Efficacy and Safety of Iodixanol in Computed Coronary Tomographic Angiography and Cardiac Catheterization

Iodixanol is an iso-osmolar non-ionic dimeric hydrophilic contrast agent with a higher viscosity than the monomeric agents. It is the only Food and Drug Administration (FDA)-approved iso-osmolar agent in the United States, and it is the only contrast agent with an FDA-approved indication for use in cardiac computed tomographic angiography (CCTA), to assist in the diagnostic evaluation of patients with suspected coronary artery disease. In clinical studies, it has been noted to have fewer side effects and similar image quality when compared to low-osmolar contrast media. This can be attributed to the pharmacological properties of iodixanol. These contrast agents are used for coronary computed tomography angiography and cardiac catheterization. In this article, the use, tolerability, and efficacy of iodixanol are reviewed, specifically evaluating the use of CCTA and coronary angiography, including outcome studies, randomized trials, and comparisons to other contrast agents.

Hemodynamic effects of intravenous bolus injection of iopromide 370 twice in abdominal contrast-enhanced CT and coronary CTA dual-site sequential examinations

Little information is available about how intravenous bolus injection of iopromide 370 twice in a short time will affect hemodynamics and whether the changes reach clinically relevant levels. In the present study, 31 healthy adult volunteers received abdominal contrast-enhanced CT and coronary CTA sequential examinations. The same dose and rate of normal saline was injected 30 min in advance as self-control. Hemodynamic data were noninvasively collected at selected time points from 1 min prior to injection to 30 min post-injection. The results showed that after iopromide 370 injection, except for stroke volume, all other indicators changed immediately during the first injection, changed most significantly during the second injection (P < 0.05), and returned to baseline within 10 min. Heart rate and cardiac output exhibited the most pronounced changes, with an increasing rate of 33.5% and 33.8%, respectively. For indicators with a change range of > 15% during the second injection, except for mean arterial pressure and total peripheral resistance, the proportions of subjects for the other indicators between the two groups were statistically different (P < 0.05). In conclusion, intravenous bolus injection of iopromide 370 twice in dual-site sequential examinations induced dose-cumulative and time-dependent hemodynamic effects, which all fluctuated within the normal ranges.

Comparative effect of iso-osmolar versus low-osmolar contrast media on vascular attenuation, image quality, and heart rate changes in coronary CT angiography: A systematic review and meta-analysis

OBJECTIVES

Comparison of iso-osmolar contrast media (IOCM) and low-osmolar contrast media (LOCM) for vascular attenuation, image quality, heart rate changes, and common patient discomfort symptoms.

METHODS

We searched PubMed, Web of Science, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL). We included only randomized controlled trials. Screening, data extraction, and quality assessment were done by three independent authors. RevMan 5.3 software was used for meta-analysis.

RESULTS

Nine studies (n = 1831 participants) were found eligible and included in the meta-analysis. There was no difference between the both contrast media for vascular attenuation (mean difference = -21.31; 95% confidence interval -49.81 to 7.19; p = 0.14), image quality (standardized mean difference = 0.13; 95% confidence interval -0.07 to 0.33; p = 0.19), heart rate variability (standardized mean difference = -0.61; 95% confidence interval -1.30 to 0.09; p = 0.09), heat sensation (risk ratio = 0.79; 95% confidence interval 0.56 to 1.11; p = 0.17), and nausea or vomiting (risk ratio = 0.82; 95% confidence interval 0.52 to 1.28; p = 0.38). Moreover, IOCM resulted in a heart rate that was lower by 0.9 beat per minute (bpm) compared to LOCM (mean difference = -0.92; 95% confidence interval -1.81 to -0.03; p = 0.04).

CONCLUSIONS

Both IOCM and LOCM have similar vascular enhancement, image quality, heart rate variability, and similar risk for patient discomfort. Furthermore, IOCM resulted in a slightly lower heart rate by 0.9 bpm.

