Severe Aortic Valve StenosisPOP ATLANTISNCT06168370
Personalized, CT-guided Antithrombotic Therapy Versus Lifelong Single Antiplatelet Therapy to Reduce Thromboembolic and Bleeding Events in Non-atrial Fibrillation Patients After Transcatheter Aortic Valve Implantation
A study testing CT guided strategy in people with Severe Aortic Valve Stenosis, run by St. Antonius Hospital at 1 site in Netherlands.
Trial summary
The POPular ATLANTIS trial aims to investigate CT-guided antithrombotic therapy compared to lifelong single antiplatelet therapy after a transcatheter aortic valve implantation (TAVI) procedure. Only patients without an indication for anticoagulants will be included in this trial. Read more about this study
- Who is it for?
- Ages 18 to 110 years
- Conditions the study is for
- Severe Aortic Valve Stenosis
- What is being tested?
- CT guided strategy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 2,500 participants
- Where
- 1 siteNetherlands
- Study dates
- 1 Dec 2023to 1 Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 to 110 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Successful TAVI (according to the VARC-3 criteria)10 with any approved device
- Ability to understand and to comply with the study protocol
- Written informed consent
Who cannot join
- Existing indication for oral anticoagulation (e.g. atrial fibrillation, obstructive valve thrombosis detected by echocardiography prior to inclusion)
- Existing indication for dual antiplatelet therapy at three months after TAVI (rare at this time point)
- Creatinine clearance <15 mL/min (based on the CKD-EPI formula) or on renal replacement therapy
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Netherlands1 site, 1 recruiting
- Recruiting
St. Antonius Hospital
Nieuwegein
Jurrien ten berg, MD PhD
About this study
Official title: Personalized, CT-guided Antithrombotic Therapy Versus Lifelong Single Antiplatelet Therapy to Reduce Thromboembolic and Bleeding Events in Non-atrial Fibrillation Patients After Transcatheter Aortic Valve Implantation: a Pragmatic, International, Multicentre, Randomized Clinical Trial
The POPular ATLANTIS trial aims to investigate CT-guided antithrombotic therapy compared to lifelong single antiplatelet therapy after a transcatheter aortic valve implantation (TAVI) procedure. Only patients without an indication for anticoagulants will be included in this trial. Currently, lifelong single antiplatelet therapy (mostly aspirin) is considered the standard of care for these patients. However, this approach poses a bleeding risk with only a minimal reduction in thromboembolic events.
After 3 months, a CT scan will be conducted to assess the presence of thrombosis on the newly implanted TAVI valve. Based on the results of a 4D CT scan, the decision will be made whether the patient should receive no anticoagulant or antithrombotic therapy with apixaban. CT-guided antithrombotic therapy holds the potential for a greater reduction in thromboembolic events without increasing the bleeding risk.
- Conditions
- Severe Aortic Valve Stenosis
- Being tested
- CT guided strategy
- Keywords
- aortic stenosis, bleeding, tavi, ct, personalized antithrombotic therapy, tavr
- Medical subject headings
- Aortic Valve Stenosis, Hemorrhage
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CT guided strategyRadiation
- With signs of subclinical valve thrombosis on 4D-CT at 3 months after TAVI are switched from SAPT to apixaban. Patients fulfilling the dose reduction criteria according to the drug label, or with a Clinical Frailty Scale ≥4 will receive 2.5mg bid, patients not meeting these criteria will receive a standard dose of 5mg bid.
- Without signs of subclinical valve thrombosis on 4D-CT at 3 months after TAVI, without another indication for antiplatelet therapy stop their SAPT.
- Without signs of subclinical valve thrombosis on 4D-CT at 3 months after TAVI with another indication for antiplatelet therapy continue life-long SAPT.
| Study group | Role | What they receive |
|---|---|---|
| CT guided strategy | Experimental | The intervention group will undergo CT scan after 3 months. If subclinical valve thrombosis is detected, anticoagulation will be started. If no subclinical valve thrombosis is detected, the SAPT is stopped, unless another indication is present. Receives: Radiation: CT guided strategy |
| Standard care | No intervention | Standard of care with lifelong SAPT after TAVI |
What is being measured
The primary outcome is the main question the study is designed to answer.
Thromboembolic events
Composite of cardiovascular death, ischaemic stroke, transient ischaemic attack, myocardial infarction, systemic embolism and clinically significant valve thrombosis according to the VARC-3 criteria
Measured: Through study completion, a median of 2.5 years
All bleeding
Defined as the composite of type 1-4 bleeding, according to the VARC-3 criteria
Measured: Through study completion, a median of 2.5 years
Secondary outcomes (11)
Net clinical benefit, defined as the composite of cardiovascular mortality, stroke, transient ischaemic attack, systemic embolism, clinically significant valve thrombosis and type 1-4 bleeding according to the VARC-3 criteria
Measured: Through study completion, a median of 2.5 years
Major bleeding (VARC-3 type 2-4)
Measured: Through study completion, a median of 2.5 years
Cerebrovascular events (All stroke and TIA according to VARC-3)
Measured: Through study completion, a median of 2.5 years
Cardiovascular mortality
Measured: Through study completion, a median of 2.5 years
All-cause mortality
Measured: Through study completion, a median of 2.5 years
Aortic bio-prosthetic valve dysfunction assessed by echocardiography yearly after TAVI (standard care), as assessed according the VARC-3 criteria for Bioprosthetic Valve Dysfunction.
