title: Long-term Outcomes and Prognostic Factors for Patients Requiring Renal Replacement Therapy After Cardiac Surgery.
abstract: OBJECTIVE
  To examine long-term outcomes, including all-cause mortality, and the likelihood and timing of renal recovery among patients requiring renal replacement therapy (RRT) for acute kidney injury after cardiac surgery.
  
  
  METHODS
  This is a single-center, historical, matched cohort study of post-cardiac surgery patients who required RRT from January 1, 2007, through December 31, 2012. We matched each case with 2 controls, each of whom did not require RRT after cardiac surgery, for age, sex, and type of surgery. The patients were followed up for 1 year after the start of RRT. The main outcomes were all-cause mortality in all patients and rate of renal function recovery in patients who required RRT.
  
  
  RESULTS
  A total of 202 patients met the inclusion criteria. The unadjusted all-cause mortality among patients requiring RRT was 64% at 1 year vs 8% for matched controls. In multivariate analysis, the hazard ratio for all-cause mortality was 12.59 (95% CI, 8.24-19.68) for cases vs controls. Increased 1-year all-cause mortality was independently associated with increased age, a history of congestive heart failure, lower preoperative creatinine level, longer interval between surgery and starting RRT, and the need for mechanical ventilation or an intra-aortic balloon pump at the time of RRT. Renal recovery occurred in 34% of cases by 90 days and in 39% by 1 year. Of those who recovered renal function, 87% were within 90 days. Only 8 (4%) of the 186 patients were alive and continued to receive RRT at 1 year.
  
  
  CONCLUSIONS
  The need for RRT after cardiac surgery is an independent risk factor for mortality. In the case of survival, the chance of renal recovery is reasonable.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN. Electronic address: charat.thongprayoon@gmail.com.
authors.forename: Charat
authors.initials: C
authors.lastname: Thongprayoon
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Wisit
authors.initials: W
authors.lastname: Cheungpasitporn
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Mayo Clinic, Rochester, MN.
authors.forename: Ishan K
authors.initials: IK
authors.lastname: Shah
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Rahul
authors.initials: R
authors.lastname: Kashyap
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Mayo Clinic, Rochester, MN.
authors.forename: Soon J
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN; Division of Pulmonary and Critical Care Medicine, Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Kianoush
authors.initials: K
authors.lastname: Kashani
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: John J
authors.initials: JJ
authors.lastname: Dillon
mesh_terms: D058186:Acute Kidney Injury / Q000453:epidemiology / Q000209:etiology / Q000628:therapy*; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002423:Cause of Death / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D011182:Postoperative Care / Q000379:methods*; D011183:Postoperative Complications; D017582:Renal Replacement Therapy / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors