title: The magnitude of acute serum creatinine increase after cardiac surgery and the risk of chronic kidney disease, progression of kidney disease, and death.
abstract: BACKGROUND
  Long-term outcomes after acute kidney injury remain poorly defined. We determined the association between the magnitude of creatinine increase after cardiac surgery and the risk of incident chronic kidney disease (CKD), CKD progression, and death.
  
  
  METHODS
  We identified 29,388 individuals who underwent cardiac surgery at Veterans Affairs hospitals between November 1999 and September 2005. The magnitude of creatinine increase was defined by the percent change from baseline to peak creatinine levels after cardiac surgery and categorized as none (≤0%) or as class I, (1%-24%), II (25%-49%), III (50%-99%), or IV (≥100%). Cox proportional hazard models were used to examine the association between the magnitude of creatinine increase and outcomes.
  
  
  RESULTS
  The relative hazards for outcomes increased monotonically with greater increases in creatinine levels compared with no change in creatinine levels. The relative hazards for adverse outcomes were significantly higher immediately after the creatinine increase and attenuated over time. Three months after surgery, creatinine increase classes I, II, III, and IV were associated with a greater risk of incident CKD (hazard ratios [HRs] 2.1, 4.0, 5.8, and 6.6, respectively; all P<.01), progression of CKD stage (HRs 2.5, 3.8, 4.4, and 8.0; all P<.01), and long-term mortality (HRs 1.4, 1.9, 2.8, and 5.0; all P<.01). At 5 years, the associations were lower in magnitude: incident CKD (HRs 1.4, 1.9, 2.3, and 2.3; all P<.01), CKD progression (HRs 1.5, 1.7, 1.7, and 2.4; all P<.01), and mortality (HRs 1.0, 1.2, 1.4, and 1.8; all P<.01, except class I).
  
  
  CONCLUSIONS
  The magnitude of creatinine increase after cardiac surgery is associated in a graded manner with an increased risk of incident CKD, CKD progression, and mortality.
authors.affiliation: Center for Epidemiology and Clinical Research, Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota 55417, USA. isha0012@umn.edu
authors.forename: Areef
authors.initials: A
authors.lastname: Ishani
authors.forename: David
authors.initials: D
authors.lastname: Nelson
authors.forename: Barbara
authors.initials: B
authors.lastname: Clothier
authors.forename: Tamara
authors.initials: T
authors.lastname: Schult
authors.forename: Sean
authors.initials: S
authors.lastname: Nugent
authors.forename: Nancy
authors.initials: N
authors.lastname: Greer
authors.forename: Yelena
authors.initials: Y
authors.lastname: Slinin
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000209:etiology* / Q000401:mortality; D000368:Aged; D002423:Cause of Death; D015331:Cohort Studies; D003131:Combined Modality Therapy; D015897:Comorbidity; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000097:blood / Q000401:mortality / Q000601:surgery*; D003404:Creatinine / Q000097:blood*; D018450:Disease Progression; D005260:Female; D006349:Heart Valve Diseases / Q000097:blood / Q000401:mortality / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation; D006787:Hospitals, Veterans; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000209:etiology* / Q000401:mortality; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood / Q000209:etiology* / Q000401:mortality; D016016:Proportional Hazards Models; D058996:Quality Improvement; D012306:Risk; D015996:Survival Rate; D014728:Veterans / Q000706:statistics & numerical data*
chemical_list: D003404:Creatinine