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Study of acetylsalicylic acid and clopidogrel treatment duration after left atrial appendage closure in patients with atrial fibrillation

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on patients with atrial fibrillation who have undergone a procedure called left atrial appendage closure, which helps prevent blood clots in the heart. The study examines two blood-thinning medications: acetylsalicylic acid (commonly known as aspirin) and clopidogrel, which are used to prevent blood clots after the procedure.

The purpose of this research is to determine the safest and most effective way to use these blood-thinning medications after the closure procedure. The study compares different durations of treatment: some patients will take both medications for 30 days and then continue with just one medication for 6 months, while others will take both medications for the full 6 months.

The medications are taken by mouth once daily, with each tablet containing 75 mg of either acetylsalicylic acid or clopidogrel. The study will monitor patients for any heart-related events and bleeding complications to determine which treatment approach provides the best balance of preventing blood clots while minimizing bleeding risks.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial medication phase

    After successful left atrial appendage closure (a procedure to prevent blood clots in the heart), you will receive two medications:

    - Acetylsalicylic acid (aspirin) taken by mouth

    - Clopidogrel taken by mouth

    Both medications need to be taken daily for the first 30 days after the procedure

  2. Step 2

    Medication adjustment period

    After the first 30 days, you will be assigned to one of two groups:

    Group 1: Continue taking only one blood-thinning medication (either aspirin or clopidogrel) until 6 months after the procedure

    Group 2: Continue taking both medications (aspirin and clopidogrel) for 6 months after the procedure

  3. Step 3

    Long-term treatment phase

    After 6 months, you will either:

    - Continue taking one blood-thinning medication, or

    - Stop all blood-thinning medications

    This phase will continue until the end of the study period

  4. Step 4

    Monitoring period

    Throughout the study, you will be monitored for:

    - Any signs of stroke or mini-stroke

    - Heart-related events

    - Any bleeding events

    The total duration of the study continues until December 31, 2027

Who can join the trial?

6 criteria

  • Had successful left atrial appendage closure (a heart procedure to prevent blood clots) with either Amplatzer or WATCHMAN devices within the past 37 days
  • Currently taking dual antiplatelet therapy (two blood-thinning medications - aspirin and clopidogrel) since the procedure
  • Age 18 years or older
  • Willing to follow all study requirements, including:
    • Taking medications as assigned by the study
    • Attending all follow-up visits
    • Able and willing to provide written informed consent

Who cannot join the trial?

15 criteria

  • Age below 18 years or above 90 years
  • Unable to provide informed consent
  • Active bleeding or high risk of bleeding that prevents use of blood-thinning medications
  • Known allergies to antiplatelet medications (medications that prevent blood clots)
  • Severe kidney disease requiring dialysis
  • Life expectancy less than 12 months
  • Pregnancy or breastfeeding
  • Recent major surgery within the last 30 days
  • History of blood clotting disorders
  • Participation in another clinical trial within the past 30 days
  • Active infection or inflammation that could affect the procedure
  • Significant heart valve disease
  • Previous stroke within the last 30 days
  • Uncontrolled high blood pressure (blood pressure that remains high despite treatment)
  • Active cancer requiring treatment
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Investigated drugs

Based on the trial information provided, the medications involved are: Aspirin - A common antiplatelet medication that helps prevent blood clots by making platelets less sticky. It's used to reduce the risk of stroke and other cardiovascular events. Clopidogrel - An antiplatelet medication that works differently from aspirin to prevent blood clots. When used together with aspirin, it's called dual antiplatelet therapy (DAPT). The trial compares different durations of antiplatelet therapy after a Left Atrial Appendage Closure (LAAC) procedure, using either single antiplatelet therapy (SAPT) with one medication or dual antiplatelet therapy (DAPT) with both medications together.

What is already known about the treatment

  • Dual Antiplatelet Therapy (DAPT)

    A combination therapy typically consisting of aspirin and a P2Y12 inhibitor, administered orally to prevent blood clots in patients with atrial fibrillation who have undergone left atrial appendage closure. This treatment approach is currently well-established in medical practice and is supported by extensive clinical research for preventing thrombotic events. The therapy works by inhibiting platelet aggregation through two different molecular pathways, providing more complete protection against blood clot formation than single antiplatelet therapy.

  • Single Antiplatelet Therapy (SAPT)

    A treatment approach using a single antiplatelet medication, typically aspirin or a P2Y12 inhibitor, taken orally to prevent blood clots while potentially reducing bleeding risks compared to dual therapy. This therapy is widely used in cardiovascular medicine and works by blocking one specific pathway of platelet activation and aggregation. SAPT represents a less aggressive but still effective approach to preventing thrombotic events in patients who have undergone left atrial appendage closure procedures.

Investigated diseases

Atrial fibrillation - A heart rhythm disorder where the upper chambers of the heart beat irregularly and out of sync with the lower chambers. This condition occurs when the heart's electrical signals become chaotic, causing an irregular and often rapid heartbeat. The irregular rhythm can cause blood to pool in the heart chambers, which affects the heart's ability to pump blood efficiently. The condition can be persistent or come and go in episodes. Atrial fibrillation often causes symptoms like heart palpitations, shortness of breath, and fatigue. People may experience different levels of symptoms, from barely noticeable to very pronounced.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-516382-37-00Protocol code2.52/IV/16Estimated enrolment200 patientsSponsorNarodowy Instytut Kardiologii Stefana Kardynala Wyszynskiego Panstwowy Instytut Badawczy

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