Systemic Hypotension Following Intravenous Administration of Nonionic Contrast Medium During Computed Tomography: Iopromide Versus Iodixanol

BACKGROUND

In light of the increasing number of radiologic interventions performed under general anesthesia, the effects of contrast media (CM) on circulation and organ perfusion are of paramount importance. The objectives of this study were to systematically quantify effects on blood pressure, heart rate, and kidney function following intravenous administration of nonionic CM with normal and low osmolality.

METHODS

In this controlled, double-blinded phase IV clinical trial, 40 consecutive patients were randomly assigned to receive repeated measures of either low-osmolar iopromide or iso-osmolar iodixanol. Normal saline solution (NSS) served as control. Blood pressure and heart rate were measured continuously from 1 minute before until 3 minutes after administration of CM and NSS. Urine output was recorded hourly.

RESULTS

Administration of iopromide resulted in systemic hypotension lasting up to 300 seconds (105 ± 61 seconds) with the lowest mean arterial pressure of 39 mm Hg (56.7 ± 12.2 mm Hg). Iopromide caused a systolic/diastolic decrease of 31/26 mm Hg (P < .001), significant increase in heart rate (P = .042), and significant diuresis with a 2-fold higher per-hour urine output (P = .010). Administration of iodixanol and NSS had no significant influence on blood pressure (P > .640).

CONCLUSIONS

Administration of low-osmolar iopromide was followed by a significant transient decrease in blood pressure and a rise in heart rate. Anesthetists and radiologists should be aware of these effects in patients in whom short episodes of disturbed tissue microcirculation may pose a clinical risk.

Comparison of Iodixanol and Iopromide in Patients With Renal Insufficiency and Congestive Heart Failure Undergoing Coronary Angiography by Hemodynamic Monitoring

We investigated the impact of contrast media (CM) with different osmolality on cardiac preload in patients with chronic kidney disease (CKD) and congestive heart failure (CHF). Patients with CKD and CHF were equally randomized to receive either iso-osmolar contrast media (IOCM) iodixanol or low-osmolar contrast media iopromide. We measured cardiac preload indexes by invasive hemodynamic monitoring before and after CM injection. Major adverse cardiac events postprocedures were recorded. Increase in extravascular lung water index was only seen in the iopromide group ( P < .001), while global end diastolic index and central venous pressure were all significantly increased from baseline in the both groups ( P < .001, respectively), and the increase in cardiac preload indexes was significantly greater in the iopromide group than in the iodixanol group ( P < 0.001). The overall incidence of acute heart failure was more frequently observed in the iopromide group ( P = 0.027). Low-osmolar contrast media iopromide significantly increased cardiac preload in patients with CKD and CHF undergoing cardiac catheterization procedures compared with IOCM iodixanol.

Comparison of patient comfort between iodixanol and iopamidol in contrast-enhanced computed tomography of the abdomen and pelvis: a randomized trial

BACKGROUND

Previous clinical studies have shown that iso-osmolar iodixanol (Visipaque®) causes less patient discomfort than low-osmolar contrast media (LOCM) when administered via intra-arterial injection. No data are available comparing these agents for patient discomfort when administered intravenously (i.v.) using power injectors.

PURPOSE

To compare the frequency and intensity of patient discomfort between iodixanol and iopamidol (Isovue®) administered i.v. using a power injector in contrast-enhanced computed tomography (CECT) of the abdomen and pelvis.

MATERIAL AND METHODS

This was a prospective, randomized, double-blind, multicenter study of iodixanol 320 mg I/mL or iopamidol 370 mg I/mL on patient discomfort. The presence of discomfort (heat, pain, coldness) and intensity was verbally rated by patients on a 0-10 scale and converted into four categories (0, none; 1-3, mild; 4-7, moderate; 8-10, severe). Image quality was evaluated.

