This article is more than a mere review. Its creation is motivated by the commemoration of the twentieth anniversary of Dr. Alain Cribier’s first TAVI implantation. Additionally, it is signed by some of the primary collaborators in the U.S. randomized clinical trials and is structured similarly to a clinical guideline or “Focus Update” document. These factors, along with its publication in one of the most prestigious cardiology journals during an “inter-guideline” period, suggest that many of its statements will not be trivial but rather shape the future direction of aortic valve disease treatment until the release of the next consensus documents.

The review begins with the well-known historical progression of the successive clinical trials conducted on Edwards® Sapien® and Medtronic® CoreValve®/Evolut® prostheses, with patients at progressively lower surgical risk. Today, age has become the most relevant factor in the decision between TAVI or surgical aortic valve replacement (SAVR). Each study’s results were integrated into subsequent guideline updates, with class I or IIa recommendations, and the FDA approval of the procedure and various device generations for each risk profile. It is commendable that the authors present an update on all-cause mortality at the longest available follow-up for each of these trials, showing consistently better results for the surgical cohort in high- and intermediate-risk patients at 5 years (PARTNER IA, CoreValve US, PARTNER 2A, SURTAVI). However, there were no significant differences in low-risk trials (NOTION at 5 years; PARTNER 3 and Evolut Low Risk at 2 years). With this, it seems the authors intend to demonstrate the low utility of predicted surgical risk in assigning patients to one treatment option over another.

Consequently, the decision between TAVI and SAVR must be based on a set of clinical and technical aspects analyzed point-by-point by the authors and summarized in a table similar to that of the 2018 European Society of Cardiology guidelines “Favours TAVR/Favours SAVR” criteria, which first introduced 75 years as a criterion for treatment allocation. Below, we will discuss the controversies surrounding each factor limiting TAVI and in which situations SAVR remains preferable.

COMMENTARY:

The main criteria for SAVR indication analyzed were:

1. Age and life expectancy: It is unsurprising that the age recommendation for TAVI has gradually decreased. This paper is the first reference document to formally suggest 70 years as the new cutoff point, leaving a gray area between 51 and 69 years and recommending surgery at 50 years. The authors argue for the use of bioprostheses in intermediate ages and present different options for patients under 50 to reduce the risk of oral anticoagulation, including low INR levels (1.5–2) and extending the application of the Ross procedure. They acknowledge that TAVI durability remains uncertain beyond 10 years and present an unconvincing argument for structural degeneration at 6–9 years. To maximize bioprosthesis implantation, they also discuss a strategy of multiple procedures in young patients, weighing the pros and cons of each:
   • SAVR-TAVI-TAVI: This is considered the optimal approach, starting with a surgical bioprosthesis, which offers better support for subsequent percutaneous procedures. Additionally, specific supports are designed for this purpose (Edwards® Inspiris®), or root/ring enlargement techniques can be performed to prevent prosthesis mismatch or allow future valve-in-valve implants.
   • TAVI-SAVR-TAVI: Here, TAVI is the initial treatment. The advantage is that the first procedure is less invasive, and in reoperation, the explant of the transcatheter prosthesis followed by surgical implantation allows for a potential fourth intervention if needed. However, the limited experience in explanting TAVI prostheses and the high complication rates reserve this strategy for cases where TAVI is justified as a bridge for patient recovery or other medical issues (e.g., awaiting cancer surgery).
   • TAVI-TAVI-TAVI: This fully percutaneous option is the least favorable, as it complicates coronary access and increases the risk of complications by the third procedure. If this route is chosen, a balloon-expandable/self-expanding/balloon-expandable prosthesis sequence is recommended to minimize coronary compromise in future procedures.

Access for percutaneous coronary approach remains unresolved. In over half of the cases, there is misalignment between the TAVI prosthesis commissures and one of the coronary ostia, compromising access in approximately 10% of patients who received a balloon-expandable prosthesis, which is less prone to this complication.

Another issue to consider in these patients, especially in those starting with TAVI, is the impact of conduction disorders. Beyond the effect on survival and quality of life, these patients are likely to require multiple generator replacements over their lifetimes. Surgical options should be prioritized for patients at risk of this complication (asymmetric calcium distribution, right bundle branch block, bifascicular block).

1. Anatomical aspects: Different factors associated with the aortic valve, aortic root, ascending aorta, and vascular access limit TAVI indication. These include:
   • Bicuspid and unicuspid aortic valves: Although randomized evidence is lacking due to these patients’ systematic exclusion from clinical trials, observational data show higher rates of paravalvular leakage, stroke, and pacemaker implantation, with no short-term mortality impact. The association with concomitant aortopathy also establishes SAVR as the only reasonable alternative for patients with appropriate surgical risk.
   • Unfavorable aortic root anatomy: The aortic annulus and root geometry can present challenges. A large annulus (area >575 mm² and/or perimeter >85 mm in systole) has been addressed with the development of 29 mm Edwards® Sapien® and 34 mm Medtronic® Evolut® prostheses. SAVR, with or without root replacement, is the preferred approach for extra-large annuli (area >683 mm² and/or perimeter >94.2 mm) to avoid severe complications (paravalvular leakage, device embolization). Similarly, while a small annulus was vaguely defined as <21 mm, new thresholds with an area <400 mm² and/or perimeter <72 mm predict increased rates of severe mismatch (EOA/BSA <0.65 cm²/m²) following TAVI. Incidence rates of mismatch are similar in surgical cohorts, though authors point out an “unrelenting” restriction in root/annulus expansion procedures. For the aortic root, the main issue arises with small roots due to the risk of sinus of Valsalva occupation by calcified leaflets and compromised coronary perfusion. Suitable anatomy for SAVR includes ostial height <10 mm and aortic root diameter <28 mm.

