title: Bilateral internal thoracic artery grafting may improve outcome of coronary artery surgery. Risk-adjusted survival.
abstract: BACKGROUND
  Excellent clinical results of the patients with single left internal thoracic artery (ITA) grafting compared with saphenous vein grafting have prompted surgeons to use both ITAs. However, long-term benefits of the bilateral ITA grafting have not been proven.
  
  
  RESULTS
  We reviewed our experience of 2826 patients (age 62 +/- 9 years [mean +/- 1 SD], 2350 men, mean follow-up 52 months) who underwent surgery with ITAs, supplemented by saphenous vein grafts when required, between 1985 and 1995. Single ITA grafting (n = 1557) was compared with double (n = 1269), by means of the Cox proportional hazards model. Significant predictors of all-cause mortality were as follows: (1) peripheral vascular disease, rate ratio (RR) = 2.4 (1.7 to 3.4 [95% CI]); (2) prior myocardial infarction, RR = 2.1 (1.5 to 3.1); (3) severe left ventricular dysfunction, RR = 3.9 (2.6 to 5.9) and moderate left ventricular dysfunction, RR = 2.0 (1.5 to 2.6); (4) age > or = 70 years, RR = 3.4 (2.4 to 4.8), and age 60 to 69 years, RR = 1.7 (1.3 to 2.4); (5) diabetes mellitus, RR = 1.7 (1.3 to 2.4); (6) carotid disease, RR = 1.7 (1.2 to 2.4); and (7) single ITA (versus bilateral ITA), RR = 1.4 (1.1 to 1.8). Number of vessels diseased, surgical status (i.e., urgent versus elective), hypertension, and sex were not significant predictors. Unadjusted actuarial survival rates at 10 years were 86 +/- 3% (mean +/- 95% CI) for bilateral ITA group and 71 +/- 5% for single ITA. Single ITA was also a predictor of all-cause mortality, late myocardial infarction, or late reoperation (RR = 1.3 [1.1 to 1.6]).
  
  
  CONCLUSIONS
  Bilateral ITA grafting may improve long-term survival and freedom from late myocardial infarction or reoperation after coronary artery surgery. Mathematical modeling may assist in developing a strategy for use of bilateral ITA grafts.
authors.affiliation: Department of Cardiac Surgery, Epworth Hospital, Victoria, Australia. bux@austin.unimelb.edu.au
authors.forename: B F
authors.initials: BF
authors.lastname: Buxton
authors.forename: M
authors.initials: M
authors.lastname: Komeda
authors.forename: J A
authors.initials: JA
authors.lastname: Fuller
authors.forename: I
authors.initials: I
authors.lastname: Gordon
mesh_terms: D001158:Arteries; D001026:Coronary Artery Bypass / Q000379:methods*; D003327:Coronary Disease / Q000401:mortality / Q000601:surgery*; D003331:Coronary Vessels / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000517:prevention & control; D012086:Reoperation / Q000401:mortality; D012307:Risk Factors; D012501:Saphenous Vein / Q000637:transplantation; D016019:Survival Analysis; D013895:Thoracic Arteries / Q000637:transplantation*; D016896:Treatment Outcome