title: Assessing intermediate left main coronary lesions using intravascular ultrasound.
abstract: BACKGROUND
  Angiographic assessment of a left main coronary artery stenosis (LMCS) is often difficult and unreliable. We aimed to evaluate the severity of ambiguous LMCSs by intravascular ultrasound (IVUS) and to clarify how frequently significant stenosis occurs in the "real world".
  
  
  METHODS
  We retrospectively found 115 consecutive patients in our clinical IVUS database with a de novo, angiographically ambiguous, intermediate LMCS who underwent IVUS evaluation. Quantitative coronary angiography (QCA) and IVUS analyses were performed. We define a significant LMCS as a diameter stenosis >50% by QCA and a minimal lumen area <6.0 mm2 by IVUS.
  
  
  RESULTS
  Ostial, mid, and distal LMCSs were seen in 44 (38.3%), 6 (5.2%), and 65 (56.5%) lesions. Overall, IVUS minimal lumen area and plaque burden measured 6.8 +/- 2.6 mm2 and 63% +/- 14%. A significant LMCS was seen in 51 (44.3%) lesions by IVUS but in only 15 (13.0%) lesions by QCA. In particular, only 36.4% of ostial lesions had a significant IVUS stenosis, and minimal lumen diameter by QCA was less well correlated with IVUS in ostial lesions than in other lesion locations.
  
  
  CONCLUSIONS
  This real-world IVUS analysis showed that less than half of intermediate LMCSs had significant stenoses by IVUS assessment, especially for lesions located at the left main ostium. Such patients deserve IVUS assessment or physiologic assessment before blindly proceeding to revascularization.
authors.affiliation: Columbia University Medical Center and Cardiovascular Research Foundation, New York, NY, USA.
authors.forename: Koichi
authors.initials: K
authors.lastname: Sano
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.forename: Stéphane G
authors.initials: SG
authors.lastname: Carlier
authors.forename: Jose
authors.initials: J
authors.lastname: de Ribamar Costa
authors.forename: Jie
authors.initials: J
authors.lastname: Qian
authors.forename: Eduardo
authors.initials: E
authors.lastname: Missel
authors.forename: Shoujie
authors.initials: S
authors.lastname: Shan
authors.forename: Theresa
authors.initials: T
authors.lastname: Franklin-Bond
authors.forename: Paul
authors.initials: P
authors.lastname: Boland
authors.forename: Giora
authors.initials: G
authors.lastname: Weisz
authors.forename: Issam
authors.initials: I
authors.lastname: Moussa
authors.forename: George D
authors.initials: GD
authors.lastname: Dangas
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Lansky
authors.forename: Edward M
authors.initials: EM
authors.lastname: Kreps
authors.forename: Michael B
authors.initials: MB
authors.lastname: Collins
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
authors.forename: Martin B
authors.initials: MB
authors.lastname: Leon
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Moses
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional / Q000379:methods*