• Calcification of the left ventricular outflow tract (LVOT): This asymmetric calcification pattern strongly predicts stroke, paravalvular leakage, and annular rupture, making SAVR preferable whenever surgical risk is not prohibitive.
• Porcelain aorta and chest radiation: Although the former was a classic reason for inoperability, the latter has traditionally led to TAVI recommendation as it was a PARTNER I selection criterion inherited in subsequent clinical trials. Post-radiation pericarditis rarely poses difficulties for surgical technique. However, cases of porcelain aorta caused by post-radiation sequelae (e.g., ostial coronary stenosis, calcification of the anterior mitral leaflet, aortic stenosis, and porcelain aorta) make the percutaneous option preferable.
• Limitations for vascular access: Assigning SAVR due to an unsuitable iliofemoral approach is currently considered unreasonable. The choice between TAVI and SAVR should be based on other factors, selecting the most appropriate access based on tomography after deciding on the transcatheter option. Traditionally, poor outcomes in the transapical cohort of the PARTNER I study were associated with greater morbidity among patients with vasculopathy, with the approach serving as a marker rather than a risk factor. Similarly, so-called “alternative” approaches, such as transaxillary or transcarotid, can be equated to the transfemoral approach in comparable patient cohorts, as shown in a meta-analysis comparing transcarotid and transfemoral TAVI published by Abraham et al. this month in the American Journal of Cardiology. Notably, the authors no longer consider transaortic or transapical approaches, though they do include the unconventional transcaval approach.

1. Concomitant heart disease: Despite the expansion of transcatheter procedures for structural heart disease, concomitant procedures with TAVI remain rare and typically yield poor outcomes, often associated with patient subgroups ineligible for surgery. Among the different conditions favoring SAVR over TAVI, the authors recommend SAVR in cases of:
   • Significant concomitant mitral valve disease, including mitral regurgitation and especially rheumatic mitral stenosis.
   • Significant tricuspid regurgitation.
   • Intracavitary thrombus, especially in the left ventricle.
   • Suspected endocarditis.
   • Dual aortic lesions with at least moderate regurgitation (as these patients were generally excluded from clinical trials, with only 4% represented, primarily cases of isolated aortic stenosis or aortic stenosis with mild regurgitation).
   • Pure aortic regurgitation (systematically excluded from clinical trials, not only for functional “non-calcified” causes but also for pathology of the leaflets from type III mechanisms).
   • Severe asymptomatic aortic stenosis with guideline indications (e.g., abnormal stress test and/or elevated proBNP levels). Lacking robust evidence to recommend TAVI in these patients, upcoming randomized clinical trials such as EARLY-TAVR, DANAVR, or EVoLVeD are awaited.
   • Hypertrophic cardiomyopathy requiring septal myectomy.
   • “Milking” coronary artery requiring myotomy.
   • Atrial fibrillation (AF) that would benefit from concomitant surgical ablation and left atrial appendage closure.

Coronary artery disease merits special mention. The authors recommend SAVR with concomitant coronary revascularization in cases of left main disease with a SYNTAX score >32 points and/or three-vessel disease with a SYNTAX score >22 points. Left main disease with a SYNTAX score <32 and/or three-vessel disease with a SYNTAX score <22 represents a gray zone, where treatment choice should depend on additional criteria, as noted by the authors.

To conclude, I would like to highlight the title of the commentary, which offers a positive perspective on SAVR, even if it is only as a complement to the limitations of TAVI. Although SAVR is no longer the only or even the primary treatment option for aortic stenosis, it is still finding its place. Its future depends on the hands of surgeons in three key aspects:

1. Participation in medical-surgical sessions with full integration into the discussion about the best therapeutic option for each patient.
2. Active involvement in generating and reviewing evidence, both at an individual level and through scientific societies, ensuring that the published information meets scientific rigor and responsibility. The ultimate expression of this role is reflected in future consensus documents or clinical guidelines.
3. Striving for excellence in surgical outcomes, which includes expanding minimally invasive approaches, using bioprostheses with proven durability, and incorporating concomitant procedures that can add a quality advantage to surgical techniques: left atrial appendage closure, AF ablation, septal myectomy, aortic root and annular enlargement, ascending aorta replacement, complete revascularization, etc., over TAVI.
4. Integration of surgeons into the Heart Team, mastering transcatheter techniques and achieving favorable outcomes in “alternative non-percutaneous approaches” that require a surgical approach and/or vascular control, allowing competition with percutaneous transfemoral approaches.

REFERENCE:

Bhogal S, Rogers T, Aladin A, Ben-Dor I, Cohen JE, Shults CC, et al. TAVR in 2023: who should not get it? Am J Cardiol. 2023 Apr 15;193:1-18. doi: 10.1016/j.amjcard.2023.01.040.