Transcatheter Aortic Valve ImplantationEMPIRE-IINCT05804903
Investigation of the NVT ALLEGRA Plus THV System in Patients With Severe Aortic Stenosis or Failed Surgical Aortic Bioprosthesis
A study testing (ALLEGRA Plus Transcatheter Heart Valve) TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis in people with Transcatheter Aortic Valve Implantation, run by NVT GmbH at 7 sites in 5 countries.
Trial summary
The EMPIRE II study evaluates the safety and performance of the entire ALLEGRA THV System. The primary safety endpoint is composite of all-cause mortality or stroke rates at 12 months. And the primary performance endpoint is device success at 7 days. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Transcatheter Aortic Valve Implantation
- What is being tested?
- (ALLEGRA Plus Transcatheter Heart Valve) TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 177 participants
- Where
- 7 sitesin 5 countries
- Study dates
- 24 Nov 2023to 1 Aug 2030
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Symptomatic severe calcific stenosis of a native aortic valve with an AVA ≤1.0 cm2 (or AVA index ≤0.6 cm2/m2), AND mean aortic pressure gradient ≥ 40mmHg OR maximal transaortic velocity ≥4.0m/s OR Doppler velocity index ≤0.25 on site-reported echocardiography OR symptomatic patients with degeneration of a surgical bioprosthetic valve (stenosis +/- insufficiency) on site-reported echocardiography
- Local multi-disciplinary Heart Team and Central Screening Committee (CSC) agree on indication and eligibility for TAVI
- Age ≥18 years
- Patient has signed the Patient Informed Consent Form
- Patient is willing and able to comply with requirements of the study, including all follow-up visits
Who cannot join
- Patient will not be included if ANY one of the following conditions exists:
- General:
- Mean aortic annulus diameter as measured by pre-procedural CT or internal diameter of the bioprosthesis is <16.5 mm or >27 mm
- Echocardiographic evidence of intracardiac thrombus or vegetation (site-reported)
- Significant disease of the aorta that would preclude safe advancement of the ALLEGRA Plus THV System
- Severe ilio-femoral vessel disease that would preclude safe placement of an 18 Fr introducer sheath or make endovascular access impossible
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- Porcelain aorta
- Severe left ventricular dysfunction with ejection fraction (EF) <20% (site-reported)
- Evidence of active endocarditis or other acute infections
- Renal failure requiring continuous renal replacement therapy
- Untreated clinically significant coronary artery disease requiring revascularization
- Any percutaneous interventional procedure (e.g. PCI with stenting) within 14 days prior of the index procedure
- Acute MI ≤30 days prior to the index procedure
- Symptomatic carotid or vertebral artery disease requiring intervention or carotid/vertebral intervention within the preceding 45 days
- Cerebrovascular accident (CVA) or transient ischemic attack (TIA) ≤6 months or prior CVA with moderate or severe disability (e.g. modified Rankin scale score >2)
- History of bleeding diathesis or coagulopathy; acute blood dyscrasias as defined: thrombocytopenia (platelets <80,000/µl), acute anemia (hemoglobin <10 g/dl), leukopenia (WBC <3000/ µl)
- Active peptic ulcer or gastrointestinal (GI) bleeding ≤3 months
- Severe (greater than 3+) mitral insufficiency (site-reported)
- Uncontrolled atrial fibrillation
- Required emergency surgery for any reason
- 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
- Life expectancy ≤12 months due to other medical illness
- Currently participating in another investigational drug or device study
- Hypertrophic obstructive cardiomyopathy
- Pregnancy or intend to become pregnant during study participation
- Specific exclusions in patients with native aortic valve disease (site-reported):
- Unicuspid or bicuspid aortic valve
- Non-calcified aortic stenosis
- Identified risk of coronary occlusion due to Sinus of Valsalva anatomy and/or bulky calcified aortic valve leaflets in close proximity to coronary ostia
- Specific exclusions in patients with degenerated surgical bioprosthetic aortic valves (valve-in-valve) (site-reported):
- High risk of coronary occlusion
- Partially detached leaflets that may obstruct a coronary ostium
Trial locations and contacts
7 sites in 5 countries.
