title: Age cut-off for the loss of benefit from bilateral internal thoracic artery grafting.
abstract: OBJECTIVE
  To identify the age-related benefit of single and bilateral internal thoracic artery (ITA) grafting on long-term cardiac-related survival in patients who survived from primary isolated coronary artery bypass grafting (CABG).
  
  
  METHODS
  A unicenter study was conducted on 12,231 consecutive survivors from primary isolated CABG who received single (n=9566 patients) or bilateral (n=1388 patients) ITA grafts, or vein grafts only (n=1277 patients) between 1992 and 2005. Data was collected prospectively. The Cox regression model estimates the hazard ratio of each independent variable on cardiac-specific survival over the entire length of follow-up. Age was a significant covariate into the statistical model. The mean follow-up was 5.7+/-3.7 years and 100% complete as of December 2005. The date and cause of death were obtained from the regional statistical institute.
  
  
  RESULTS
  After adjustments for different risk factors, the cardiac-related survival benefit in patients undergoing CABG with two ITAs was superior to that of single ITA grafting up to 60 years of age, displaying a constant decrease over time. The use of a single ITA was beneficial on cardiac-related survival in all age groups, including octogenarians, compared to patients receiving only vein grafts.
  
  
  CONCLUSIONS
  The use of at least one ITA is associated with increased long-term cardiac-specific survival in all age groups compared to venous-only CABG, even in octogenarians. The additional survival benefit of using a second ITA decreases gradually with age, and is lost after 60 years of age.
authors.affiliation: Department of Cardiac surgery, Laval Hospital, 2725 chemin Ste-Foy, Québec city, QC, Canada, G1V 4G5.
authors.forename: Siamak
authors.initials: S
authors.lastname: Mohammadi
authors.forename: François
authors.initials: F
authors.lastname: Dagenais
authors.forename: Daniel
authors.initials: D
authors.lastname: Doyle
authors.forename: Patrick
authors.initials: P
authors.lastname: Mathieu
authors.forename: Richard
authors.initials: R
authors.lastname: Baillot
authors.forename: Eric
authors.initials: E
authors.lastname: Charbonneau
authors.forename: Jean
authors.initials: J
authors.lastname: Perron
authors.forename: Pierre
authors.initials: P
authors.lastname: Voisine
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007387:Internal Mammary-Coronary Artery Anastomosis / Q000379:methods / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011792:Quebec / Q000453:epidemiology; D016896:Treatment Outcome