title: Intravascular ultrasound-guided treatment for angiographically indeterminate left main coronary artery disease: a long-term follow-up study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the efficacy of an intravascular ultrasound (IVUS)-guided strategy for patients with angiographically indeterminate left main coronary artery (LMCA) disease.
  
  
  BACKGROUND
  The assessment of LMCA lesions using coronary angiography is often challenging; IVUS provides useful information for assessment of coronary disease.
  
  
  METHODS
  Intravascular ultrasound was performed on 121 patients with angiographically normal LMCAs to determine the lower range of normal minimum lumen area (MLA), defined as the mean - 2 SD. We conducted IVUS studies on 214 patients with angiographically indeterminate LMCA lesions, and deferral of revascularization was recommended when the MLA was larger than this predetermined value.
  
  
  RESULTS
  The lower range of normal LMCA MLA was 7.5 mm(2). Of the patients with angiographically indeterminate LMCAs, 83 (38.8%) had an MLA <7.5 mm(2), and 131 (61.2%) an MLA > or =7.5 mm(2). Left main coronary artery revascularization was performed in 85.5% (71 of 83) of patients with an MLA <7.5 mm(2) and deferred in 86.9% (114 of 131) of patients with an MLA > or =7.5 mm(2). Long-term follow-up (mean 3.3 +/- 2.0 years) showed no significant difference in major adverse cardiac events (target vessel revascularization, acute myocardial infarction, and death) between patients with an MLA <7.5 mm(2) who underwent revascularization and those with an MLA > or =7.5 mm(2) deferred for revascularization (p = 0.28). Based on outcome, the best cut-off MLA by receiver operating characteristic was 9.6 mm(2). Multivariate predictors of cardiac events were age, smoking, and number of non-LMCA vessels diseased.
  
  
  CONCLUSIONS
  Intravascular ultrasound is an accurate method to assess angiographically indeterminate lesions of the LMCA. Furthermore, deferring revascularization for patients with a minimum lumen area > or =7.5 mm(2) appears to be safe.
authors.affiliation: Center of Coronary Physiology and Imaging, Cardiac Catheterization Laboratory, Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: Amir-Ali
authors.initials: AA
authors.lastname: Fassa
authors.forename: Kenji
authors.initials: K
authors.lastname: Wagatsuma
authors.forename: Stuart T
authors.initials: ST
authors.lastname: Higano
authors.forename: Verghese
authors.initials: V
authors.lastname: Mathew
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Barsness
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Lennon
authors.forename: David R
authors.initials: DR
authors.lastname: Holmes
authors.forename: Amir
authors.initials: A
authors.lastname: Lerman
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization; D015203:Reproducibility of Results; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional