title: [Bilateral Internal Mammary Artery Versus Single Internal Mammary Artery in Myocardial Revascularization Surgery. Propensity Score - Adjusted Survival Analysis].
abstract: BACKGROUND
  Although arterial grafts are superior to venous grafts in terms of long-term patency, single internal mammary artery (SIMA) is still the preferred strategy in most cardiac surgical centres. Our main aim was to compare long- -term survival between BIMA and SIMA at our own tertiary care centre.
  
  
  METHODS
  Retrospective cohort including patients referred to Centro Hospitalar São João (CHSJ), from 2004 to 2011, who underwent isolated CABG and received two or more bypass with at least 1 IMA graft. Kaplan-Meier, Cox regression and propensity score matching 2:1 were used to compare long-term survival between BIMA and SIMA.
  
  
  RESULTS
  BIMA was performed in 696 (29.3%) out of 2329 eligible procedures. Mean follow-up time was 5.1 years (2-9.9 years). All-cause mortality was superior in patients with only one internal mammary artery - cumulative survival of 75% for SIMA vs 88% for BIMA. Because of discrepancy between groups regarding preoperative and surgical characteristics, we ran a propensity score matching which revealed BIMA as an independent predictor of survival (n=1510, 40.3% BIMA, HR: 0.648, 95% CI: 0.452-0.927).
  
  
  CONCLUSIONS
  BIMA is associated with significantly better long-term survival than SIMA in CABG. A higher sample size might clarify BIMA advantages, discriminating specific groups that might profit the most with this approach.
authors.affiliation: Departamentos de Fisiologia e Cirurgia Cardiotorácica da Faculdade de Medicina da Universidade do Porto e Serviço de Cirurgia Cardiotorácica do Centro Hospitalar São João, Portugal.
authors.forename: Francisca
authors.initials: F
authors.lastname: Saraiva
authors.forename: Noélia
authors.initials: N
authors.lastname: Vilas Boas
authors.forename: Mário Jorge
authors.initials: MJ
authors.lastname: Amorim
authors.forename: Pedro
authors.initials: P
authors.lastname: Cidade Silva
authors.forename: Tânia
authors.initials: T
authors.lastname: B Azevedo
authors.forename: Rui
authors.initials: R
authors.lastname: J Cerqueira
authors.forename: Ana
authors.initials: A
authors.lastname: C Pinho-Gomes
authors.forename: André
authors.initials: A
authors.lastname: P Lourenço
authors.forename: Paulo
authors.initials: P
authors.lastname: Pinho
authors.forename: Adelino
authors.initials: A
authors.lastname: Leite-Moreira