NT-proBNP as an Independent Predictor of Long-Term All-Cause Mortality in Heart Failure Across the Spectrum of Glomerular Filtration Rate

Background/Objectives: The coexistence of heart failure (HF) and chronic kidney disease (CKD) complicates management and worsens prognosis. NT-proBNP is a recognized biomarker for HF diagnosis and prognosis, yet its interpretation in CKD can be challenging due to confounding factors increasing its levels. This study aimed to evaluate the predictive value of NT-proBNP for all-cause long-term mortality in HF patients across various stages of renal dysfunction. Methods: Hospitalized HF patients were included in this observational, retrospective analysis. NT-proBNP levels and serum creatinine were measured on admission. The primary outcome was all-cause mortality. Patients were divided into three groups according to renal function estimated using the CKD-EPI formula: eGFR1 (>60 mL/min/1.73 m²), eGFR2 (30–60 mL/min/1.73 m²) and eGFR3 (<30 mL/min/1.73 m²). Results: The study included 716 HF patients with a mean age of 71 ± 10 years, 49% males. All-cause long-term mortality was 35% after a median follow-up of 59 months. The mortality rate increased from 29% in eGFR1 patients, to 43% in eGFR2, to 68% in eGFR3. Median NT-proBNP increased from 997 pg/mL in eGFR1 patients to 1586 pg/mL in eGFR2 to 4928 pg/mL in eGFR3. Cut-off values for predicting all-cause long-term mortality were NT-proBNP >1837 pg/mL in eGFR1 patients, >1413 pg/mL in eGFR2 and >6415 pg/mL in eGFR3. In multivariable Cox analysis, NT-proBNP was an independent predictor of all-cause long-term mortality in all eGFR groups. Conclusions: NT-proBNP on admission was an independent predictor of long-term all-cause mortality in hospitalized HF patients across all eGFR subgroups, with increasing cut-off levels in patients with renal dysfunction.