title: Lessons learned from the use of 1,977 in-situ bilateral internal mammary arteries: a retrospective study.
abstract: BACKGROUND
  We sought to determine the early and long-term results of in-situ bilateral internal mammary artery (BIMA) grafting in patients undergoing coronary artery bypass graft surgery (CABG).
  
  
  METHODS
  Between 1992 and 2011, 16,364 patients underwent primary isolated CABG involving at least one in-situ IMA at our institution. Among these, 1,977 patients underwent in-situ BIMA grafting: the right IMA was used to revascularize the right coronary artery system in 1,279, the circumflex system in 454 patients, and the left anterior descending (LAD) in 244. Logistic and Cox regression analyses were used to predict in-hospital mortality and cumulative late death.
  
  
  RESULTS
  Late survival among BIMA patients was negatively and independently influenced by chronic obstructive pulmonary disease (hazard ratio (HR) 2.4, 95% confidence interval (CI) 1.6-3.4, p = 0.0005), age (HR 1.2, 95% CI 1.1-1.3, p < 0.001), and mediastinitis (HR 2.1, 95% CI 1.1-4.2, p < 0.03). Gender, body mass index, diabetes, choice of target for the second (non-LAD) IMA, and conduit grafted to the LAD (RIMA vs. LIMA) did not influence late survival among BIMA patients. A BIMA grafting strategy was significantly beneficial for younger patients. However, it was not associated with superior late survival for patients aged 66 years and above at the time of CABG, and showed a trend to harm among octogenarians (HR 1.05, 95% CI 0.70-1.56, p = 0.80).
  
  
  CONCLUSIONS
  Female gender, non-insulin dependent diabetes, and the site of second IMA anastomosis did not influence early and long-term outcomes in patients undergoing CABG with in-situ BIMA grafting. The right and left IMAs are equally effective conduits for the LAD. However, advanced age, chronic obstructive pulmonary disease, and insulin-treated diabetes mellitus have a negative impact on late survival among patients with BIMA grafts.
authors.forename: Siamak
authors.initials: S
authors.lastname: Mohammadi
authors.forename: Francois
authors.initials: F
authors.lastname: Dagenais
authors.forename: Pierre
authors.initials: P
authors.lastname: Voisine
authors.forename: Eric
authors.initials: E
authors.lastname: Dumont
authors.forename: Richard
authors.initials: R
authors.lastname: Baillot
authors.forename: Daniel
authors.initials: D
authors.lastname: Doyle
authors.forename: Eric
authors.initials: E
authors.lastname: Charbonneau
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung Institute, Quebec City, QC, Canada. dimitri.kalavrouziotis@criucpq.ulaval.ca.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Kalavrouziotis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003324:Coronary Artery Disease / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality; D006801:Humans; D007387:Internal Mammary-Coronary Artery Anastomosis / Q000379:methods* / Q000401:mortality; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016896:Treatment Outcome