Safety of Gadolinium Versus Iodinated Contrast Agents for Diagnostic or Therapeutic Angiographies: A Systematic Review and Meta-Analysis

Background
Gadolinium has been proposed as an alternative to iodinated contrast agents for use in angiographies due to their renal safety in patients with or without pre-existing renal insufficiency. However, the data relating to the safety of such an approach remain scarce. We sought to perform a meta-analysis of studies comparing the use of gadolinium to iodinated contrast agents for diagnostic and therapeutic angiographies.

Methods
PubMed, MEDLINE and EMBASE databases were searched for studies comparing the use of gadolinium to iodinated contrast agents. Acute kidney injury (AKI) and AKI requiring hemodialysis (HD) and mortality were the primary endpoints. Nephrogenic Systemic Fibrosis (NSF) and allergic reaction were the secondary endpoints. Mantel-Haenszel random-effects model was used to calculate the odds ratio (OR) and 95% confidence intervals (CI).

Results
Our analysis included six observational studies with a total of 651 patients. We included renal, cerebral, coronary and peripheral arterial angiograms. There was no significant difference between the use of gadolinium versus iodinated contrast agents in terms of AKI (OR= 0.85[0.41,1.76]p=0.66), AKI requiring HD (OR=1.83[0.22,15.16]p=0.67) and mortality (OR= 1.94[0.07,56.08]p=0.7). None of the studies reported NSF and allergic reactions with the use of gadolinium-based contrast agents.

Conclusions
The use of gadolinium does not offer any advantage over iodinated contrast agents to prevent contrast-induced AKI. Further studies are needed to identify the optimal contrast media in the setting of renal insufficiency.