title: Kidney function after off-pump or on-pump coronary artery bypass graft surgery: a randomized clinical trial.
abstract: OBJECTIVE
  Most acute kidney injury observed in the hospital is defined by sudden mild or moderate increases in the serum creatinine concentration, which may persist for several days. Such acute kidney injury is associated with lower long-term kidney function. However, it has not been demonstrated that an intervention that reduces the risk of such acute kidney injury better preserves long-term kidney function.
  
  
  OBJECTIVE
  To characterize the risk of acute kidney injury with an intervention in a randomized clinical trial and to determine if there is a difference between the 2 treatment groups in kidney function 1 year later.
  
  
  METHODS
  The Coronary Artery Bypass Grafting Surgery Off- or On-pump Revascularisation Study (CORONARY) enrolled 4752 patients undergoing first isolated coronary artery bypass graft (CABG) surgery at 79 sites in 19 countries. Patients were randomized to receive CABG surgery either with a beating-heart technique (off-pump) or with cardiopulmonary bypass (on-pump). From January 2010 to November 2011, 2932 patients (from 63 sites in 16 countries) from CORONARY were enrolled into a kidney function substudy to record serum creatinine concentrations during the postoperative period and at 1 year. The last 1-year serum creatinine concentration was recorded on January 18, 2013.
  
  
  METHODS
  Acute kidney injury within 30 days of surgery (≥50% increase in serum creatinine concentration from prerandomization concentration) and loss of kidney function at 1 year (≥20% loss in estimated glomerular filtration rate from prerandomization level).
  
  
  RESULTS
  Off-pump (n = 1472) vs on-pump (n = 1460) CABG surgery reduced the risk of acute kidney injury (17.5% vs 20.8%, respectively; relative risk, 0.83 [95% CI, 0.72-0.97], P = .01); however, there was no significant difference between the 2 groups in the loss of kidney function at 1 year (17.1% vs 15.3%, respectively; relative risk, 1.10 [95% CI, 0.95-1.29], P = .23). Results were consistent with multiple alternate continuous and categorical definitions of acute kidney injury or kidney function loss, and in the subgroup with baseline chronic kidney disease.
  
  
  CONCLUSIONS
  Use of off-pump compared with on-pump CABG surgery reduced the risk of postoperative acute kidney injury, without evidence of better preserved kidney function with off-pump CABG surgery at 1 year. In this setting, an intervention that reduced the risk of mild to moderate acute kidney injury did not alter longer-term kidney function.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00463294.
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada2Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada3Department of Clinical Epidemiology and Biostatistics, McMaster Universit.
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada4Population Health Research Institute, Hamilton, Ontario, Canada.
authors.forename: P J
authors.initials: PJ
authors.lastname: Devereaux
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada4Population Health Research Institute, Hamilton, Ontario, Canada.
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada5Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Meaghan S
authors.initials: MS
authors.lastname: Cuerden
authors.affiliation: Section of Nephrology, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Chirag R
authors.initials: CR
authors.lastname: Parikh
authors.affiliation: Section of Nephrology, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Coca
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada4Population Health Research Institute, Hamilton, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Walsh
authors.affiliation: Division of Cardiac Surgery, Western University, London, Ontario, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Novick
authors.affiliation: Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cook
authors.affiliation: SAL Hospital and Medical Institute, Ahmadabad, India.
authors.forename: Anil R
authors.initials: AR
authors.lastname: Jain
authors.affiliation: Department of Cardiovascular Surgery, Fuiwai Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
authors.forename: Xiangbin
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Cardiac Surgery, Centre Hospitalier de l'Université de Montréal CHUM, Montreal, Quebec, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Noiseux
authors.affiliation: University Hospital Motol, Praha, Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Vik
authors.affiliation: Instituto do Coracao do Hospital das Clinicas da, São Paulo, Brazil.
authors.forename: Noedir A
authors.initials: NA
authors.lastname: Stolf
authors.affiliation: Essex Cardiothoracic Centre and Anglia Ruskin University, Essex, England.
authors.forename: Andrew
authors.initials: A
authors.lastname: Ritchie
authors.affiliation: Department of Cardiovascular Surgery, Hospital Universitario Fundacion Favaloro, Buenos Aires, Argentina.
authors.forename: Roberto R
authors.initials: RR
authors.lastname: Favaloro
authors.affiliation: Mercy Hospital, Springfield, Missouri.
authors.forename: Sirish
authors.initials: S
authors.lastname: Parvathaneni
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada4Population Health Research Institute, Hamilton, Ontario, Canada16Division of Cardiac Surgery, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Whitlock
authors.affiliation: Population Health Research Institute, Hamilton, Ontario, Canada.
authors.forename: Yongning
authors.initials: Y
authors.lastname: Ou
authors.affiliation: Population Health Research Institute, Hamilton, Ontario, Canada.
authors.forename: Mitzi
authors.initials: M
authors.lastname: Lawrence
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada4Population Health Research Institute, Hamilton, Ontario, Canada16Division of Cardiac Surgery, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Andre
authors.initials: A
authors.lastname: Lamy
mesh_terms: D058186:Acute Kidney Injury / Q000517:prevention & control*; D000368:Aged; D002315:Cardiopulmonary Bypass; D047549:Coronary Artery Bypass, Off-Pump; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D003404:Creatinine