Bioprosthetic Valve Dysfunction can be split into 'Structural Valve Deterioration' Non-Structural Valve Dysfunction', 'Thrombosis' and 'Endocarditis'. For exact definitions of the sub-groups, VARC-3 criteria can be consulted.
Measured: Through study completion, a median of 2.5 years
Quality of life as assessed by EuroQol- 5 Dimension 5 Level (EQ-5D-5L) at baseline, 3 and 12 months, and then yearly after TAVI procedure.
The EQ-5D-5L is a standardized health-related quality of life instrument that assesses individuals across five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. It generates a health profile that can be converted into a single index value, commonly ranging from -0.594 to 1, where 1 represents full health, 0 indicates a state equivalent to death, and negative values reflect health states perceived as worse than death.
Measured: Through study completion, a median of 2.5 years
Quality of life as assessed by Kansas City Cardiomyopathy Questionnaire (KCCQ) at baseline, 3 and 12 months, and then yearly after TAVI procedure.
The Kansas City Cardiomyopathy Questionnaire (KCCQ) is a disease-specific instrument assessing heart failure patients across domains such as Total Symptoms, Physical Limitation, and Quality of Life, with scores ranging from 0 to 100. Higher scores indicate better health-related quality of life, while lower scores suggest increased symptomatology and functional limitations in heart failure patients.
Measured: Through study completion, an median of 2.5 years
Quality of life as assessed by Short Form Health Survey (SF-12) at baseline, 3 and 12 months, and then yearly after TAVI procedure.
The Short Form 12 (SF-12) is a widely used health survey that measures health-related quality of life across physical and mental domains. It generates two summary scores, the Physical Component Summary (PCS) and the Mental Component Summary (MCS), both ranging from 0 to 100, where higher scores indicate better health status, and these summaries provide a concise assessment of an individual's overall physical and mental well-being.
Measured: Through study completion, a median of 2.5 years
Medication adherence as assessed by the Medication Adherence Report Scale (MARS-5) yearly after randomization.
The Medication Adherence Report Scale (MARS) is a self-report questionnaire designed to assess medication adherence in patients. It consists of five items, and scores range from 1 to 5 for each item, with higher scores indicating better medication adherence. Interpretation involves understanding that higher total scores on the MARS reflect a higher level of adherence to prescribed medications.
Measured: Through study completion, a median of 2.5 years
Cost-effectiveness assassment of a CT-guided antithrombotic strategy after TAVI using EQ-5D-5L
The EQ-5D-5L questionnaire measures health status across five dimensions, providing a standardized index value that is widely used in cost-effectiveness analyses, particularly for estimating Quality-Adjusted Life Years (QALYs) and assessing the impact of healthcare interventions on health-related quality of life.
Measured: Through study completion, a median of 2.5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Dec 2023
- Study start1 Dec 2023
- Primary completion1 Dec 2028 (estimated)
- Study completion1 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Severe Aortic Valve StenosisStudies 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
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 2,500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- St. Antonius Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- ZonMw: The Netherlands Organisation for Health Research and Development, Pitié-Salpêtrière Hospital
- Responsible party
- Principal investigator, Jurriën M. ten Berg, MD, PhD, St. Antonius Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06168370
- Sponsor's protocol ID
- 2023-504637-42-01
- Other IDs
- 2023
- Acronym
- POP ATLANTIS
- Status last verified
- May 2026
- First submitted
- 20 Oct 2023
- Last updated
- 19 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 19 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Personalized, CT-guided Antithrombotic Therapy Versus Lifelong Single Antiplatelet Therapy to Reduce Thromboembolic and Bleeding Events in Non-atrial Fibrillation Patients After Transcatheter Aortic Valve Implantation: a Pragmatic, International, Multicentre, Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT06168370
- Acronym / sponsor ID
- POP ATLANTIS / 2023-504637-42-01
- Conditions
- Severe Aortic Valve Stenosis
- Keywords
- aortic stenosis, bleeding, tavi, ct, personalized antithrombotic therapy, tavr
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 2,500 participants (estimated)
- Lead sponsor
- St. Antonius HospitalUniversity, hospital or other
- Collaborators
- ZonMw: The Netherlands Organisation for Health Research and Development, Pitié-Salpêtrière Hospital
- Study start
- 1 Dec 2023 (actual)
- Primary completion
- 1 Dec 2028 (estimated)
- Study completion
- 1 Dec 2028 (estimated)
- First posted
- 13 Dec 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 POPular ATLANTIS trial aims to investigate CT-guided antithrombotic therapy compared to lifelong single antiplatelet therapy after a transcatheter aortic valve implantation (TAVI) procedure. Only patients without an indication for anticoagulants will be included in this trial. Currently, lifelong single antiplatelet therapy (mostly aspirin) is considered the standard of care for these patients. However, this approach poses a bleeding risk with only a minimal reduction in thromboembolic events.
