My patient is 59 years old, has symptomatic severe aortic stenosis (AS) with a bicuspid aortic valve (BAV), and his proximal aorta is 3.6 cm in diameter. He has no important comorbidities and was referred for advice as to whether he should have a surgical (SAVR) or transcatheter (TAVR) aortic valve replacement. What should I counsel him?

This month's cover story discusses how difficult this decision can be. In an age of evidence-based medicine, there are no guidelines or randomized trials to help me with patients like mine. The ACC/American Heart Association guideline embraces patients >65 years old,¹ and the more conservative European Society of Cardiology/European Association for Cardio-Thoracic Surgery guideline lists age >75 as the cut-off for TAVR.²

For BAV, the ACC/AHA guideline recommends SAVR, whereas the ESC/EACTS guideline offers no formal recommendation but notes that SAVR is more appropriate in the setting of BAV and in those with associated aortopathy. That makes sense, but my patient has no aortic issues.

Does that really mean TAVR should not be considered for my patient? In clinical reality, data from the Vizient Registry from 2015 to 2021 show there was near equal utilization between TAVR and SAVR in younger (<65 years) patients by 2021 (47.5% TAVR vs. 52.5% SAVR) albeit younger patients with BAV were more likely to have SAVR.³ It seems that young patients with BAV are certainly having TAVR!

The operative words that support SAVR are "bicuspid" and "age." Both need consideration. Placing a TAVR inside a BAV can be problematic. The orifice is not user friendly to TAVR (think of a circle placed in a slit vs. in a tri-cornered hat) and the BAV is often heavily calcified with nodules extending below the annulus. Paravalvar leak is more common after TAVR for BAV and patient selection demands a close look at that variable. Nonetheless, a number of observational trials have shown that TAVR in patients with BAV can be successful. SAVR excises the valve and can debride calcium nodules which aides prosthetic valve placement.

Considering age <65, when many patients with BAV become symptomatic, raises a central question about the fate of bioprosthetic leaflets over time. Data on durability are needed but just last month the NOTION trial showed that in patients with severe AS and lower risk, randomized to TAVR or SAVR, the risk of major clinical outcomes was not different at the 10-year follow-up and the risk of structural valve deterioration was lower after TAVR than SAVR.⁴ That does not lay the issue to rest but helps.

TAVR is different than SAVR. Both demand consideration about a lifetime strategy in any "young" patient with or without BAV. Apart from a surgical mechanical valve which demands lifelong anticoagulation, both SAVR and TAVR patients with a bioprosthetic valve will likely need a second or even third valve procedure. Saying multiple TAVRs can be done (one inside the previous one) raises other questions.

Are several layers of metal struts deleterious to the aortic annulus/root? What about patient/prosthetic mismatch as the aortic orifice becomes smaller with each subsequent valve implant? What about leaflet overhang and coronary sinus exclusion and what about future coronary access should a coronary issue arise? All of these questions are unique to TAVR, but SAVR is still SAVR and patients are rarely enthusiastic about chest surgery.

If TAVR is chosen and a second TAVR-in-TAVR follows, is a third procedure, if needed, a SAVR with removal of all that metal at a time much later when the patient's risk profile is higher because of advancing age? Various strategic sequences of SAVR/TAVR/TAVR, TAVR/SAVR/TAVR, etc., are possible, but none solve the problem easily. A comprehensive review of the data-driven conclusions we can make is fully outlined by Windecker, et al., in the European Heart Journal.⁵ It is worth keeping as a reference for what we now understand.

We all await the results of the NAVIGATE, BELIEVER and YOUNG TAVR trials described in our cover story. They will expand our knowledge. But the outcomes of these trials are years away. My patient cannot wait that long. What must occur right now to help make the best decision for my patient? Multiple data sets require evaluation, ranging from his CT scans and catheterization data to his surgical risk evaluation, etc. Patient inclusion in the decision process is critical.

For now, Heart Teams and "shared decision-making" do this as best we can. Looking forward, more data, more experience, and perhaps artificial intelligence, will make decisions about the best therapeutic strategies for our young patients simpler.

Enjoy this issue! As always, please send your thoughts and feedback to CardiologyEditor@acc.org.

*Headline courtesy of Yoda.

Click here to access the paper by Windecker, et al.

References

1. Otto CM, Nishimura RA, Bonow RO, et al. 2020 ACC/AHA guideline for the management of patients with valvular heart disease. J Am Coll Cardiol 2021;77:e25-e197.
2. Vahanian A, Beyersdorf F, Praz F, et al. 2021 ESC/EACTS guidelines for the management of valvular heart disease. Eur Heart J 2021;43:561-632.
3. Sharma T, Krishnan A, Lahoud R, et al. National trends in TAVR and SAVR for patients with severe isolated aortic stenosis. J Am Coll Cardiol 2022;80:2054-56. https://doi.org/10.1016/j.jacc.2022.08.787.2
4. Thyregod HGH, Jorgensen TH, Ihlemann N, et al. Transcatheter or surgical aortic valve implantation: 10-year outcomes of the NOTION trial. Eur Heart J 2024;Feb 7:[Epub ahead of print].
5. Windecker S, Okuno T, Unbehaun A, et al. Which patients with aortic stenosis should be referred to surgery rather than transcatheter aortic valve implantation? Eur Heart J 2022;43:2729-50.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Aortic Surgery, Cardiac Surgery and Arrhythmias, Cardiac Surgery and CHD and Pediatrics, Cardiac Surgery and VHD, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Interventions, Interventions and Structural Heart Disease

Keywords: Cardiology Magazine, ACC Publications, Transcatheter Aortic Valve Replacement, Aortic Valve, Calcium, Bicuspid Aortic Valve Disease, Thoracic Surgery, Aortic Valve Stenosis

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