TAVI Sees Rapid Growth for Severe AS Across Age Spectrum in US

BOSTON, MA—Growth in the use of TAVI for treating isolated symptomatic severe aortic stenosis (AS) has continued to skyrocket from 2015 to 2021, not just in the elderly but also in younger patients under age 65, according to numbers from a large US database.

The findings, published Friday in the Journal of the American College of Cardiology, are slated to be presented by lead author Toishi Sharma, MD (University of Vermont Medical Center, Burlington), Saturday as an oral abstract here at TCT 2022.

By 2021, TAVI “was almost the default strategy” in those older than 80, senior author Harold Dauerman, MD (University of Vermont Medical Center), observed. And in the youngest patients, “it was almost a coin flip” which intervention they’d receive, he noted.

Up until a year prior, American College of Cardiology/American Heart Association (ACC/AHA) recommendations based the decision between TAVI and SAVR on STS score, classifying patients as low, intermediate, high, and extreme risk. But as of 2020, the latest guidelines for valvular heart disease, Dauerman pointed out, say heart teams now should risk stratify based on age: < 65 years, 65 to 80 years, and > 80 years. The new document suggests “strongly that TAVR was the preferred strategy in those over 80, that surgery was the preferred strategy in those who are less than 65, with a gray zone between 65 and 80 related to patient preference, shared decision-making, and other comorbidities,” he noted.

Toby Rogers, MD, PhD (MedStar Washington Hospital Center, Washington, DC, and National Institutes of Health, Bethesda, MD), one of the authors of a review article last year discussing the factors that influence decision-making below the age of 65 years, told TCTMD these results don’t come entirely as a surprise. “I think it’s what everyone predicted would happen,” given that US Food and Drug Administration approval sets no limits on age, he explained. Over the past few years, since low-risk TAVI got the green light in 2019, “there’s been a marked difference.”

It’s impossible to truly know from observational data what’s driving the shifts, Rogers pointed out. Nor is it possible to predict whether the changes will level off in the coming years. “The other thing you have to factor in is this does include the past 2 years of COVID, and COVID I think across the board had an impact of driving patients and physicians to less-invasive treatment options,” he added.

For Rogers, the most important themes this study brings to mind are the role of the multidisciplinary heart team and the need for shared decision-making with patients. “We do live in an era now when patients and physicians have a choice,” he emphasized. “TAVR is approved without a lower-age cutoff, . . . so we have to be careful when we look at data like this that [gives] a 30,000-foot overview that we’re not inferring that wrong decisions or bad decisions are being made.”

Changes Over 7 Years

In a paper that came out earlier this year, Sharma, Dauerman, and colleagues studied patterns in northern New England from 2016 to 2019 and also identified an upswing in TAVI. The current report expands upon that knowledge by looking at a nationwide cohort and by tracking trends after the new guidelines’ debut.

For this analysis, the researchers used the Vizient Clinical Database, which includes around 250 US centers performing both SAVR and TAVI, to identify 142,953 patients treated for isolated severe AS between October 2015 and December 2021. In all, 12.2% of patients treated were younger than 65, 44.8% were between the ages of 65 and 80, and 43% were older than 80.

In 2015-2016, TAVI accounted for 64% of the procedures and SAVR for 36%. By 2021, the prevalence of TAVI had risen to 88%, with just 12% being SAVR.

Sharma et al then divided usage according to the three groups specified by the 2020 guidelines. Over the course of the study period, the proportion of TAVI cases nearly tripled in the below-65 age bracket.

Proportion of Patients Receiving TAVI (vs SAVR)

Among patients younger than 65, independent predictors that they would undergo TAVI, rather than SAVR, included congestive heart failure (OR 3.84; 95% CI 3.56-4.13) and prior CABG (OR 3.49; 95% CI 2.98-4.08). Having bicuspid aortic valve disease was linked to a decreased likelihood of TAVI (OR 0.20; 95% CI 0.17-0.23).

The “near-equal utilization” for TAVI and SAVR by 2021 has “implications for lifetime management strategies in young patients with severe AS, including issues related to lifetime coronary access, valve durability, and the potential for subsequent TAVR procedures over time,” the investigators conclude.

Dauerman said the patterns they observed aren’t necessarily concerning, but rather are thought-provoking. “I always think that when there’s a discrepancy between the guidelines and clinical practice, which is what we’re seeing, something more needs to happen. For example, we’ve [had] clinical trials of low, intermediate, and high risk. It’s probably time to do a clinical trial of surgery versus TAVR in young people,” he suggested.

Rogers noted that lifetime management does indeed factor in when discussing the options with adults below age 65. “It has become an increasing part of our thought process with the heart team decision-making process. I find myself a lot of times counseling patients on that very fact. They ask the question: ‘How long is this valve going to last?’ And when you tell them and they do the math themselves, they then ask the follow-up question: ‘What will happen in the future?’”

He said it’s not uncommon for patients, when they hear about the possibility of future surgery after TAVI, to decide to go ahead and have SAVR, when they’re younger and healthier. “That being said,” Rogers noted, “for every one patient like that, there’s another patient that says, ‘I will deal with 10 years from now in 10 years’ time. I just want to have the procedure that I’ll get through the quickest now that will get me back to cycling 20 miles a day or back to work as quickly as possible.’

“That’s not an unreasonable decision for a patient to make, and it’s perfectly within the approved indications for the valves. I don’t think we should be critical of those decisions,” Rogers continued.

As of now, Dauerman noted, very little is known about how these younger patients will fare over the next several decades, and as such, valve durability is becoming ever more important. “If we want to give advice to patients on what’s the better long-term strategy and they’re 65 or less, we have no idea based on the clinical trials we’ve done,” he said.

But, with accruing evidence, TAVI could well come out ahead in the end, he concluded. “It may be the right answer is to do TAVR in people less than 65. Maybe clinicians are using their gut and choosing the right strategy. [We just] don’t know.”