title: Calcification analysis by intravascular ultrasound to define a predictor of left circumflex narrowing after cross-over stenting for unprotected left main bifurcation lesions.
abstract: OBJECTIVE
  The aim of this study was to identify predictors of significant LCx-ostium compromise after distal unprotected left main coronary artery (ULMCA) stenting on the basis of baseline intravascular ultrasound (IVUS).
  
  
  BACKGROUND
  Provisional single-stenting is considered as the default strategy for non-true bifurcation lesions in ULMCA. However, in certain cases, left circumflex artery (LCx)-ostium stenting is necessary.
  
  
  METHODS
  A total of 77 patients underwent percutaneous coronary intervention with drug-eluting stents for non-true bifurcation lesions in ULMCA and had IVUS evaluation. Pre-procedural IVUS was performed to measure cross-sectional areas at the following segments: left main trunk, left anterior descending artery (LAD)-ostium. Post-stenting-narrowing at the circumflex ostium (PSN-LCx) was defined as the presence of more than 50% diameter stenosis at the LCx-ostium as determined by quantitative coronary angiography analysis.
  
  
  RESULTS
  PSN-LCx occurred in 27 (35%) patients. The presence of calcified plaque at the culprit lesion as identified by IVUS was more frequently observed in the PSN-LCx group as compared to the non-PSN-LCx group (81.5% vs. 22.0%, p<0.001). Calcium arc in the PSN-LCx group was significantly greater than that in the non-PSN-LCx group (118.1°±69.9° vs. 36.9°±63.0°, p<0.001). On multivariable analysis, a calcium arc>60° was an independent predictor of PSN-LCx (odds ratio: 5.12, 95% confidence interval: 1.21-25.01, p=0.03).
  
  
  CONCLUSIONS
  The presence of calcified plaque at the culprit lesion appears to be one of the factors involved in LCx-ostial compromise in non-true bifurcation ULMCA lesions, especially when the calcium arc is >60°.
authors.affiliation: Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy; Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Kastsumasa
authors.initials: K
authors.lastname: Sato
authors.affiliation: Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
authors.forename: Toru
authors.initials: T
authors.lastname: Naganuma
authors.affiliation: Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
authors.forename: Charis
authors.initials: C
authors.lastname: Costopoulos
authors.affiliation: Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Takebayashi
authors.affiliation: Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Goto
authors.affiliation: Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Miyazaki
authors.affiliation: Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamane
authors.affiliation: Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Arata
authors.initials: A
authors.lastname: Hagikura
authors.affiliation: Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Yuetsu
authors.initials: Y
authors.lastname: Kikuta
authors.affiliation: Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Taniguchi
authors.affiliation: Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Hiramatsu
authors.affiliation: Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
authors.forename: Azeem
authors.initials: A
authors.lastname: Latib
authors.affiliation: Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.affiliation: Fukuyama Cardiovascular Hospital, Fukuyama, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Haruta
authors.affiliation: Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy. Electronic address: info@emocolumbus.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Colombo
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D054855:Drug-Eluting Stents; D006801:Humans; D007558:Italy; D007564:Japan; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation*; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000628:therapy*
keywords: Bifurcation; Intravascular ultrasound; Left main coronary artery stenosis; Plaque morphology