RESULTS

Of the 299 evaluable patients enrolled at nine centers, 151 received iodixanol and 148 received iopamidol. The average age was 58 years. Iodixanol patients experienced significantly less moderate/severe discomfort (35.1% vs. 67.3%; P < 0.0001) or heat (29.8% vs. 63.9%; P < 0.0001), and severe discomfort (2.6% vs. 16.3%; P = 0.0004) or heat (2.6% vs. 15%; P = 0.0008), but three times more no discomfort (21.2% vs. 7.5%; P = 0.0008) than iopamidol patients. Excellent image quality was in 95.4% of iodixanol vs. 89.9% of iopamidol patients (P = 0.0508). Overall, adverse event (AE) rate excluding patient discomfort was 19.9% in the iodixanol group and 14.9% in the iopamidol group (P = 0.2870), but contrast-related AEs were comparable: 11.3% vs. 10.1% (P = 0.8522). Delayed skin reactions occurred in 2.6% of patients in the iodixanol group and in no patient in the iopamidol group (P = 0.1226).

CONCLUSION

Patients receiving iodixanol had significantly lower moderate-to-severe or severe discomfort than patients receiving iopamidol, with heat being the major contributor. Iodixanol use trended towards better image quality but the difference was not statistically significant. No significant differences in incidences of overall or contrast-related AEs or delayed skin reactions were seen between the two groups. These data support that CM osmolality may be a key determinant of patient discomfort.

Contrast-induced kidney injury: mechanisms, risk factors, and prevention

In general, iodinated contrast media (CM) are tolerated well, and CM use is steadily increasing. Acute kidney injury is the leading life-threatening side effect of CM. Here, we highlight endpoints used to assess CM-induced acute kidney injury (CIAKI), CM types, risk factors, and CIAKI prevention. Moreover, we put forward a unifying theory as to how CIAKI comes about; the kidney medulla's unique hyperosmolar environment concentrates CM in the tubules and vasculature. Highly concentrated CM in the tubules and vessels increases fluid viscosity. Thus, flow through medullary tubules and vessels decreases. Reducing the flow rate will increase the contact time of cytotoxic CM with the tubular epithelial cells and vascular endothelium, and thereby damage cells and generate oxygen radicals. As a result, medullary vasoconstriction takes place, causing hypoxia. Moreover, the glomerular filtration rate declines due to congestion of highly viscous tubular fluid. Effective prevention aims at reducing the medullary concentration of CM, thereby diminishing fluid viscosity. This is achieved by generous hydration using isotonic electrolyte solutions. Even forced diuresis may prove efficient if accompanied by adequate volume supplementation. Limiting the CM dose is the most effective measure to diminish fluid viscosity and to reduce cytotoxic effects.

Patient discomfort associated with the use of intra-arterial iodinated contrast media: a meta-analysis of comparative randomized controlled trials

Background

Discomfort characterized by pain and warmth are common adverse effects associated with the use of intra-arterial iodinated contrast media (CM). The objective of this review was to pool patient-reported outcomes available from head-to-head randomized controlled trials (RCTs) and to compare the discomfort rates associated with iso-osmolar contrast media (IOCM; i.e., iodixanol) to those reported with various low-osmolar contrast media (LOCM).

Methods

A review of the literature published between 1990 and 2009 available through Medline, Medline Preprints, Embase, Biological Abstracts, BioBase, Cab Abstracts, International Pharmaceutical Abstracts, Life Sciences Collection, Inside Conferences, Energy Database, Engineering Index and Technology Collection was performed to compare rates of discomfort associated with the use of the IOCM (iodixanol) vs. various LOCM agents in head-to-head RCTs. All trials with a Jadad score ≥2 that reported patient discomfort data following intra-arterial administration of CM were reviewed, coded, and extracted.

