AzTrials
AzTrials

Mitral RegurgitationPhase 4STOP CLOTNCT05305612

Optimal PeriproCeduraL AnticOagulation in Structural Transseptal Interventions

A Phase 4 study testing early anticoagulation and late anticoagulation in people with Mitral Regurgitation and Atrial Fibrillation, run by National Institute of Cardiology, Warsaw, Poland at 5 sites in Poland.

Enrolling by invitation

Enrolling by invitation. The study team selects and invites participants, usually from an existing group of patients.

Sites and contacts
Official record
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Trial summary

The transcatheter edge to edge mitral valve repair (TEER) and left atrial appendage closure (LAAC) are the interventional cardiology procedures that require periprocedural anticoagulation with unfractionated heparin (UFH). Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
early anticoagulation and late anticoagulation
Type of treatment
Injection or infusion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
410 participants
Where
5 sitesPoland
Study dates
13 Mar 2022to Mar 2027
Phase
Phase 4
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 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age ≥ 18 years on the day of signing the informed consent form.
  • Planned treatment of mitral regurgitation using the TEER technique (MitraClip or Pascal system) or planned left atrial appendage closure (Watchman system or Amplatzer system).
  • The participant expresses willingness to comply with the study protocol, in particular the protocol-defined follow-up visits.
  • The participant is willing to provide written informed consent to participate in the study.

Who cannot join

  • Pregnant or lactating women, and women of childbearing potential who do not agree to use at least two methods of contraception (oral contraceptives, barrier methods, approved contraceptive implants, injectable depot contraceptives, intrauterine devices, or tubal ligation). This does not apply to women who are postmenopausal (≥ 1 year from last menses) for ≥ 2 years AND, if < 55 years old, have a negative pregnancy test within 24 hours prior to randomization, or have undergone surgical sterilization.
  • Any diagnosed, acquired, or congenital bleeding or coagulation disorders (e.g., diagnosed thrombophilia, bleeding diatheses).
  • INR > 1.5 within 24 hours prior to the procedure in patients chronically treated with vitamin K antagonists.
  • Last dose of non-vitamin K antagonist oral anticoagulant (NOAC) < 48 hours before the procedure, in patients receiving NOAC therapy.
  • Last dose of low-molecular-weight heparin (LMWH) < 12 hours before the procedure, in patients receiving LMWH therapy.
  • Presence of contraindications to brain magnetic resonance imaging (e.g., claustrophobia, metallic implants/prostheses).
Show all 14Show fewer
  • Presence of cardiac implantable electronic devices (implantable cardioverter-defibrillator [ICD], permanent pacemaker, or cardiac resynchronization therapy [CRT] system) in the following situations:
  • Epicardial leads
  • Left disconnected leads or non-functional or damaged devices
  • Devices implanted within abdominal wall
  • Pacemaker dependent patients (Lack of escape rhythm > 30 bpm).
  • Patients in whom less than 6 weeks have elapsed since system implantation or replacement.
  • Patients in whom pre-MRI system interrogation reveals abnormalities in system function or cardiac arrhythmias that, in the opinion of the supervising electrophysiology team, could compromise MRI safety.
  • Patients whose device battery on the day of the MRI examination has less than 20% voltage between nominal and ERI, or the projected device longevity is less than 1 year.

Trial locations and contacts

5 sites in 1 country. Contact the study team or a site near you to ask about taking part.

5 sites in 1 country

Poland5 sites

  • Uniwersyteckie Centrum Kliniczne Gdański Uniwersytet Medyczny

    Gdansk, 80-952

  • Górnośląskie Centrum Medyczne im. Leszka Gieca Śląskiego Uniwersytetu Medycznego

    Katowice

  • Samodzielny Publiczny Szpital Kliniczny nr 4 w Lublinie

    Lublin

  • Uniwersytecki Szpital Kliniczny w Poznaniu

    Poznan, 60-355

  • Uniwersyteckie Centrum Kliniczne Warszawskiego Uniwersytetu Medycznego

    Warsaw

Other trials in Poland

About this study

Official title: Strategy To Optimize PeriproCeduraL AnticOagulation in Structural Transseptal Interventions

The transcatheter edge to edge mitral valve repair (TEER) and left atrial appendage closure (LAAC) are the interventional cardiology procedures that require periprocedural anticoagulation with unfractionated heparin (UFH). The UFH is administered either before or immediately after transseptal puncture, at the discretion of the operator

The aim of the study is to establish the optimal timing of initiation of periprocedural anticoagulation in patients undergoing structural heart interventions requiring transseptal puncture (TEER and LAAC), Patients who undergo TEER implantation or LAAC procedure will be randomized to two groups:

  1. Early UFH administration. The iv. bolus of UFH (100Units/kg) will be given after obtained femoral vein access and at least 5 minutes prior to the start of the TSP.
  2. Late UFH administration. The iv. bolus of UFH (100Units/kg) will be given immediately after TSP, defined as the introduction of transseptal sheath into the left atrium.
Being tested
early anticoagulation, late anticoagulation
Medical subject headings
Mitral Valve Insufficiency, Atrial Fibrillation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • early anticoagulationOther

    Anticoagulation prior to transseptal puncture

  • late anticoagulationOther

    Anticoagulation after transseptal puncture

Study groups in NCT05305612
Study groupRoleWhat they receive
Early UFH administrationExperimentalThe iv. bolus of UFH (100Units/kg) will be given after obtained femoral vein access and at least 5 minutes prior to the start of the TSP.
Receives: Other: early anticoagulation
Late UFH administrationActive comparatorThe iv. bolus of UFH (100Units/kg) will be given immediately after TSP, defined as the introduction of transseptal sheath into the left atrium.
Receives: Other: late anticoagulation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. 1. MACCE 2. Intraprocedural fresh thrombus formation in the right or left atrium as assessed with periprocedural transsesophageal echocardiography 3. Occurrence of new ischemic lesions with diameter ≥4 mm in brain MR performed 2-5 days after procedure

    Major adverse cardiac and cerebrovascular events (MACCE) will include: death (all-cause and cardiovascular), stroke, TIA, non-fatal myocardial infarction or peripheral embolization, within 30 days from the index procedure.

    Measured: Within 30 days from the index procedure

Secondary outcomes (4)

  1. Moderate and severe bleeding complications (BARC 2-5) including cardiac tamponade requiring intervention during the index hospitalization

    Measured: during the hospitalization related to the index procedure but up to 30 days from randomization

  2. Intraprocedural fresh thrombus formation in the right or left atrium as assessed with periprocedural transsesophageal echocardiography

    Measured: during index procedure

  3. Occurrence of new ischemic brain lesion in the MR examination performed within 2-5 days post index procedure.

    Measured: within 2-5 days post index procedure

  4. Major adverse cardiac and cerebrovascular events death (all-cause and cardiovascular), stroke, TIA, non-fatal myocardial infarction or peripheral embolization, within 30 days from the index procedure.

    Measured: within 30 days from index procedure

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted31 Mar 2022
  2. Study start13 Mar 2022
  3. Primary completionJan 2027 (estimated)
  4. Study completionMar 2027 (estimated)

Resources

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 4
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Patients will be randomized to: Early unfractionated heparin administration. The iv. bolus of UFH (100Units/kg) will be given after obtained femoral vein access and at least 5 minutes prior to the start of the TSP. Late unfractionated heparin administration. The iv. bolus of UFH (100Units/kg) will be given immediately after TSP, defined as the introduction of transseptal sheath into the left atrium.
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
410 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05305612
Sponsor's protocol ID
ABM/2020/1/00002
Acronym
STOP CLOT
Status last verified
Sep 2026
First submitted
14 Mar 2022
Last updated
17 Sep 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: to be defined

Publications

  • Pregowski J, Pracon R, Mioduszewska A, Skowronski J, Sondergaard L, Mintz GS, Capodanno D, Kim SW, De Baker O, Wacinski P, Wojakowski W, Rdzanek A, Grygier M, Chmielecki M, Franco LN, Stoklosa P, Firek B, Marczak M, Milosz B, Chmielak Z, Demkow M, Witkowski A. Strategy to optimize PeriproCeduraL AnticOagulation in structural transseptal interventions: Design and rationale of the STOP CLOT trial. Am Heart J. 2024 May;271:68-75. doi: 10.1016/j.ahj.2024.02.015. Epub 2024 Feb 22.

    PubMed 38401649

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing early anticoagulation and late anticoagulation in people with Mitral Regurgitation and Atrial Fibrillation, run by National Institute of Cardiology, Warsaw, Poland at 5 sites in Poland.

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 4 inclusion and 14 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: enrolling by invitation, as of the sponsor's last update on 17 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 5 sites in Poland. 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.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

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?

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?

1. MACCE 2. Intraprocedural fresh thrombus formation in the right or left atrium as assessed with periprocedural transsesophageal echocardiography 3. Occurrence of new ischemic lesions with diameter ≥4 mm in brain MR performed 2-5 days after procedure (time frame: Within 30 days from the index procedure). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05305612, which also lists 1 linked publication.

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 17 Sep 2026.

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