Elevation of urinary liver-type fatty acid binding protein after cardiac catheterization related to cardiovascular events

Abstract

Purpose

Contrast medium (CM) induces tubular hypoxia via endothelial damage due to direct cytotoxicity or viscosity. Urinary liver-type fatty acid binding protein (L-FABP) increases along with tubular hypoxia and may be a detector of systemic circulation injury. The aim of this study was to evaluate the clinical usefulness of detecting increases in urinary L-FABP levels due to administration of CM, as a prognostic biomarker for cardiovascular disease in patients without occurrence of CM-induced nephropathy undergoing cardiac catheterization procedure (CCP).

Methods

Retrospective longitudinal analyses of the relationship between urinary L-FABP levels and occurrence of cardiovascular events were performed (n=29). Urinary L-FABP was measured by ELISA before CCP, and at 6, 12, 24, and 48 hours after CCP.

Results

Urinary L-FABP levels were significantly higher at 12 hours (P<0.05) and 24 hours (P<0.005) after CCP compared with before CCP, only in the patients with occurrence of cardiovascular events (n=17), but not in those without cardiovascular events (n=12). The parameter with the largest area under the curve (0.816) for predicting the occurrence of cardiovascular events was the change in urinary L-FABP at 24 hours after CCP. The difference in urinary L-FABP levels (ΔL-FABP ≥11.0 μg/g creatinine) between before CCP and at 24 hours after CCP was a risk factor for the occurrence of cardiovascular events (hazard ratio, 4.93; 95% confidence interval, 1.27–19.13; P=0.021).

Conclusion

Measurement of urinary L-FABP before CCP and at 24 hours after CCP in patients with mild to moderate renal dysfunction may be an important indicator for risk stratification of onset of cardiovascular events.

Keywords:

• chronic kidney disease
• urinary liver-type fatty acid binding protein
• L-FABP
• contrast medium
• urinary biomarker
• cardiovascular event
• renal dysfunction

Acknowledgments

We are grateful to Ms Seiko Hoshino, Kimie Katayama, Aya Sakamaki, and Sanae Ogawa for assistance with the collection of urine and serum samples. We would also like to thank Dr Hiroyo Sasaki for obtaining informed consent from the patients.

Disclosure

T Sugaya is the Director and Senior Scientist of CMIC Holdings Co, Ltd, the company that produced the kits for L-FABP analysis. None of the other authors have conflicts of interest or financial disclosures of any relevance to the present study.