A comparison of the efficacy and safety of iopamidol-370 and iodixanol-320 in patients undergoing multidetector-row computed tomography.

Abstract

OBJECTIVES:

To prospectively compare the effects on heart rate (HR) and contrast enhancement efficacy of iopamidol-370 and iodixanol-320 in contrast-enhanced, multidetector-row computed tomography (CE-MDCT).

METHODS:

IMPACT is a multicenter, double-blind study involving 166 patients undergoing CE-MDCT of the liver (n = 121) or peripheral arteries (n = 45) randomized to receive equi-iodine doses (40 gI) of iopamidol-370 or iodixanol-320 intravenous at 4 mL/s. CE-MDCT was performed using 16-MDCT scanners according to predefined imaging protocols. HR was measured with the patient in the supine position before and continuously for 5 minutes after contrast medium administration. Mean and peak increases in HR and the proportion of subjects with predefined HR increases (>5 to <10, 10 to <15, 15 to <20, >20 bpm) were compared in the 2 populations. Liver images were assessed by 2 independent, blinded readers for contrast enhancement [Hounsfield unit (HU)], using predefined regions-of-interest during the arterial and portal-venous phase of enhancement.

RESULTS:

Effects on HR: Eighty-four subjects received iopamidol-370 whereas 82 received iodixanol-320. Mean age, gender distribution, weight, total iodine dose, dose/body weight, concomitant medications and use of beta-blockers were comparable in the 2 groups. Mean baseline HR was similar in the 2 groups (iopamidol-370: 72.3 +/- 12.5 bpm; iodixanol-320: 74.5 +/- 11.9 bpm). Mean changes from baseline to peak postdose were similar in the 2 groups (8.0 +/- 9.3 bpm after iopamidol-370 and 8.4 +/- 14.7 after iodixanol-320, P = 0.72). The proportion of subjects in each group having increases of <5, >5 to <10, 10 to <15, 15 to <20, or >20 bpm was comparable (P = 0.87). Two subjects experienced postcontrast tachycardia (HR increase >70 bpm, peak HR of 146 and 164 bpm), both in the iodixanol-320 group (2.4%). Contrast Enhancement: Of the 121 patients undergoing liver CT, 60 received iopamidol-370 whereas 61 received iodixanol-320. Mean age, gender distribution, weight, total iodine dose, and dose/body weight were comparable in the 2 groups. Iopamidol-370 provided significantly higher HU values in abdominal aorta during the arterial phase of enhancement for both readers [R1: 301.3 +/- 80.2 vs. 273.6 +/- 65.9 HU, 95% confidence interval (6.1-56.8), P = 0.02; R2: 302.0 +/- 73.6 vs. 275.1 +/- 62.9 HU, 95% confidence interval (2.3-51.3), P = 0.03]. No significant difference was observed between the 2 contrast medium during the portal venous phase of enhancement.

CONCLUSIONS:

When the same injection rate and iodine dose is used, the effects on HR of bolus intravenous injections of iopamidol-370 and iodixanol-320 were similar. Iopamidol-370 provides significantly greater enhancement during the arterial phase and similar enhancement during the portal venous phase compared with iodixanol-320.

• Authors: Dushyant V Sahani, Gilles Soulez, Ke-Min Chen, Luigi Lepanto, Jian-Rong Xu, Rendon C Nelson, Luigi Grazioli, Angelo Vanzulli, Jay P Heiken, Investigators of the IMPACT Study
• Journal: Investigative radiology (Invest Radiol) Vol. 42 Issue 12 Pg. 856-61 (Dec 2007) ISSN: 0020-9996 [Print] United States
• PMID: 18007158 (Publication Type: Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Contrast Media
• Triiodobenzoic Acids
• iodixanol
• Iopamidol

Topics

• Aged
• Aorta, Abdominal (diagnostic imaging, drug effects)
• Contrast Media (administration & dosage, toxicity)
• Double-Blind Method
• Drug-Related Side Effects and Adverse Reactions
• Female
• Heart Rate (drug effects)
• Humans
• Iopamidol (administration & dosage, toxicity)
• Kidney (diagnostic imaging, drug effects)
• Kidney Diseases (diagnostic imaging)
• Liver (blood supply, diagnostic imaging)
• Male
• Prospective Studies
• Radiographic Image Enhancement
• Tomography, X-Ray Computed (instrumentation, methods)
• Triiodobenzoic Acids (administration & dosage, toxicity)