Plasma Volume and Renal Function Predict Six-Month Survival after Hospitalization for Acute Decompensated Heart Failure

Abstract

Background: Plasma volume (PV) is contracted in stable patients with heart failure (HF) due to decongestion strategies. On the other hand, increased PV can adversely affect the trajectory of HF. We therefore examined the effects of increased percentage change in PV (%ΔPV), blood urea nitrogen (BUN), and %ΔPV stratified by BUN and glomerular filtration rate (GFR) on survival after discharge in patients hospitalized for acute decompensated HF (ADHF). Methods: We used the Strauss-Davis-Rosenbaum formula to calculate the %ΔPV between baseline and hospital discharge in a cohort from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial (ESCAPE). Kaplan-Meier curves were constructed for survival over 6 months. Cox proportional hazards regression was used to obtain adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) for the associations between survival after discharge and %ΔPV, BUN, and %ΔPV stratified by BUN and GFR. Results: Of the 324 patients included in our study (age 56.1 ± 13.6 years, 26.5% female), those with increased or no %ΔPV at discharge were less likely to survive at 6 months compared with those having reduced %ΔPV (log rank, p = 0.0093). Increased %ΔPV (HR 1.08 per 10% increase; 95% CI: 1.02-1.14) and increased BUN at discharge (HR 1.02 per mg/dL; 95% CI: 1.01-1.03) were independently associated with worse survival. Decreasing %ΔPV had a greater association with improved survival in patients with discharge BUN <31 mg/dL (p = 0.02) and discharge GFR >40 mL/min/1.73 m2 (p = 0.047). Conclusions: Increased %ΔPV and BUN at discharge predicted worse 6-month survival in patients with ADHF. Decreased %ΔPV with low BUN or high GFR at discharge was associated with improved survival.