Non-antithrombotic Versus. Single Antiplatelet Therapy Following Left Atrial Appendage Closure

NCT07125417 | Recruiting Phase 4 DMC

• 1 other identifier: NAPT-LAAC trial
• Study Type: interventional
• Target: 500
• Locations: 1 country
• Sites: 21

Brief Summary

The goal of this clinical trial is to verify that Non-Antithrombotic Therapy (NAPT) followed by Oral Anticoagulants (OAC) monotherapy for 45 days after Left Atrial Appendage Closure (LAAC) is non-inferior to Single Antiplatelet Therapy (SAPT) with aspirin during the period from randomization to the end of observational period (4 years at the maximum) in non-valvular atrial fibrillation subjects with high bleeding risk. The primary endpoint is a composite endpoint consisting of all-cause mortality, myocardial infarction, stroke, systemic embolism, major bleeding, or clinically relevant non-fatal bleeding from randomization to the end of study observation (up to a maximum follow-up of 4 years).

• Participants will be enrolled in this study until the day following the implementation of LAAC and will be randomized to the SAPT arm and NAPT arm in a 1:1 ratio.
• Participants will be observed for 4 years from the time the first subject is enrolled in this study.
• Participants will visit the hospital at 45 days, 1 year, and 2 years after enrollment, and will also be followed up by telephone, basically at the end of the observation period (up to a maximum follow-up of 4 years). \<Study treatment duration\> In both arms, OAC monotherapy will be initiated in the first 24 hours of enrollment and continued for 45 days (allowed window period: plus 2 weeks)..
• SAPT arm will continue to receive 45 days of OAC monotherapy followed by low-dose aspirin (75～100 mg/day) as an antithrombotic agent required through the end of the study observation period.
• NAPT arm do not receive antithrombotic medication after 45 days of OAC monotherapy through the end of the study observation period.

Conditions

Nonvalvular Atrial Fibrillation; Aspirin; Non-Antithrombotic Therapy; High Bleeding Risk; Left Atrial Appendage Closure

Keywords

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

Outcome Measures

Primary Outcomes (1)

• A composite endpoint consisting of all-cause mortality, myocardial infarction, stroke, systemic embolism, major bleeding, or clinically relevant non-fatal bleeding

  The definition of major bleeding or clinically significant nonfatal bleeding for the primary endpoint is BARC type 2, 3, or 5 bleeding among BARC type 1, 2, 3, 4, and 5. Surviving cases with no events shall be censored as of the date of discontinuation of study treatment or the date of last confirmation of survival. Planned enrollment term is two years, and all subjects will be obsserved until 4 years after first enrollment.

  Through study completion, maximum of four years, with a minimum follow-up period of two years from the time of randomization.

Secondary Outcomes (4)

• Non-procedure-related BARC bleeding events of Type 1 or greater

  Through study completion, maximum of four years, with a minimum follow-up period of two years from the time of randomization.

• ISTH major bleeding not related to the procedure and clinically relevant non-fatal bleeding

  Through study completion, maximum of four years, with a minimum follow-up period of two years from the time of randomization.

• Incidence of device-related thrombus (DRT) detected by CT and/or transesophageal echocardiography (TEE)

  at Visit 1 (46~60days after randomization), 1 year, and 2 years after randomization

• Combined endpoint consisting of the occurrence of ischemic stroke and systemic embolism

  Through study completion, maximum of four years, with a minimum follow-up period of two years from the time of randomization.

Study Arms (2)

SAPT Arm (Single Antiplatelet Therapy Arm)

ACTIVE COMPARATOR

Drug: Single Antiplatelet Therapy or No Therapy (Control)

NAPT Arm (Non-Antithrombotic Therapy Arm)

EXPERIMENTAL

Other: Non-Antithrombotic Therapy

Interventions

Single Antiplatelet Therapy or No Therapy (Control) DRUG

Monotherapy with oral anticoagulants (OAC) including direct oral anticoagulants (DOAC) and vitamin K antagonist oral anticoagulants (VKA) for 45 days after left atrial appendage closure (LAAC), followed by aspirin-directed antiplatelet monotherapy (Single Antiplatelet Therapy: SAPT) through the end of the observational period.

