Background: Glomerular filtration rate (GFR) and natriuretic response to diuretics represent important treatment targets in acute decompensated heart failure (ADHF).
Methods and results: Consecutive ADHF patients (n = 50) with ejection fraction ≤ 45% and clinical signs of volume overload received protocol-driven decongestive therapy. Serum creatinine (Cr), cystatin C (CysC), and β-trace protein (βTP) were measured on admission and three subsequent days of treatment. Worsening renal function (WRF) was defined as a ≥ 0.3 increase in absolute biomarker levels or ≥ 20% decrease in estimated GFR. Consecutive 24-hour urinary collections were simultaneously performed to measure Cr clearance and natriuresis. Serum Cr, CysC, and βTP were strongly correlated at admission (ρ = 0.788-0.909) and during decongestive treatment (ρ = 0.884-888). Moreover, derived GFR estimates correlated well with Cr clearance (ρ = 0.820-0.908). Nevertheless, WRF incidence differed markedly according to Cr- (26%-30%), CysC- (46%-54%), or βTP-based definitions (31%-48%). WRF by any definition was not associated with all-cause mortality or ADHF readmission, in contrast to stronger natriuresis per loop diuretic dose [hazard ratio 0.20 (95% confidence interval 0.06-0.64); P = .007].
Conclusions: Serial measurements of CysC/βTP, compared with serum Cr, more frequently indicate WRF during decongestive treatment in ADHF. However, adverse clinical outcome in such patients might be better predicted by the natriuretic response to diuretic therapy.
Keywords: Glomerular filtration rate; congestive heart failure; natriuresis.
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