title: Long-term Effects of Off-Pump Coronary Bypass Versus Conventional Coronary Bypass Grafting on Renal Function.
abstract: OBJECTIVE
  This study aimed to evaluate the short- and long-term effects of conventional on-pump coronary bypass grafting (cCABG) compared with off-pump coronary artery bypass (OPCAB) on renal function.
  
  
  METHODS
  A retrospective review of patients undergoing coronary bypass grafting from 2004 through 2013 at a single center was conducted. Preoperative renal function, perioperative acute kidney injury, and long-term glomerular filtration were evaluated. Multivariable analyses were used to determine factors contributing to short- and long-term renal impairment.
  
  
  RESULTS
  A total of 234 patients underwent cCABG, and 582 underwent OPCAB. Patients undergoing OPCAB were significantly older, had greater preoperative renal dysfunction, had greater functional dependence, and took more hypertension medications. Multivariable analyses found that 30-day acute kidney injury was an independent risk factor for a 10% decline in glomerular filtration rate at 1 and 5 years (P < 0.0001 and 0.002, respectively). However, the use of cardiopulmonary bypass was not found to influence long-term renal function (P = 0.78 at 1 year, P = 0.76 at 5 years). The percentage of patients experiencing a 10% drop in renal function from baseline at 1 year (33% OPCAB, 35% cCABG; P = 0.73) and 5 years (16% OPCAB, 16% cCABG; P = 0.93) were not significantly different. Independent predictors of acute kidney injury included baseline kidney function (P = 0.04) and age (P < 0.0001), whereas cardiopulmonary bypass did not affect the incidence (P = 0.17). A propensity-matched analysis confirmed these findings.
  
  
  CONCLUSIONS
  Acute kidney injury is a risk factor for long-term renal dysfunction after either bypass method and was not greater after cCABG compared with OPCAB. Patients undergoing OPCAB did not experience greater decrease in long-term kidney function despite having worse baseline kidney function.
authors.affiliation: From the *Division of Cardiothoracic Surgery, Veterans Affairs Medical Center, Washington, DC USA; †Division of Cardiothoracic Surgery, The George Washington University, Washington, DC USA; and Divisions of ‡Critical Care Medicine, and §Cardiology, Veterans Affairs Medical Center, Washington, DC USA.
authors.forename: Conor F
authors.initials: CF
authors.lastname: Hynes
authors.forename: Sanchez
authors.initials: S
authors.lastname: Colo
authors.forename: Richard L
authors.initials: RL
authors.lastname: Amdur
authors.forename: Lakhmir S
authors.initials: LS
authors.lastname: Chawla
authors.forename: Michael D
authors.initials: MD
authors.lastname: Greenberg
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Trachiotis
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology* / Q000503:physiopathology; D000368:Aged; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods*; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors