Comparative effect of contrast media type on the incidence of contrast-induced nephropathy a systematic review and meta-analysis

Background: Iodine contrast media are essential components of many imaging procedures. An important potential side effect is contrast-induced nephropathy (CIN). Purpose: To compare CIN risk for contrast media within and between osmolality classes in patients receiving diagnostic or therapeutic imaging procedures. Data Sources: PubMed, EMBASE, Cochrane Library, Clinical Trials.gov, and Scopus through June 2015. Study Selection: Randomized, controlled trials that reported CIN-related outcomes in patients receiving low-osmolar contrast media (LOCM) or iso-osmolar contrast media for imaging. Data Extraction: Independent study selection and quality assessment by 2 reviewers and dual extraction of study characteristics and results. Data Synthesis: None of the 5 studies that compared types of LOCM reported a statistically significant or clinically important difference among study groups, but the strength of evidence was low. Twenty-five randomized, controlled trials found a slight reduction in CIN risk with the iso-osmolar contrast media agent iodixanol compared with a diverse group of LOCM that just reached statistical significance in a meta-analysis (pooled relative risk, 0.80 [95% CI, 0.65 to 0.99]; P = 0.045). This comparison's strength of evidence was moderate. In a meta regression of randomized, controlled trials of iodixanol, no relationship was found between route of administration and comparative CIN risk. Limitations: Few studies compared LOCM. Procedural details about contrast administration were not uniformly reported. Few studies specified clinical indications or severity of baseline renal impairment. Conclusion: No differences were found in CIN risk among types of LOCM. Iodixanol had a slightly lower risk for CIN than LOCM, but the lower risk did not exceed a criterion for clinical importance.