Aortic Valve Stenosis and/or InsufficiencySYMMETRYNCT07872020
SYMmetric Valve fraME Expansion To Reduce hYpoattenuated Leaflet Thickening After Balloon-expandable TAVI: the SYMMETRY Trial
A study testing Double-TAP post-dilatation in people with Aortic Valve Stenosis and/or Insufficiency and Hypoattenuated Leaflet Thickening, run by Erasmus Medical Center at 5 sites in 2 countries.
Trial summary
Rationale: Transcatheter aortic valve implantation (TAVI) has become the standard of care for aortic stenosis across all surgical risk categories, including low-risk, younger patients (≥70 years). Read more about this study
- Who is it for?
- Ages 70 years and older
- Conditions the study is for
- Aortic Valve Stenosis and/or Insufficiency, Hypoattenuated Leaflet Thickening, Valve Expansion
- What is being tested?
- Double-TAP post-dilatation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 422 participants
- Where
- 5 sitesin 2 countries
- Study dates
- 1 Nov 2026to 1 Nov 2033
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 70 years and older
- All sexes
- No healthy volunteers
- Older adult
Who may be able to join
- Age ≥ 70 years
- Patients with severe aortic stenosis undergoing TAVI with a balloon-expandable valve
- Written informed consent
Who cannot join
- Significant valve frame under-expansion and/or ≥ moderate paravalvular leakage warranting post-dilatation at the discretion of the treating physician
- Shallow implantation depth with increased risk of valve embolization upon post-dilatation
- Sievers type 1 bicuspid aortic valve with calcified raphe
- Indication for oral anticoagulant therapy
- Estimated glomerular filtration rate <30 ml/min
- Iodine contrast allergy
Trial locations and contacts
5 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
5 sites in 2 countries
Netherlands4 sites
Amsterdam University Medical Center
Amsterdam
Ronak Delewi, MD PhD, +31205669111
Amphia Hospital
Breda
B.J.L. van den Branden, MD PhD, +310765955000
Maastricht University Medical Center
Maastricht
Pieter Vriesendorp, MD PhD, +31433876543
Erasmus Medical Center Rotterdam
Rotterdam
Rutger-Jan M Nuis, MD PhD, +31614858291, r.nuis@erasmusmc.nl
Germany1 site
Uniklinik Düsseldorf
Düsseldorf
T. Zeus, Prof. Dr. med., +492118118801
About this study
Rationale: Transcatheter aortic valve implantation (TAVI) has become the standard of care for aortic stenosis across all surgical risk categories, including low-risk, younger patients (≥70 years). As many of these patients are expected to outlive their prosthetic valves, the durability of the valve becomes an increasingly critical factor. Hypoattenuated leaflet thickening (HALT), a finding on post-TAVI computed tomography (CT), occurs in approximately 20% of patients and is associated with bioprosthetic valve dysfunction. Balloon-expandable valves seem more susceptible to HALT with an occurrence rate of 21%, compared to 16% for self-expanding valves.
A recent study identified underexpansion of the transcatheter heart valve prosthesis as a key predictor of HALT at 30 days, which in turn was associated with a sixfold increase in cardiovascular mortality and a threefold increase in all-cause mortality at 1 year. Moreover, data suggest that, in the absence of post-dilatation, more than 95% of balloon-expandable valve implants exhibit some degree of underexpansion. In contrast, routine post-dilatation enhances valve expansion and hemodynamic performance without significantly increasing adverse events. The double-TAP technique-re-inflation of the TAVI delivery balloon after initial valve deployment-achieves a 9-10% increase in valve frame expansion, potentially reducing HALT risk and improving long-term outcomes.
Read more
Objective: To determine whether routine double-TAP post-dilatation after balloon-expandable TAVI is safe and can reduce the incidence of HALT.
Study design: Investigator-initiated, multicenter, open-label, randomized trial with 1:1 allocation to routine post-dilatation using double-TAP versus no post-dilatation immediately after balloon expandable valve deployment.
Study population: 422 Patients undergoing balloon-expandable TAVI for native aortic valve stenosis Investigational intervention: TAVI with a balloon-expandable valve followed by double-TAP post-dilatation.
Study design: Investigator-initiated, multicenter, open-label, randomized trial with 1:1 allocation to routine post-dilatation using double-TAP versus no post-dilatation immediately after balloon expandable valve deployment.
Study population: 422 Patients undergoing balloon-expandable TAVI for native aortic valve stenosis
Investigational intervention: TAVI with a balloon-expandable valve followed by double-TAP post-dilatation.