After 3 months, a CT scan will be conducted to assess the presence of thrombosis on the newly implanted TAVI valve. Based on the results of a 4D CT scan, the decision will be made whether the patient should receive no anticoagulant or antithrombotic therapy with apixaban. CT-guided antithrombotic therapy holds the potential for a greater reduction in thromboembolic events without increasing the bleeding risk.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CT guided strategy | Experimental | Radiation: CT guided strategyThe intervention group will undergo CT scan after 3 months. If subclinical valve thrombosis is detected, anticoagulation will be started. If no subclinical valve thrombosis is detected, the SAPT is stopped, unless another indication is present. |
| Standard care | No intervention | –Standard of care with lifelong SAPT after TAVI |
Who may qualify
- Ages
- 18 to 110 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Successful TAVI (according to the VARC-3 criteria)10 with any approved device
- Ability to understand and to comply with the study protocol
- Written informed consent
Key exclusion criteria (3 listed)
- Existing indication for oral anticoagulation (e.g. atrial fibrillation, obstructive valve thrombosis detected by echocardiography prior to inclusion)
- Existing indication for dual antiplatelet therapy at three months after TAVI (rare at this time point)
- Creatinine clearance <15 mL/min (based on the CKD-EPI formula) or on renal replacement therapy
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 |
|---|---|---|
| CT guided strategy1. With signs of subclinical valve thrombosis on 4D-CT at 3 months after TAVI are switched from SAPT to apixaban. Patients fulfilling the dose reduction criteria according to the drug label, or with a Clinical Frailty Scale ≥4 will receive 2.5mg bid, patients not meeting these criteria will receive a standard dose of 5mg bid. 2. Without signs of subclinical valve thrombosis on 4D-CT at 3 months after TAVI, without another indication for antiplatelet therapy stop their SAPT. 3. Without signs of subclinical valve thrombosis on 4D-CT at 3 months after TAVI with another indication for antiplatelet therapy continue life-long SAPT. | Radiation | CT guided strategy |
Primary outcome
Thromboembolic events
Time frame: Through study completion, a median of 2.5 years
Composite of cardiovascular death, ischaemic stroke, transient ischaemic attack, myocardial infarction, systemic embolism and clinically significant valve thrombosis according to the VARC-3 criteria
All bleeding
Time frame: Through study completion, a median of 2.5 years
Defined as the composite of type 1-4 bleeding, according to the VARC-3 criteria
11 secondary outcomes
Net clinical benefit, defined as the composite of cardiovascular mortality, stroke, transient ischaemic attack, systemic embolism, clinically significant valve thrombosis and type 1-4 bleeding according to the VARC-3 criteria
Time frame: Through study completion, a median of 2.5 years
Major bleeding (VARC-3 type 2-4)
Time frame: Through study completion, a median of 2.5 years
Cerebrovascular events (All stroke and TIA according to VARC-3)
Time frame: Through study completion, a median of 2.5 years
Cardiovascular mortality
Time frame: Through study completion, a median of 2.5 years
All-cause mortality
Time frame: Through study completion, a median of 2.5 years
Aortic bio-prosthetic valve dysfunction assessed by echocardiography yearly after TAVI (standard care), as assessed according the VARC-3 criteria for Bioprosthetic Valve Dysfunction.
Time frame: Through study completion, a median of 2.5 years
Quality of life as assessed by EuroQol- 5 Dimension 5 Level (EQ-5D-5L) at baseline, 3 and 12 months, and then yearly after TAVI procedure.
Time frame: Through study completion, a median of 2.5 years
Quality of life as assessed by Kansas City Cardiomyopathy Questionnaire (KCCQ) at baseline, 3 and 12 months, and then yearly after TAVI procedure.
Time frame: Through study completion, an median of 2.5 years
Quality of life as assessed by Short Form Health Survey (SF-12) at baseline, 3 and 12 months, and then yearly after TAVI procedure.
Time frame: Through study completion, a median of 2.5 years
Medication adherence as assessed by the Medication Adherence Report Scale (MARS-5) yearly after randomization.
Time frame: Through study completion, a median of 2.5 years
Cost-effectiveness assassment of a CT-guided antithrombotic strategy after TAVI using EQ-5D-5L
Time frame: Through study completion, a median of 2.5 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 May 2026.
- Individual participant dataSharing planned: Undecided
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing CT guided strategy in people with Severe Aortic Valve Stenosis, run by St. Antonius Hospital at 1 site in Netherlands.
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 3 inclusion and 3 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: looking for participants now, as of the sponsor's last update on 19 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Netherlands. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Christiaan Overduin (+31883200931, c.overduin@antoniusziekenhuis.nl), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Thromboembolic events (time frame: Through study completion, a median of 2.5 years). The study lists 2 primary outcomes in all. 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 19 May 2026.