Congestion as a crucial factor determining albuminuria in patients with cardiorenal disease

Background. Albuminuria could potentially emerge as a novel marker of congestion in acute heart failure. However, the current evidence linking albuminuria and congestion in patients with congestive heart failure (CHF) remains somewhat scarce. This study aimed to evaluate the prevalence of albuminuria in a cohort of patients with CHF, identify the independent factors associated with albuminuria and analyse the correlation with different congestion parameters. Methods. This is a subanalysis of the Spanish Cardiorenal Registry, in which we enrolled 864 outpatients with heart failure and a value of urinary albumin:creatinine ratio (UACR) at the first visit. Results. The median age was 74 years, 549 (63.5%) were male and 438 (50.7%) had a reduced left ventricular ejection fraction. A total of 350 patients (40.5%) had albuminuria. Among these patients, 386 (33.1%) had a UACR of 30-300 mg/g and 64 (7.4%) had a UACR >300 mg/g. In order of importance, the independent variables associated with higher UACR were estimated glomerular filtration rate determined by the Chronic Kidney Disease Epidemiology Collaboration equation (R-2 = 57.6%), systolic blood pressure (R-2 = 21.1%), previous furosemide equivalent dose (FED; R-2 = 7.5%), antigen carbohydrate 125 (CA125; R-2 = 6.1%), diabetes mellitus (R-2 = 5.6%) and oedema (R-2 = 1.9%). The combined influence of oedema, elevated CA125 levels and the FED accounted for 15.5% of the model's variability. Conclusions. In patients with chronic stable heart failure, the prevalence of albuminuria is high. The risk factors of albuminuria in this population are chronic kidney disease and hypertension. Congestion parameters are also associated with increased albuminuria.