Clinical and prognostic significance of urinary albumin-to-creatinine ratio in heart failure: insights from the RICA-2 registry

BACKGROUND: Heart failure (HF) is frequently accompanied by renal dysfunction and systemic congestion, reflecting the complex interaction between the heart and the kidneys within the cardiorenal syndrome. The urinary albumin-to-creatinine ratio (UACR) is a simple marker of glomerular injury and endothelial dysfunction. However, its clinical significance in HF remains incompletely defined. METHODS: We analyzed patients from the RICA-2 registry, a prospective multicentre cohort including individuals with HF managed in different clinical settings. Patients with available UACR measurements were included. UACR was evaluated both as a categorical variable (300 mg/g) and as a continuous variable using ln (UACR +1). The primary endpoint was a composite of all-cause mortality or HF rehospitalization at 365 days. RESULTS: Among 2376 patients in the registry, 818 had available UACR measurements. Higher UACR levels were associated with a greater burden of comorbidities and significantly higher concentrations of NT-proBNP and CA125. Event-free survival differed across UACR categories in unadjusted analyses (log-rank p = 0.019). However, UACR was not independently associated with the primary endpoint after multivariable adjustment, despite being associated with higher unadjusted risk (HR 1.20 [0.77 - 1.87]; p=0.422). CONCLUSIONS: In this real-world cohort of HF patients, higher UACR levels were associated with a greater burden of comorbidities and congestion-related biomarkers but were not independently associated with clinical outcomes. Albuminuria may therefore be associated with cardiorenal interaction and systemic congestion, and with an increased unadjusted risk, although it did not provide independent prognostic information after multivariable adjustment in this cohort.