7 sites in 5 countries
Poland2 sites
Klinika Kardiochirurgii
Gdansk, 80-214
III Katedra Kardiologii
Katowice, 40-635
About this study
Official title: InvEstigation of the Safety and Performance of the NVT ALLEGRA Plus THV SysteM in Patients With Severe aortIc Stenosis or Failed suRgical Aortic bioprosthEsis
The EMPIRE II study evaluates the safety and performance of the entire ALLEGRA THV System.
The primary safety endpoint is composite of all-cause mortality or stroke rates at 12 months. And the primary performance endpoint is device success at 7 days.
Based on the outcomes of a study with a similar device and considering a drop-out rate of 5%, 177 patients need to be enrolled in the study.
- Conditions
- Transcatheter Aortic Valve Implantation
- Being tested
- (ALLEGRA Plus Transcatheter Heart Valve) TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis
- Keywords
- TAVI, Aortic valve stenosis, ALLEGRA Plus, IMPERIA, NVT
- Medical subject headings
- Aortic Valve Stenosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
(ALLEGRA Plus Transcatheter Heart Valve) TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesisDevice
Implantation of the ALLEGRA Plus Transcatheter Heart Valve in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis
| Study group | Role | What they receive |
|---|---|---|
| TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis | Experimental | Not described Receives: Device: (ALLEGRA Plus Transcatheter Heart Valve) TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Composite of all-cause mortality or stroke rates
Measured: 12 months
Secondary outcomes (14)
All-cause mortality rate
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Cardiovascular mortality rate
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Any stroke rate
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Transient ischemic attack rate
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Device success rate
Device success at 30 days (In-hospital may be used if 30-day data are not available):
- Technical success
- Freedom from mortality
- Freedom from surgery or intervention related to the device (excluding permanent pacemaker) or to a major vascular or access-related or cardiac structural complication
- Intended performance of the valve‡(mean gradient<20 mmHg, peakvelocity<3 m/s, Doppler velocity index ≥0.25, and less than moderate aortic regurgitation
Measured: 30 days
Effective orifice area (EOA) as assessed by transthoracic echocardiogram (TTE)
as determined by an independent Echo Core Lab
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Transvalvular mean and peak pressure gradient as assessed by transthoracic echocardiogram (TTE)
as determined by an independent Echo Core Lab
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Transvalvular mean and peak pressure gradient as assessed by transthoracic
as determined by an independent Echo Core Lab
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
NYHA classification
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Life-threatening/major bleeding (BARC 3b or more)
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Major vascular complications according to VARC-3
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Early safety profile according to VARC-3
Measured: 30 days
Quality of life as assessed using the Kansas City Cardiomyopathy Questionnaire (KCCQ-12)
Assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ-12). Patients are asked questions about physical limitation, symptom frequency, quality of life, and social limitation. Responses are given on a Likert scale that for each individual item is scored on a scale of 0-100 with higher scores indicating better health.
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
New pacemaker implantation rate
Measured: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Apr 2023
- Study start24 Nov 2023
- Primary completion31 Aug 2025
- Study completion1 Aug 2030 (estimated)
Why it stopped: Interim analysis showed ALLEGRA Plus did not provide clinically meaningful benefit over the CE-marked ALLEGRA THV System. Sponsor discontinued ALLEGRA Plus as a standalone product. Not terminated for safety reasons.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Transcatheter Aortic Valve ImplantationStudies of the same condition, open and under way.
- 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 177 participants (estimated)
Sponsor and investigators
- Lead sponsor
- NVT GmbH
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05804903
- Sponsor's protocol ID
- NVT06EMP2
- Acronym
- EMPIRE-II
- Status last verified
- Mar 2026
- First submitted
- 14 Mar 2023
- Last updated
- 9 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- InvEstigation of the Safety and Performance of the NVT ALLEGRA Plus THV SysteM in Patients With Severe aortIc Stenosis or Failed suRgical Aortic bioprosthEsis
- ClinicalTrials.gov ID
- NCT05804903
- Acronym / sponsor ID
- EMPIRE-II / NVT06EMP2
- Conditions
- Transcatheter Aortic Valve Implantation
- Keywords
- TAVI, Aortic valve stenosis, ALLEGRA Plus, IMPERIA, NVT
- Study type
- Interventional
- Recruitment status
- SuspendedReason stopped: Interim analysis showed ALLEGRA Plus did not provide clinically meaningful benefit over the CE-marked ALLEGRA THV System. Sponsor discontinued ALLEGRA Plus as a standalone product. Not terminated for safety reasons.
