TAVI Use Rising in Young US Patients, Yet Another Analysis Shows

Yet another registry analysis—this time with data spanning across three US states—is pointing to potential overuse of TAVI, with researchers finding that more than half of patients under age 65 with severe aortic stenosis treated in 2021 received TAVI instead of guideline-recommended SAVR.

Importantly, after propensity matching, TAVI was associated with a more than doubled risk of mortality over 8 years.

The findings, presented at the American Association for Thoracic Surgery (AATS) 2024 meeting last week, support what has been seen in two similar studies reported this year looking at data across California as well as northern New England. Both showed a growing trend of TAVI performed in patients under the age of 60 and 65, respectively, with the former also showing worse mortality outcomes compared with SAVR.

“It demonstrates a lack of concordance between clinical practice and the American guidelines regarding treatment of aortic stenosis in younger patients,” Michael E. Bowdish, MD (Cedars-Sinai Medical Center, Los Angeles, CA), who presented the data, told TCTMD. “Ultimately, I think it supports the feasibility of a randomized controlled trial comparing long-term outcomes of TAVR versus SAVR in patients under 65.”

Joseph Bavaria, MD (Jefferson Health, Philadelphia, PA), who co-moderated the AATS session, told TCTMD that what has been shown, now in three studies, proves “an incredibly interesting phenomenon is happening.” It remains unclear why practice has shifted to TAVI in younger patients on a “fairly reasonable scale,” especially because “it’s basically completely off guidelines, which usually doesn’t happen very much in modern American medicine.”

It demonstrates a lack of concordance between clinical practice and the American guidelines. Michael Bowdish

Megan Coylewright, MD (Erlanger Health System, Chattanooga, TN), a structural interventional cardiologist, argued that because the new study excluded patients who received mechanical valves or who underwent additional cardiac surgeries like a Ross procedure or aneurysm repair—procedures she said are designed for people with longer lifespans—the remaining registry patients appear to be appropriately treated with TAVI.

Further, “20% of the patients were dialysis dependent and almost three out of four had congestive heart failure,” said Coylewright, noting that patients with those diagnoses and some of the other comorbidities are not likely to live for 20 years. That, “importantly, is not outside the guidelines,” she told TCTMD. “It’s within the guidelines, because the guidelines emphasize that age is just a proxy for longevity.”

Bowdish said the researchers wanted to have “as much [of an] apples to apples [comparison] as you possibly could,” so they made a conscious decision to exclude patients with mechanical valves because TAVI was likely not considered for those patients in the first place.

TAVI Use Increasing

The study is based on claims data for 9,886 patients younger than 65 years who received either TAVI (26%) or SAVR (74%) at 185 hospitals in California, New Jersey, and New York between 2013 to 2021. TAVI use increased in this population from 7.1% in 2013 to 54.7% in 2021 (P < 0.001), and patients who underwent TAVI were generally older, sicker, frailer, and less often had bicuspid valve anatomy. Median follow-up was 4.1 years.

After propensity-score matching by year, the researchers identified 1,994 matched pairs. In the matched cohorts, 30-day rates of mortality and heart failure hospitalization were similar for SAVR and TAVI, but new permanent pacemaker implantations were more common after TAVI (6.2% vs 10.7%; P < 0.001).

By 8 years, the mortality rate was significantly higher after TAVI in the matched analysis (15.3% vs 27.5%; HR 2.27; 95% CI 1.82-2.83). No differences were observed for heart failure hospitalization, stroke, or reoperation at this time point, but the need for new pacemaker remained higher for TAVI-treated patients (P < 0.001).

It’s basically completely off guidelines, which usually doesn’t happen very much in modern American medicine. Joseph Bavaria

Multiple sensitivity analyses, including those limited to patients aged 50-65, treatment in years 2019-2021, patients not undergoing dialysis, and excluding 2020 to rule out any influence from the COVID-19 pandemic, confirmed the main results.

Bowdish said a strength of the study is its “huge sample size,” noting the analysis reflects about 20% of the total US population. “Now it is a fairly large urban sample size,” he acknowledged. “Regardless, it's a very large number of patients.”

As for limitations, Bowdish conceded that they did not have information on what types of valves patients received or any echocardiographic follow-up that could specify cause of death. “Because it is a retrospective study, there is the potential for unmeasured confounders and you can argue whether we really have [similar] groups,” he said. “But I think it is the biggest study of young patients looking at treatment trends and long-term outcomes that's been done.”

