Optimal PeriproCeduraL AnticOagulation in Structural Transseptal Interventions (STOP CLOT)

September 14, 2026 updated by: National Institute of Cardiology, Warsaw, Poland

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Enrolling by invitation

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
410

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Poland
      • Gdansk, Poland, 80-952
        • Uniwersyteckie Centrum Kliniczne Gdański Uniwersytet Medyczny
      • Katowice, Poland
        • Górnośląskie Centrum Medyczne im. Leszka Gieca Śląskiego Uniwersytetu Medycznego
      • Lublin, Poland
        • Samodzielny Publiczny Szpital Kliniczny nr 4 w Lublinie
      • Poznan, Poland, 60-355
        • Uniwersytecki Szpital Kliniczny W Poznaniu
      • Warsaw, Poland
        • Uniwersyteckie Centrum Kliniczne Warszawskiego Uniwersytetu Medycznego

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

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

Exclusion Criteria:

  1. 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.
  2. Any diagnosed, acquired, or congenital bleeding or coagulation disorders (e.g., diagnosed thrombophilia, bleeding diatheses).
  3. INR > 1.5 within 24 hours prior to the procedure in patients chronically treated with vitamin K antagonists.
  4. Last dose of non-vitamin K antagonist oral anticoagulant (NOAC) < 48 hours before the procedure, in patients receiving NOAC therapy.
  5. Last dose of low-molecular-weight heparin (LMWH) < 12 hours before the procedure, in patients receiving LMWH therapy.
  6. Presence of contraindications to brain magnetic resonance imaging (e.g., claustrophobia, metallic implants/prostheses).

  7. 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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: 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.
Other: early anticoagulation
Anticoagulation prior to transseptal puncture
Active Comparator: 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.
Other: late anticoagulation
Anticoagulation after transseptal puncture

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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
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.
Within 30 days from the index procedure

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Moderate and severe bleeding complications (BARC 2-5) including cardiac tamponade requiring intervention during the index hospitalization
Time Frame: during the hospitalization related to the index procedure but up to 30 days from randomization
during the hospitalization related to the index procedure but up to 30 days from randomization
Occurrence of new ischemic brain lesion in the MR examination performed within 2-5 days post index procedure.
Time Frame: within 2-5 days post index procedure
within 2-5 days post index procedure
Intraprocedural fresh thrombus formation in the right or left atrium as assessed with periprocedural transsesophageal echocardiography
Time Frame: during index procedure
during index procedure
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.
Time Frame: within 30 days from index procedure
within 30 days from index procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
National Institute of Cardiology, Warsaw, Poland

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Medical Research Agency, Poland
Soft Communication, Poland

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jerzy Pręgowski, MD, PhD, National Institute of Cardiology

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 13, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 14, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 28, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 31, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ABM/2020/1/00002

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

to be defined

IPD Sharing Time Frame

IPD sharing will be considered after study completion and publication of the results.

IPD Sharing Access Criteria

to be defined

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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