Should We Worry about TAVR Durability?Should We Worry about TAVR Durability?

As many as half of valves in transcatheter aortic valve replacements (TAVR/TAVI) may show degeneration within eight years, according to new data presented earlier this week at EuroPCR 2016 in Paris. The findings have added a new element to the long debate over the relatively new technology's durability versus surgical aortic valves. Industry, clinicians, and patients anticipate a future where younger, less-severe aortic stenosis patients are eligible for TAVR, so durability is a key topic.

The study, the first to examine TAVR long-term durability, was presented by lead author Danny Dvir, MD, of St. Paul's Hospital in Vancouver. There were 378 patients  who underwent repeated echocardiographic examinations for up to 10 years after TAVR implantation between April 2002-May 2011 at two centers in Vancouver, Canada and Rouen, France. There were 100 patients who lived for at least five years after the TAVR procedure. In the study, 35 cases of valve degeneration were found, of which two-thirds were linked to intravalvular regurgitation, the other third associated with valvular stenosis, and a few cases with both, according to a press release summarizing the data.

Between five and seven years after the TAVR procedure, there were a significant number of degenerating valves, according to Dvir. A Kaplan-Meier estimate pointed to an approximately 50% degeneration rate within eight years.

The patients were implanted with the Sapien, Sapien XT, and Cribier-Edwards valves, all older-generation valves from Edwards Lifesciences. The company's newer offering, the Sapien 3, received FDA approval for use in high-risk, symptomatic aortic stenosis patients last year.

"Physicians performing TAVI in younger patients and in those expected to survive long after the procedure should be aware that the long-term rate of THV degeneration is not negligible, at least for first-generation THV devices," Dvir said in the press release. "Physicians must be mindful of the limitations of the THV they implant and whether patients can be safely treated by another transcatheter approach, such as valve-in-valve, if a THV fails years later," he added.

An Edwards Lifesciences spokesperson said in a statement, "These data presented at EuroPCR are new information and inconsistent with our robust datasets and experiences around the world. We look forward to seeing a peer-reviewed publication to better understand and evaluate these outcomes from the cohort of patients at two centers."

Research analysts keeping a close eye on TAVR developments did not express alarm over the findings. Larry Biegelsen, senior analyst at Wells Fargo, pointed out a few limitations of the study in a May 17 research note: 

In a May 19 research note, Joanne Wuensch, analyst at BMO Capital Markets wrote, "We believe [the degeneration data] can be compared with last year's leaflet thrombosis discussion--a lot of noise that did not change the revenue trajectory. In conclusion, while it clearly needs to be watched, this is not a new concern. This is not the study to hang our hat on given the limitations of the data . . ."

[Image courtesy of EDWARDS LIFESCIENCES]