Severe Aortic StenosisNCT05493657
Aspirin vs Clopidogrel After TAVR
A study testing Aspirin single antiplatelet therapy and Clopidogrel single antiplatelet therapy in people with Severe Aortic Stenosis, run by Yonsei University at 1 site in South Korea.
Trial summary
Currently, the optimal antithrombotic therapy after transcatheter aortic valve replacement (TAVR) remains still unknown., The purpose of the study is to compare aspirin versus clopidogrel monoantiplatelet therapy for preventive effect on leaflet thrombosis in patients undergoing TAVR for severe aortic stenosis. Read more about this study
- Who is it for?
- Ages 19 years and older
- Conditions the study is for
- Severe Aortic Stenosis
- What is being tested?
- Aspirin single antiplatelet therapy and Clopidogrel single antiplatelet therapy
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 270 participants
- Where
- 1 siteSouth Korea
- Study dates
- 2 Feb 2023to 21 Jul 2027
- 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 19 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients >19 years old
- Patients who underwent TAVR symptomatic severe AS
- Provision of informed consent
Who cannot join
- Patients requiring dual antiplatelet therapy longer than 4 weeks
- Any conditions requiring specific antiplatelet therapy aspirin or clopidogrel
- History of stroke or transient ischemic attack (TIA) within 6 months
- Planned major surgery
- Cardiogenic shock or hemodynamic instability
- Chronic kidney disease stage 4 or 5 (eGFR <30mL/min)
Show all 9Show fewer
- Valve-in-valve TAVR procedure
- Hypersensitivity or contraindication to aspirin or clopidogrel
- Indication for anticoagulation therapy
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
South Korea1 site, 1 recruiting
- Recruiting
Yonsei University Health System, Severance Hospital
Seoul
Young-Guk Ko, MD, PhD, 82-2-2228-8460, ygko@yuhs.ac
About this study
Official title: Aspirin Versus Clopidogrel for Leaflet Thrombosis Prevention in Patients Undergoing Transcatheter Aortic Valve Replacement: ACLO-TAVR Trial
Currently, the optimal antithrombotic therapy after transcatheter aortic valve replacement (TAVR) remains still unknown., The purpose of the study is to compare aspirin versus clopidogrel monoantiplatelet therapy for preventive effect on leaflet thrombosis in patients undergoing TAVR for severe aortic stenosis. This study is designed as a prospective, multicenter, open label, randomized controlled study. Eligible patients will be randomized to aspirin or clopidogrel monotherapy after TAVR. Patients will have dual antiplatelet therapy of aspirin 100 mg and clopidogrel 75 mg for 4 weeks after TAVR and then subsequent monoantiplatelet therapy of either aspirin 100 mg or clopidogrel 75 mg according to the randomization. Leaflet thrombosis will be assessed with cardiac computed tomography (CT) and transthoracic echocardiography at 3 months after TAVR. Patients will be clinically followed for 6 months. The primary endpoint is the Incidence of leaflet thrombosis on cardiac CT at 3 months.
Read the detailed description
- Prospective, multicenter, open label, randomized controlled study
- Eligible patients will be randomized to aspirin or clopidogrel monotherapy after TAVR
- All patients will have dual antiplatelet therapy of aspirin 100 mg and clopidogrel 75 mg for 4 weeks after TAVR and then subsequent monoantiplatelet therapy of either aspirin 100 mg or clopidogrel 75 mg.
- Leaflet thrombosis will be assessed with cardiac computed tomography (CT) and transthoracic echocardiography at 3 months after TAVR
- Clinical follow-up up to 6 months
- Conditions
- Severe Aortic Stenosis
- Being tested
- Aspirin single antiplatelet therapy, Clopidogrel single antiplatelet therapy
- 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.
Aspirin single antiplatelet therapyDrug
Patients receive the aspirin (100 mg/day) single antiplatelet therapy after 4 weeks of dual antiplatelet therapy of aspirin (100 mg/day) and clopidogrel (75 mg/day) after TAVR.
Clopidogrel single antiplatelet therapyDrug
Patients receive the clopidogrel (75 mg/day) single antiplatelet therapy after 4 weeks of dual antiplatelet therapy of aspirin (100 mg/day) and clopidogrel (75 mg/day) after TAVR.
| Study group | Role | What they receive |
|---|---|---|
| Aspirin group | Active comparator | Patients receive the aspirin (100 mg/day) single antiplatelet therapy after 4 weeks of dual antiplatelet therapy of aspirin (100 mg/day) and clopidogrel (75 mg/day) after TAVR. Receives: Drug: Aspirin single antiplatelet therapy |
| Clopidogrel group | Experimental | Patients receive the clopidogrel (75 mg/day) single antiplatelet therapy after 4 weeks of dual antiplatelet therapy of aspirin (100 mg/day) and clopidogrel (75 mg/day) after TAVR. Receives: Drug: Clopidogrel single antiplatelet therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of leaflet thrombosis
Incidence of leaflet thrombosis on cardiac CT at 3 months after TAVR
Measured: At 3 months after TAVR
Secondary outcomes (10)
Any stroke
Measured: 3 months and 6 months after TAVR
Ischemic Stroke
Measured: 3 months and 6 months after TAVR
Transient ischemic attack
Measured: 3 months and 6 months after TAVR
Thromboembolic events (composite of any stroke, myocardial infarction, systemic embolism (not involving the central nervous system), deep-vein thrombosis, or pulmonary embolism)
Measured: 3 months and 6 months after TAVR
Echocardiographic parameters (maximum and mean aortic valve pressure gradient)
Measured: at 3 months after TAVR
Echocardiographic parameters (doppler velocity index)
Measured: at 3 months after TAVR
Echocardiographic parameters (paravalvular regurgitation)
Measured: at 3 months after TAVR
Echocardiographic parameters (leaflet thrombosis)
Measured: at 3 months after TAVR
VARC-3 type 3 or 4 bleeding
Measured: 3 months and 6 months after TAVR
VARC-3 type 2 bleeding
Measured: 3 months and 6 months after TAVR
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Aug 2022
- Study start2 Feb 2023
- Primary completion21 Jul 2026 (estimated)
- Study completion21 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Severe Aortic StenosisStudies of the same condition, open and under way.
- More trials run by Yonsei UniversityThe 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
- 270 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yonsei University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Young-Guk Ko, MD, PhD, Principal investigator, Division of Cardiology, Yonsei Cardiovascular Hospital, Yonsei University College of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05493657
- Sponsor's protocol ID
- 4-2022-0744
- Status last verified
- Jun 2026
- First submitted
- 8 Aug 2022
- Last updated
- 30 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Aspirin Versus Clopidogrel for Leaflet Thrombosis Prevention in Patients Undergoing Transcatheter Aortic Valve Replacement: ACLO-TAVR Trial
- ClinicalTrials.gov ID
- NCT05493657
- Acronym / sponsor ID
- 4-2022-0744
- Conditions
- Severe Aortic Stenosis
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 270 participants (estimated)
- Lead sponsor
- Yonsei UniversityUniversity, hospital or other
- Study start
- 2 Feb 2023 (actual)
- Primary completion
- 21 Jul 2026 (estimated)
- Study completion
- 21 Jul 2027 (estimated)
- First posted
- 9 Aug 2022 (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.
Currently, the optimal antithrombotic therapy after transcatheter aortic valve replacement (TAVR) remains still unknown., The purpose of the study is to compare aspirin versus clopidogrel monoantiplatelet therapy for preventive effect on leaflet thrombosis in patients undergoing TAVR for severe aortic stenosis. This study is designed as a prospective, multicenter, open label, randomized controlled study. Eligible patients will be randomized to aspirin or clopidogrel monotherapy after TAVR. Patients will have dual antiplatelet therapy of aspirin 100 mg and clopidogrel 75 mg for 4 weeks after TAVR and then subsequent monoantiplatelet therapy of either aspirin 100 mg or clopidogrel 75 mg according to the randomization. Leaflet thrombosis will be assessed with cardiac computed tomography (CT) and transthoracic echocardiography at 3 months after TAVR. Patients will be clinically followed for 6 months. The primary endpoint is the Incidence of leaflet thrombosis on cardiac CT at 3 months.
Detailed description
- Prospective, multicenter, open label, randomized controlled study
- Eligible patients will be randomized to aspirin or clopidogrel monotherapy after TAVR
- All patients will have dual antiplatelet therapy of aspirin 100 mg and clopidogrel 75 mg for 4 weeks after TAVR and then subsequent monoantiplatelet therapy of either aspirin 100 mg or clopidogrel 75 mg.