Next Steps

As for what’s leading younger patients to increasingly receive TAVI, Bowdish believes “it's driven somewhat by marketing—patients know about it and they know they can get a quicker, easier procedure and be done, and that's very appealing. . . . It reiterates the importance of having thoughtful heart team conversations among surgeons and interventional cardiologists about appropriate treatment for patients.”

Commenting on the data for TCTMD, Society of Thoracic Surgeons President Jennifer C. Romano, MD (University of Michigan Congenital Heart Center, Ann Arbor), called for more heart team education about decision-making for young patients with aortic stenosis, especially for clinicians who can’t always travel to large conferences to learn from their colleagues.

Bringing together all the individual practitioners who care for patients with aortic stenosis is at the root of the heart team, and its members should be able to work together to provide the best possible information to patients to aid them in making informed decisions, she said. “In addition, these heart team discussions should not just focus on what is best for the patient today, but what is the best life-long management strategy of their AS. For example, if a patient agrees to have a SAVR, as surgeons what do we need to do at the initial SAVR to ensure the patient is a candidate for future valve in valve therapy, if needed.”

These data showing an uncontrolled, off-guidelines tsunami tell us we must do the proper trial. D. Craig Miller

Several surgeons said they are worried about the trends of increasing use of TAVI in younger patients.

“We think it’s a bad thing, but we’re not necessarily sure it’s a bad thing because there’s no data,” Bavaria said. However, it’s unlikely that a randomized trial of TAVI and SAVR in young patients will be funded by any of the device manufacturers, since the percutaneous valves are already approved for use. A deep dive into large statewide databases might be possible, he said.

Bowdish, however, said it would be cost prohibitive to continue to do more analyses of state databases, since they each cost “hundreds of thousands of dollars” and would likely only confirm what is now known.

Linking the STS Adult Cardiac Surgery Database with the STS/American College of Cardiology TVT Registry is another option. Bavaria said he would support this kind of collaboration but explained that several potential legal and administrative hurdles have gotten in the way of that happening.

Speaking with TCTMD, cardiothoracic surgeon D. Craig Miller, MD (Stanford University School of Medicine, Palo Alto, CA), said money is the biggest barrier in the way of this kind of linkage, especially the cost of cross-checking mortality data with the National Death Index.             

It’s within the guidelines because the guidelines emphasize that age is just a proxy for longevity. Megan Coylewright

He, too, argued in favor of a randomized trial comparing TAVI and SAVR. “These data showing an uncontrolled, off-guidelines tsunami tell us we must do the proper trial,” Miller said, but he conceded it’s unlikely to happen. “It's going to be a funding decision. The manufacturers are doing everything they can to torpedo it, sabotage it for obvious reasons. The companies have done that for 10 years for valve-in-valve. Because they've got the market. Why should they even think about funding something that might cut their sales? It's really a perverse economic mess here, which is true of all of American medicine.”

Ultimately, Bowdish argued, “our patients want an answer that goes beyond a year or 2 years or 3 years or even 5 years. To me, a trial in this population is different than a trial in the older or higher-risk patients. It needs to be a more pragmatic, clinically driven trial that's going to look at lifetime management of these younger patients, and that's a tough trial to design.”

Right Treatment for Right Patient

For now, Coylewright stressed that TAVI and SAVR with a bioprosthetic valve are not the only two options for younger patients expected to live for some time, noting that the Ross procedure, mechanical aortic valve replacement, and even aortic valve repair are valid possibilities.

But, “if we want to understand more about how bioprosthetic valves last in young patients, then we need trials that are following patients for 15-20 years,” she said, adding that the existing data on valve durability show “very minimal differences between the valve types out to 8 years so far.”

Miller, who commented during the session, urged the surgical and cardiology communities to come together for the good of patients. “Now with TAVR going crazy in these young people, literally crazy, I'm not sure any of these patients are seeing a surgeon as the [national coverage determination] insisted, or tried to insist,” he said. “What's happening is obvious, and I think it's wrong. And I think we have to do something to try and balance the equation here.”

Bowdish agreed, stressing that the right choice is what’s best for each individual patient. “I'm neither a proponent of either, I'm a proponent of what is the right thing for our patients,” he said.