title: Post-operative acute kidney injury and five-year risk of death, myocardial infarction, and stroke among elective cardiac surgical patients: a cohort study.
abstract: BACKGROUND
  The prognostic impact of acute kidney injury (AKI) on long-term clinical outcomes remains controversial. We examined the five-year risk of death, myocardial infarction, and stroke after elective cardiac surgery complicated by AKI.
  
  
  METHODS
  We conducted a cohort study among adult elective cardiac surgical patients without severe chronic kidney disease and/or previous heart or renal transplant surgery using data from population-based registries. AKI was defined by the Acute Kidney Injury Network (AKIN) criteria as a 50% increase in serum creatinine from baseline level, acute creatinine rise of ≥26.5 μmol/L (0.3 mg/dL) within 48 hours, and/or initiation of renal replacement therapy within five days after surgery. We followed patients from the fifth post-operative day until myocardial infarction, stroke or death within five years. Five-year risk was computed by the cumulative incidence method and compared with hazards ratios (HR) from a Cox proportional hazards regression model adjusting for propensity score.
  
  
  RESULTS
  A total of 287 (27.9%) of 1,030 patients developed AKI. Five-year risk of death was 26.5% (95% CI: 21.2 to 32.0) among patients with AKI and 12.1% (95% CI: 10.0 to 14.7) among patients without AKI. The corresponding adjusted HR of death was 1.6 (95% CI: 1.1 to 2.2). Five-year risk of myocardial infarction was 5.0% (95% CI: 2.9 to 8.1) among patients with AKI and 3.3% (95% CI: 2.1 to 4.8) among patients without AKI. Five-year risk of stroke was 5.0% (95% CI: 2.8 to 7.9) among patients with AKI and 4.2% (95% CI: 2.9 to 5.8) among patients without AKI. Adjusted HRs were 1.5 (95% CI: 0.7 to 3.2) of myocardial infarction and 0.9 (95% CI: 0.5 to 1.8) of stroke.
  
  
  CONCLUSIONS
  AKI, within five days after elective cardiac surgery, was associated with increased five-year mortality and a statistically insignificant increased risk of myocardial infarction. No association was seen with the risk of stroke.
authors: Malene Kærslund
authors: MK
authors: Hansen
authors: Henrik
authors: H
authors: Gammelager
authors: Martin Majlund
authors: MM
authors: Mikkelsen
authors: Vibeke Elisabeth
authors: VE
authors: Hjortdal
authors: J Bradley
authors: JB
authors: Layton
authors: Søren Paaske
authors: SP
authors: Johnsen
authors: Christian Fynbo
authors: CF
authors: Christiansen
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000209:etiology*; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002423:Cause of Death; D015331:Cohort Studies; D017558:Elective Surgical Procedures / Q000009:adverse effects*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology*; D011379:Prognosis; D012307:Risk Factors; D020521:Stroke / Q000209:etiology*; D013997:Time Factors