The Utility of Novel Kidney Injury Biomarkers in Early Detection of CSA-AKI

Abstract

Cardiac surgery-associated acute kidney injury (CSA-AKI) is one of the most common complications of cardiac surgery procedures. In this study, the authors attempt to provide new data regarding the application of novel kidney injury biomarkers in the early diagnostics of CSA-AKI. 128 adult patients undergoing elective cardiac surgery procedures with the use of cardiopulmonary by-pass (CPB) were enrolled in this study. Novel kidney injury biomarkers were marked in the plasma and urine 6 h after weaning from the CPB. A significant difference in the postoperative biomarkers' concentration between the AKI and no-AKI group was found, regarding plasma IL-8, plasma TNF-α and urine NGAL, normalized for creatinine excretion (NGAL/Cr). These were also independent predictors of CSA-AKI. An independent risk factor for CSA-AKI proved to be preoperative CKD. Plasma IL-8 and TNF-α, as well as urine NGAL/Cr, are independent early indicators of CSA-AKI and pose a promising alternative for creatinine measurements. The cut-off points for these biomarkers proposed in this investigation should be confronted with more data and revised to achieve a suitable diagnostic value.

Keywords: CSA-AKI; cardiac surgery; cardiopulmonary by-pass; kidney injury biomarkers.

Figure 1

Postoperative biomarker concentrations in the control group and the AKI group (p-value < 0.001 in all cases). The Y-axis was logarithmized for improved data clarity. (a) Plasma IL-8 (pg/mL), (b) plasma TNF-α (pg/mL), (c) urine NGAL normalized for creatinine excretion (ng/mg).

Figure 2

ROC analysis of the selected AKI indicators: (a) plasma IL-8, (b) plasma TNF-α and (c) urine NGAL normalized for creatinine excretion—NGAL/Cr. AUC—area under a curve.