Influence of a New Monomeric Nonionic Radiographic Contrast Medium (Iobitridol-350 versus NaCl) on Cutaneous Microcirculation: Single-Center, Prospective, Randomized, Double-Blind Phase IV Study in Parallel Group Design

This single-center, prospective, randomized, double-blind phase IV study with parallel-group design was performed to test whether injection of a newly designed non-ionic monomeric radiographic contrast medium in the axillary artery influences the ipsilateral cutaneous microcirculation. Twenty patients with coronary heart disease or suspected coronary heart disease were investigated. Ten patients received iobitridol and 10 normal saline solution. The confirmatory target variable was the capillary erythrocyte velocity (vRBC). The vRBC was continuously recorded before and up to 3 min after the injection of iobitridol or normal saline solution and subsequently evaluated off-line. Thirty seconds after injection of 20 ml iobitridol, vRBC was reduced by 32% (P < 0.05). This was the strongest reduction, but vRBC was reduced at all time points measured up to 180 s following the injection (P < 0.05 up to 180 s). The overall reduction in vRBC was also statistically significant (P 0.0446). In contrast, there was a tendency toward an increase in vRBC following injection of 20 ml normal saline (P 0.0512). There was also a tendency toward a difference in the time course of changes in vRBC following injection of iobitridol compared to normal saline (P 0.0607). The decrease in vRBC following iobitridol injection (standardized difference (SD) according to Cohen, 0.67) can be regarded as biometrically weak, and the increase following normal saline injection (SD, 0.24) as very weak. The microcirculatory disturbance induced by iobitridol injection is less severe than that due to comparable high-viscosity contrast media.