Safety profile of ultrasound enhancing agents in echocardiography

Introduction: Ultrasound enhancing agents (UEAs) are often utilized to enhance ultrasound image quality; however, concerns about adverse reactions have limited their use. Moreover, these agents had been either contraindicated or are labeled with a warning in patients with intra-cardiac shunts because of a theoretic risk of systemic microvascular obstruction. This labeling was recently removed in the United States, but data in these patients are lacking. Methods: Over a 15-month period, patients receiving three different FDA-approved UEAs at our center were prospectively evaluated for clinically significant adverse events (AEs). Results: A total of 5521 UEA administrations were performed (Definity^®: 3306, Lumason^®: 2137, Optison^®: 78). There were 14 AEs (0.25%) reported (Lumason^®: 0.05% [n = 1] vs Definity^®: 0.39% [n = 13], P = 0.02). Back pain was the most common complaint (n = 9), followed by headache (n = 2), rash (n = 2), dyspnea (n = 2), and palpitations (n = 1). Among the 33 patients known to have intra-cardiac shunts, there were no AEs. Known right-to-left shunts with positive saline bubble study were present in 20 patients (Lumason^®: n = 9, Definity^®: n = 11). Left-to-right atrial shunts based on color Doppler were present in 10 patients (Lumason^®: n = 5, Definity^® n = 5). Three patients were known to have ventricular septal defect with left-to-right flow (Definity^®: n = 2, Optison^®: n = 1). Conclusion: Adverse events were significantly higher with Definity^®; however, overall incidences were low, and AEs were minor. Furthermore, no AEs were reported in patients with known intra-cardiac shunts. UEAs showed a good safety profile in our study and should be afforded to all appropriate patients, including those with known intra-cardiac shunts.