Study indicates signal for valve degeneration in TAVI patients by eight years

Danny Dvir
Danny Dvir

Speaking at EuroPCR (17–20 May, Paris, France), Danny Dvir reported that there is a significant increase in valve degeneration between five and seven years after a transcatheter aortic valve implantation (TAVI) device is implanted. Although stressing that this was a “preliminary analysis” using early-generation devices and, therefore, “we must be cautious”, he estimated that, based on these findings, about half of patients who undergo TAVI may show early signs of valve degeneration within eight years of implantation.

Dvir (St Paul’s Hospital, Vancouver, Canada), who was presenting the data on behalf of the teams in Vancouver Canada and Rouen France, commented that as a result of TAVI being “increasingly being performed” in younger and lower risk patients, more patients are expected to survive “long after” transcatheter heart valve implantation. However, he noted that durability of TAVI devices has “only been assessed over the short- and intermediate-term” and, therefore, he and his colleagues “aimed to evaluate the long-term risk of transcatheter heart valve degeneration after TAVI.”

In the study, Dvir et al reviewed data for patients who underwent TAVI with a early-generation balloon-expandable device (Cribier-Edwards, Sapien, Sapien XT, all Edwards Lifesciences) between April 2002 and April 2011. They defined degeneration, Dvir reported, as “at least moderate regurgitation and/or mean gradient ≥20mmHg, which did not appear within 30 days of the procedure and was not related to endocarditis”.

Describing the 378 patients in the study as the “typical, high-risk, TAVI patients”, Dvir stated that they had a mean age of 82.6±7.5 and a mean Society of Thoracic Surgeons score of 8.3±4.9. Just under half (49.7%) of the patients underwent TAVI with an Edwards Sapien valve and, overall, 72% had mild aortic regurgitation at 30 days. The median survival time was 51 months with two patients surviving 10 years.

Thirty-five patients were found to have evidence of valve degeneration with the average time to degeneration being 61 months. Of these, 23 showed signs of aortic regurgitation and 12 showed signs of aortic stenosis/mixed regurgitation. Dvir commented that the “vast majority” of patients with aortic regurgitation had intravalvular regurgitation and that among patients with stenosis, “stenosis indices appeared only in long-term follow-up”. In terms of valves that degenerated, three were a Cribier-Edwards device, 19 were a Sapien valve, and 13 were a Sapien XT. 

He said: “Up to four years after implantation, 94% of patients were free from degeneration—which is quite good and what we already know from previous studies”. At four to six years after implantation of a TAVI device, we saw this percentage drop to 82%. There was significant drop between six and eight years. We estimate that, according to our preliminary data with early- generation devices, approximately half of these devices have degeneration according to the definition we used in our study.” Renal failure was a strongest correlate for transcatheter heart valve degeneration, with
Dvir commenting: “When we compared patients with and without chronic renal failure, we saw significant differences.”

Concluding his presentation, Dvir stated that “we must be cautious” as this preliminary analysis includes a first-look at the data, but the risk of valve degeneration after TAVI should be considered “especially when treating relatively young patients and those at lower surgical risk”. “Physicians must be mindful of limitations of the bioprotheses they implant and whether these valves can be safely and effectively treated by transcatheter approach—valve in valve—if these valves fail years later. Future studies should explore long-term durability of next generation and other transcatheter heart valve platforms,” he added.

Commenting on the results, EuroPCR discussant Pieter Kappetein (Department of Cardiothoracic Surgery, Thoraxcenter Erasmus, Rotterdam, The Netherlands) said: “This is a very important study that puts transcatheter heart valve implantation in a very different light. Only seven weeks ago, we were very excited when we heard about a study—Sapien 3—at the American College of Cardiology annual meeting that showed a clear advantage with TAVI over surgery in the intermediate-risk patient population.” Noting that the study focused patients who received a first-generation device, he commented that durability devices for newer generation devices “may show better results; we do not know yet”. “This study points to the fact the trials in lower risk patients are justified. We cannot just start implanting TAVI devices in lower risk patients without relevant data,” Kappetein concluded.

Read Michael Reardon’s commentary on Dvir et al’s data: TAVI durability: A rose by any other name is still a rose