Results

A total of 22 RCTs (n = 8087) were included. Overall discomfort (regardless of severity) was significantly different between patients receiving IOCM and various LOCMs (risk difference [RD] -0.049; 95% confidence interval [CI]: -0.076, -0.021; p = 0.001). IOCM was favored over all LOCMs combined with a summary RD value of -0.188 (95% CI: -0.265, -0.112; p < 0.001) for incidence of pain, regardless of severity. A greater reduction in the magnitude of pain was observed with IOCM (iodixanol), particularly with selective limb and carotid/intracerebral procedures. Similarly, the meta-analysis of warmth sensation, regardless of severity, favored IOCM over LOCMs with an RD of -0.043 (95% CI: -0.074, -0.011; p = 0.008). A positive linear relationship was observed between the discomfort effect size and age and a negative relationship with increasing proportion of women. The opposite trends were observed with warmth sensation.

Conclusions

IOCM was associated with less frequent and severe patient discomfort during intra-arterial administration. These data support differences in osmolality as a possible determinant of CM discomfort.

Iodixanol Versus Low-Osmolar Contrast Media for Prevention of Contrast Induced Nephropathy

Background—

Contrast-induced nephropathy (CIN) is associated with significant morbidity and mortality. The objective of our meta-analysis was to assess the efficacy of iodixanol compared with low-osmolar contrast media (LOCM) for prevention of CIN.

Methods and Results—

We searched MEDLINE, the Cochrane Central Register of Controlled Trials, and internet sources of cardiology trial results for individual and relevant reviews of randomized, controlled trials, for the terms contrast media, contrast nephropathy, renal failure, iodixanol, Visipaque, and low-osmolar contrast media. All studies reported an incidence rate of CIN for each study group; there was no restriction on the definition of CIN. There were no restrictions on journal type or patient population. Overall, 36 trials were identified for analysis of aggregated summary data on 7166 patients; 3672 patients received iodixanol and 3494 patients received LOCM. Overall, iodixanol showed no statistically significant reduction in CIN incidence below that observed with heterogeneous comparator agents ( P =0.11). Analysis of patient subgroups revealed that there was a significant benefit of iodixanol when compared with iohexol alone (odds ratio, 0.25; 95% confidence interval, 0.11 to 0.55; P <0.001) but not when compared with LOCM other than iohexol or with other ionic dimers or among patients receiving intra-arterial contrast injections or among patients undergoing coronary angiography with or without percutaneous intervention.

Conclusions—

Analysis of aggregated summary data from multiple randomized, controlled trials of iodixanol against diverse LOCMs for heterogeneous procedures and definitions of CIN show an iodixanol-associated reduction that is suggestive but statistically nonsignificant.

The relative renal safety of iodixanol compared with low-osmolar contrast media: a meta-analysis of randomized controlled trials

OBJECTIVES

We sought to compare the nephrotoxicity of the iso-osmolar contrast medium, iodixanol, to low-osmolar contrast media (LOCM).

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) is a common cause of in-hospital renal failure. A prior meta-analysis suggested that iodixanol (Visipaque, GE Healthcare, Princeton, New Jersey) was associated with less CI-AKI than LOCM, but this study was limited by ascertainment bias and did not include the most recent randomized controlled trials.

METHODS

We searched Medline, Embase, ISI Web of Knowledge, Google Scholar, Current Contents, and International Pharmaceutical Abstracts databases, and the Cochrane Central Register of Controlled Trials from 1980 to November 30, 2008, for randomized controlled trials that compared the incidence of CI-AKI with either iodixanol or LOCM. Random-effects models were used to calculate summary risk ratios (RR) for CI-AKI, need for hemodialysis, and death.

