Few Patients Under 65 Get TAVI: Those Who Do Are Especially Sick

WASHINGTON, DC—Patients younger than 65 years old represent less than 6% of the total population undergoing balloon-expandable TAVI for severe aortic stenosis, according to contemporary data from the Society for Thoracic Surgeons (STS)/American College of Cardiology (ACC) TVT Registry.

These younger patients are generally sicker at baseline and have higher mortality rates at 1 year compared with those 65 years and older, confirming the appropriateness of the less-invasive treatment versus surgery, the authors argue.

With several observational studies published this year, including from California and New England, showing high rates of TAVI in younger patients that incited worry over indication creep, researchers say these concerns should be put to rest.

“This validated the fact that, for the most part, programs are doing it right,” senior author Molly Szerlip, MD (Baylor Scott and White, The Heart Hospital, Plano, TX), told TCTMD. “They are not willy-nilly doing [TAVI] in young people because they can, but they're affording these young people who otherwise would do poorly with surgery or not get anything done at all a chance to have something done in a safe manner. It’s affirmation that we're all doing it right.”

Firas Zahr, MD (Oregon Health & Science University, Portland), who was not involved in the study, agreed. “All of this shows that having a blanket statement about whether or not TAVR should be used in patients who are younger than 65 is not the way to go,” he commented to TCTMD. “We should say that, especially for those patients who are young, the role of a heart team in terms of addressing the patient comorbidity as well as the patient anatomy and suitability for both TAVR and SAVR is critical.”

The findings were presented at TCT 2024 by Megan Coylewright, MD, MPH, editor of the American College of Cardiology's CardioSmart/Patient Voice Program, and simultaneously published in JAMA Cardiology.

Younger Patient Characteristics, Outcomes

For the study, Coylewright, Szerlip, and colleagues looked at the 241,420 patients with severe aortic stenosis from the STS/ACC TVT Registry who underwent balloon-expandable TAVI with a Sapien device (Edwards Lifesciences) between August 2019 and September 2023. For the 5.7% of patients who were younger than 65 years old, the mean age was 59.7 years, 65.5% were male, and the mean STS risk score was 3.1. For the 52.1% aged 65-80 years, the mean age was 74.1 years, 61.8% were male, and the mean STS risk score was 3.3.

Compared with those aged 65-80, the younger patients were more likely to have bicuspid anatomy (25.2% vs 7.6%; P < 0.001) and were more likely to have comorbidities like congestive heart failure, chronic lung disease, diabetes, and end-stage kidney disease needing dialysis, and to be immunocompromised. History of serious cardiovascular disease was more likely in the younger cohort with higher rates of atrial fibrillation, prior MI, or cardiac surgery.

Baseline quality of life as measured by the Kansas City Cardiomyopathy Questionnaire was significantly lower for the youngest patients compared with those aged 65-80 years (47.7 vs 52.9), and mean gait speed measured by the 5-meter walk test was also slower (6.6 vs 7.0 seconds; P < 0.001 for both).

There were no differences in the implant success and procedural complication rates between the younger and older groups, though those younger than 65 did have a higher rate of in-hospital mortality (1.0% vs 0.7%; P = 0.004)

One-year rates of hospital readmission (28.2% vs 26.1%) as well as all-cause mortality (9.9% vs 8.2% were significantly higher for patients younger than 65 compared with those aged 65-80 years (P < 0.001 for both). When patients were propensity matched, the younger cohort still had higher rates of readmission at 1 year (28.2% vs 26.8%; P < 0.03) but mortality was comparable (9.9% vs 10.1%; P = 0.55).

“Even though they were younger, they acted as if they were much older with more comorbidities,” Szerlip said of the propensity analysis. “So we're choosing right.”

Interestingly, the researchers noted that the overall percentage of patients younger than 65 years undergoing balloon-expandable TAVI declined over the 4-year study period. The STS risk score fell slightly over time, but the comorbidity burden of these patients remained high.

The Appropriateness Question

In an accompanying editorial, Robert O. Bonow, MD (Northwestern University Feinberg School of Medicine, Chicago, IL), and Patrick T. O’Gara, MD (Brigham and Women’s Hospital, Boston, MA), write that this study “provides a different perspective” than the observational analyses in this space published earlier in the year.

“The current study adds to the ongoing discussion of what represents appropriate decision-making in younger patients with limited life expectancy and to what extent there may be indication creep and underscores why further clinical trials in younger patients are needed,” they add.

Notably, the editorialists point out that restricting this analysis to TAVI with balloon expandable devices limits its statistical ability. While younger patients had a high comorbidity burden, there is limited information about what drove the decision to perform TAVI in those without comorbidities, they add. “Absence of data on SAVR in the registry also does not allow comparisons of procedural volumes, comorbid conditions, and outcomes of young patients referred for TAVR vs SAVR.”

In his experience, Zahr said many factors go into deciding to perform TAVI in a patient under the age of 65, including bicuspid anatomy, valve durability, chance of procedural success, and presence of comorbidities. “That makes it crucial to have an in-depth heart team discussion about TAVR versus SAVR,” he said.

The lack of a surgical arm in this study leaves open the question of how a similar cohort of patients might fare with surgery, Zahr said, adding that “drawing a conclusion about SAVR based on these data is also premature.”

Ultimately, there is a need for further study of patients younger than 65 years in this space, he observed. “This is a patient population that will need to be followed for a long period of time (ie, 10 years if not more), because honestly, the younger the patient, the more important the follow-up is before we can say that all of those patients should be treated with a specific single therapy.”

Szerlip agreed that “we constantly need to be evaluating who we're doing TAVR in.” With time, experience, and new device iterations, the data change and long-term outcomes remain elusive, she said, adding that TAVI-in-TAVI research will especially be important to younger patients who may need multiple valves over their lifetimes.

With continued heart team involvement around patient selection, “we will be appropriately choosing TAVR in young patients [and] we won't be doing it just because we can,” Szerlip said.