- Conditions
- Aortic Valve Stenosis and/or Insufficiency, Hypoattenuated Leaflet Thickening, Valve Expansion, Transcatheter Aortic Valve Replacement
- Being tested
- Double-TAP post-dilatation
- Keywords
- Aortic valve stenosis, Aortic valve regurgitation, Post-dilatation, Balloon-expandable valves
- Medical subject headings
- Aortic Valve Stenosis, Aortic Valve Insufficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Double-TAP post-dilatationProcedure or surgery
If patient is randomized to treatment arm the TAVI delivery balloon is aligned at valve level and reinflated to nominal volume for 3 seconds under rapid pacing.
| Study group | Role | What they receive |
|---|---|---|
| Double-TAP post-dilatation | Active comparator | Not described Receives: Procedure: Double-TAP post-dilatation |
| No post-dilatation | No intervention | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
Hypoattenuated Leaflet Thickening (HALT)
HALT (at least one thickened TAV leaflet involving > 25% of the leaflet curvilinear dimension as assessed at cardiac CT)
Measured: 30 days
Co-primary: VARC-3-defined safety
Composite of 1) freedom from all-cause mortality; 2) freedom from all new stroke; 3) freedom from VARC type 2 to 4 bleeding; 4) freedom from major vascular, access-related, or cardiac structural complications; 5) freedom from acute kidney injury stage 3 or 4; 6) freedom from moderate or severe aortic regurgitation; 7) freedom from new permanent pacemaker implantation caused by procedure related conduction abnormalities; and 8) freedom from surgery or intervention related to the device in accordance with the third Valve Academic Research Consortium (VARC-3) criteria at 30 days.
Measured: 30 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Oct 2026
- Study start1 Nov 2026 (estimated)
- Primary completion1 Nov 2028 (estimated)
- Study completion1 Nov 2033 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (17)Papers the sponsor has linked to this study.
- Other trials for Aortic Valve Stenosis and/or InsufficiencyStudies of the same condition, open and under way.
- More trials run by Erasmus Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 422 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Erasmus Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- Edwards Lifesciences
- Responsible party
- Principal investigator, Rutger-Jan Nuis, Erasmus Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07872020
- Sponsor's protocol ID
- SYMMETRY-trial
- Acronym
- SYMMETRY
- Status last verified
- Oct 2026
- First submitted
- 7 Oct 2026
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Kappetein AP, Head SJ, Genereux P, Piazza N, van Mieghem NM, Blackstone EH, Brott TG, Cohen DJ, Cutlip DE, van Es GA, Hahn RT, Kirtane AJ, Krucoff MW, Kodali S, Mack MJ, Mehran R, Rodes-Cabau J, Vranckx P, Webb JG, Windecker S, Serruys PW, Leon MB. Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document. Eur Heart J. 2012 Oct;33(19):2403-18. doi: 10.1093/eurheartj/ehs255.
PubMed 23026477Nishimura Y, Tanabe K, Higashino A, Yokozuka M, Horiuchi Y, Taniwaki M, Yuzawa H, Komiyama K, Tanaka J, Asami M. Hemodynamic Improvement With the Double-Tap Technique During Transcatheter Aortic Valve Replacement Using a Pressure-Sensing Guidewire. JACC Case Rep. 2026 May 27;31(21):107860. doi: 10.1016/j.jaccas.2026.107860. Epub 2026 Apr 12.
PubMed 41973885Leon MB, Mack MJ, Pibarot P, Hahn RT, Thourani VH, Kodali SH, Genereux P, Kapadia SR, Cohen DJ, Pocock SJ, Zhang Y, Szerlip M, Ternacle J, Malaisrie SC, Herrmann HC, Szeto WY, Russo MJ, Babaliaros V, Nazif T, Webb JG, Makkar RR; PARTNER 3 Investigators. Transcatheter or Surgical Aortic-Valve Replacement in Low-Risk Patients at 7 Years. N Engl J Med. 2026 Feb 19;394(8):773-783. doi: 10.1056/NEJMoa2509766. Epub 2025 Oct 27.
PubMed 41144631Costa G, Saia F, Pilgrim T, Abdel-Wahab M, Garot P, Valvo R, Gandolfo C, Branca L, Latib A, Santos IA, Mylotte D, De Marco F, De Backer O, Franco LN, Akodad M, Mazzapicchi A, Tomii D, Laforgia P, Cannata S, Fiorina C, Scotti A, Lunardi M, Poletti E, Mazzucca M, Quagliana A, Hennessey B, Meier D, Adamo M, Sgroi C, Reddavid CM, Strazzieri O, Motta SC, Frittitta V, Dipietro E, Comis A, Melfa C, Thiele H, Webb JG, Sondergaard L, Tamburino C, Barbanti M. Transcatheter Aortic Valve Replacement With the Latest-Iteration Self-Expanding or Balloon-Expandable Valves: The Multicenter OPERA-TAVI Registry. JACC Cardiovasc Interv. 2022 Dec 12;15(23):2398-2407. doi: 10.1016/j.jcin.2022.08.057. Epub 2022 Sep 16.
PubMed 36121242Husain A, Jelisejevas J, Millar K, Alnuwakhtha A, Ferkh A, Delarive J, Gill H, Althekrallah J, Offen S, Tzimas G, Ye J, Leipsic JA, Blanke P, Sathananthan J, Wood DA, Sellers SL, Meier D, Webb JG. Routine post-dilatation at nominal volume to optimise the expansion of balloon-expandable valves: the DOUBLE-TAP study. EuroIntervention. 2025 Oct 6;21(19):e1159-e1168. doi: 10.4244/EIJ-D-25-00258.
