Better durability with self-expanding TAVI? TAVI UK indices

Although the analysis took into account patients treated with early devices, the findings have implications for life planning, experts say.

PARIS, France—Updated data from the UK TAVI registry on long-term valve function monitoring indicates that severe structural valve degeneration (SVD) has affected nearly 6% of patients who received a first-generation TAVI device. Additionally, severe damage appears to be more common with balloon-expandable devices than with self-expanding devices.

Noman Ali, BMBS, PhD (Leeds Teaching Hospitals NHS Trust, England), who presented the data here at EuroPCR 2022, acknowledged to TCTMD the pitfalls of observational data and any established comparison between devices.

“Obviously there are limitations given that these are first-generation valves, but the fundamental differences between the Sapien and the CoreValve have not changed in terms of the supra-annular. [and] one being intra-annular, the other balloon expandable, and the other self-expanding,” Ali told TCTMD. “These differences are still present in the current iterations. There have been some improvements, but I think the fundamental message is that the supra-annular design seems to lend itself to a slower rate of degeneration, and I think this will still be seen in newer valves. The overall numbers might be lower in both, but I suspect that difference might still be there.

A previous snapshot from the UK TAVI, of only 149 patients followed for a median of 5.8 years, indicated a slightly higher incidence of moderate SVD, with around half of the cases due to new aortic regurgitation and 43% to restenosis.

In this latest data with longer follow-up, however, investigators focused on severe SVD and focused on differences between valve types among 221 adults who underwent TAVI at one of 11 centers in the Kingdom. United between 2007 and 2011. All patients had undergone echocardiograms after the procedure and again at some point beyond 5 years, allowing assessment of SVD.

Overview of valve durability

The UK TAVI investigators used a definition of severe SVD adapted from the guidelines of the European task force committee. These specify at least one of the following: mean gradient of ≥ 40 mmHg and/or increase ≥ 20 mmHg from baseline; a maximum speed ≥ 4 m/s and/or ≥ 2 m/s increase over baseline; or severe, new, or worsening intraprosthetic aortic regurgitation.

The median follow-up presented here today was 7.0 years (ranging from 5 to 13 years), with 43 patients having more than 10 years post-TAVI. Just over two-thirds of patients (mean age 79 years) had been treated with the CoreValve (Medtronic), while 31.3% had received a Sapien/Sapien XT valve (Edwards Lifesciences). Transfemoral access was used in 79% of patients and valve deployment was successful in 97.2% of patients.

During the extended follow-up period, 13 patients (5.9%) developed severe SVD, a median of 7.8 years after TAVI. In three cases the SVD was due to aortic regurgitation and in 10 cases the underlying cause was stenosis. Hemodynamic valve function remained stable for most patients and in some cases even improved over time. However, when analyzed by valve type, a higher proportion of patients treated with the balloon expandable valve than those treated with the self-expanding valve developed severe SVD (11.9% versus 3.5%, P = 0.02).

Speaking to TCTMD, Ali said he hopes this data can help inform lifelong management considerations for patients.

“We know we’re going to be using TAVIs in younger and younger patients, and that just adds another variable to the decision-making process,” he said. “You have to consider the possibility of TAVI-in-TAVI, which perhaps favors a balloon expandable valve to start with, followed by a self-expanding valve. Then you have to balance that with the prospect that it may escalate faster .

On the other hand, for a slightly older patient, you might consider a self-expanding valve to start with, as its longevity may more closely match the patient’s.

“I think the workup is just about integrating that information into the overall decision-making process for the lifelong management of these patients, and I think we need to move, as cardiac teams, from just finding the best valve for this patient now thinking about what’s going to be the next valve beyond that,” he said. “When TAVI first came out, we were basically looking at 5 years because the patients were 85 years old. Now, when they’re 70, we have to think about 15, 20 years later, and I think that data can be used as part of that decision-making process.

We need to move, as cardiac teams, from just finding the best valve for this patient now to think about what’s going to be the next valve beyond that. Noman Ali

Commenting on the TCTMD data, session moderator Jonathan Schwartz, MD (Sanger Heart & Vascular Institute, Charlotte, NC), noted that the UK TAVI figures represent the largest data set for post-TAVR patients at 10 years or more.

“It’s hard to extrapolate too much because there were only 43 patients in this cohort, but as mentioned, this is the best we have to date,” Schwartz said.

This analysis, he pointed out, focused exclusively on leaflet durability related to regurgitation and stenosis, but other factors likely also play a role in SVD, including endocarditis, leakage paravalvular, commissural alignment, appropriate valve expansion, supra-annular versus intra-annular design. , and the associated post-operative gradients.

Ongoing questions about thrombosis and mobility of hypoattenuated leaflets, and how these may influence valve durability, remain unanswered, he said. In British TAVI patients, ‘to what extent does this correspond to true deterioration of the leaflets? We know that younger, active patients and patients with end-stage renal disease on hemodialysis exhibit leaflet deterioration at a significantly accelerated rate compared to older, sedentary, non-dialysis patients.

Another consideration is the material of the package insert, Schwartz continued, noting that some devices use bovine pericardium and others porcine. “It’s changed little from the previous generation valves,” he said, although polymer-derived leaflet platforms are an area of active investigation.

“Time will tell where valve innovation goes from here, with significant improvements made since the days of the bioprostheses used in this study. Although current TAVR platforms have evolved considerably since those featured in this trial, this is an illuminating first glimpse of long-term outcomes for TAVR patients, and the new valves will likely only show even better results. .“Schwartz said.

Correction: This story has been edited to correct an error in a previous title, which misidentified balloon-expandable devices as having better durability in this analysis.