RESULTS

A total of 16 trials including 2,763 subjects were pooled. There was no significant difference in the incidence of CI-AKI in the iodixanol group than in the LOCM group overall (summary RR: 0.79, 95% confidence interval [CI]: 0.56 to 1.12, p = 0.19). There was no significant difference in the rates of post-procedure hemodialysis or death. There was a reduction in CI-AKI when iodixanol was compared with ioxaglate (RR: 0.58, 95% CI: 0.37 to 0.92; p = 0.022) and iohexol (RR: 0.19, 95% CI: 0.07 to 0.56; p = 0.002), but no difference when compared with iopamidol (RR: 1.20, 95% CI: 0.66 to 2.18; p = 0.55), iopromide (RR: 0.93, 95% CI: 0.47 to 1.85; p = 0.84), or ioversol (RR: 0.92, 95% CI: 0.60 to 1.39; p = 0.68).

CONCLUSIONS

This meta-analysis including 2,763 subjects suggests that iodixanol, when compared with LOCM overall, is not associated with less CI-AKI. The relative renal safety of LOCM compared with iodixanol may vary based on the specific type of LOCM.

Contrast medium use

Various properties of iodinated contrast media (osmolality, ionic versus nonionic, and viscosity) may contribute to contrast-induced nephropathy (CIN). Therefore, the choice of contrast medium affects the risk for CIN. There is good evidence that low-osmolar contrast media are less nephrotoxic than high-osmolar contrast media in patients at increased risk for CIN who receive intra-arterial iodinated contrast. Current evidence suggests that nonionic isosmolar contrast presents the lowest risk for CIN in patients with chronic kidney disease (CKD), particularly in those patients with diabetes mellitus. Intra-arterial administration of contrast media may be associated with a greater risk for CIN above that observed with intravenous administration. The use of gadolinium or CO(2) as alternative contrast media to avoid the risk of nephrotoxicity cannot be substantiated by clinical trials and therefore cannot be recommended. Most studies show that, within a class, higher volumes (>100 mL) of iodinated contrast medium are associated with a higher risk for CIN. However, in patients at high risk, such as those with CKD and diabetes, even small volumes of contrast medium can have adverse effects on renal function.

A Meta-Analysis of the Renal Safety of Isosmolar Iodixanol Compared With Low-Osmolar Contrast Media

OBJECTIVES

We sought to compare the nephrotoxicity of isosmolar contrast medium (IOCM) iodixanol with low-osmolar contrast media (LOCM) and to identify predictors of contrast-induced nephropathy (CIN).

BACKGROUND

Contrast-induced nephropathy is a serious complication of diagnostic and interventional procedures.

METHODS

Pooled individual patient data (n = 2,727) from 16 double-blind, randomized, controlled trials in which patients received either intra-arterial IOCM iodixanol (n = 1,382) or LOCM (n = 1,345) were included. Patients were stratified according to chronic kidney disease (CKD), diabetes mellitus (DM), or both. Outcome measures were the maximum increase in serum creatinine (Cr) over baseline and the incidence of postprocedural CIN.

RESULTS

The maximum Cr increase within 3 days after contrast medium (CM) administration was significantly smaller in the iodixanol group compared with the LOCM group (0.06 mg/dl vs. 0.10 mg/dl, p < 0.001), particularly in patients with CKD (0.07 mg/dl vs. 0.16 mg/dl, p = 0.004) and CKD + DM (0.10 mg/dl vs. 0.33 mg/dl, p = 0.003). Contrast-induced nephropathy, defined as an increase in Cr > or =0.50 mg/dl within 3 days after CM administration, occurred less frequently in the iodixanol group than in the LOCM group in all patients (1.4% vs. 3.5%, p < 0.001), in CKD patients (2.8% vs. 8.4%, p = 0.001), and in CKD + DM patients (3.5% vs. 15.5%, p = 0.003). Independent predictors of CIN included CKD, CKD + DM, and use of LOCM.

CONCLUSIONS

This meta-analysis of pooled data from 2,727 patients indicates that use of the IOCM iodixanol is associated with smaller rises in Cr and lower rates of CIN than LOCM, especially in patients with CKD or CKD + DM.

Follow-up of patients with contrast-induced nephropathy

In this chapter, we review the approach to following the patient after contrast is administered. We first discuss the clinical importance of renal injury for if there were no clinically significant consequences of this renal injury, we would have far less concern for the adequacy of follow-up. We next look at markers of renal injury and what tests are used in clinical practice to define contrast-induced nephropathy (CIN). Finally, we discuss the steps that should be taken in those who do develop CIN to limit the impact of the injury and protect them from future adverse events.

A comparison of a non-ionic dimer, iodixanol with a non-ionic monomer, iohexol in low dose intravenous urography

A prospective, double-blind study of 392 patients randomized into four groups was performed to establish whether diagnostic intravenous urograms could be obtained with a lower dose of iodine when using the dimeric, non-ionic contrast medium iodixanol compared with the monomeric, non-ionic iohexol. Patients received iodixanol or iohexol containing either 9 or 12 g of iodine (gI). The primary parameter was the diagnostic quality of the 6 min film, assessed in a blinded fashion, by consensus, by four radiologists. Iodixanol at both doses was diagnostic in over 90% of cases. Iohexol was only diagnostic in 74% (9 gI) and 81.8% (12 gI). Pairwise comparisons revealed that iodixanol 9 gI was significantly better than both iohexol 9 gI (p = 0.0005) and 12 gI (p = 0.014). No significant difference was present for different doses within the same contrast medium group. Iodixanol resulted in poorer bladder distension than iohexol. Iodixanol caused significantly less discomfort than iohexol.

Injection-associated pain in femoral arteriography: a European multicenter study comparing safety, tolerability, and efficacy of iodixanol and iopromide

PURPOSE

To evaluate injection-associated pain, safety, and efficacy with the isotonic contrast medium iodixanol (Visipaque 270 mg I/ml) compared with iopromide (Ultravist 300 mg I/ml) in femoral arteriography.

METHODS

A multicenter, double-blind, randomized, parallel-group clinical investigation was carried out in 54 hospitals in Europe. Of the patients evaluated, 1225 received iodixanol and 1227 iopromide in conventional and/or digital subtraction angiography.

RESULTS

The iodixanol group reported statistically significantly less injection-associated pain (0.9%) than the iopromide group (9.5%) (p << 0.001). Further, 4.1% in the iodixanol group experienced pain and/or severe heat sensation vs 19. 8% in the iopromide group (p << 0.001). In the iodixanol group, 1.8% of the patients experienced contrast-related adverse events vs 2.4% in the iopromide group (p = NS). Overall diagnostic information was optimal for 94.1% in the iodixanol group and 95.3% in the iopromide group (p = NS).

CONCLUSIONS

Iodixanol 270 mg I/ml causes significantly less injection-associated pain during femoral arteriography and is as safe and efficacious as iopromide 300 mg I/ml.

High-volume nonionic dimeric contrast medium: first experiences during complex coronary interventions

Interventional cardiology is a rapidly developing field of medicine with annually increasing numbers of coronary interventions. Especially through the development of alternative techniques for coronary angioplasty, new indications have been found and more difficult lesions are tackled. Inevitably, such complex interventions are time-consuming and require high amounts of contrast medium. Newer, mostly nonionic agents have been developed with improved tolerability as well as fewer cardiac and renal side effects due to their nonionic, hydrophilic structure, and their osmolality isotonic to plasma. This study sought to investigate the effects of high-volume nonionic, dimeric contrast medium during coronary interventions with special emphasis on renal and hemodynamic side effects during routine hospital stays. Retrospectively, 25 consecutive patients (age 56 +/- 10 yr) with normal renal and cardiac function receiving > 500 ml of the nonionic dimeric contrast medium iodixanol during complex coronary interventions were analyzed. The analysis was based on serum creatinine levels 1 day before and 2 days after contrast medium administration for the monitoring of renal function. Additionally, heart rate and left ventricular pressures were evaluated before and after left ventricular angiography. Mean serum creatinine rose from 0.9 +/- 0.2 mg/dl to 1.1 +/- 0.2 mg/dl (P < 0.05) after 2 days of coronary intervention. Heart rate, left ventricular systolic pressure, and left ventricular end-diastolic pressure did not change significantly. No major side effects were encountered in the short follow-up period of 2 days. Based on this retrospective analysis, high-volume nonionic, dimeric contrast medium administration in patients without preexisting renal insufficiency is associated with little impairment of renal function, and has only minor hemodynamic and general side effects. Iodixanol 320 mg I/ml is well-tolerated and effective for the use of cardioangiography. Given the limitations of this retrospective analysis, future prospective studies should systematically address the effects of high-volume contrast medium administration in otherwise healthy patients as well as in high-risk patients undergoing coronary interventions.

