Comparative trial of Omnipaque 350 (iohexol) and Telebrix 350 (sodium-meglumine-ioxithalamate) in left ventriculography and coronary arteriography

In a double-blind randomized trial, the hemodynamic and electrophysiologic effects of the low-osmolar nonionic contrast medium iohexol (Omnipaque) and the standard high-osmolar ionic monomer sodium-meglumine-ioxithalamate (Telebrix) at left ventricular angiography and selective coronary arteriography were evaluated. Sixty patients were divided into two groups of 30 patients; one group received Omnipaque in a dosage of 350 mgI/ml and the other group received Telebrix in a dosage of 350 mgI/ml. The Omnipaque showed significantly less effects on heart rate and myocardial contractility, and induced less electrophysiological changes than did Telebrix. However, there was a significant increase of 10% in the diameter of the left coronary artery following selective coronary injection with Telebrix, while Omnipaque induced practically no change in vessel diameter. All hemodynamic and electrophysiologic effects proved to be short-lasting. We conclude that ionic and nonionic agents are similarly efficacious in providing adequate images with minimal risk to the patient. However, the nonionic agents exert slightly more alterations in cardiac hemodynamics and in electrocardiographic intervals. The vasodilatory effect on coronary artery diameter by Telebrix may entail a more rapid clearance of contrast medium from the coronary circulation, which might be of some advantage over nonionic contrast media.