title: Prospective application of pre-defined intravascular ultrasound criteria for assessment of intermediate left main coronary artery lesions results from the multicenter LITRO study.
abstract: OBJECTIVE
  This study is a prospective validation of 6 mm(2) as a minimum lumen area (MLA) cutoff value for revascularization of left main coronary artery (LMCA) lesions.
  
  
  BACKGROUND
  Lesions involving the LMCA are prognostically relevant. Angiography has important limitations in the evaluation of LMCA lesions with intermediate severity. An MLA of 6 mm(2) assessed by intravascular ultrasound has been proposed as a cutoff value to determine lesion severity, but there are no large studies evaluating the prospective application and safety of this approach.
  
  
  METHODS
  We have designed a multicenter, prospective study. Consecutive patients with intermediate lesions in unprotected LMCA were evaluated with intravascular ultrasound. An MLA <6 mm(2) was used as criterion for revascularization.
  
  
  RESULTS
  A total of 354 patients were included in 22 centers. LMCA revascularization was performed in 90.5% (152 of 168) of patients with an MLA <6 mm(2) and was deferred in 96% (179 of 186) of patients with an MLA of 6 mm(2) or more. A large scatter was observed between both groups regarding angiographic parameters. In a 2-year follow-up period, cardiac death-free survival was 97.7% in the deferred group versus 94.5% in the revascularized group (p = 0.5), and event-free survival was 87.3% versus 80.6%, respectively (p = 0.3). In the 2-year period, only 8 (4.4%) patients in the deferred group required subsequent LMCA revascularization, none with an infarction.
  
  
  CONCLUSIONS
  Angiographic measurements are not reliable in the assessment of intermediate LMCA lesions. An MLA of 6 mm(2) or more is a safe value for deferring revascularization of the LMCA, given the application of the clinical and angiographic inclusion criteria used in this study.
authors.affiliation: Hospital Marques de Valdecilla, IFIMAV, Santander, Spain.
authors.forename: Jose M
authors.initials: JM
authors.lastname: de la Torre Hernandez
authors.forename: Felipe
authors.initials: F
authors.lastname: Hernández Hernandez
authors.forename: Fernando
authors.initials: F
authors.lastname: Alfonso
authors.forename: Jose R
authors.initials: JR
authors.lastname: Rumoroso
authors.forename: Ramon
authors.initials: R
authors.lastname: Lopez-Palop
authors.forename: Mario
authors.initials: M
authors.lastname: Sadaba
authors.forename: Pilar
authors.initials: P
authors.lastname: Carrillo
authors.forename: Juan
authors.initials: J
authors.lastname: Rondan
authors.forename: Iñigo
authors.initials: I
authors.lastname: Lozano
authors.forename: Juan M
authors.initials: JM
authors.lastname: Ruiz Nodar
authors.forename: Jose A
authors.initials: JA
authors.lastname: Baz
authors.forename: Eduard
authors.initials: E
authors.lastname: Fernandez Nofrerias
authors.forename: Fernando
authors.initials: F
authors.lastname: Pajin
authors.forename: Tamara
authors.initials: T
authors.lastname: Garcia Camarero
authors.forename: Hipolito
authors.initials: H
authors.lastname: Gutierrez
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional