OBJECTIVES. This article reviews the safety profile of nonionic versus ionic contrast media, focussing on those aspects specific to the cardiac catheterization laboratory.
DATA ANALYZED. Comparative electrophysiologic and hemodynamic effects, nephrotoxicity, thrombosis-related complications, and other possible adverse effects are discussed. Volume limitations and approaches to efficient use of nonionic agents also are considered.
RESULTS. Previous investigations indicate that cardiac electrophysiologic and hemodynamic effects are less with nonionic contrast media than with conventional high-osmolar ionic agents. Studies assessing potential adverse reactions suggest an advantage with nonionics, compared with high-osmolar ionic agents, mostly regarding reduction in mild-to-moderate adverse events. In general, studies on the risk of nephrotoxicity among cardiac angiography patients demonstrate no difference between nonionic and ionic contrast or a slight beneficial effect with nonionics among those with pre-existing renal dysfunction. There is no convincing evidence for an increased incidence of thrombosis-related events with nonionic agents during coronary angiography and data regarding nonionic contrast-related thrombosis in patients undergoing coronary angioplasty are conflicting.
CONCLUSIONS. At the present time, there is no justification for avoiding nonionic contrast agents based on the risk of thrombosis. Research findings on the effect of contrast volume are also inconclusive.