Glomerular filtration decrease after diagnostic cardiac catheterisation in children with congenital cardiac malformation – the role of serum creatinine, cystatin C, neutrophil gelatinase and urine output monitoring

Introduction: Diagnosis of contrast induced-nephropathy (CIN) by a classic renal biomarker such as creatinine concentration can be delayed because of various factors that can influence this marker. Changes in new biomarkers such as neutrophil-gelatinase associated lipocalin (NGAL) and cystatin C are postulated to be more sensitive for recognizing patients prone to CIN-acute kidney injury (AKI). Aim: To investigate the role of NGAL and cystatin C as early biomarkers in the diagnosis of kidney injury after cardiac catheterisation. Material and methods: The study group consisted of 50 patients with congenital heart malformation admitted for scheduled cardiac catheterisation. The biomarkers serum creatinine, serum NGAL and serum cystatin C were tested at 5 time-points sequentially from start to 48 h after the procedure. Results: Significant changes were noted during the research in the serum creatinine concentration (p < 0.001) and serum NGAL concentration (p < 0.001). CIN-AKI, diagnosed by the modified Schwartz formula, occurred in 16 (32%) patients after 24 h and in 8 (16%) after 48 h. Subsequent analysis showed that serum creatinine significantly rose in the first 2 h of the study with simultaneous reduction in the eGFR. Maximum growth in serum NGAL occurred at 6 h after contrast administration and then returned to the baseline values at 24 h. Serum cystatin C level did not significantly change during the study. Conclusions: We observed a transient decrease in eGFR and a rise of serum NGAL after 2 h but NGAL was most pronounced at 6 h after the procedure. The potential role of cystatin C as a biomarker of CIN-AKI was not proved.