Are We Overly Concerned About NSF in CKD Patients?

Over the past decade or so, the concern about nephrogenic systemic fibrosis (NSF) has blossomed. NSF is no doubt a devastating condition, but are we just a little too concerned about NSF? NSF has been reported in patients who have severe renal impairment and have been exposed to a gadolinium (Gd)-based contrast agent during magnetic resonance imaging (MRI). Accordingly, many patients with CKD who could benefit by this imaging modality have been turned away for fear of NSF.

A recent study in the Clinical Journal of the American Society of Nephrology has taken another look at the safety of Gd-MRI in patients with CKD and varying levels of estimated GFR (eGFR).

The study was retrospective analysis of 2053 unselected patients from the United Kingdom who had CKD and had received Gd-MRI between 1999 and 2009, so as to determine the risk for NSF related to level of CKD, nature of Gd preparation, and Gd dosage.

Results: Overall, 2053 patients (63.5% men; mean age 60.6 ± 15.7 years) had 2278 Gd-MRI scans; their mean eGFR was 40.7 ± 23.7 ml/min. A total of 918 (44.7%) patients had stage 3, 491 (23.9%) had stage 4, and 117 (5.7%) had predialysis stage 5 CKD. No cases of NSF were identified during an average follow-up period of 28.6 ± 18.2 months.

Conclusions: In this study, no patients developed NSF during extended follow-up, even after multiple Gd doses in some. Gd-MRI can be safely undertaken in the majority of patients with CKD, but caution is merited for dialysis patients and those with acute kidney injury, with relative caution for predialysis patients with stage 5 CKD.

This is one study from the UK with limitations. But, I tend to agree that perhaps we have gone from not recognizing this devastating affliction... to now becoming a little overly concerned about NSF. Perhaps we should consider softening restrictions to Gd-MRIs which in many centers are not being allowed in any patient with a CrCl < 30 ml/min due to the fear of NSF.