Right heart cardiac ultrasound contrast agent for shunts enters U.S. trial
Currently there are no U.S. Food and Drug Administration (FDA) cleared, echocardiography contrast agents commercially available for use on the right side of the heart to detect shunts. But the FDA has given Agitated Solutions Inc. (ASI) the green light for an investigational new drug (IND) application for its novel contrast agent, ASI-02, paving the way for the company’s Phase 3 clinical trial.
The multi-center, randomized study will assess the safety and efficacy of ASI-02 in up to 300 patients in the U.S. and Canada who undergoing transthoracic echocardiography (TTE) with agitated saline contrast. ASI-02 is a novel right heart contrast agent that produces consistent microbubbles designed to improve image quality and facilitate diagnosis of right-to-left shunts caused by a patent foramen ovale (PFO) or pulmonary arteriovenous malformation (PAVM). The company said its new agent can improve workflow efficiency because it can be administered by a single sonographer, eliminating the current need for a second person to agitate and inject the contrast, and it will enable much more consistent delivery of microbubbles.
The current standard of care for these studies is use of agitated saline to create bubbles that are then injected into the patient to visualize right-to-left shunts. The condition causes improper blood flow and can be a leading cause of cryptogenic stroke, particularly in young people. But these studies require one sonographer to agitate and inject the saline, while a second captures the images, making bubble studies resource intensive and time-consuming. This manual process also generates variable and inconsistent bubbles, which can impact image quality and diagnosis.
“ASI-02 is the first innovation in over 60 years specifically designed to tackle the issues associated with image quality and efficiency in bubble studies. Currently, there is no FDA approved right heart contrast agent.” said Morgan Evans, CEO of Agitated Solutions. “This IND clearance is a significant milestone, allowing us to begin our Phase 3 trial aimed at demonstrating a more consistent and simple method to definitively diagnose shunts with our novel contrast agent.”
Why current commercial echo bubble contrast cannot be used for shunt exams
Commercially available ultrasound enhancing agents (UEA) such as Definity, Optison and Lumason are used for left heart contrast because their microscopic bubbles are small enough to make their way through the pulmonary system to the left side. They are not appropriate for use on the right side to detect shunts because they pass through to the left side of the heart whether or not there is a shunt and therefore are not diagnostic.
Agitated saline is used to detect cardiac shunts because it produces larger bubbles than the UEA agents, which cannot pass through the pulmonary circulation. This means the right heart will be the only structure that is well opacified unless there is a shunt present and bubbles are able to cross to the left side of the heart.
ASI-02 is an investigational new drug and is not approved for use in the U.S. outside of this IND. It is currently approved for use in Canada.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: [email protected]