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.