Effect of Transient and Sustained Acute Kidney Injury on Readmissions in Acute Decompensated Heart Failure

Am J Cardiol. 2017 Jun 1;119(11):1809-1814. doi: 10.1016/j.amjcard.2017.02.044. Epub 2017 Mar 16.


Although acute kidney injury (AKI) is common in heart failure, yet the impact of the onset, timing, and duration of AKI on short-term outcomes is not well studied. AKI was defined as an increase in serum creatinine SCr of ≥0.3 mg/dl or 1.5 times relative to the admission and further categorized as transient AKI (T-AKI: SCr returning to within 10% of baseline); sustained AKI (S-AKI: those with at least 72 hours of hospital stay and did not meet T-AKI); and unknown duration AKI (U-AKI: those with less than 72 hours stay and did not meet T-AKI). Reference category was no AKI (stable or <0.3 mg/dl change in SCr). The main outcome was 30-day all-cause hospital readmission. Unadjusted and adjusted association between AKI category of interest and main outcome was represented as percent and relative risks with 95% CIs. Statistical significance was set at an alpha of 0.05. From the Cerner Health Facts sample, 14,017 of 22,059 available subjects met the eligibility criteria. Approximately, 19.2% of our sample met the primary outcome. Compared with no AKI (readmission rate of 17.7%; 95% CI 16.4% to 18.9%), the adjusted rate of readmission was highest in patients with S-AKI (22.8%, 95% CI 20.8% to 24.8%; p <0.001), followed by 20.2% (95% CI 17.5% to 22.8%; p = 0.05) in T-AKI patients. Compared with no AKI, the adjusted relative risk of 30-day readmission was 1.29 (95% CI 1.17 to 1.42), 1.14 (95% CI 1.00 to 1.31), and 1.12 (95% CI, 1.01 to 1.26) in S-AKI, T-AKI, and U-AKI, respectively. In conclusion, both sustained AKI and patients with transient elevation still remain at a higher risk of readmission within 30 days. Future studies should focus on examining process-of-care after discharge in patients with different patterns of AKI.

Publication types

  • Multicenter Study

MeSH terms

  • Acute Disease
  • Acute Kidney Injury / diagnosis
  • Acute Kidney Injury / epidemiology
  • Acute Kidney Injury / etiology*
  • Aged
  • Creatinine / blood
  • Female
  • Follow-Up Studies
  • Heart Failure / complications*
  • Heart Failure / mortality
  • Humans
  • Incidence
  • Kidney Function Tests
  • Male
  • Patient Readmission / trends*
  • Retrospective Studies
  • Risk Assessment / methods*
  • Risk Factors
  • Survival Rate / trends
  • Time Factors
  • United States / epidemiology


  • Creatinine