Peripheral arteriography with a new nonionic agent: comparison of iomeprol with iopamidol

Lowering iodinated contrast concentration in infrainguinal endovascular interventions: a three-armed randomized controlled non-inferiority trial

Objectives

To determine the influence of lowering iodinated contrast concentration on confidence of interventional radiologists in diagnosing and treating lesions during endovascular interventions in patients with symptomatic peripheral arterial disease (PAD).

Methods

A randomized controlled non-inferiority trial was performed in 60 patients. Intervention was performed with contrast concentrations (in mg of iodine per mL, mgI/mL) of 300 (standard), 240, or 140 mgI/mL. Primary outcome was confidence (score 0-100 %) of radiologists in diagnosing and treating arterial lesions. Secondary outcomes were procedural iodine load and image quality (i.e. non-diagnostic, limited, diagnostic, exemplary).

Results

Median confidence scores in diagnosing lesions were 100 % (range 81-100 %) for the 300 group (n = 21), 100 % (range 82-100 %) for the 240 group (n = 19), and 100 % (range 91-100 %) for the 140 group (n = 20) (both p = 1.00 compared to the 300 group). Median scores for treating lesions in the 240 and 140 groups, 100 % (range 79-100 %, p = 0.40), and 100 % (range 63-100 %, p = 0.25), respectively, were not lower compared to the 300 group (median 100 %, range 78-100 %). Procedural iodine load was lower in the 240 (24.3 ± 7.6 g, p = 0.022) and 140 groups (17.8 ± 5.6 g, p < 0.001) compared to the 300 group (29.7 ± 6.3 g). Image quality was diagnostic for all groups.

Conclusion

Using iodine contrast of 140 mgI/mL for diagnosis and interventions in PAD patients significantly reduces administered iodine load without compromising image quality. Future use of lower iodine dose is recommended.

Key Points

• Lower iodinated contrast concentration during endovascular intervention does not decrease radiologist’s confidence.

• Image quality of standardized angiographies remains diagnostic using 140 mgI/mL iodinated contrast concentration.

• Iodine load during intervention can be decreased by >40 % when using 140 mgI/mL.

• Implementing the use of a lower iodinated contrast concentration will reduce the costs of the procedure.

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.

Pain in femoral arteriography. A double-blind, randomized, clinical study comparing safety and efficacy of the iso-osmolar iodixanol 270 mgI/ml and the low-osmolar iomeprol 300 mgI/ml in 9 European centers

PURPOSE

To compare the injection-associated pain and heat sensation after administration of the iso-osmolar contrast medium (IOCM) iodixanol (Visipaque trade mark 270 mg I/ml) and the low osmolar contrast medium (LOCM) iomeprol (Iomeron trade mark 300 mg I/ml) in femoral arteriography.

MATERIAL AND METHODS

352 patients received iodixanol or iomeprol in a prospective, double-blind, randomized, parallel-group clinical trial. The first injection during femoral arteriography (DSA with automated stepping) was standardized. Injection-associated pain and heat sensation, efficacy and safety up to 72 h were evaluated.

RESULTS

The iodixanol group reported significant less injection-associated pain than the iomeprol group after the first injection (7.4% vs. 17.6%; p = 0.007), and after all injections (11% vs. 19.4%; p = 0.045). Iodixanol caused less heat sensation after the first injection (p = 0.007) and after all injections (p = 0.029). Heat sensations in the iodixanol group were less intense after all injections (p < 0.0001). No difference was found between the groups regarding the frequency of patients having adverse reactions (5.1% vs. 4%).

CONCLUSION

The IOCM iodixanol caused significantly less frequent injection-associated pain and heat sensation than the LOCM iomeprol during femoral arteriography.

Transient partial amnesia complicating cardiac and peripheral arteriography with nonionic contrast medium

The aim of this study was to present a case of disruption of the blood-brain barrier during the coronary and lower extremity angiographies with radiological and clinical findings. This condition was secondary to intraarterial use of a nonionic, monomeric contrast medium. A total of 450 cc contrast media was used. Computed tomography examination showed contrast enhancement of the right occipital and frontoparietal cortical regions, which returned to normal one day after. The patient also fully recovered from the neurological symptoms within 24 h. We discussed the possible mechanism for blood-brain barrier disruption in this case.

Iomeprol: current and future profile of a radiocontrast agent

RATIONALE AND OBJECTIVES

To review the safety and efficacy profiles of iomeprol by examining the most indicative comparative clinical studies of iomeprol with widely used low-osmolar ionic or nonionic contrast agents, and to illustrate the recent development in iomeprol liposomal formulations for liver imaging and intravascular enhancement.

METHODS

Randomized, double-blind, comparative studies were performed of iomeprol versus iopamidol, iopromide, ioxaglate, iopentol, iodixanol, ioversol, and iohexol. In all studies, safety controls included pre- and postadministration physical examinations, monitoring of vital signs, electrocardiography, clinical laboratory investigations, and 24- or 72-hour postadministration monitoring of patients for adverse events. Technically adequate images were rated for diagnostic efficacy by masked assessors.

