Complete Recovery of Renal Function After Acute Kidney Injury is Associated with

1
Complete Recovery of Renal Function After Acute
Kidney Injury is Associated with Long-Term
All-Cause Mortality In a Large Managed Care
Organization Jennifer deGraauw MD1, John
Holmen, PhD2, Jason Jones, PhD2, Sid Thornton,
PhD2, Jim Stinson, MD2, Michel Chonchol,
MD1 1University of Colorado Denver, Aurora, CO
2Homer Warner Center Intermountain Healthcare,
Salt Lake City, UT
Background
Results

• Acute Kidney Injury (AKI) is increasingly common
  and is associated with high in-hospital
  mortality.
• The incidence of AKI from all causes has
  increased over the past decade.
• Previous studies have demonstrated an increased
  risk of long-term mortality after an episode of
  AKI.
• Less is known about the long-term outcomes of
  patients that have full renal recovery after an
  episode of AKI.
• Our study sought to determine the long-term
  mortality risk in subjects that have complete
  recovery of renal function after an episode of
  AKI.

Figure 2 Risk of Long-term Mortality in Subjects
with AKI by Participant Characteristics
Table 1 Baseline Characteristics of AKI Group
Parameter With AKI (n1411) p-value (Balance)
Age , mean (SD), years 6317 0.06
Female () 45 0.99
Race, Black, () 9 0.99
Hypertension () 74 0.99
Diabetes Mellitus () 58 0.99
Myocardial Infarction () 19 0.33
Heart failure () 39 0.99
Perivascular Disease () 21 lt0.0001
Cerebrovascular Disease () 23 lt0.0001
Methods

• Study Population
• Retrospective matched cohort study using a large
  comprehensive database from Intermountain
  Healthcare System.
• Adults with at least one hospitalization between
  January 1999-March 2009 and had 1 yr of health
  care prior to date of hospitalization. Median
  IQR follow-up 2.8 1.35.6 years.
• Normal renal function (SCr lt 1.3 mg/dL) within 90
  days prior to hospital admission.
• Predictor
• AKI cases were identified within the
  hospitalization by comparing the highest serum
  creatinine value during the index hospitalization
  with the lowest serum creatinine value recorded
  in the 90 days prior the index admission.
• Ratio of those two values greater than 1.5, the
  hospitalization was classified as with AKI
  (AKIN definition).
• Completed renal recovery existed if the serum
  creatinine returned to a level less than 50
  above baseline serum creatinine.
• A total of 1,411 patients with AKI and 1,411
  matched controls were included in this analyses.
• Outcome
• All-cause mortality occurring after hospital
  discharge.
• Analyses
• Follow-up was performed until March 31, 2010.
• Hazard ratios and 95 confidence intervals were
  derived from Cox proportional hazard models,
  incorporating the 11 matched design, and
  adjusting for differences not addressed by the
  matching procedure.

Conclusions
All values are expressed as mean standard
deviations or percentage of patients
Figure 1 KaplanMeier Curve for All-cause
mortality

• Table 1 demonstrates the baseline characteristics
  of the AKI group.
• Figure 1 illustrates the Kaplan-Meier curve for
  long-term mortality (log rank test, p lt 0.0001).
• Table 2 demonstrates the Hazard Ratios (95 CI)
  for all-cause mortality. After adjusting for
  differences not addressed by the matching
  procedure patients with AKI had a 36 increase
  risk in all-cause mortality.
• Figure 2 illustrates the risk of long-term
  mortality in subjects with AKI by participant
  characteristics.

___ AKI group ___ No AKI group log rank
test, p lt0.0001
Conclusions
Conclusions

• Subjects with complete renal recovery after an
  episode of AKI have an increased risk of
  long-term mortality as compared to matched
  controls, even after adjusting for important
  confounders.
• The leading causes of death in the AKI group were
  malignancy, cardiovascular, and infectious.
• Further studies are needed to confirm these
  results in other populations.

Table 2 Hazard ratio (95 CI) for All-Cause
Mortality
Unadjusted HR (95 CI) 1.76 (1.54 2.01)
Adjusted HR (95 CI) 1.36 (1.17 1.57)
Printed by
Adjusted for PVD, CVA, Liver Disease, Malignancy,
CTD and PUD