
authors: Nishigaki
authors: Genzou
authors: G
authors: Takemura
authors: Hisayoshi
authors: H
authors: Fujiwara
authors: Shinya
authors: S
authors: Minatoguchi
mesh_terms: D000368:Aged; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D058226:Plaque, Atherosclerotic / Q000150:complications / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional