Worsening renal function is not associated with response to treatment in acute heart failure

Abstract

Background: About a fourth of acute decompensated heart failure (ADHF) patients develop renal dysfunction during their admission. To date, the association of ADHF treatment with the development of worsening renal function (WRF) remains contentious. Thus, we examined the association of WRF with changes in BNP levels and with mortality.

Methods: We performed retrospective chart review of patients admitted with ADHF who had BNP, eGFR, creatinine and blood urea nitrogen (BUN) values measured both on admission and discharge. Survival analysis was conducted using Cox proportional hazards model and correlation was measured using Spearman's rank correlation test.

Results: 358 patients admitted for ADHF were evaluated. WRF was defined as >20% reduction in eGFR from admission to discharge and response to treatment was assessed by ΔBNP. There was a statistically significant reduction in BNP and increase in BUN during the admission. ΔBNP did not correlate with either ΔGFR or ΔBUN. Patients who developed WRF and those who did not, had a similar reduction in BNP. On univariate survival analysis, ΔBUN, but not ΔeGFR, was associated with 1-year mortality. In multivariate Cox proportional hazards model, BUN at discharge was associated with 1-year mortality (HR: 1.02, p<0.001), but ΔeGFR and ΔBUN were not associated with the primary endpoint.

Conclusion: During ADHF treatment, ΔBNP was not associated with changes in renal function. Development of WRF during ADHF treatment was not associated with mortality. Our study suggests that development of WRF should not preclude diuresis in ADHF patients in the absence of volume depletion.

Keywords: BNP; Heart failure; Renal function.

Figure 1

Box plot showing 1) Non-significant difference in change in Brain Natriuretic Peptide (BNP) levels from admission to discharge between patients without cardiorenal syndrome and patients with cardiorenal syndrome defined by A) >20% reduction in eGFR (n=298 and 60, respectively) and B) ≥ 0.3 mg/dl increase in creatinine (n=292 and 66, respectively).

Figure 2

Box plots showing non-significant difference in 1) change in eGFR (ΔeGFR), 2) change in creatinine (Δcreatinine), and 2) change in Blood Urea Nitrogen (ΔBUN) from admission to discharge, between patients with either no change or increase in BNP (n=104) and patients with reduction in BNP levels (n=254).