Acute kidney injury patterns in acute heart failure: The prognostic value of worsening renal function and its timing

Introduction: Acute decompensated heart failure (ADHF) admissions are frequently complicated by different patterns of serum creatinine (SCr) elevation. We aimed to assess the prognostic impact of worsening renal function (WRF) based on the timing of its occurrence.

Methods: This was a retrospective cohort of patients admitted for ADHF. Standard WRF was defined as an increase in SCr of ≥0.3 mg/dl during hospitalization. WRF timing was classified as early (within 48 hours of admission) or late (>48 hours). Acute kidney injury (AKI) at admission was defined as a rise in SCr of ≥0.3 mg/dl from outpatient baseline measurement to first measurement at admission. The primary endpoint was a composite of all-cause mortality or hospitalization for cardiovascular events at one-year follow-up.

Results: Overall, 249 patients were included (mean age 77±11 years, 62% with preserved left ventricular ejection fraction). Early WRF occurred in 49 patients (19.7%) and was associated with a higher risk of the primary outcome (HR 2.49; 95% CI 1.66-3.73), whereas late WRF was not (p=0.411). After stratification for the presence of early WRF and/or AKI at admission, only patients with early WRF but no AKI at admission and patients with both AKI at admission and early WRF showed a higher risk of the primary outcome after multivariate Cox regression.

Conclusion: Early WRF was associated with a higher risk of the primary outcome. The timing of WRF seems to be an important factor to take into account when considering the prognostic impact of creatinine variations during hospitalization for ADHF.