- Enrolment
- 177 participants (estimated)
- Lead sponsor
- NVT GmbHIndustry (pharma, biotech, devices)
- Study start
- 24 Nov 2023 (actual)
- Primary completion
- 31 Aug 2025 (actual)
- Study completion
- 1 Aug 2030 (estimated)
- First posted
- 7 Apr 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The EMPIRE II study evaluates the safety and performance of the entire ALLEGRA THV System.
The primary safety endpoint is composite of all-cause mortality or stroke rates at 12 months. And the primary performance endpoint is device success at 7 days.
Based on the outcomes of a study with a similar device and considering a drop-out rate of 5%, 177 patients need to be enrolled in the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis | Experimental | Device: (ALLEGRA Plus Transcatheter Heart Valve) TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Symptomatic severe calcific stenosis of a native aortic valve with an AVA ≤1.0 cm2 (or AVA index ≤0.6 cm2/m2), AND mean aortic pressure gradient ≥ 40mmHg OR maximal transaortic velocity ≥4.0m/s OR Doppler velocity index ≤0.25 on site-reported echocardiography OR symptomatic patients with degeneration of a surgical bioprosthetic valve (stenosis +/- insufficiency) on site-reported echocardiography
- Local multi-disciplinary Heart Team and Central Screening Committee (CSC) agree on indication and eligibility for TAVI
- Age ≥18 years
- Patient has signed the Patient Informed Consent Form
- Patient is willing and able to comply with requirements of the study, including all follow-up visits
Key exclusion criteria (32 listed)
- Mean aortic annulus diameter as measured by pre-procedural CT or internal diameter of the bioprosthesis is <16.5 mm or >27 mm
- Echocardiographic evidence of intracardiac thrombus or vegetation (site-reported)
- Significant disease of the aorta that would preclude safe advancement of the ALLEGRA Plus THV System
- Severe ilio-femoral vessel disease that would preclude safe placement of an 18 Fr introducer sheath or make endovascular access impossible
- Porcelain aorta
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| (ALLEGRA Plus Transcatheter Heart Valve) TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesisImplantation of the ALLEGRA Plus Transcatheter Heart Valve in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis | Device | TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis |
Primary outcome
Composite of all-cause mortality or stroke rates
Time frame: 12 months
14 secondary outcomes
All-cause mortality rate
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Cardiovascular mortality rate
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Any stroke rate
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Transient ischemic attack rate
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Device success rate
Time frame: 30 days
Effective orifice area (EOA) as assessed by transthoracic echocardiogram (TTE)
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Transvalvular mean and peak pressure gradient as assessed by transthoracic echocardiogram (TTE)
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Transvalvular mean and peak pressure gradient as assessed by transthoracic
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
NYHA classification
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Life-threatening/major bleeding (BARC 3b or more)
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Major vascular complications according to VARC-3
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Early safety profile according to VARC-3
Time frame: 30 days
Quality of life as assessed using the Kansas City Cardiomyopathy Questionnaire (KCCQ-12)
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
New pacemaker implantation rate
Time frame: 7 days, 30 days, 6 months, 12 months, 2 years, 3 years , 4 years, 5 years
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Mar 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
7 sites in 5 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing (ALLEGRA Plus Transcatheter Heart Valve) TAVI in severe calcified aortic stenosis or in failed surgical aortic bioprosthesis in people with Transcatheter Aortic Valve Implantation, run by NVT GmbH at 7 sites in 5 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 32 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: paused, as of the sponsor's last update on 9 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in Poland, Spain, Finland, Germany, Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Composite of all-cause mortality or stroke rates (time frame: 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Mar 2026.