Early Post-Discharge Albuminuria Trajectory and Clinical Outcomes After Acute Heart Failure

Background: Albuminuria is a marker of cardiovascular and renal risk and may reflect dynamic haemodynamic changes in acute heart failure (AHF). However, the prognostic value of early urine albumin-to-creatinine ratio (UACR) monitoring during the vulnerable post-discharge phase remains unclear. Methods: We conducted a prospective single-centre study, including 88 patients with hospitalization for AHF. UACR was measured at discharge and at a two-week follow-up visit. Patients were stratified according to UACR trajectory: (1) persistent normoalbuminuria; (2) microalbuminuria with significant reduction (>50%) or normalization; and (3) persistent microalbuminuria without significant reduction or macroalbuminuria. Clinical outcomes included HF readmissions, all-cause mortality and a composite endpoint of HF readmission or all-cause mortality. Results: Albuminuria was prevalent in 64.8% of patients. Group 3 showed a higher burden of comorbidities, worse renal function and higher congestion markers. During a median follow-up of 553 days, group 3 had a higher incidence of HF events and the composite endpoint. In multivariable analysis, group 3 was independently associated with HF hospitalization (HR 3.09, 95% CI 1.19-8.04; p = 0.021) and the composite endpoint (HR 3.31, 95% CI 1.18-9.35; p = 0.024), whereas no independent association was observed for group 2. Renal function remained stable in groups 1 and 2, while group 3 showed worse renal outcomes. Conclusions: Albuminuria is frequently observed during AHF and is closely related to haemodynamic congestion. Persistent albuminuria identifies a high-risk phenotype, whereas early reduction was associated with more favourable unadjusted outcomes. Early post-discharge UACR trajectory may improve risk stratification during the vulnerable phase.