No blood-thinners versus aspirin after left atrial appendage closure

Non-Antithrombotic Versus. Single antiPlatelet Therapy Following Left Atrial Appendage Closure：NAPT-LAAC Randomized Controlled Trial

This trial tests whether skipping antithrombotic drugs after left atrial appendage closure (using only 45 days of oral anticoagulant) is as safe and effective as taking aspirin for people with nonvalvular atrial fibrillation who are at high bleeding risk.

Quick facts

• Phase: Phase 4
• Study type: Interventional
• Enrollment: 500 (estimated)
• Sex: All
• Sponsor: OCEAN-SHD Study Group (Academic / other)
• Locations: 21 sites (Nagoya, Aichi-ken and 20 other locations)
• Trial ID: NCT07125417 on ClinicalTrials.gov

What this trial studies

Adults with nonvalvular atrial fibrillation and high bleeding risk who undergo successful left atrial appendage closure are randomized 1:1 to either single antiplatelet therapy with aspirin or a non-antithrombotic strategy with a short course of oral anticoagulant for 45 days. Enrollment occurs up to the day after the LAAC procedure and participants are followed for up to four years. The primary outcome is a composite of all-cause death, myocardial infarction, stroke, systemic embolism, major bleeding, or clinically relevant non-fatal bleeding from randomization through the observation period. The trial focuses on patients whose LAA anatomy accommodates the WATCHMAN FLX Pro device and who meet predefined safety and follow-up requirements.

Who should consider this trial

Good fit: Ideal candidates are people with nonvalvular atrial fibrillation (CHA2DS2-VA ≥2) who had a successful LAAC with no significant residual leak (>3 mm), are judged suitable for the study medication regimens, and can attend required follow-up visits.

Not a fit: Patients with mechanical heart valves or severe mitral stenosis, those with significant residual LAA leak after the procedure, those with low bleeding risk, or those unable to follow the medication or visit schedule are unlikely to benefit from this approach.

Why it matters

Potential benefit: If successful, patients at high bleeding risk could avoid long-term antithrombotic drugs and reduce bleeding complications without increasing risk of stroke or death.

How similar studies have performed: Smaller and observational studies have suggested less intensive antithrombotic strategies after LAAC may be safe, but randomized comparisons specifically of no antithrombotic therapy versus single antiplatelet therapy remain limited.

Eligibility criteria

Inclusion Criteria:

1. Patient has documented non-valvular atrial fibrillation (i.e, atrial fibrillation without severe mitral stenosis or mechanical valves)
2. Patient has CHA2DS2-VA score of 2 or greater
3. Patient meets the guidelines for proper use of the left atrial appendage closure system including patient who has an increased risk of bleeding.
4. Individual with nonvalvular atrial fibrillation who underwent successful LAAC (defined as no significant residual circumferential leak \[\>3 mm\] or major morbidity by the time of procedure completion).
5. Patient suitable for pharmacotherapy as defined in this study protocol in both NAPT and SAPT arms
6. LAA anatomy is accommodate Boston Scientific WATCHMAN FLX Pro and LAAC procedure
7. The patient and the investigator and/or subinvestigator agree that the patient will return for all required VISITs after LAAC procedure
8. Patient has thoroughly understood the purpose of the study and has provided written informed consent to participate in the study

Exclusion Criteria:

1. Patients who are currently enrolled in other clinical trials, except when the patient is participating in a mandatory governmental registries or purely observational registries with no associated treatment.
2. Individuals require long-term anticoagulation therapy for reasons other than atrial fibrillation (AF)-related stroke risk reduction (e.g.,thrombophilic conditions, previous pulmonary embolism, or deep venous thrombosis).
3. Patients requiring oral antiplatelet therapy for reasons other than LAAC (e.g.,history of myocardial infarction, history of endovascular treatment, history of stroke/transient ischemic attack, significant coronary stenosis proven by myocardial ischemia, severe carotid stenosis requiring invasive treatment,hematologic disease such as antiphospholipid syndrome or if the investigator and/or subinvestigator judged the need for antiplatelet therapy).
4. Patients who meet one or more of the following criteria

