Joao Cavalcante, MD, FSCCT, FACC, director, cardiac MRI and structural CT labs, Minneapolis Heart Institute, and director, Cardiovascular Imaging Research Center and Core Lab, Minneapolis Heart Institute Foundation, discusses new structural heart interventions to treat tricuspid valve regurgitation. 

His hospital has been involved in the TRILUMINATE trial evaluating the safety and efficacy of the Abbott TriClip device. He has been involved in the imaging assessments of the valve and said it is likely the amount of tricuspid regurgitation (TR) in these patients is higher than what is assessed in most patients. 

Long called "the forgotten valve" because it is difficult to treat and surgical valve replacements often have poor outcomes, the tricuspid valve is now seeing a lot of interest at cardiac imaging and structural heart conferences. Several structural heart vendors have developed and are testing transcatheter devices to treat TR. 

The estimate of how much TR is also often under reported. 

"What we are calling moderate TR might not be moderate, it might be a lot more, but as imagers our eyes Arte calibrated to looking at the mitral valve," Cavalcante explained. "The left atrium is a large structure, so by the time the regurgitant jet fills the right atrium, it is a torrential amount of regurgitation. That is why it is the only valve with 5 grades for regurgitation." 

Tricuspid valve regurgitation was also frequently dismissed because it is not fatal, it just impacts quality of life, he said. Although, Cavalcante said it can be very debilitating and make the patient feel horrible. 

"The symptoms are like 'gosh, I must just be getting old,' but it is not," he said. 

Imaging these patients to assess TR and possible structural heart interventions can be challenging. Cavalcante said about 90% of these patients have atrial fibrillation and often have a pacemaker or ICD where the leads go through the valve. These patients also often cannot hold their breath for images, and have chronic kidney disease, so it can limit how much, or if any, imaging contrast can be used. It also can be challenging to properly time the contrast injection with the cycle of the heart to get the optimal imaging for the tricuspid valve.

"Now, tricuspid interventions are starting to transom this imaging to become more mainstream, and there are trials underway where imaging plays a key role," Cavalcante said. 

"What we have seen with the procedures for the tricuspid valve, and I am talking about clip devices like the MitraClip, transcatheter edge-to-edge repair (TEER), such as in TRILUMINATE early feasibility study and many other multi-center registries, the procedure is safe and effective. So, we don't kill the patient, and we do reduce the TR and they feel better. It might not abolish completely the TR. But depending on where you start from, such as torrential and going down to severe, you reduce down two grades and now these patients feel so much better."

The duration and effectiveness long-term is still something that needs to be determined in studies and registries over the coming years, he said.