Contrast echo: really safe after all?

Echocardiography has been integrated into clinical practice as an indispensable tool providing adjunctive diagnostic and prognostic information, crucial for optimal patient management. In addition, contrast echocardiography is regarded as a major technological breakthrough in the field of cardiovascular imaging as it provides not only images of superior quality, but also extents the clinical application of echocardiography in a variety of clinical scenarios including the assessment of coronary artery disease, cardiomyopathies and structural heart disease. However, several experimental studies and data deriving from post-market observations have put contrast agents to the test due to raised concerns regarding their safety profile. Specifically, animal studies have demonstrated detrimental bioeffects, presumably attributed to a phenomenon called inertial cavitation, which lead to endothelial dysfunction of various organs including the heart. Therefore, the European Medicines Agency (EMEA) and the Food and Drug Administration (FDA), in 2004 and 2007 respectively, issued warnings, according to which contrast implementation in echocardiography was considered hazardous, as it was connected to fatalities occurring several minutes after intravenous infusion. On the other hand, multiple large clinical trials have contradicted contrast incrimination, by illustrating an excellent safety profile of contrast agent utilization in a variety of clinical settings such as hospitalized patient in the Intensive Care Unit and stress echocardiography, condition that could render patients prone to ischemic and arrhythmic events. Moreover, the documented clinical efficacy of contrast agents has led both the EMEA and the FDA to reconsider their initial statements and reinstate contrast deployment during echocardiographic examinations. As a result, the American Society of Echocardiography published in 2008 a consensus statement, according to which an extended list of applications was recommended.