- Leaflet thrombosis will be assessed with cardiac computed tomography (CT) and transthoracic echocardiography at 3 months after TAVR
- Clinical follow-up up to 6 months
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Aspirin group | Active comparator | Drug: Aspirin single antiplatelet therapyPatients receive the aspirin (100 mg/day) single antiplatelet therapy after 4 weeks of dual antiplatelet therapy of aspirin (100 mg/day) and clopidogrel (75 mg/day) after TAVR. |
| Clopidogrel group | Experimental | Drug: Clopidogrel single antiplatelet therapyPatients receive the clopidogrel (75 mg/day) single antiplatelet therapy after 4 weeks of dual antiplatelet therapy of aspirin (100 mg/day) and clopidogrel (75 mg/day) after TAVR. |
Who may qualify
- Ages
- 19 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients >19 years old
- Patients who underwent TAVR symptomatic severe AS
- Provision of informed consent
Key exclusion criteria (9 listed)
- Patients requiring dual antiplatelet therapy longer than 4 weeks
- Any conditions requiring specific antiplatelet therapy aspirin or clopidogrel
- History of stroke or transient ischemic attack (TIA) within 6 months
- Planned major surgery
- Cardiogenic shock or hemodynamic instability
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 |
|---|---|---|
| Aspirin single antiplatelet therapyPatients receive the aspirin (100 mg/day) single antiplatelet therapy after 4 weeks of dual antiplatelet therapy of aspirin (100 mg/day) and clopidogrel (75 mg/day) after TAVR. | Drug | Aspirin group |
| Clopidogrel single antiplatelet therapyPatients receive the clopidogrel (75 mg/day) single antiplatelet therapy after 4 weeks of dual antiplatelet therapy of aspirin (100 mg/day) and clopidogrel (75 mg/day) after TAVR. | Drug | Clopidogrel group |
Primary outcome
Incidence of leaflet thrombosis
Time frame: At 3 months after TAVR
Incidence of leaflet thrombosis on cardiac CT at 3 months after TAVR
10 secondary outcomes
Any stroke
Time frame: 3 months and 6 months after TAVR
Ischemic Stroke
Time frame: 3 months and 6 months after TAVR
Transient ischemic attack
Time frame: 3 months and 6 months after TAVR
Thromboembolic events (composite of any stroke, myocardial infarction, systemic embolism (not involving the central nervous system), deep-vein thrombosis, or pulmonary embolism)
Time frame: 3 months and 6 months after TAVR
Echocardiographic parameters (maximum and mean aortic valve pressure gradient)
Time frame: at 3 months after TAVR
Echocardiographic parameters (doppler velocity index)
Time frame: at 3 months after TAVR
Echocardiographic parameters (paravalvular regurgitation)
Time frame: at 3 months after TAVR
Echocardiographic parameters (leaflet thrombosis)
Time frame: at 3 months after TAVR
VARC-3 type 3 or 4 bleeding
Time frame: 3 months and 6 months after TAVR
VARC-3 type 2 bleeding
Time frame: 3 months and 6 months after TAVR
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 30 Jun 2026.
- Individual participant dataSharing planned: No
Related trials for Severe Aortic Stenosis
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Not yet recruitingPhase 4
Application of TAVI at Experienced Interventional Cardiac Centers Without On-site Cardiac Surgery (ATLAS Study)
Aortic Stenosis, Severe Aortic Stenosis
RecruitingObservational study
PERFECT - Portuguese Evolut Registry Studying the Outcomes of Medtronic Evolut™ FX+ TAVI System by Evaluating an Optimal Care Pathway for TAVI
Severe Symptomatic Aortic Stenosis (Defined as New York Heart Association (NYHA) Class ≥ II)
Recruiting
A Study to Obtain Imaging Data in 40 Patients Having Transcatheter Aortic Valve Implantation (TAVI)
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Recruiting
ALLIANCE: Safety and Effectiveness of the SAPIEN X4 Transcatheter Heart Valve
Aortic Stenosis, Severe
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.
Young-Guk Ko, MD, PhD principal investigator
Division of Cardiology, Yonsei Cardiovascular Hospital, Yonsei University College of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Aspirin single antiplatelet therapy and Clopidogrel single antiplatelet therapy in people with Severe Aortic Stenosis, run by Yonsei University at 1 site in South Korea.
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 9 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 30 Jun 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 South Korea. 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 Young-Guk Ko, MD, PhD (82-2-2228-8460, ygko@yuhs.ac), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of leaflet thrombosis (time frame: At 3 months after TAVR). 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 30 Jun 2026; AzTrials last refreshed its copy on 31 Oct 2026.