title: Effect of prior cardiac operations on survival after coronary artery bypass grafting.
abstract: BACKGROUND
  We examined a recent regional experience to determine the effect of a prior cardiac operation on short-term and midterm outcomes after coronary artery bypass grafting (CABG).
  
  
  METHODS
  We identified 20,703 patients who underwent nonemergent CABG at 8 centers in northern New England from 2000 to 2008, of whom 818 (3.8%) had undergone prior cardiac operations. Prior CABG using a minimal or full sternotomy was considered a prior sternotomy. Survival data out to 4 years were obtained from a link with the Social Security Administration Death Index. Hazard ratios were estimated using a Cox proportional hazards regression model, and adjusted survival curves were estimated using inverse probability weighting. In a separate analysis, 1,182 patients were matched 1:1 by a patient's propensity for having undergone prior CABG.
  
  
  RESULTS
  Patients with prior sternotomies had a greater burden of comorbid diseases and increased acuity and had a greater likelihood of returning to the operating room for bleeding and low cardiac output failure. Prior sternotomy was associated with an increased risk of death out to 4 years for patients undergoing CABG, with an unmatched hazard ratio of 1.34 (95% confidence interval, 1.10 to 1.64) and a matched hazard ratio of 1.36 (95% confidence interval, 1.01 to 1.81).
  
  
  CONCLUSIONS
  Analyses of our recent regional experience with nonemergent CABG showed that a prior cardiac operation was associated with a nearly twofold increased hazard of death at up to 4 years of follow-up.
authors.affiliation: Department of Medicine, Dartmouth College, Hanover, NH, USA. donald.likosky@dartmouth.edu
authors.forename: Donald S
authors.initials: DS
authors.lastname: Likosky
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Surgenor
authors.forename: Robert S
authors.initials: RS
authors.lastname: Kramer
authors.forename: Louis
authors.initials: L
authors.lastname: Russo
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Leavitt
authors.forename: Meredith J
authors.initials: MJ
authors.lastname: Sorensen
authors.forename: Robert E
authors.initials: RE
authors.lastname: Helm
authors.forename: Gerald L
authors.initials: GL
authors.lastname: Sardella
authors.forename: Francis V
authors.initials: FV
authors.lastname: Dipierro
authors.forename: Yvon R
authors.initials: YR
authors.lastname: Baribeau
authors.forename: David J
authors.initials: DJ
authors.lastname: Malenka
authors.forename: Todd A
authors.initials: TA
authors.lastname: Mackenzie
authors.forename: Jeremiah R
authors.initials: JR
authors.lastname: Brown
authors.forename: Cathy S
authors.initials: CS
authors.lastname: Ross
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures; D001026:Coronary Artery Bypass / Q000401:mortality*; D003324:Coronary Artery Disease / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009511:New England / Q000453:epidemiology; D011184:Postoperative Period; D057216:Propensity Score; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors