July 11, 2012 — Lantheus Medical Imaging Inc., a developer, manufacturer and distributor of diagnostic imaging agents, announced the publication of results from the CaRES (Contrast Echocardiography Registry for Safety Surveillance) multicenter safety registry for its ultrasound imaging agent Definity Vial for (Perflutren Lipid Microsphere) Injectable Suspension. The CaRES study found that Definity was well-tolerated in patients of different types undergoing clinically-indicated Definity-enhanced echocardiography in a broad range of typical clinical settings. The results were published in the July 2012 issue of the Journal of the American Society of Echocardiography (Weiss et al, 2012).
The prospective, open-label, nonrandomized registry study was designed to assess the risk of adverse clinical events occurring within 30 minutes of Definity administration in a routine clinical setting. Among the 1,053 patients who completed the study, no deaths, life-threatening events, serious adverse events or serious anaphylactoid (allergic) reactions were reported during or after Definity administration. The overall adverse event (AE) rate was 10.8 percent, and drug-related AE rate was 3.5 percent. Of the AEs that occurred during or after Definity administration, a substantial majority 96.5 percent were mild to moderate in intensity.
The CaRES study complements another recently published study on the hemodynamic effects of Definity in patients with pulmonary hypertension. Published in the May 2012 issue of the Journal of the American Society of Echocardiography (Wei et al, 2012), this prospective study evaluated 32 patients, half of whom had elevated baseline pulmonary artery systolic pressures. The study found that Definity administration did not result in any clinically meaningful changes in systemic and pulmonary artery hemodynamic measurements among patients with either normal or elevated pulmonary artery pressure. In addition, no serious or fatal adverse events occurred. Overall, Definity demonstrated a positive safety profile and was well-tolerated.
Both the CaRES study and the pulmonary hypertension study were developed in conjunction with the U.S. Food and Drug Administration (FDA) in 2008 as part of a risk assessment program for perflutren-based ultrasound contrast agents such as Definity. In October 2011, the FDA approved several revisions to the Definity prescribing information, including the removal of mandatory physiologic monitoring requirements for patients with pulmonary hypertension or unstable cardiopulmonary conditions. Data from both the CaRES and pulmonary hypertension studies were included in the updated Definity labeling.
For more information: www.definityimaging.com
July 24, 2025 
