Anatomical Determinants and Outcomes of Small Annulus Patients Undergoing TAVR in Different ASIAN Ethnicity

Transcatheter aortic valve implantation (TAVI) presents unique challenges for Asian patients compared to Caucasians, largely due to the prevalence of small aortic annulus (SAA) defined based on Caucasians' data (430 mm²), bicuspid aortic valve (BAV), and substantial calcium deposits. No universally accepted cutoff value for defining SAA exists among Asian patients, who tend to have smaller body-built, resulting in inconsistencies across various studies. For the new-generation 20-/23-mm balloon expandable valve, a SAA is categorized as <330 mm². Additionally, Asian Japanese patients have been identified to have extremely SAA (<314 mm²), associated with unexpectedly larger residual transvalvular gradients following TAVI.

Previous research on patient prosthesis mismatch (PPM) impact within the Asian population has also shown inconsistency. The OCEAN-TAVI registry with 1,546 Japanese patients found no significant differences in one-year all-cause and cardiovascular mortality between PPM and non-PPM groups. A study on the Sapien 3 balloon expandable valve in patients with SAA (<430 mm²) found comparable clinical outcomes to non-SAA patients up to five years post-procedure, consistent with findings from a South Korean study. However, a Taiwan study involving 201 patients with PPM indicated higher rates of adverse outcomes at mid-term follow-up. Moreover, TAVI with self-expanding valves (SEV) has shown improved hemodynamic outcomes and reduced PPM incidence compared to balloon expandable valves (BEV) in patients with extreme SAA.

To date, research on inter-racial differences in TAVI among Asian populations is lacking. This multicenter registry aims to evaluate SEV versus BEV outcomes in diverse Asian patients, particularly those with extreme SAA, and to address ethnic-specific challenges in TAVI.

Study Overview

• Status: Enrolling by invitation
• Conditions: Aortic Stenosis

• Study Type: Observational
• Enrollment (Estimated): 31

Contacts and Locations

Study Locations

• Hong Kong
  • Shatin
    • Hong Kong, Shatin, Hong Kong, 0000
      • Prince of Wales Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Retrospective data collection will be carried out at multiple TAVI sites in Asia. Patients with severe AS who underwent TAVI (SEV/ BEV) will be identified from retrospective records (Physical/ Electronic). Consecutive patients who underwent pre-procedural computed tomography (CT) scans for aortic valve evaluation from 2018-1-1 to 2024-12-31 were included.

Description

Inclusion Criteria:

• Aortic Stenosis patients treated with Transcatherter Aortic Valve Intervention

Exclusion Criteria:

• Transcatherter Aortic Valve Intervention for pure Aortic Regurgitation
• Emergent procedure for any reason;
• Previous aortic valve replacement

Study Plan

How is the study designed?

Number of groups / cohorts

7

Cohorts and Interventions

Group / Cohort
AS TAVI patient in Prince of Wales Hospital
AS TAVI patient in Sarawak Heart Centre/University Malaysia Sarawak
AS TAVI patient in National Heart Centre Malaysia
AS TAVI patient in King Chulalongkorn Memorial Hospital
AS TAVI patient in Ramathibodi Hospital
AS TAVI patient in St. Luke's Medical Cente
AS TAVI patient in Sapporo Cardiovascular Clinic

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Bioprosthetic Structural Valve Dysfunction (SVD) at 12 months	12 months Post-Operation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mortality rate		Mortality of patients 12 months post-operation
Disabling stroke rate		Rate of disabling stroke 12 months post-operation
Heart failure re-hospitalization rate		Heart failure re-hospitalization rate at 12 month post-operation
Rate of moderate prosthesis-patient mismatch (PPM)	In patients with a body mass index <30 kg/m2, PPM was defined as none or mild if the indexed EOA (iEOA) was>0.85 cm2/m2, moderate if the iEOA was 0.85-0.66 cm2/m2 and severe if the iEOA was ≤0.65 cm2/m2. In patients with a body mass index ≥30 kg/m2, PPM was defined as none or mild if the iEOA was>0.70 cm2/m2, moderate if the iEOA was 0.56-0.70 cm2/m2 and severe if the iEOA was ≤0.55 cm2/m2	Rate of moderate prosthesis-patient mismatch (PPM) at 12 month post-operation
Rate of severe prosthesis-patient mismatch (PPM)		Rate of severe prosthesis-patient mismatch (PPM) at 12 month post-operation
Device success rate		Device success rate at 30-days post-operation
Device safety rate		Device safety rate at 30-days post-operation
Rate of Bioprosthetic Structural Valve Dysfunction		Bioprosthetic Structural Valve Dysfunction (SVD) at follow-up
Rate of endocarditis		Rate of endocarditis at 12 month
Rate of Non-structural valve dysfunction (NSVD)	≥Moderate aortic regurgitation rate of moderate or severe PPM (PPM: In patients with a body mass index <30 kg/m2, PPM was defined as none or mild if the indexed EOA (iEOA) was>0.85 cm2/m2, moderate if the iEOA was 0.85-0.66 cm2/m2 and severe if the iEOA was ≤0.65 cm2/m2. In patients with a body mass index ≥30 kg/m2, PPM was defined as none or mild if the iEOA was>0.70 cm2/m2, moderate if the iEOA was 0.56-0.70 cm2/m2 and severe if the iEOA was ≤0.55 cm2/m2, PVL, and DVI (severe <0.25, moderate 0.25-0.5, mild >0.5)	Rate of Non-structural valve dysfunction (NSVD) at 12 month

Collaborators and Investigators

• Sponsor: Prince of Wales Hospital, Shatin, Hong Kong
• Collaborators: Ramathibodi Hospital; King Chulalongkorn Memorial Hospital; University Malaysia Sarawak; St. Luke's Medical Center, Philippines; Sarawak Heart Centre; Sapporo Heart Center
• Investigators: Principal Investigator: Chak Yu Kent So, Clinicnal Assistant Professor, Chinese University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2025
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): June 30, 2028

Study Registration Dates

• First Submitted: November 16, 2025
• First Submitted That Met QC Criteria: November 16, 2025
• First Posted (Estimated): November 20, 2025

Study Record Updates

• Last Update Posted (Actual): November 25, 2025
• Last Update Submitted That Met QC Criteria: November 19, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Aortic Valve Disease; Cardiovascular Diseases; Heart Diseases; Heart Valve Diseases; Ventricular Outflow Obstruction; Aortic Valve Stenosis
• Other Study ID Numbers: ADAPT-ASIAN

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No