Double-blind comparison of the clinical, hemodynamic, and electrocardiographic effects of sodium meglumine ioxaglate or iohexol during diagnostic cardiac catheterization

Iodixanol in Cardioangiography

Iodixanol (Visipaque) 320 mg I/ml, a non-ionic, dimeric, isotonic contrast medium, was compared to ioxaglate (Hexabrix) 320 mg I/ml in cardioangiography. One hundred and two patients with normal renal function were included in the study. The objectives were to evaluate safety, tolerability, radiographic efficacy and effects on renal function. Adverse events, discomfort, vital signs, clinical chemistry parameters, diagnostic information and radiographic density were recorded. Both contrast media had minor effects on the renal function parameters monitored. The patients who received iodixanol experienced fewer adverse events, significantly less discomfort and had a lower increase in heart rate than did the patients in the ioxaglate group. The radiographic efficacy was good in both groups. Iodixanol 320 mg I/ml is safe and effective for use in cardioangiography.

A prospective randomised controlled trial to determine the early and late reactions after the use of iopamidol 340 (Niopam™) and iomeprol 350 (Iomeron®) in cardiac catheterisation

A new generation of intravascular contrast agents, the non-ionic monomers have safety profiles that are superior to those of older ionic compounds. There are, however, significant differences between these agents.

AIM

The aim of this study was to determine the incidence of early (<24h) and late (>24h to 7 days) reactions to two non-ionic contrast agents currently used during cardiac catheterisation: iopamidol 340 (Niopam Bracco UK Ltd.) and iomeprol 350 (Iomeron Bracco UK Ltd.).

METHODS

This was a prospective, randomised, double blinded trial. One thousand nine hundred and eighty-five patients undergoing cardiac catheterisation received one of the following contrast agents on a weekly basis: iopamidol 340 (Niopam) and iomeprol 350 (Iomeron). Reactions that were possibly related to the contrast agents were recorded on predefined data collection forms during the first 24h of the procedure (early reaction) and after 24h to 7 days (late reaction) by means of a questionnaire.

RESULTS

The baseline characteristics were matched in both the groups. There was no significant difference in the incidence of heat sensation experienced between the two groups (p=0.1). Early non-heat reactions occurred in 2.7% of patients receiving iopamidol 340 (Niopam) and 4% of those receiving iomeprol 350 (Iomeron) (p=0.1). Significant electrocardiographic changes were recorded in 1.7% of patients who received iopamidol 340 (Niopam), and 1% of those who received iomeprol 350 (Iomeron) (p=0.2). Bradycardia occurred more frequently in the iopamidol 350 group (0.8%) compared to the iomeprol 350 group (0.1%) p=0.02. Late reactions occurred in 16.2% of those receiving iopamidol 340 (Niopam) and 21.7% of those receiving iomeprol 350 (Iomeron) (p=0.02). A total of 23 (3.7%) patients in the iopamidol group and 39 (6.2%) patients in the iomeprol group reported nausea, p=0.01.

CONCLUSIONS

The incidence of early adverse reactions was similar with the two non-ionic contrast agents. Although bradycardia was slightly more frequent using iopamidol 340, nausea was reported more commonly 24h after the procedure in patients receiving Iomeron 350 (Iomeron). We conclude that there were only minor clinical differences between these agents; both are safe and well tolerated.

Hemodynamic effects of iodixanol and iohexol during ventriculography in patients with compromised left ventricular function

A crossover study was performed to compare the hemodynamic effects of the iso-osmolar contrast agent iodixanol (Visipaque) 320 mg I/ml to those of the low-osmolar iohexol (Omnipaque) 350 mg I/ml. The main hypothesis was that iodixanol and iohexol would affect left ventricular end-diastolic pressure (LVEDP) to different degrees. In 48 patients with reduced cardiac function (mean ejection fraction 33. 4%), one ventricular injection was performed with each contrast medium. Ventricular, aortic and right atrial pressures and heart rate were measured continuously. Cardiac output (using Fick's principle) and systemic vascular resistance were calculated. LVEDP increased with both agents, but significantly less after iodixanol than after iohexol (P < 0.01), also in subgroups of patients in whom baseline LVEDP was severely increased and in whom 3-vessel disease was present. Immediate changes in variables reflecting vasodilatation were similar with both agents. In conclusion, both contrast agents influenced hemodynamics during ventriculography, but iodixanol had significantly less influence on LVEDP than did iohexol.

