Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 4INTERVENTIONAL

Optimal Antiplatelet Therapy Following Left Atrial Appendage Closure

Q: Who can participate in NCT03445949?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

Q: How do I contact the trial site for NCT03445949?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Q: Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Q: Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

Optimal Antiplatelet Treatment to Achieve Stroke Avoidance and Fall in Bleeding Events Following Left Atrial Appendage Closure (SAFE-LAAC). Comparative Health Effectiveness Randomized Trial - PILOT Study

Optimal Antiplatelet Therapy Following Left Atrial Appendage Closure (NCT03445949) is a Phase 4 interventional studying Atrial Fibrillation, sponsored by National Institute of Cardiology, Warsaw, Poland. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

SAFE-LAAC Trial has been designed to gather data on the most optimal strategy of antiplatelet therapy after transcatheter left atrial appendage occlusion with Amplatzer or WATCHMAN device

What Stage of Research Is This?

Phase 4 studies happen after a treatment has been approved by the FDA. They monitor long-term safety, real-world effectiveness, and any rare side effects that only emerge in larger populations over longer periods. Phase 4 results sometimes lead to label changes, additional warnings, or — rarely — withdrawal of approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 200 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Atrial Fibrillation subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: - Successful left atrial appendage occlusion with Amplatzer or WATCHMAN device within 37 days before randomization - Treatment with dual antiplatelet therapy (clopidogrel and acetylsalicylic acid) between left atrial appendage closure and randomization - Participant's age 18 years or older at the time of signing the willing to sign a consent form form - Participant is willing to follow all study procedures; especially the randomized antiplatelet treatment regimen - Participant is willing to sign the study willing to sign a consent form form Who Should NOT Join This Trial: - Indications to dual antiplatelet therapy other than atrial fibrillation and/or left atrial appendage occlusion at the time of enrollment or predicted appearance of such indications within the duration of the trial (e.g. planned coronary revascularization) - Indications to anticoagulation at the time of enrollment and/or predicted appearance of such indications within the duration of the trial (e.g. pulmonary embolism) - Known allergy to clopidogrel and/or acetylsalicylic acid precluding its administration as specified by the protocol - Any known inborn or acquired coagulation disorders - Peridevice leak \>5mm on imaging study preceding enrollment - Left atrial thrombus on an imaging study performed after successful left atrial appendage closure but before enrollment - Life expectancy of fewer than 18 months - Participation in other clinical studies with experimental therapies at the time of enrollment and preceding 3 months - Chronic kidney disease stage IV and V - Women who are pregnant or breastfeeding; women of childbearing potential who do not consent to apply at least two methods of contraception. This criterion does not apply to women 2 years post menopause (with negative pregnancy test 24 hours prior to randomization if \<55 years old) or after surgical sterilization Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * Successful left atrial appendage occlusion with Amplatzer or WATCHMAN device within 37 days before randomization * Treatment with dual antiplatelet therapy (clopidogrel and acetylsalicylic acid) between left atrial appendage closure and randomization * Participant's age 18 years or older at the time of signing the informed consent form * Participant is willing to follow all study procedures; especially the randomized antiplatelet treatment regimen * Participant is willing to sign the study informed consent form Exclusion Criteria: * Indications to dual antiplatelet therapy other than atrial fibrillation and/or left atrial appendage occlusion at the time of enrollment or predicted appearance of such indications within the duration of the trial (e.g. planned coronary revascularization) * Indications to anticoagulation at the time of enrollment and/or predicted appearance of such indications within the duration of the trial (e.g. pulmonary embolism) * Known allergy to clopidogrel and/or acetylsalicylic acid precluding its administration as specified by the protocol * Any known inborn or acquired coagulation disorders * Peridevice leak \>5mm on imaging study preceding enrollment * Left atrial thrombus on an imaging study performed after successful left atrial appendage closure but before enrollment * Life expectancy of fewer than 18 months * Participation in other clinical studies with experimental therapies at the time of enrollment and preceding 3 months * Chronic kidney disease stage IV and V * Women who are pregnant or breastfeeding; women of childbearing potential who do not consent to apply at least two methods of contraception. This criterion does not apply to women 2 years post menopause (with negative pregnancy test 24 hours prior to randomization if \<55 years old) or after surgical sterilization

Treatments Being Tested

DRUG

short postimplantation dual antiplatelet therapy

continuing dual antiplatelet therapy up until 6 months after left atrial appendage occlusion with Amplatzer or WATCHMAN device

DRUG

extended postimplantation dual antiplatelet therapy

stopping dual antiplatelet therapy after 30 days after left atrial appendage occlusion with Amplatzer or WATCHMAN device

DRUG

long-term treatment with a single antiplatelet agent

continuing long-term treatment with single antiplatelet agent

DRUG

6 months treatment with a single antiplatelet agent

continuing single antiplatelet agent up until 6 months

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

National Institute of Cardiology

Warsaw, Masovian Voivodeship, Poland

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT03445949), the sponsor (National Institute of Cardiology, Warsaw, Poland), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT03445949 clinical trial studying?

SAFE-LAAC Trial has been designed to gather data on the most optimal strategy of antiplatelet therapy after transcatheter left atrial appendage occlusion with Amplatzer or WATCHMAN device The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT03445949?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT03445949?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT03445949. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT03445949. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.