Learning curve
Flurpiridaz comes with “a really interesting and important” learning curve, Dr. Udelson said. “The images are really crisp, and they look very different from what most people are used to. The GE folks are going to have to make sure that the American Society of Nuclear Cardiology and other professional societies are tuned in to help in the education part, because it’s not an easy, automatic switch. Very good image readers can adapt, but it’s not just one day you do one, then switch to the other.”
A “somewhat apt” analogy would be the difference between an echocardiogram and an MRI, he explained. “The MRI is much crisper. You’re seeing edges more crisply. You’re seeing the difference between a thicker and a thinner segment of the wall more crisply, and that’s actually real. You can’t say the thinner segment is abnormal; it’s just that you’re seeing it better. So, with this tracer, normal differences in the thickness of a wall can almost look like a defect if you’re not used to knowing that’s the new normal.”
The expected approval of flurpiridaz “will be a win for cardiac PET, broadening the range of sites that could perform PET,” Dr. Salerno commented. “However, it is worth cautioning that all of the prior data with PET using different agents does not necessarily equate to the same performance with the new agent, given that the performance seems to be lower than that shown in prior PET studies using other agents.”
Dr. Salerno would like to see additional studies comparing flurpiridaz with rubidium or ammonia, as well as studies performing quantification with flurpiridaz, “which theoretically should have some advantages,” he said.
Dr. Udelson noted that MedTrace, a company in Denmark, is working on a radiolabeled water tracer based on 15-O-water that is just starting a pivotal trial. Dr. Udelson is a consultant to the company and is a steering committee member for the pivotal trial.
For now, “the big take-home is that there are a lot of ways these days to test people for CAD,” he said. “As the types of things we can do to test people expand, individuals and centers need to make sure they focus on providing any new service, however they do it, with really superb quality and experience.”
“You don’t just do something new because it’s new,” he added. “It has to be done really well. If you do the new thing badly, you’re not going to get better information.”
Dr. Udelson is a consultant and advisory board member for GE Healthcare, a consultant to MedTrace, and a steering committee member for MedTrace’s pivotal trial. Dr. Bourque has served on a GE Healthcare advisory board for amyloid imaging. Dr. Salerno reports no relevant financial relationships.
A version of this article first appeared on Medscape.com.