Image quality and safety after iodixanol in intravenous urography; a comparison with iohexol

A double-blind, randomized phase III study compared intravenous urography in 100 adult patients receiving iodixanol 320 mgI ml-1 (Visipaque) with 99 patients receiving iohexol 350 mgI ml-1 (Omnipaque). The aim of the study was to investigate differences in image quality between a non-ionic dimeric contrast medium (CM) and a non-ionic monomer at 40 ml per patient and 60-100 ml per patient volume levels. There were no statistically significant differences between iodixanol and iohexol with respect to overall diagnostic information, which was found to be optimal in 86% and 79%, respectively. Immediately after the injection, the renal border was better delineated with iohexol than with iodixanol (p = 0.0001). Marked papillary blush occurred more often in the iodixanol group (16%) than in the iohexol group (0%), as did visualization of the collecting ducts (24% vs 5%) (p = 0.001). The incidence of adverse events was similar and low for both contrast media. In patients who received the higher doses of CM (60-100 ml), the frequency of discomfort was significantly lower after iodixanol than after iohexol (p = 0.006). We conclude that, in intravenous urography, iodixanol provides at least as good image quality as does iohexol. Iodixanol may cause less discomfort than iohexol, in particular when larger volumes of CM are injected.

The non-ionic isotonic contrast agents. Perspectives and controversies

The non-ionic isotonic contrast agents represent a new class of intravascular iodinated x-ray contrast agents. They are highly hydrophilic, resulting in low chemotoxicity, are non-ionic, thereby eliminating Coulomb interactions, and are formulated in solutions iso-osmolar with the respective body fluids. Invitro testing, organ specific toxicity studies and overall systemic toxicity assessments such as LD50 measurements all point to an excellent toxicity profile. This justify their application in high dose procedures where their low toxicity may be distinctly advantageous. Their iso-osmolality, possibly combined with a slower diffusion of the larger molecules across vessel walls and out of the vascular space, may play a significant role in producing better quality venous phase images following arteriography and arterial phase images following venous injection. This may have implications for the quality of IV-DSA, the venous phase of arteriograms, CT-portography and spiral CT arteriography.

Immediate and late adverse reactions in coronary angiography. A comparison between iodixanol and ioxaglate

PURPOSE AND METHODS

In 120 patients in a double-blind, randomized, pa rallel study, iodixanol (Visipaque), a nonionic dimer isotonic with blood, was compared with ioxaglate (Hexabrix), an ionic low-osmolar dimer, in coronary angiography regarding early and late adverse reactions. Haemodynamic and electrophysiologic parameters were also analyzed.

RESULTS

Visipaque resulted in significantly fewer early adverse contrast medium-related reactions (p<0.05). Visipaque also demonstrated significantly fewer effects on electrophysiologic parameters. Both contrast media reduced systolic and diastolic blood pressures at the 1st injection in the left coronary artery. Late adverse reactions were unusual with both contrast media and occurred only as urticaria with a frequency of 1.7%, which is lower than reported in i.v. studies. One serious adverse reaction, a myocardial infarction in a male patient with severe cardiovascular disease, occurred in the Visipaque group. This event was considered to be procedure- and disease-related rather than related to the type of contrast medium used.

