title: A comparison of long-term mortality for off-pump and on-pump coronary artery bypass graft surgery.
abstract: BACKGROUND
  The survival difference between off-pump and on-pump coronary artery bypass graft surgery for follow-up longer than 5 years is not well-understood. The objective of this study is to examine the difference in 7-year mortality after these 2 procedures.
  
  
  RESULTS
  The state of New York's Cardiac Surgery Reporting System was used to identify the 2640 off-pump and 5940 on-pump patients discharged from July through December 2000. The National Death Index was used to ascertain patients' vital statuses through 2007. A logistic regression model was fit to predict the probability of receiving an off-pump procedure using baseline patient characteristics. Off-pump and on-pump patients were matched with a 1:1 ratio based on the probability of receiving an off-pump procedure. Kaplan-Meier survival curves for the 2 procedures were compared using the propensity-matched data, and the hazard ratio for death for off-pump in comparison with on-pump procedures was obtained. In subgroup analyses, the significance of interactions between type of surgery and baseline risk factors was tested. In this study, 2631 pairs of off-pump and on-pump patients were propensity matched. The 7-year Kaplan-Meier survival rates were 71.2% and 73.4% (P=0.07) for off-pump and on-pump surgery, respectively. The hazard ratio for death (off-pump versus on-pump) was 1.10 (95% confidence interval: 0.99 to 1.21, P=0.07). No statistical significance was detected for the interaction terms between the type of surgery and a number of different baseline risk factors.
  
  
  CONCLUSIONS
  The difference in long-term mortality between on-pump and off-pump coronary artery bypass graft surgery is not statistically significant.
authors.affiliation: Department of Public Health Sciences, Penn State Hershey College of Medicine, Hershey, PA 17033, USA. chuntao.wu@psu.edu
authors.forename: Chuntao
authors.initials: C
authors.lastname: Wu
authors.forename: Fabian T
authors.initials: FT
authors.lastname: Camacho
authors.forename: Alfred T
authors.initials: AT
authors.lastname: Culliford
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Gold
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Wechsler
authors.forename: Robert S D
authors.initials: RS
authors.lastname: Higgins
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Lahey
authors.forename: Craig R
authors.initials: CR
authors.lastname: Smith
authors.forename: Desmond
authors.initials: D
authors.lastname: Jordan
authors.forename: Edward L
authors.initials: EL
authors.lastname: Hannan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001026:Coronary Artery Bypass / Q000401:mortality; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007423:Intra-Aortic Balloon Pumping / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009518:New York; D015995:Prevalence; D012307:Risk Factors; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome