Coronary stent evaluation with coronary computed tomographic angiography: comparison between low-osmolar, high-iodine concentration iomeprol-400 and iso-osmolar, lower-iodine concentration iodixanol-320

Background: Reliability of coronary angiography by multidetector row CT (MDCT-CA) for stent evaluation is still a matter for debate, and it is unknown whether contrast medium characteristics may affect diagnostic performance of MDCT-CA. Objective: We compared iomeprol-400 with iodixanol-320 to evaluate coronary stents with MDCT-CA. Methods: We randomly assigned 254 patients undergoing coronary stent follow-up with the use of MDCT-CA to iomeprol-400 at 5.0 mL/sec flow rate (group 1; n= 83), iodixanol-320 at 6.2 mL/sec flow rate (group 2; n= 87), and iodixanol-320 at 5.0 mL/sec flow rate (group 3; n= 84). Heart rate (HR) immediately before and at the end of scanning, HR variation, premature heart beats, and heat sensation by visual analog scale during scanning were recorded. Mean attenuation was measured in the aortic root and coronary arteries. Image quality score and type of artifacts were assessed. Results: Mean attenuation was significantly lower in group 3 than in the other groups. In group 3, stent evaluability was significantly higher and artifact rate was significantly lower than in group 2 (99% vs 91% and 4% vs 15%) and group 1 (99% vs 92% and 4% vs 17%), respectively, mainly because of a significant lower rate of beam-hardening artifacts (3cases in group 3 vs 22 and 27 in groups 2 and 3, respectively). In group 3, visual analog scale, HR at the end of imaging, and number of patients with premature heart beats during the scan were significantly lower than in the other groups. Conclusions: Iodixanol-320 provides better image quality of coronary stents, allowing higher MDCT-CA evaluability, than iomeprol-400.