Combined evaluation of plasma B-type natriuretic peptide and urinary liver-type fatty acid-binding protein/creatinine ratio is related to worsening renal function in patients undergoing elective percutaneous coronary intervention

Background: There are few reports on the significance for the combined evaluation of blood humoral factors and urinary biomarkers in terms of worsening renal function (WRF) after coronary angiography (CAG)/percutaneous coronary arterial intervention (PCI). Method and results: Urinary liver type-fatty acid-binding protein (L-FABP), neutrophil gelatinase associated lipocalin (NGAL), and adrenomedullin (AM) were measured less than 24 h before and 3 h, 6 h, 1 day, and 2 days after CAG/PCI. WRF was defined as a > 20% decrease in the estimated GFR. WRF occurred in seven of 100 patients and the increase in L-FABP/creatinine (Cr) at 1 day after CAG/PCI was significantly higher in the WRF group than in the non-WRF group. Plasma B-type natriuretic peptide (BNP) before CAG/PCI and L-FABP/Cr at 1 day after CAG/PCI were independent predictors for WRF. The areas under the receiver-operating characteristic curves were as follows: 0.760 for BNP before CAG/PCI, 0.731 for L-FABP/Cr at 1 day after CAG/PCI, and 0.892 for BNP and L-FABP/Cr. Urinary AM levels after PCI/CAG were negatively correlated only to serum potassium levels. Gene expressions of AM and AM-receptor were detectable in renal tubule epithelial cells. AM increased intracellular second messenger levels in a dose-dependent manner. Conclusions: Our results suggest that combined evaluation of plasma BNP and urinary L-FABP/Cr is useful as a predictor of renal dysfunction in CAG/PCI patients.