The role of albuminuria in acute heart failure: from admission to early post-discharge outcomes

Introduction

Albuminuria is a well-established risk marker for cardiovascular disease and heart failure (HF). The urinary albumin-to-creatinine ratio (UACR) may reflect dynamic changes in congestion during hospitalization. However, its role during acute heart failure (AHF) and its link with other biomarkers remain underexplored, suggesting potential prognostic and monitoring value.

Purpose

To assess the impact of the UACR and its association with other biomarkers during an AHF admission and after discharge.

Methods

In this prospective and observational study, ninety-nine consecutive patients with AHF admitted to the Cardiology Department from February to June 2024 were included. Blood and urine tests were performed onadmission, discharge and two weeks after discharge. Patients were classified according to UACR: grade 1 (< 30 mg/g), grade 2 (30-300 mg/g or microalbuminuria), and grade 3 (>300 mg/g or macroalbuminuria).

Results

Patients mean age was 70.8 ± 12.2 years, 43% were women. 52% of patients had reduced HF, 33% preserved HF, 15% mildly reduced HF. At admission, UACR was present in 65.7% (45.5% in grade 2 and 20.2% in grade 3). Patients in grade 2 - 3 had more comorbidities, higher previous albuminuria levels and had a higher prior admission rate for HF (Figure 1).

Echocardiographic data show group 3 had a trend towards lower left ventricular ejection fraction and tricuspid annular plane systolic excursion/systolic pulmonary artery pressure coupling (TAPSE/PAPs ratio).

The UACR worsened from before admission and improved at discharge, reflecting the congestion dynamics. UACR trajectory was independent of LVEF and early implementation of guideline directed medical therapy during admission (Figure 2). NT-proBNP, CA 125 and N/L ratio showed similar patterns. Patients in groups 2-3 had higher cardiac biomarkers regardless the time of measurement.

A higher UACR at admission was associated with diabetes, lower eGFR, previous HF admission, higher clinical congestion score, mixed or right-sided congestive phenotype, higher NT-proBNP and CA 125 levels. Independent predictors of higher UACR at admission were diabetes, reduced renal function, higher AST and lower vitamin D levels.

In the mixed linear regression analysis, lower eGFR, and higher AST levels remained independently associated with UACR trajectory. Admission UACR correlated with congestion score and predicted higher in-hospital mortality and early HF readmissions (<30 days).

Conclusions

Albuminuria is common in AHF and follows a dynamic pattern that improves with decongestion. Higher UACR at admission is associated with systemic congestion, cardiorenal dysfunction and poorer short-term outcomes. These findings support its role as a promising biomarker for congestion monitoring and a possible therapeutic target in HF.Clinical characteristics between groupsFor image description, please refer to the figure legend and surrounding text.UACR trajectoryFor image description, please refer to the figure legend and surrounding text.