Albuminuria and acute heart failure. A new biomarker for congestion and follow-up?

Introduction: This study evaluated the trajectory of the urine albumin-to-creatinine ratio (UACR) in patients hospitalized with acute Heart Failure (HF) from pre-admission (baseline), through hospital admission, discharge and two weeks post-discharge. We also assessed its association with congestion-related biomarkers, including NT-proBNP, CA 125 and the neutrophil-to-lymphocyte (N/L) ratio. Methods: Prospective, observational study including ninety-nine consecutive patients admitted with acute HF. Blood and urine analyses were performed at admission, at discharge and two weeks post-discharge. Patients were stratified according to UACR at admission and the trajectories of UACR and biomarkers were evaluated. The clinical, analytical and echocardiographic predictors of UACR were analysed. Results: Mean age was 70.812.2 years, 57% were men. At admission albuminuria was present in 65.7% of patients (45.5% microalbuminuria, 20.2% macroalbuminuria, respectively). 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. The UACR worsened from baseline to admission and improved at discharge, reflecting the congestion dynamics. NT-proBNP, CA 125 and N/L ratio showed similar patterns. 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 acute HF and exhibits a dynamic change in relation to congestion. These findings suggest a potential role as a biomarker for congestion monitoring. However, given the study limitations, the results should be considered exploratory and warrant confirmation in larger prospective studies.