Effects of extrinsically warmed contrast media on image quality and clinical adverse events in patients undergoing coronary computed tomography angiography: a randomized controlled trial

Coronary computed tomography angiography (CCTA) relies on contrast media for accurate diagnoses, and the impact of extrinsically warmed contrast agents on image quality and clinical outcomes remains understudied. This study aimed to identify the effect of extrinsically prewarmed contrast material (CM) on image quality and safety in patients undergoing CCTA.

A prospective collection of 224 patients with chest pain or coronary artery disease participated in this randomized non-inferiority trial and were randomly divided into two groups. A standardized contrast medium (iopamidol, 370 mgI/mL) injection protocol was administered to the two groups at room temperature (23 ℃) and prewarmed temperature (37 ℃), respectively. Both groups received the same total dose of contrast media (0.9 mL/kg). Objective image quality was assessed by calculating the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) at three coronary bifurcations. Subjective image quality was independently rated by two blinded readers using a four-point Likert scale. Repeated measures analysis of variance (RM-ANOVA) evaluated the statistical significance of inter-group differences in these image quality parameters between the three bifurcation points with bilateral 95% confidence intervals (CIs). Potential adverse events, including extravasation, allergic reactions, and physiological reactions, were evaluated through a questionnaire survey and recorded by researchers.

The image quality of the group receiving contrast media prewarmed to basal body temperature (BBT-CM group) significantly improved [SNR of right coronary artery (RCA): RT-CM =11.85±10.55, BBT-CM =14.76±4.92, P<0.0001]. Prewarmed CM had different attenuation effects on different bifurcations: a significant decrease at RCA [absolute difference: +10.51 Hounsfield units (HU), 95% CI: -123.61 to -65.32], no significant change at left anterior descending artery (absolute difference: +8.37 HU, 95% CI: -37.29 to 20.55), and a significant increase at the left circumflex artery (absolute difference: +61.89 HU, 95% CI: 57.92 to 117.20). Prewarming CM did not have a significantly different impact on the incidence of adverse reactions.

Prewarmed CM improves image quality depending on the coronary bifurcations and has important clinical significance.

This trial is registered with ClinicalTrials.gov (NCT05489055).