title: In vivo quantitative tissue characterization of angiographically normal coronary lesions and the relation with risk factors: a study using integrated backscatter intravascular ultrasound.
abstract: BACKGROUND
  Autopsy studies have shown atherosclerotic changes in angiographically normal coronary lesions (ANCL), and conventional intravascular ultrasound shows intimal thickening in these lesions, but cannot differentiate the lipid core. Accurate characterization of ANCL is essential to prevent progression to coronary artery disease.
  
  
  RESULTS
  ANCL (n=120) were analyzed by integrated backscatter intravascular ultrasound (IB-IVUS) in 30 patients with stable angina pectoris. Of the 120 arterial segments analyzed by IB-IVUS, 78 (65%) showed lipid cores of 0.69+/-0.35 mm2 with fibrous caps of 200+/-100 microm thick, 44 (37%) had intimal hyperplasia with a thickness of 350+/-100 microm, and 65 (54%) showed fibrosis in the intimal wall without lipid core with a thickness of 450+/-150 microm. The diabetes mellitus (DM) group (n=14) had significantly (p<0.05) bigger lipid cores (0.62+/-0.38 mm2) and thinner intimal hyperplasia (100+/-100 microm) compared with the non-DM group (0.31+/-0.33 mm2, 150+/-150 microm, respectively). The hypertension (HT) group (n=23) had significantly more intimal hyperplasia (150+/-150 microm) compared with the non-HT group (50+/-100 microm). Hyperlipidemia (n=16) or smoking (n=6) did not significantly affect tissue characteristics.
  
  
  CONCLUSIONS
  IB-IVUS showed various types of plaque in ANCL and the plaque characteristics were affected by DM and HT. The results provide new clinical insight into the early stage of human coronary atherosclerosis.
authors.affiliation: Regeneration & Advanced Medical Science, Division of Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Sano
authors.forename: Masanori
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Munenori
authors.initials: M
authors.lastname: Okubo
authors.forename: Haruko
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ito
authors.forename: Ichijiro
authors.initials: I
authors.lastname: Murata
authors.forename: Takao
authors.initials: T
authors.lastname: Kawai
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nishigaki
authors.forename: Genzou
authors.initials: G
authors.lastname: Takemura
authors.forename: Shinya
authors.initials: S
authors.lastname: Minatoguchi
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Zhou
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujita
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Fujiwara
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014463:Ultrasonography