Contrast-induced nephropathy after a second contrast exposure

Abstract

Background: The risk of contrast-induced nephropathy (CIN) after repeated contrast exposure has not been evaluated. Methods: We prospectively evaluated the effects of two contrast exposures during an investigational study of a new computerized tomography (CT) scanner. Adult subjects who underwent a variety of contrast-enhanced imaging procedures with conventional apparatus, as part of routine care, were invited to undergo a second contrast-enhanced research scan. Subjects were required to have an estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m² and a serum creatinine (sCr) value measured immediately prior to the second contrast exposure that was <125% of that measured prior to the first imaging study. Results: Twenty-eight subjects underwent a second contrast exposure after a mean interval of 20 ± 13 days (75% males, 89% Caucasians, 21% diabetics, mean age 60.6 ± 6 years, mean contrast volume 130 ± 42 mL). There was a significant increase in mean sCr and decline in eGFR after the second contrast exposure (sCr 0.93 ± 0.14 vs. 0.86 ± 0.15 mg/dL prior, p = 0.027; eGFR 83.9 ± 13.5 vs. 89.8 ± 13 mL/min/1.73 m² prior, p = 0.028). Four subjects (14.3% of the population) developed CIN. Conclusion: Even in subjects with relatively preserved renal function there is a notable risk of CIN after repeated contrast exposure. This conclusion was unaltered by several sensitivity analyses.

Keywords:

• contrast media
• nephrotoxicity
• acute kidney injury
• acute renal failure

Acknowledgments

We thank the study coordinators Elizabeth Weill and, particularly, Clara Schindler for their invaluable assistance in the project. We thank Aniko Szabo, PhD, and Qun Xiang, MS, for statistical assistance and Aditya Trivedi for mathematical calculations. We also thank Diane Breitenfeld, BS M.T. (ASCP), and Paul Jannetto, PhD, for providing pertinent information about the sCr testing procedure and again Dr. Jannetto for kindly reviewing the relevant section of the manuscript.

Declaration of interest: Hariprasad Trivedi, MD– no conflict of interest. W. Dennis Foley, MD - GE Healthcare: medical advisory board, honoraria.