title: Performing coronary artery bypass grafting off-pump may compromise long-term survival in a veteran population.
abstract: BACKGROUND
  There are ample data regarding the short-term outcomes of on-pump and off-pump coronary artery bypass grafting (CABG), but little is known about the long-term survival associated with these approaches.
  
  
  METHODS
  Using the Veterans Affairs (VA) Continuous Improvement in Cardiac Surgery Program, we identified all VA patients (n = 65,097) who underwent primary isolated CABG from October 1997 to April 2011. The primary outcome measure was all-cause mortality. Age, 17 preoperative risk factors, and year of operation were used to calculate propensity scores for each patient. A greedy-match algorithm using the propensity scores matched 8,911 off-pump with 26,733 on-pump patients. Survival functions were estimated by the Kaplan-Meier method and compared by using the log-rank test.
  
  
  RESULTS
  In the complete cohort, off-pump was used in 11,629 of 65,097 (17.9%) operations. For the matched cohort, the median follow-up was 6.7 years (interquartile range, 3.72 to 9.35 years). Risk-adjusted mortality did not differ significantly between the off-pump and on-pump groups at 1 year (4.67% vs 4.78%; risk ratio [RR], 0.98; 95% confidence interval [CI], 0.88 to 1.09) or 3 years (9.21% vs 8.89%; RR, 1.04; 95% CI, 0.96 to 1.12). However, risk-adjusted mortality was higher in the off-pump group at 5 years (14.47% vs 13.45%; RR, 1.08; 95% CI 1.02 to 1.15) and 10 years (25.18% vs 23.57%; RR, 1.07; 95% CI, 1.03 to 1.12). Overall, the hazard ratio for off-pump vs on-pump was 1.06 (95% CI, 1.00 to 1.13; p = 0.04).
  
  
  CONCLUSIONS
  Off-pump CABG may be associated with decreased long-term survival. Further studies are needed to identify the reasons behind this finding.
authors: Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas, USA. fbakaeen@bcm.edu
authors: Faisal G
authors: FG
authors: Bakaeen
authors: Danny
authors: D
authors: Chu
authors: Rosemary F
authors: RF
authors: Kelly
authors: Herbert B
authors: HB
authors: Ward
authors: Michael E
authors: ME
authors: Jessen
authors: G John
authors: GJ
authors: Chen
authors: Nancy J
authors: NJ
authors: Petersen
authors: William L
authors: WL
authors: Holman
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002423:Cause of Death; D015331:Cohort Studies; D016001:Confidence Intervals; D001026:Coronary Artery Bypass / Q000379:methods / Q000401:mortality; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods / Q000401:mortality*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000401:mortality*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D006084:Graft Rejection; D006085:Graft Survival; D017052:Hospital Mortality / Q000639:trends*; D006787:Hospitals, Veterans; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000401:mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D011859:Radiography; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D017741:Survivors; D013781:Texas