title: Target lesion thin-cap fibroatheroma defined by virtual histology intravascular ultrasound affects microvascular injury during percutaneous coronary intervention in patients with angina pectoris.
abstract: BACKGROUND
  Several reports suggest that virtual histology intravascular ultrasound (VH-IVUS) assessment could predict microvascular damage during percutaneous coronary intervention (PCI). A novel index of microcirculatory resistance (IMR) has been developed as a reproducible and less hemodynamic-dependent index. The purpose of this study was to investigate the relationship between thin-cap fibroatheroma (TCFA) defined by VH-IVUS and a change in the IMR during PCI in patients with angina pectoris (AP).
  
  
  RESULTS
  The study investigated 30 lesions from 28 AP patients. VH-IVUS imaging was performed before PCI. TCFA was defined as the presence of confluent necrotic core (>10%) without detectable overlying fibrous cap segment. Patients were divided into 2 groups according to the presence of TCFA. Using a pressure guidewire, IMR were measured before and after PCI. After successful PCI, patients were prospectively followed up clinically. TCFA was detected in 9 lesions (30%). IMR tended to improve after PCI in the non-TCFA group, but tended to worsen in the TCFA group. DeltaIMR (=IMR after PCI-IMR before PCI) was significantly higher in the TCFA group compared with the non-TCFA group (13.2+/-29.9 vs -4.4+/-16.0, P=0.04). During follow-up (mean 20 months), survival free of major adverse cardiac events was significantly less in the TCFA group than in the non-TCFA group.
  
  
  CONCLUSIONS
  Target lesion TCFA may be related to both microvascular injury and the long-term clinical outcome after successful PCI in patients with AP.
authors.affiliation: Division of Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Yamada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okura
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Kume
authors.forename: Yoji
authors.initials: Y
authors.lastname: Neishi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kawamoto
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Koichiro
authors.initials: K
authors.lastname: Imai
authors.forename: Ken
authors.initials: K
authors.lastname: Saito
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hayashida
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000628:therapy*; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D055806:Microvessels / Q000293:injuries*; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D014655:Vascular Resistance