What is the clinical evidence from this study?

Study design: Observational. Population: Japanese patients with failed surgical aortic bioprosthetic valves undergoing transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) procedure, mean age 82.4 years, 46.4% female (n=185). Intervention: Transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) procedure vs. Comparison by initial surgical aortic valve size ≤21 mm versus >21 mm. Primary outcome: Overall 4-year survival (p=0.79).

What does this research mean for the field?

Transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) procedures in patients with small initial surgical valves (≤21 mm) yield comparable 4-year survival and cardiovascular mortality rates to those with larger valves (>21 mm). Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

What question did this study set out to answer?

This study aims to evaluate the mid-term outcomes of transcatheter valve-in-surgical valve procedures based on bioprosthetic valve size.

March 1, 2026Open Access

Clinical impact of initial surgical aortic bioprosthetic valve size on mid-term outcomes of transcatheter valve-in-valve in Japanese patients

Key Result

TAV-in-SAV in patients with small initial surgical valve sizes (≤21 mm) yielded comparable 4-year survival of 69.1% versus 79.6% in patients with >21 mm valves (p=0.79).

Key Points

This study aims to evaluate the mid-term outcomes of transcatheter valve-in-surgical valve procedures based on bioprosthetic valve size.
Analyzed 185 TAV-in-SAV procedures from a multicenter registry in Japan.
Compared outcomes between patients with bioprosthetic valves ≤ 21 mm and > 21 mm.
Used Kaplan–Meier survival analysis to assess 4-year survival and freedom from cardiovascular mortality.
4-year survival rates were 69.1% for the small valve group and 79.6% for the non-small group (p = 0.79).
Freedom from cardiovascular mortality was 91.3% in the small group vs. 90.1% in the non-small group (p = 0.096).
Overall mid-term outcomes of TAV-in-SAV in this cohort were satisfactory and comparable to international reports.

Study Design

Type

Observational (n=185)

Multicenter

Yes

Structured PICO

Does TAV-in-SAV in patients with small initial surgical aortic valves (≤ 21 mm) result in comparable 4-year survival to those with larger valves (> 21 mm)?

Population

185 Japanese patients with failed surgical bioprosthetic valves undergoing transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) procedures, mean age 82.4 years, 46.4% female.

Intervention

Transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) for initial small surgical aortic valves (≤ 21 mm label size).

Comparator

Transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) for initial non-small surgical aortic valves (> 21 mm label size).

Outcome

Overall 4-year survival estimated using the Kaplan–Meier method.hard clinical

TAV-in-SAV yields satisfactory mid-term survival in Japanese patients regardless of initial surgical valve size, suggesting it is a viable option even for those with small (≤ 21 mm) bioprostheses.

Main Result

Absolute Event Rate: 69.1% vs 79.6%

p-value: p=0.79

Limitations

Retrospective observational design with small cohort limiting statistical power and possibility of type II error
Lack of echocardiographic core laboratory may introduce inter-institution variability in assessments
Absence of CT data limited evaluation of anatomical risk factors
No adjudication of cardiovascular death, stroke, and hospitalization by clinical events committee

Abstract

Clinical outcomes of transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) procedures have been reported to be poor in patients initially implanted with small bioprosthetic valves. The aim of this study was to evaluate mid-term outcomes of TAV-in-SAV for small SAVs using data from a Japanese multicenter registry. A total of 185 TAV-in-SAV procedures performed between January 2013 and March 2024 at 10 centers in Japan were analyzed. The primary endpoint was overall 4-year Kaplan–Meier survival. Clinical outcomes were also compared between initial ≤ 21 mm SAV (small group) vs. > 21 mm SAV (non-small group). The mean age was 82.4 years; 46.5% were female. One hundred sixteen (62.7%) patients were in the small group (≤ 21 mm SAV in 40 patients; > 21 mm SAV in 76 patients). The Evolut platform was used in 150 patients (81.1%), especially in the small group (103 patients, 88.8%). The 4-year survival in the small group (69.1%) was comparable to that in the non-small group (79.6%) (p = 0.79). Similarly, freedom from cardiovascular mortality at 4 years in the small group (91.3%) was comparable to that in the non-small group (90.1%) (p = 0.096). This multicenter retrospective study shows that TAV-in-SAV in Japanese patients yields satisfactory mid-term outcomes. Despite advanced age, overall and freedom from cardiovascular mortality at 4 years were comparable to previous international reports, with no significant difference by valve size. (ClinicalTrials.gov number, NCT06826027.)

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