Large analysis suggests echo contrast agents associated with reduced mortality
Compared with patients not receiving a contrast agent, administration of perflutren lipid microsphere (PLM) injectable suspension contrast agent during echocardiography was associated with a 24 percent decreased risk of mortality, according to a retrospective analysis in the December issue of the American Journal of Cardiology.

The authors noted that although the FDA recently relaxed the issued warnings for perflutren-containing ultrasound contrast agents on May 13, concerns still exist regarding the safety of these compounds, particularly in critically ill patients.

Michael L. Main, MD, of Saint Luke's Mid America Heart Institute in Kansas City, Mo., and colleagues examined patients undergoing echocardiography during hospitalization, which were separated into those performed without contrast enhancement and those performed with PLM injectable suspension contrast agent (Definity from Lantheus Medical Imaging of North Billerica, Mass.). Vital status within one day of the echocardiogram was available for all patients using hospital billing data.

Between Jan. 1, 2002 and Oct. 31, 2007, approximately 4.3 million patients underwent transthoracic echocardiography at rest during hospitalization: unenhanced studies were 4,242,712 and contrast-enhanced studies were 58,254.

The researchers used a multivariate logistic regression analysis to compare 24-hour mortality, controlling for case mix and clinical covariates. They found that one-day mortality rates were 1.08 percent (45,789 deaths) for patients undergoing non-contrast enhanced studies and 1.06 percent (616 deaths) for patients undergoing contrast-enhanced exams.

Main and colleagues found that in patients undergoing an echocardiogram, patients receiving PLM injectable suspension contrast agent were 24 percent less likely to die within one-day than patients not receiving a contrast agent.

They concluded that acute crude mortality was not increased in patients receiving PLM injectable suspension contrast agent.

Lantheus provided funding for this study.