Prognostic Value of the NT-proBNP-to-Albumin Ratio (NTAR) for In-Hospital Mortality in Chronic Heart Failure Patients

Background: Chronic heart failure (CHF) continues to present significant prognostic challenges despite advances in diagnosis and therapy. While the N-terminal prohormone of brain natriuretic peptide (NT-proBNP) is widely recognized as a key marker of cardiac stress, and serum albumin reflects systemic inflammation and nutritional status, their integration into a single parameter-the NT-proBNP-to-albumin ratio (NTAR)-may improve risk stratification. This study aimed to evaluate the NTAR as a novel biomarker for predicting in-hospital mortality in patients with CHF. Methods: We performed an exploratory, retrospective, observational, single-center study involving 542 patients (306 males) admitted for CHF between January 2022 and August 2024. NTAR was calculated as log₁₀(NT-proBNP/albumin). Statistical analyses included ROC curves, univariate and multivariable Cox regression, and Kaplan-Meier survival analysis. Sex-specific performance of NTAR was compared against NT-proBNP and serum albumin alone. Results: Females had significantly lower serum albumin levels than males, while NT-proBNP levels were similar across sexes. NTAR increased with NYHA functional class and was highest in patients with heart failure with reduced ejection fraction (HFrEF). NTAR showed very good discriminatory performance for predicting in-hospital mortality (AUC = 0.840, 95% CI: 0.794-0.879, p < 0.001), marginally but statistically outperforming NT-proBNP in the male subgroup. In univariate Cox regression analyses, higher serum albumin was significantly associated with reduced in-hospital mortality risk in males (HR = 0.352; 95% CI: 0.154-0.803; p = 0.010) and females (HR = 0.169; 95% CI: 0.072-0.399; p < 0.001). Elevated NT-proBNP levels were associated with increased mortality risk in males (HR = 8.627; 95% CI: 1.956-38.042; p < 0.001) and females (HR = 6.060; 95% CI: 1.498-24.521; p = 0.002) with similar findings in NTAR (HR_males = 10.318, 95% CI: 2.452-43.417, p < 0.001 and HR_females = 7.542, 95% CI: 1.874-30.358, p < 0.001). Multivariable analysis identified NTAR as the strongest independent predictor for in-hospital mortality among males. Conclusions: These findings suggest that NTAR effectively integrates cardiac and systemic dysfunction to improve mortality risk stratification in CHF, particularly in male patients. Its ease of calculation from routinely available biomarkers supports its clinical applicability.