RESULTS

Iomeprol showed similar safety and diagnostic efficacy compared with the nonionic monomers iopamidol, iohexol, and ioversol, and no statistically significant differences were observed. No differences in diagnostic efficacy between iomeprol and iopromide were observed, but in one study on 1,200 patients, the incidence of adverse events and adverse reactions was significantly higher with iopromide than with iomeprol. Iomeprol caused significantly less heat/pain than iopentol in one study; it showed similar safety and tolerability to the nonionic dimer iodixanol, the two agents causing no or modest, superimposable pain and heat sensation at injection and showing similar renal tolerability after intra-arterial injection. A comparison of iomeprol versus ionic dimer ioxaglate in 2,000 patients undergoing percutaneous coronary interventions showed that the incidence of thrombus-related events was similar with the two agents, but ioxaglate caused a significantly higher incidence of allergy-like reactions. First results with iomeprol-containing liposomal formulations show that these agents may facilitate the CT assessment of intrahepatic malignancies and CT angiography procedures.

CONCLUSIONS

The overall results of numerous randomized, double-blind, comparative clinical studies in a variety of indications show that the diagnostic efficacy of iomeprol solutions does not differ significantly from that of the low-osmolar contrast media available on the marketplace when similar iodine strengths are used, although iomeprol may have better tolerability and safety than the ionic dimer and some of the nonionic monomers in selective applications. First results obtained with iomeprol-containing liposomal formulations are promising and may foster additional clinical testing.

Iomeprol: a review of its use as a contrast medium

Iomeprol is a nonionic, monomeric iodinated contrast medium. Unlike the older ionic agents, iomeprol has low chemotoxicity, osmolality and viscosity and high water solubility. Compared with other nonionic contrast media, the osmolality and viscosity are lower and the water solubility is reported to be higher with iomeprol. Most radiographs (about 67 to 100%) obtained with iomeprol (containing 150 to 400 mg/ml of iodine) were of good or excellent quality in noncomparative and comparative trials recruiting 40 to 6127 patients undergoing various radiographic procedures. As expected, the diagnostic efficacy of iomeprol did not differ significantly from that of other nonionic agents (iopamidol, iopromide, iohexol and iotrolan). Iomeprol (containing 150 to 400 mg/ml of iodine) was well tolerated in clinical trials. Most adverse events were transient and of mild to moderate intensity and were similar to those observed with other contrast media. The overall incidence of adverse events ranged from 3 to 49.7% and mainly included localised pain (< or =6%) and heat sensations (8 to 45%), taste disturbances (3 to 27%) and various pseudoallergic reactions (< or =20% for each type of event). The incidence of heat or pain and taste disturbances with iomeprol was similar to that observed with iopromide and iopamidol. Pain (but not heat sensations) was reported significantly less frequently and taste disturbances reported significantly more frequently with iomeprol than with iohexol in a comparative trial. Pseudoallergic reactions (such as nausea, vomiting, skin reactions, dizziness, headache) were significantly less common with iomeprol than with ioxaglate and occurred at a similar frequency to that with iopromide and iopamidol. Cardiovascular events were rarely observed with iomeprol. Currently available iomeprol solutions contain a range of iodine concentrations (150 to 400 mg/ml) and are approved for a wide variety of diagnostic procedures. Iomeprol solutions are chemically stable which negates the need for chelating agents. Formulations of this agent are therefore the first not to contain edetic acid (EDTA).

CONCLUSIONS

Iomeprol shows equivalent diagnostic efficacy, and a similar adverse event profile, to that of other nonionic contrast media. The availability of a range of iodine concentrations enables iomeprol to be used in a variety of diagnostic procedures. Iomeprol, like others in its class, is suitable for use in diagnostic imaging.

Evaluation of liposomal contrast agents for liver CT in healthy rabbits

RATIONALE AND OBJECTIVES

To evaluate the efficiency of two new liposomal contrast agents aimed at the reticuloendothelial system for liver CT in comparison to an extracellular contrast agent.

METHODS

Two liposomal contrast agents (BR2 and BR21, respectively), containing free as well as encapsulated iomeprol at different concentrations, and commercially available free extracellular iomeprol were studied. In 60 experiments, the three contrast agents were tested at five different doses in rabbits. Intravenous injection was followed by dynamic CT studies over a period of 0 to 120 minutes (0 to 6 hours in 3 animals). A quantitative analysis of the enhancement in aorta and liver was performed.

RESULTS

In healthy rabbits, the two liposomal contrast agents induced a significantly higher and more persistent increase in liver density at doses of > or = 1.5 mL/kg compared with the extracellular agent. The density enhancement induced by the two liposomal agents was dose-dependent and reached a maximum of +102 Hounsfield units (HU), compared with +87 HU for the extracellular contrast agent, at 2.0 mL/kg, without any appreciable increases at higher dosages. An adequate liver enhancement of at least +40 HU persisted for up to 90 minutes after injection of the liposomal contrast agents, compared with < 5 minutes after the extracellular agent. BR2 tended to provide a higher and more persistent enhancement than BR21.

CONCLUSIONS

Liposomal contrast agents induce a more pronounced and much more persistent increase in liver density than conventional extracellular agents. Liposomes thus have the potential for optimizing CT examinations of the liver by providing a larger imaging window.