Contrast Echocardiography in Heart Failure: Update 2023

PURPOSE OF REVIEW

The application of ultrasound-enhancing agents (contrast agents) has improved the accuracy and reproducibility of echocardiography. The review focuses on the currently approved and evolving indications for contrast echocardiography in patients with heart failure, specifically examining clinical studies conducted after the publication of the guidelines in 2017 and 2018.

RECENT FINDINGS

The current ASE/EACVI recommendations for contrast echocardiography are based on its accuracy and reproducibility in comparison to non-enhanced echocardiography or other imaging modalities like cardiac MRI. However, tissue characterization remains limited with contrast echocardiography. During the last few years, several studies have demonstrated the clinical impact of using contrast agents on the management of patients with heart failure. There is growing evidence on the benefit of using contrast echocardiography in critically ill patients where echocardiography without contrast agents is often suboptimal and other imaging methods are less feasible. There is no risk of worsening renal function after the administration of ultrasound-enhancing agents, and these agents can be administered even in patients with end-stage renal disease. Contrast echocardiography has become a valuable tool for first-line imaging of patients with heart failure across the spectrum of patients with chronic heart failure to critically ill patients.

Safety findings after intravenous administration of sulfur hexafluoride microbubbles to 463,434 examinations at 24 centers

OBJECTIVES

We aimed to evaluate the safety of the ultrasound contrast agent sulfur hexafluoride microbubbles in a large group of patients referred for routine contrast-enhanced ultrasound (CEUS).

METHODS

A retrospective assessment was made of all patients that received sulfur hexafluoride microbubbles intravenously for CEUS at 24 centers between January 2006 and April 2019. Patient demographic details, examination type, and the dose of sulfur hexafluoride microbubbles administered were recorded with specific adverse events (AEs) documentation tools at each center. All AEs were recorded as serious or non-serious. Non-serious AEs were classified by intensity as mild, moderate, or severe according to ACR criteria. The frequencies of AEs across patient subgroups were compared using the chi-square test.

RESULTS

A total of 463,434 examinations were evaluated. Overall, 157 AEs (153 [0.033%] non-serious; 4 [0.001%] serious) were reported after sulfur hexafluoride microbubbles administration, giving an AE frequency of 0.034% (157/463,434). Among the non-serious AEs, 66 (0.014%) were mild, 70 (0.015%) moderate, and 17 (0.004%) severe in intensity. The liver was the most common examination site, presenting an AE frequency of 0.026%. The highest AE frequency (0.092%) was for patients undergoing CEUS for vascular disease. There were no significant gender differences in either the total number or the severity of non-serious AEs (chi-square = 2.497, p = 0.287). The onset of AEs occurred within 30 min of sulfur hexafluoride microbubbles administration in 91% of cases.

CONCLUSION

The frequency of AEs to sulfur hexafluoride microbubbles is very low and severe reactions are rare, confirming that sulfur hexafluoride microbubbles are appropriate for routine CEUS applications.

KEY POINT

• The frequency of AEs to sulfur hexafluoride microbubbles is very low and severe reactions are rare.