Baseline Albumin Predicts Worsening Renal Function in Acute Decompensated Heart Failure Patients receiving Continuous Infusion Loop Diuretics

Purpose: Loop diuretics are a mainstay of therapy in patients hospitalized for acute decompensated heart failure (ADHF).  Aggressive diuresis with loop diuretic infusions is often necessary for symptom relief.  Overly aggressive diuresis can consequently lead to worsened renal function (WRF), which has been associated with increased mortality.  We hypothesized that baseline clinical characteristics of ADHF patients receiving loop diuretic infusions could predict the development of WRF.

Methods: A retrospective observational analysis of 177 ADHF patients receiving continuous infusion loop diuretics was performed.  All patients admitted to the University of Michigan Health System with ADHF, receiving continuous loop diuretic infusions from January 2006 through June 2009 were included. Patients with incomplete medical records, less than 24 hours of loop diuretic infusion treatment, concurrent nephrotoxic agents (aminoglycosides, tacrolimus, cyclosporine, and sirolimus), patients transferred already given loop infusions, and those less than 18 years of age were excluded.  The primary outcome of this study was to identify baseline predictors of time to WRF in an ADHF patient population receiving continuous infusion loop diuretics. WRF was defined as an increase in serum creatinine ≥ 0.3 mg/dL from baseline.  Cox regression time-to-event analysis was used to determine the time to WRF based on different variables.  

Results: Mean patient age was 61 years, 37% were female, approximately 45% were classified as NYHA III, and median length of loop diuretic infusion was 4 days.  Forty-eight patients (27%) experienced WRF and 34 patients (19%) died during hospitalization.  Baseline albumin ≤ 3 g/dL was found to be the only significant predictor of WRF (HR 2.87; 95% CI (1.60 - 5.16); p = 0.0004) and remained significant despite inclusion of other univariate variables. 

Conclusion: Albumin ≤ 3 g/dL is a practical baseline characteristic to predict development of WRF in ADHF patients receiving continuous infusion loop diuretics.