Potential aetiologies and prognostic implications of worsening renal function in acute decompensated heart failure.

Background: One third of patients hospitalized for acute decompensated heart failure (ADHF) develop a worsening renal function (WRF) that is associated with increased in-hospital morbidity and mortality. However, previous investigations have not evaluated the various etiologies of WRF and its impact on prognosis.

Methods: A retrospective chart review was performed of patients admitted with ADHF who had a rise of serum creatinine ≥ 0.3 mg/dl on admission or during their hospital stay. The chart notes were reviewed for the suggested etiology of WRF. Cases were defined as ADHF associated WRF (ADHF-WRF) when there was no other explanation for WRF, plus an objective evidence of hypervolemia. Cases with WRF after 48 hours of a negative fluid balance were classified as diuresis-associated WRF (DA-WRF).

Results: ICD-9 codes identified 319 admissions with ADHF complicated with WRF. Fifty admissions were excluded. The most common causes of WRF were ADHF-WRF (43.1%) and DA-WRF (42.8%). Other causes included nephrotoxins (5.9%) and surgery (3.7%). The mortality rate was significantly lower with DA-WRF compared to ADHF-WRF; odds ratio 0.059 (95% CI 0.007 to 0.45, P = 0.006). Readmission at 30 days was higher in cases with ADHF-WRF (42%).

Conclusions: WRF with ADHF is a heterogeneous group, and cases with ADHF-WRF had a higher in-hospital mortality and readmission rates.