title: Bilateral internal thoracic artery use in patients with low ejection fraction: is there any additional long-term benefit?
abstract: OBJECTIVE
  The use of bilateral internal thoracic arteries (BITA) has been associated with improved long-term outcomes following coronary artery bypass graft (CABG) surgery. The objective of this study was to evaluate the impact of BITA use on long-term survival among patients with low ejection fraction (EF) undergoing CABG.
  
  
  METHODS
  Between April 1991 and October 2011, 2035 consecutive patients underwent primary BITA grafting. Among them, there were 129 patients with left ventricular EF ≤40%. During the same time period, 1666 primary CABGs were performed using a single internal thoracic artery (SITA) in patients with EF ≤40%. A propensity score optimal matching algorithm was used to create the matched SITA and BITA groups (n = 111 in each group). Also, Cox regression multivariable analyses were performed to determine the independent risk factors for long-term mortality. The date of death was obtained from provincial vital statistics.
  
  
  RESULTS
  There was no difference in operative mortality between matched BITA and SITA (n = 2, 1.8% vs n = 1, 0.9%, respectively, P = 0.6) groups. The mean follow-up was 8.6 ± 5.1 and 7.7 ± 5.5 years for BITA and SITA groups, respectively (P = 0.2). Five-, 10- and 15-year survival rates were 93.7, 77.5 and 59.0% in the matched BITA patients vs 82.8, 68.1 and 65.2% in the matched SITA patients (P = 0.3). In multivariate analysis, the independent risk factors for late mortality among hospital survivors were: insulin-dependent diabetes [adjusted hazard ratio (HR): 3.4, 95% confidence interval (CI): 1.4-8.4, P = 0.008], perioperative intra-aortic balloon pump insertion (HR: 3.2, 95% CI: 1.5-6.9, P = 0.004), postoperative deep sternal wound infection (HR: 7.4, 95% CI: 2.2-24.1, P = 0.001) and neurological complications (HR: 3.5, 95% CI: 1.4-8.4, P = 0.006). Choice of BITA versus SITA was not an independent predictor of long-term mortality (P = 0.3).
  
  
  CONCLUSIONS
  The use of a second internal thoracic artery (ITA) does not prolong late survival in patients with low EF undergoing CABG compared with a propensity-matched group of SITA graft patients.
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung University Hospital, Quebec City, Quebec, Canada siamak.mohammadi@fmed.ulaval.ca.
authors.forename: Siamak
authors.initials: S
authors.lastname: Mohammadi
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung University Hospital, Quebec City, Quebec, Canada.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Kalavrouziotis
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung University Hospital, Quebec City, Quebec, Canada.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cresce
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung University Hospital, Quebec City, Quebec, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Dagenais
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung University Hospital, Quebec City, Quebec, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Dumont
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung University Hospital, Quebec City, Quebec, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Charbonneau
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung University Hospital, Quebec City, Quebec, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Voisine
mesh_terms: D000368:Aged; D015331:Cohort Studies; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008323:Mammary Arteries / Q000637:transplantation*; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D013318:Stroke Volume; D016019:Survival Analysis
keywords: Bilateral internal thoracic arteries; Coronary artery bypass; Long-term survival