CONCLUSION

We found Visipaque safe for coronary angiography, causing fewer early adverse reactions than Hexabrix and also fewer effects on electrophysiologic parameters. Late adverse reactions seemed to be unusual with intra-arterial administration of contrast media.

A comparison of iodixanol with iopamidol in aorto-femoral angiography

This double-blind, randomized, parallel group clinical investigation in 140 consecutive patients undergoing aorto-femoral arteriography was carried out to compare iodixanol (Visipaque) 270 mgI ml-1 with iopamidol (Iopamiro) 300 mgI ml-1. The aims of the study were to compare adverse events and discomfort, clinical chemistry parameters in blood, haemodynamics and diagnostic information of the angiograms in the two groups. The main parameter for statistical analysis was the visual analogue scale (VAS) score for overall discomfort experienced by the patients during the examination. 134 patients, 69 and 65 receiving iodixanol and iopamidol, respectively, were examined according to the protocol and included in the evaluation. The two groups of patients were judged to be comparative. Statistically significant milder discomfort was felt with iodixanol than with iopamidol (p = 0.0001); mean VAS values 16 mm and 51 mm, respectively. Pain was reported far less frequently after iodixanol than after iopamidol (7.4% versus 50.8%) whereas sensation of warmth was less intense after iodixanol than after iopamidol. Four patients in the iodixanol group and two in the iopamidol group reported transient, non-serious adverse events. The difference was not statistically significant (p = 0.68). Systolic blood pressure was affected to a slightly greater degree after injection of iopamidol than after injection of iodixanol. Measurements of diastolic blood pressure, as well as clinical chemistry parameters in blood, revealed no changes of clinical importance, and all arteriograms performed were of diagnostic value. The conclusion is that iodixanol 270 mgI ml-1 is as efficacious as iopamidol 300 mgI ml-1, but produces less discomfort during arteriography. As such, iodixanol is a good alternative to iopamidol in aorto-femoral angiography.

Cardioangiography and the hemodynamic effects of iodixanol

Patient safety should be in focus when using contrast media (CM) in diagnostic and interventional cardiac procedures. Side-effects that occur during cardioangiography due to hemodynamic effects of CM include direct effects on the heart, effects on the systemic and pulmonary circulation, and effects on the blood volume. Although not a totally inert solution, iodixanol (Visipaque) has less pronounced direct inotropic effects on the heart than have other CM; its vasodilatory effects on peripheral arteries are smaller, and the increase in blood volume is smaller after administering iodixanol than after other CM. Thus, iodixanol represents a further step forward in terms of reducing side-effects during contrast-enhanced diagnostic and interventional cardiac procedures.

Main results of the first comparative clinical studies on Visipaque

The results are reviewed from 18 European clinical vascular studies in 1950 patients where iodixanol (Visipaque) - a new isotonic, dimeric, nonionic contrast medium (CM) - is compared to other CM. Visipaque gave better patient comfort, i.e., less pain and heat sensation after vascular injections than the comparative CM. Adverse events reported after Visipaque were otherwise similar to nonionic CM but lower than after ioxaglate (Hexabrix) and other ionic CM. Human renal safety of Visipaque has been extensively studied. Only small changes in glomerular filtration rate and serum creatinine were measured with the monomeric nonionic CM as well as with Visipaque. The excretion of marker enzymes for renal tubular cell function was generally lowest for Visipaque. Thus Visipaque was highly tolerable in the kidneys. To study cardiac safety, electrophysiological and hemodynamic changes were recorded. Visipaque had generally no electrophysiological or hemodynamic effects, or less pronounced effects compared to the other CM. Radiograms revealed that Visipaque 320 mg I/ml yielded the same attenuation as 350 to 370 mg I/ml of the other CM and, similarly, 270 mg I/ml of Visipaque gave as good visualization as 300 mg I/ml of comparative CM.