One of the major challenges of severe aortic stenosis are patients with small aortic annuli, defined as ≤430 mm² aortic valve area. This condition represents a complex scenario both for surgical replacement and the strategy the surgeon will choose.
In the context of transcatheter aortic valve replacement (TAVR) we currently have self-expanding valves (SEV), with supra annular implantation, and balloon expandable valves (BEV), with intra annular implantation.
Even though the SMART trial had shown SEV are superior at 12 months, there are still questions in this scenario as to the most adequate valve for implantation.
This was a retrospective analysis conducted between October 2009 and December 2022, including 565 patients with a small annulus; 361 (63.9%) received BEV, and the rest SEV.
The BEV used were SAPIEN, SAPIEN XT and SAPIEN 3; while SEV corresponded to CoreValve, Evolut R, Evolut PRO and Evolut PRO+.
Mean patient age was 84, 87% were women, and mean STS was 6.7%. Hypertension prevalence was 79%, COPD 16%, heart disease 22%, prior CABG 7%, and atrial fibrillation 17.5%. Glomerular filtration was 50 mL/min/1.73 m², and the presence of diabetes was higher among BEV patients.
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Mean ejection fraction was 65%. Area derived from ring diameter was 21.6 mm. Aortic valve area was smaller among SEV patients, with higher gradient and greater velocity.
Most procedures used the femoral approach. After implantation, SEV patients presented lower peak velocity (1.84 vs. 2.27 m/s, p<0.001), lower mean gradient (7.41 mmHg vs. 11.49 mmHg, p<0.001), larger valve area (1.88 vs. 1.6 cm², p<0.001), and higher indexed aortic area (1.37 vs. 1.17 cm²/m², p<0.001), with no significant differences in presence of moderate or severe leak.
During mean followup 3.6 years (ranging from 2 to 5.7 years, up to maximum 12 years), SEV showed less valve structure deterioration and lower incidence of bioprosthesis failure (1.1% vs. 9.1% at 5 years and 0.7% vs. 8.1% at 5 years respectively).
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Fine-Gray sub-distribution analysis revealed SEV presented lower structural deterioration (HR: 0.19; CI 95%: 0.06–0.61, p=0.005) vs BEV, as well as lower bioprosthesis failures rate (HR: 0.30; IC 95%: 0.11–0.85, p=0.024).
Conclusion
Self-expanding valves appear to be the most suitable in terms of durability in patients with small annuli.
Reference: Yutaka Matsuhiro, el tal. Catheterization and Cardiovascular Interventions, 2025; 105:990–997 https://doi.org/10.1002/ccd.31415.
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