Association of albuminuria with kidney function and hemodynamic disturbance in pre-school children who undergo congenital heart disease surgery

Background We validated the prevalence of albuminuria and its association with kidney function and hemodynamics in pre-school children who underwent surgery for congenital heart disease (CHD). Methods From 403 patients who had undergone surgery for CHD at least 6 months before pre-school and were admitted to our hospital between 2011 and 2015, 75 who underwent blood and urine tests and cardiac catheterization were included in this study. The urinary albumin-to-creatinine ratio (ACR) was quantified, and the relationship of ACR with physical and laboratory findings and hemodynamics assessed using cardiac catheterization was analyzed. Results The study cohort was divided into three groups: Fontan group ( n = 25), tetralogy of Fallot (TOF) group ( n = 18), and control group (other biventricular CHDs; n = 32). The median age of patients was 5.9 years. ACR was higher in the Fontan group than in the TOF and control groups (median: 15.0 vs. 5.0 and 0.0 mg/g, p < 0.001). Moreover, albuminuria (ACR > 30 mg/g) was observed in 20.0% of Fontan patients, while ACR was associated with potential complicating factors of Fontan circulation: high central venous pressure, high mean pulmonary artery pressure, and worse than moderate atrioventricular regurgitation. ACR showed a moderate correlation with the cystatin C-based estimated glomerular filtration rate ( r = − 0.725, p < 0.001). Conclusions Measurement of albuminuria in Fontan patients before they join elementary school is useful because it reflects kidney function and hemodynamic factors that can worsen their condition. Identification and management of patients with albuminuria may facilitate early therapeutic intervention for worsening Fontan factors, eventually delaying the deterioration of kidney function. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information