Table 18.

Definition of Changes in Renal Function in Heart Failure

Chronic Kidney Injury

General definition: abnormal renal function present for > 3 mo

CKD Stage 1

Normal eGFR ≥ 90 mL/min/1.73 m2

CKD stage 2

Mildly decreased eGFR 60–89 mL/min/1.73 m2

CKD Stage 3a

Mildly to moderately decreased eGFR 45–59 mL/min/1.73 m2

CKD Stage 3b

Moderately to severely decreased eGFR 30–44 mL/min/1.73 m2

CKD stage 4

Severely decreased eGFR 15–29 mL/min/1.73 m2

CKD stage 5

Kidney failure eGFR < 15 mL/min/1.73 m2

Acute Kidney Injury

AKI Stage 1

AKI that fulfils at least 1 of the following criteria: Increase in serum creatinine ≥ 150%-200% ( ≥ 1.5–2.0 × increase) within 7 d compared with baseline Increase in creatinine to ≥ 25% of baseline or increase ≥ 0.3 mg/dL ( ≥ 26.4 mmol/L) within 48 h of the index procedure

AKI Stage 2

AKI that fulfils the following criterion: Increase in serum creatinine ≥ 200%-300% ( ≥ 2.0–3.0x increase) within 7 d compared with baseline

AKI Stage 3

AKI that fulfils at least one of the following criteria: Increase in serum creatinine ≥ 300% ( ≥ 3.0 × increase) within 7 d compared with baseline Serum creatinine ≥ 4.0 mg/dL ( ≥ 354 mmol/L) with an acute increase of ≥ 0.5 mg/dL ( ≥ 44 mmol/L)

AKI Stage 4

AKI requiring new temporary or permanent renal replacement therapy

AKI definitions adapted with permission from KDIGO. Clinical Practice Guidelines for Acute Kidney Injury 2012. Accessed August 15, 2023. https://kdigo.org/guidelines/acute-kidney-injury/. After Mullens et al⁶⁷ and Abraham et al.⁷¹

AKI = acute kidney injury; CKD = chronic kidney disease.