PubMed 41051150Pibarot P, Weissman NJ, Stewart WJ, Hahn RT, Lindman BR, McAndrew T, Kodali SK, Mack MJ, Thourani VH, Miller DC, Svensson LG, Herrmann HC, Smith CR, Rodes-Cabau J, Webb J, Lim S, Xu K, Hueter I, Douglas PS, Leon MB. Incidence and sequelae of prosthesis-patient mismatch in transcatheter versus surgical valve replacement in high-risk patients with severe aortic stenosis: a PARTNER trial cohort--a analysis. J Am Coll Cardiol. 2014 Sep 30;64(13):1323-34. doi: 10.1016/j.jacc.2014.06.1195.
PubMed 25257633Wang N, Lal S. Post-dilation in transcatheter aortic valve replacement: A systematic review and meta-analysis. J Interv Cardiol. 2017 Jun;30(3):204-211. doi: 10.1111/joic.12378. Epub 2017 Mar 21.
PubMed 28321917Goel K, Nkomo VT, Slusser JP, Lennon R, Brown RD, Greason KL, Holmes DR Jr. Relationship between procedural characteristics and cerebrovascular events after transcatheter aortic valve replacement. Open Heart. 2018 Oct 7;5(2):e000816. doi: 10.1136/openhrt-2018-000816. eCollection 2018.
PubMed 30364522Hahn RT, Pibarot P, Webb J, Rodes-Cabau J, Herrmann HC, Williams M, Makkar R, Szeto WY, Main ML, Thourani VH, Tuzcu EM, Kapadia S, Akin J, McAndrew T, Xu K, Leon MB, Kodali SK. Outcomes with post-dilation following transcatheter aortic valve replacement: the PARTNER I trial (placement of aortic transcatheter valve). JACC Cardiovasc Interv. 2014 Jul;7(7):781-9. doi: 10.1016/j.jcin.2014.02.013.
PubMed 25060022Krishnamoorthy P, Onishi T, Singh S, Zaid S, Khera S, Hooda A, Goel S, Safi LM, Lerakis S, Dangas GD, Sharma SK, Kini AS, Tang GHL. Double Inflation ("Double Tap") on Valve Expansion and Short-Term Outcomes After the Latest-Generation Balloon-Expandable TAVR. JACC Cardiovasc Interv. 2026 Feb 23;19(4):488-501. doi: 10.1016/j.jcin.2025.11.004. Epub 2025 Nov 16.
PubMed 41741067Bogyi M, Schernthaner RE, Loewe C, Gager GM, Dizdarevic AM, Kronberger C, Postula M, Legutko J, Velagapudi P, Hengstenberg C, Siller-Matula JM. Subclinical Leaflet Thrombosis After Transcatheter Aortic Valve Replacement: A Meta-Analysis. JACC Cardiovasc Interv. 2021 Dec 27;14(24):2643-2656. doi: 10.1016/j.jcin.2021.09.019.
PubMed 34949391Sellers SL, Turner CT, Sathananthan J, Cartlidge TRG, Sin F, Bouchareb R, Mooney J, Norgaard BL, Bax JJ, Bernatchez PN, Dweck MR, Granville DJ, Newby DE, Lauck S, Webb JG, Payne GW, Pibarot P, Blanke P, Seidman MA, Leipsic JA. Transcatheter Aortic Heart Valves: Histological Analysis Providing Insight to Leaflet Thickening and Structural Valve Degeneration. JACC Cardiovasc Imaging. 2019 Jan;12(1):135-145. doi: 10.1016/j.jcmg.2018.06.028. Epub 2018 Nov 15.
PubMed 30448122Cartlidge TRG, Doris MK, Sellers SL, Pawade TA, White AC, Pessotto R, Kwiecinski J, Fletcher A, Alcaide C, Lucatelli C, Densem C, Rudd JHF, van Beek EJR, Tavares A, Virmani R, Berman D, Leipsic JA, Newby DE, Dweck MR. Detection and Prediction of Bioprosthetic Aortic Valve Degeneration. J Am Coll Cardiol. 2019 Mar 19;73(10):1107-1119. doi: 10.1016/j.jacc.2018.12.056.
PubMed 30871693Hein M, Schoechlin S, Schulz U, Minners J, Breitbart P, Lehane C, Neumann FJ, Ruile P. Long-Term Follow-Up of Hypoattenuated Leaflet Thickening After Transcatheter Aortic Valve Replacement. JACC Cardiovasc Interv. 2022 Jun 13;15(11):1113-1122. doi: 10.1016/j.jcin.2022.04.018.
PubMed 35680190Fukui M, Bapat VN, Garcia S, Dworak MW, Hashimoto G, Sato H, Gossl M, Enriquez-Sarano M, Lesser JR, Cavalcante JL, Sorajja P. Deformation of Transcatheter Aortic Valve Prostheses: Implications for Hypoattenuating Leaflet Thickening and Clinical Outcomes. Circulation. 2022 Aug 9;146(6):480-493. doi: 10.1161/CIRCULATIONAHA.121.058339. Epub 2022 Jul 8.
PubMed 35862182