Kidney Function After Off-Pump or On-Pump Coronary Artery Bypass Graft Surgery: A Randomized Clinical Trial | Cardiology | JAMA | JAMA Network
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Original Investigation
June 4, 2014

Kidney Function After Off-Pump or On-Pump Coronary Artery Bypass Graft Surgery: A Randomized Clinical Trial

Author Affiliations
  • 1Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada
  • 2Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada
  • 3Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
  • 4Population Health Research Institute, Hamilton, Ontario, Canada
  • 5Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada
  • 6Section of Nephrology, Yale University School of Medicine, New Haven, Connecticut
  • 7Division of Cardiac Surgery, Western University, London, Ontario, Canada
  • 8SAL Hospital and Medical Institute, Ahmadabad, India
  • 9Department of Cardiovascular Surgery, Fuiwai Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
  • 10Department of Cardiac Surgery, Centre Hospitalier de l’Université de Montréal CHUM, Montreal, Quebec, Canada
  • 11University Hospital Motol, Praha, Czech Republic
  • 12Instituto do Coracao do Hospital das Clinicas da, São Paulo, Brazil
  • 13Essex Cardiothoracic Centre and Anglia Ruskin University, Essex, England
  • 14Department of Cardiovascular Surgery, Hospital Universitario Fundacion Favaloro, Buenos Aires, Argentina
  • 15Mercy Hospital, Springfield, Missouri
  • 16Division of Cardiac Surgery, McMaster University, Hamilton, Ontario, Canada
JAMA. 2014;311(21):2191-2198. doi:10.1001/jama.2014.4952

Importance  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.

Objectives  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.

Design, Setting, and Participants  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.

Main Outcomes and Measures  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 and Relevance  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.

Trial Registration Identifier: NCT00463294