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Active, not recruitingNCT03613246FOLLOWUpdated Nov 17, 2025

NVT ALLEGRA TAVI System TF in Failing Calcified Aortic Heart Valves in a Real-world Patient Population

An observational study in Transcatheter Aortic Valve Implantation, sponsored by NVT GmbH. Active, not recruiting at 14 sites in 6 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-11-17.

Sponsored by NVT GmbH · Observational

Study type
Observational
Model
Other
Time perspective
Prospective
Enrollment
346
Ages
18 Years and older
Sex
All
01

Study summary

The study collects real-world data of patients who were treated with the ALLEGRA TAVI System TF and evaluates early and midterm clinical and quality of life outcome.

02

Conditions studied

  • Transcatheter Aortic Valve Implantation

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Keywords

  • TAVI
  • Aortic valve stenosis
  • ALLEGRA
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

Symptomatic patients with elevated surgical risk and candidate for TAVI with severe calcified and stenotic aortic valves or failing surgical bioprosthetic aortic valves.

Inclusion criteria

  1. Symptomatic degeneration of severe calcified aortic heart valve OR failing surgical aortic bioprosthetic valve
  2. Acceptable candidate for elective treatment with the ALLEGRA TAVI System TF (according to the most recent version of the ALLEGRA Instructions For Use)
  3. High risk for surgery as assessed by the heart team
  4. Has signed the Patient Informed Consent Form >= 18 years

Exclusion criteria

Exclusion Criteria:

General:

  1. Echocardiographic evidence of intracardiac thrombus or vegetation
  2. Significant aortic disease such as severe obstructive calcification or marked tortuosity or kinking which will preclude a safe advancement of the ALLEGRA TAVI System TF
  3. Iliofemoral vessel conditions such as severe obstructive calcification, severe tortuosity or kinking that would preclude safe placement of an 18 Fr introducer sheath or make endovascular access to the aortic valve impossible
  4. Severe ventricular dysfunction with LVEF \<20%
  5. Evidence of active endocarditis or other acute infections
  6. Renal failure requiring continuous renal replacement therapy
  7. Known hypersensitivity to contrast media, which cannot be adequately pre-medicated or contraindication to anticoagulant or anti-platelet medication or to nitinol alloy or to bovine tissue
  8. Life expectancy ≤ 12 months due to other medical illness
  9. Currently participating in another investigational drug or device study

Patients with native aortic valve disease:

  1. Unicuspid or bicuspid aortic valve
  2. Non-calcified aortic stenosis
  3. Combined aortic valve disease with predominant aortic regurgitation > 3
  4. Distance between aortic valve basal plane and the orifice of the lowest coronary artery \< 8 mm

Patients with degenerated surgical bioprosthetic aortic valves:

  1. Low position of the coronary ostia, especially in combination with shallow sinuses
  2. Internal diameter of the bioprosthesis is ≤16 mm or >28 mm
  3. Partially detached leaflets that in the aortic position may obstruct a coronary ostium
04

Study design

Observational model
Other
Time perspective
Prospective
Enrollment
346 participants (actual)
Patient registry
No

Groups and cohorts

  • Cohort 1: Patients who undergo TAVI for symptomatic severe stenosed aortic heart valves
  • Cohort 2:

    patients undergoing a VIV procedure in failing surgical bioprostheses.

05

What researchers measure

Primary outcomes

  1. Cardiovascular death

    Time frame: 30 days post-index procedure

Secondary outcomes

  1. All-cause mortality

    Time frame: up to five years

  2. Technical success of implantation

    Technical success of implantation, as defined by: * absence of procedural mortality AND * correct positioning of a single prosthetic heart valve into the proper anatomical location AND * no prosthesis - patient mismatch AND * mean aortic valve gradient \<20 mmHg, AND * no moderate or severe prosthetic valve regurgitation

    Time frame: day of procedure

  3. Assesment of NYHA classification

    Time frame: 30 days, 12 month, 24 month, 36 month, 48 month, 60 month

  4. Safety profile according to VARC II

    Early Safety * All-cause mortality * All stroke (disabling and non-disabling) * Life-threatening bleeding * Acute kidney injury-Stage 2 or 3 (including renal replacement therapy) * Coronary artery obstruction requiring intervention * Major vascular complication * Valve-related dysfunction requiring repeat procedure Time-related valve safety * Structural valve deterioration as defined by * Requiring repeat procedure (transcatheter or surgical heart valve replacement) * Valve-related dysfunction defined by * mean aortic valve gradient ≥20 mmHg and * no moderate or severe prosthetic valve regurgitation * Prosthetic valve endocarditis * Prosthetic valve thrombosis * Thrombo-embolic events (e.g. stroke) * VARC bleeding, unless clearly unrelated to valve therapy

    Time frame: 30 days

  5. In-hospital mortality

    Time frame: date of procedure till date of estimated discharge, assessed up to two weeks

  6. Quality of life (EQ5D 5L)

    Time frame: 30 days, 12 month, 24 month, 36 month, 48 month, 60 month

  7. New pacemaker implantation

    Time frame: up to five years

  8. assessment of mean aortic gradient post-implantation

    Time frame: up to five years

06

Study locations

14 sites
  • Oulu University Hospital
    Oulu, 90220, Finland
  • Herz- und Gefäßzentrum Bad Bevensen
    Bad Bevensen, 29549, Germany
  • Schuechtermann-klinik
    Bad Rothenfelde, Germany
  • Kath. Marienkrankenhaus
    Hamburg, 22087, Germany
  • MH Hannover
    Hanover, 30625, Germany
  • SLK-Kliniken Heilbronn
    Heilbronn, 74078, Germany
  • Ospedale San Raffaele
    Milan, 20132, Italy
  • Clinica Mediterranea Neapel
    Naples, Italy
  • Heartcentre Catharina Hospital Eindhoven
    Eindhoven, 5623 EJ, Netherlands
  • Hospital Universitario La Paz
    Madrid, 28046, Spain
  • Hospital Universitario Virgen de la Victoria
    Málaga, 29010, Spain
  • Hospital Universitario de Salamanca
    Salamanca, 37007, Spain
  • Hospital Alvaro Cunqueiro
    Vigo, 36213, Spain
  • Morriston Hospital
    Swansea, United Kingdom
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT03613246
Lead sponsor
NVT GmbH
Responsible party
Sponsor
First posted
Aug 3, 2018
Start date
Feb 20, 2019
Primary completion
Dec 20, 2024
Completion
Jan 26, 2029 (estimated)
Last update
Nov 17, 2025

Study contacts

Ulrich Schäfer, MD
principal investigator · Herz-und Gefäßzentrum Bad Bevensen, Germany

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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