Selective coronary artery perfusion in vitro: a method to study cardiac effects of contrast media

RATIONALE AND OBJECTIVES

The authors evaluated selective perfusion of the coronary arteries in the isolated rat heart as a model for studying contrast medium-induced cardiac effects and compared the effects of iodixanol, iotrolan, and ioxaglate with this model.

MATERIALS AND METHODS

Isolated, spontaneously beating rat hearts were used. Control hearts were perfused in the Langendorff or the selective perfusion mode receiving Krebs Henseleit buffer. Contrast media were injected selectively into the left coronary artery. Left ventricular pressure and electrocardiographic parameters were monitored continuously throughout the experiments.

RESULTS

The stability of the selective perfusion preparation was similar to that of the conventional Langendorff preparation. Ioxaglate (0.3 g iodine per kilogram body weight) significantly (P < .05) depressed left ventricular contractility and decreased (P < .05) left ventricular pressure. Iodixanol and iotrolan had minor cardiac effects.

CONCLUSION

Selective coronary artery perfusion seems to be a suitable model for studying direct cardiac effects of contrast media. The nonionic dimers, iodixanol and iotrolan, induce only minor changes in cardiac function.

Cardiac effects of iodixanol compared to those of other nonionic and ionic contrast media on the isolated rat heart

This study was designed to compare the cardiac electrophysiology and mechanical effects of iodixanol to those of iotrolan, iopromide, ioxaglate and diatrizoate. Two consecutive injections of contrast media (CM) (0.3 g I/kg and 0.9 g I/kg b.w.) were given to spontaneously beating, Langendorff-perfused rat hearts. CM were given as a single, short-lasting bolus injection (i.e. over 2 and 5 s). Changes in aortic pressure, left ventricular pressures and ECG were continuously recorded during constant volume perfusion. The nonionic CM had less pronounced effects on aortic pressure than had the ionic media. The peak rate of isovolumetric contraction (LV dP/dt(max)) was slightly decreased by iodixanol and iotrolan, slightly more decreased by iopromide and markedly decreased by ioxaglate and diatrizoate. Similarly, the peak rate of pressure decline (LV dP/dt (min)) was only slightly decreased by iodixanol and iotrolan. Also, the 2 nonionic dimers had the smallest effects on the left ventricular end diastolic pressure (LVEDP) and heart rate. Ioxaglate lengthened the PQ-interval, but less so than diatrizoate. THe QT-interval was only slightly lengthened by iodixanol and iotrolan, as compared to the lenghthening caused by iopromide, ioxaglate and diatrizoate. Single ventricular extrasystoles were seen in all groups. Extrasystoles up to 3 coupled beats were registered after ioxaglate and diatrizoate. No episodes of ventricular fibrillation occurred with any CM. In conclusion, the nonionic dimers, and in particular iodixanol, induce only minor changes in cardiac function, whereas the ionic dimer ioxaglate and the ionic monomer diatrizoate induce pronounced effects.

Role of sodium addition to nonionic contrast medium in preventing ventricular fibrillation during coronary arteriography in dogs

RATIONALE AND OBJECTIVES

We studied the effect of the addition of sodium to nonionic contrast medium (CM) on the incidence of ventricular fibrillation (VF) during coronary arteriography in dogs.

METHODS

We infused 20 ml (0.5 ml/sec) of iohexol, iohexol plus 30 mmol of Na+ per liter, and NaCl-Ringer's acetate in randomized order through a wedged catheter placed in the right coronary artery (RCA) or in the left anterior descending coronary artery (LAD) in 12 anesthetized dogs. In addition to electrocardiographic and hemodynamic measurements, epicardial monophasic action potential durations and ventricular activation times were recorded during infusions into the LAD.

RESULTS

All infusions with iohexol into the RCA and the LAD (n = 16) caused VF. Seven of 19 infusions with iohexol plus 30 mmol of Na+ per liter caused VF. Infusions with iohexol plus 30 mmol of Na+ per liter that did not cause VF lengthened monophasic action potential durations and increased ventricular activation times more in the CM-perfused area than in the control area.

CONCLUSION

The addition of sodium to iohexol reduces the incidence of VF when infused through a wedged catheter. The protective mechanisms may be attributable to a lengthened repolarization phase and an increased activation time in the CM-perfused area.