Severe acute kidney disease is associated with worse kidney outcome among acute kidney injury patients

Abstract

Acute kidney disease (AKD) comprises acute kidney injury (AKI). However, whether the AKD staging system has prognostic values among AKI patients with different baseline estimated glomerular filtration (eGFR) remains a controversial issue. Algorithm-based approach was applied to identify AKI occurrence and to define different AKD stages. Risk ratio for major adverse kidney events (MAKE), including (1) eGFR decline > 35% from baseline, (2) initiation of dialysis, (3) in-hospital mortality of different AKD subgroups were identified by multivariable logistic regression. Among the 4741 AKI patients identified from January 2015 to December 2018, AKD stages 1-3 after AKI was common (53% in the lower baseline eGFR group and 51% in the higher baseline eGFR group). In the logistic regression model adjusted for demographics and comorbidities at 1-year follow-up, AKD stages 1/2/3 (AKD stage 0 as reference group) were associated with higher risks of MAKE (AKD stage: odds ratio, 95% confidence interval [95% CI], AKD 1: 1.85, 1.56-2.19; AKD 2: 3.43, 2.85-4.12; AKD 3: 10.41, 8.68-12.49). Regardless of baseline eGFR, staging criteria for AKD identified AKI patients who were at higher risk of kidney function decline, dialysis and mortality. Post-AKI AKD patients with severer stage need intensified care and timely intervention.

Figure 1

Algorithm for the staging of acute kidney disease. Algorithm for the staging of acute kidney disease (AKD), based on the 16th Acute Disease Quality Initiative (ADQI) consensus, which is congruent with AKI staging. SCr serum creatinine, RV reference value. Patients with AKD stage 0 by this algorithm were considered as reference group in the following statistical analysis. Conversion factors for serum creatinine in mg/dL to μmol/L, × 88.4.

Figure 2

Flowchart demonstrating the inclusion of eligible patients. Flowchart demonstrates the selection criteria and process of eligible acute kidney injury patients for investigating the risk of major adverse kidney events. AKI acute kidney injury, SCr serum creatinine, eGFR estimated glomerular filtration rate, AKD acute kidney disease.

Figure 3

Adjusted odds of major adverse kidney event at 1-year follow-up in lower baseline eGFR group. Odds of major adverse kidney events stratified by most severe stage of AKD between 7–90 days after AKI, according to 16th Acute Disease Quality Initiative (ADQI) recommendations, in lower baseline eGFR group. Adjusted odds ratios (dots) and 95% CIs (lines) were calculated using logistic regression, where the reference category was patients who were AKD stage 0. Logistic regression was adjusted for age, sex, hypertension, heart disease, diabetes, anemia, cerebrovascular disease, cancer, COPD and digestive tract disease. Clinical significance was observed while comparing AKD stages 1–3 versus stage 0. AKD acute kidney disease, AKI acute kidney injury, eGFR estimated glomerular filtration rate, COPD chronic obstructive pulmonary disease.

Figure 4

Adjusted odds of major adverse kidney event at 1-year follow-up in higher baseline eGFR group. Odds of major adverse kidney events stratified by most severe stage of AKD between 7–90 days after AKI, according to 16th Acute Disease Quality Initiative (ADQI) recommendations, in higher baseline eGFR group. Adjusted odds ratios (dots) and 95% CIs (lines) were calculated using logistic regression, where the reference category was patients who were AKD stage 0. Logistic regression was adjusted for age, sex, hypertension, heart disease, diabetes, anemia, cerebrovascular disease, cancer, COPD and digestive tract disease. Clinical significance was observed while comparing AKD stages 1–3 versus stage 0. AKD acute kidney disease, AKI acute kidney injury, eGFR estimated glomerular filtration rate, COPD chronic obstructive pulmonary disease.