Purpose: To determine prospectively the incidence of adverse events in angiography related to contrast agents, and the relative incidence of events with use of high-osmolality contrast agents (HOCAs) and low-osmolality contrast agents (LOCAs) and to ascertain if risk factors can help identify increased risk of an adverse event and patients likely to benefit from use of LOCAs.
Materials and methods: From 26 high-volume institutions, data were collected on every patient who underwent angiography from July 1, 1990, to June 30, 1992. Information included demographic and risk factors, general medical status, previous administration of contrast media, procedural information, occurrence and characteristics of all adverse events up to 12 hours after procedures, and relation to contrast agents, treatment, and outcome.
Results: In 60,891 patients, there were 75,616 studies, 56% with nonionic LOCAs, 8% with the ionic LOCA, and 36% with HOCAs. Most major risk factors correlated with an increased incidence of adverse events related to contrast media. Incidence of these adverse events varied with type of procedure, with a higher incidence associated with cardiac and interventional procedures. Overall adverse events related to contrast media and those for which treatment was necessary were significantly increased (P < .001) with use of HOCAs for all but arterial interventional procedures. Serious adverse events were not different between the two classes of agents except for cardiac procedures. Previous reaction to contrast medium was the most important risk factor in prediction of an adverse event.
Conclusion: The safety benefit of use of LOCAs is limited. Patients most likely to benefit are those with a previous reaction or more than one other major risk factor. Selective use of LOCAs is an appropriate strategy.