   * Patients who are contraindicated for DOAC or VKA
   * Patients with a contraindication to aspirin
   * Patients diagnosed with an allergy to aspirin
5. Those who have or are scheduled to undergo cardiac or noncardiac intervention or surgery 45 days or 60 days before or after LAAC (e.g.,cardioversion, PCI, cardiac ablation, cataract surgery, other structural heart interventions).
6. Patients with stroke (either ischemic or hemorrhagic) or transient ischemic attack within 30 days prior to enrollment
7. Patients with active bleeding
8. Individuals who lack LAA or whose LAA has been surgically ligated
9. Individuals who experienced a myocardial infarction (with or without intervention) recorded as a non-ST elevation myocardial infarction or ST elevation myocardial infarction in the 30-day period prior to enrollment
10. Patients with previous atrial septal repair or with atrial septal defect/patent foramen ovale device
11. Patients with mechanical valve prostheses at any site
12. Persons with known contraindications to TEE
13. Patients with active infection
14. Individuals with NYHA class related IV congestive heart failure at enrollment
15. Patients who are pregnant, breastfeeding, or wishing to become pregnant
16. Patients with an expected life expectancy of less than 2 years
17. Patients requiring emergency surgery for any reason
18. Patients who, at the discretion of the investigator, have other medical, social, or psychological conditions that preclude adherence to appropriate consent or the follow-up tests required by the protocol
19. Other patients whose investigator or subinvestigator judges their participation in the study to be inappropriate

Where this trial is running

Nagoya, Aichi-ken and 20 other locations

• Nagoya Heart Center — Nagoya, Aichi-ken, Japan (Recruiting)
• Toyohashi Heart Center — Toyohashi, Aichi-ken, Japan (Recruiting)
• New Tokyo Hospital — Matsudo, Chiba, Japan (Recruiting)
• Kokura Kinen Hospital — Kitakyushu, Fukuoka, Japan (Recruiting)
• Gifu Heart Center — Gifu, Gifu, Japan (Recruiting)
• Medical Corporation Sapporo Heart Center Sapporo Cardio Vascular Clinic — Sapporo, Hokkaido, Japan (Recruiting)
• Sapporo Higashi Tokushukai Hospital — Sapporo, Hokkaido, Japan (Recruiting)
• Tokai University Hospital — Isehara, Kanagawa, Japan (Recruiting)
• St.Marianna University Hospital — Kawasaki, Kanagawa, Japan (Recruiting)
• Sendai Kousei Hospital — Sendai, Miyagi, Japan (Recruiting)
• Kurashiki Central Hospital — Kurashiki, Okayama-ken, Japan (Recruiting)
• The Sakakibara Heart Institute of Okayama — Okayama, Okayama-ken, Japan (Recruiting)
• Kindai University Hospital — Ōsaka-sayama, Osaka, Japan (Recruiting)
• Juntendo University Hospital — Bunkyo-ku, Tokyo, Japan (Recruiting)
• Mitsui Memorial Hospital — Chiyoda-ku, Tokyo, Japan (Recruiting)
• Sakakibara Heart Institute — Fuchū, Tokyo, Japan (Recruiting)
• Teikyo University Hospital — Itabashi-ku, Tokyo, Japan (Recruiting)
• IMS Tokyo Katsushika General Hospital — Katsushika-ku, Tokyo, Japan (Not_yet_recruiting)
• Toho University Omori Medical Center — Ōta-ku, Tokyo, Japan (Recruiting)
• Keio University Hospital — Shinjuku-ku, Tokyo, Japan (Recruiting)
• Toyama University Hospital — Toyama, Toyama, Japan (Recruiting)

Study contacts

• Study coordinator: EPS Corporation

Conditions Nonvalvular Atrial Fibrillation; Aspirin; Non-Antithrombotic Therapy; High Bleeding Risk; Left Atrial Appendage Closure; High bleeding risk; Non-Antithrombotic therapy; Nonvalvular Artial Fibrillation