Contrast-Enhanced CT in Patients With Kidney Disease: Some Considerations in Response to the ACR/NKF Consensus (2020)

We read with interest the American College of Radiology/National Kidney Foundation (ACR/NKF) consensus statements1Davenport M.S. Perazella M.A. Yee J. et al.Use of intravenous iodinated contrast media in patients with kidney disease: consensus statements from the American College of Radiology and the National Kidney Foundation.Kidney Med. 2020; 2: 85-93Abstract Full Text Full Text PDF Scopus (35) Google Scholar and would like to emphasize the following points.•The low risk perception is mostly based on retrospective propensity-matched analyses, hardly “well-controlled” with potential selection bias, and has been graded as low evidence2Nyman U. Ahlkvist J. Aspelin P. et al.Preventing contrast medium-induced acute kidney injury: side-by-side comparison of Swedish-ESUR guidelines.Eur Radiol. 2018; 28: 5384-5395Crossref PubMed Scopus (26) Google Scholar•We believe that more research is needed on biomarkers indicating early structural kidney damage induced by contrast material and on acute kidney injury (AKI) definition3Breglia A. Godi I. Virzi G.M. et al.Subclinical contrast-induced acute kidney injury in patients undergoing cerebral computed tomography.Cardiorenal Med. 2020; 10: 125-136Crossref PubMed Scopus (6) Google Scholar,4Murray P.T. Mehta R.L. Shaw A. et al.Potential use of biomarkers in acute kidney injury: report and summary of recommendations from the 10th Acute Dialysis Quality Initiative consensus conference.Kidney Int. 2014; 85: 513-521Abstract Full Text Full Text PDF PubMed Scopus (304) Google Scholar•All referenced retrospective studies used iso-osmolar contrast media (IOCM) and low-osmolar contrast media (LOCM); however, IOCM was used in high-risk patients. LOCM was acknowledged as a significant risk factor at estimated glomerular filtration rates (eGFRs) ≤ 30 mL/min/1.73 m2 (trend toward significant at 30-44 mL/min/1.73 m2)5Davenport M.S. Khalatbari S. Cohan R.H. Dillman J.R. Myles J.D. Ellis J.H. Contrast material-induced nephrotoxicity and intravenous low-osmolality iodinated contrast material: risk stratification by using estimated glomerular filtration rate.Radiology. 2013; 268: 719-728Crossref PubMed Scopus (268) Google Scholar•The only referenced meta-analysis found no clinically relevant difference between IOCM and LOCM (defined arbitrarily as a 25% relative risk reduction) but was statistically significant in favor of IOCM. “Clinical relevance” is of particular interest. Even subclinical contrast-induced AKI, as indicated by structural tubular damage, may put patients at higher long-term risks, and specific patient cohorts may be considered for a special management algorithm including IOCM•To increase the safety margins, one may not only consider “high risks” but also “moderate risks” (GFRs of 30-44 mL/min/1.73 m2). In addition, due to poor precision, 10% to 30% of GFR estimates exceed 30% of measured GFRs, and to be 95% certain that measured GFR is > 30 mL/min/1.73 m2, eGFR threshold may need to be at least 45 mL/min/1.73 m2.2Nyman U. Ahlkvist J. Aspelin P. et al.Preventing contrast medium-induced acute kidney injury: side-by-side comparison of Swedish-ESUR guidelines.Eur Radiol. 2018; 28: 5384-5395Crossref PubMed Scopus (26) Google Scholar Every single case of AKI should be worth avoiding. According to the precautionary principle, the burden of proof is placed on those claiming that contrast material at GFRs ≥ 30 mL/min/1.73 m2 is harmless with the present scientific uncertainty. Dr Nyman has received lecture fees from GE Healthcare and reimbursement for letting GE Healthcare distribute the computer program OmniVis to estimate GFR and set up computed tomography contrast medium protocols based on body weight. Received April 9, 2020. Accepted April 19, 2020, after editorial review by the Editor-in-Chief. Use of Intravenous Iodinated Contrast Media in Patients With Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney FoundationKidney MedicineVol. 2Issue 1PreviewIntravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Full-Text PDF Open AccessIn Reply to ‘Contrast-Enhanced CT in Patients With Kidney Disease: Some Considerations in Response to the ACR/NKF Consensus’Kidney MedicineVol. 2Issue 4PreviewWe thank Ronco and Nyman1 for their commentary on the ACR/NKF consensus statements2 on the use of intravenous iodinated contrast media in patients with kidney disease. We agree that safety is a major consideration. We stated: “in individual high-risk circumstances (eg, numerous risk factors, recent AKI, borderline eGFR), prophylaxis may be considered in patients with eGFRs of 30 to 44 mL/min/1.73 m2 at the discretion of the ordering clinician,”2 despite lacking evidence that prophylaxis in this population is beneficial. Full-Text PDF Open Access