SAPT Arm (Single Antiplatelet Therapy Arm)

Non-Antithrombotic Therapy OTHER

Monotherapy with OAC for 45 days after LAAC, followed by no antithrombotic therapy (Non-Antithrombotic Therapy: NAPT) from enrollment through the end of the observational period.

NAPT Arm (Non-Antithrombotic Therapy Arm)

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Patient has documented non-valvular atrial fibrillation (i.e, atrial fibrillation without severe mitral stenosis or mechanical valves)
• Patient has CHA2DS2-VA score of 2 or greater
• Patient meets the guidelines for proper use of the left atrial appendage closure system including patient who has an increased risk of bleeding.
• 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).
• Patient suitable for pharmacotherapy as defined in this study protocol in both NAPT and SAPT arms
• LAA anatomy is accommodate Boston Scientific WATCHMAN FLX Pro and LAAC procedure
• The patient and the investigator and/or subinvestigator agree that the patient will return for all required VISITs after LAAC procedure
• Patient has thoroughly understood the purpose of the study and has provided written informed consent to participate in the study

You may not qualify if:

• 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.
• 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).
• 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).
• 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
• 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).
• Patients with stroke (either ischemic or hemorrhagic) or transient ischemic attack within 30 days prior to enrollment
• Patients with active bleeding
• Individuals who lack LAA or whose LAA has been surgically ligated
• 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
• Patients with previous atrial septal repair or with atrial septal defect/patent foramen ovale device
• Patients with mechanical valve prostheses at any site
• Persons with known contraindications to TEE

Sponsors & Collaborators

• OCEAN-SHD Study Group: lead
• Boston Scientific Corporation: collaborator

Study Sites (21)

Nagoya Heart Center

Nagoya, Aichi-ken, 461-0045, Japan

RECRUITING

Toyohashi Heart Center

Toyohashi, Aichi-ken, 441-8530, Japan

RECRUITING

New Tokyo Hospital

Matsudo, Chiba, 270-2232, Japan

RECRUITING

Kokura Kinen Hospital

Kitakyushu, Fukuoka, 802-8555, Japan

RECRUITING

Gifu Heart Center

Gifu, Gifu, 500-8384, Japan

RECRUITING

Medical Corporation Sapporo Heart Center Sapporo Cardio Vascular Clinic

Sapporo, Hokkaido, 007-0849, Japan

RECRUITING

Sapporo Higashi Tokushukai Hospital

Sapporo, Hokkaido, 065-0033, Japan

RECRUITING

Tokai University Hospital

Isehara, Kanagawa, 259-1193, Japan

RECRUITING

St.Marianna University Hospital

Kawasaki, Kanagawa, 216-8511, Japan

RECRUITING

Sendai Kousei Hospital

Sendai, Miyagi, 981-0914, Japan

RECRUITING

Kurashiki Central Hospital

Kurashiki, Okayama-ken, 710-8602, Japan

RECRUITING

The Sakakibara Heart Institute of Okayama

Okayama, Okayama-ken, 700-0804, Japan

RECRUITING

Kindai University Hospital

Ōsaka-sayama, Osaka, 589-8511, Japan

RECRUITING

Juntendo University Hospital

Bunkyo-ku, Tokyo, 113-8431, Japan

RECRUITING

Mitsui Memorial Hospital

Chiyoda-ku, Tokyo, 101-8643, Japan

RECRUITING

Sakakibara Heart Institute

Fuchū, Tokyo, 183-0003, Japan

RECRUITING

Teikyo University Hospital

Itabashi-ku, Tokyo, 173-8606, Japan

RECRUITING

IMS Tokyo Katsushika General Hospital

Katsushika-ku, Tokyo, 124-0025, Japan

NOT YET RECRUITING

Toho University Omori Medical Center

Ōta-ku, Tokyo, 143-8541, Japan

RECRUITING

Keio University Hospital

Shinjuku-ku, Tokyo, 160-8582, Japan

RECRUITING

Toyama University Hospital

Toyama, Toyama, 930-0194, Japan

RECRUITING

Central Study Contacts

EPS Corporation

CONTACT

+81-6-7176-5731; prj-laac-napt@eps.co.jp

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 24, 2025
• First Posted: August 15, 2025
• Study Start: May 29, 2025
• Primary Completion (Estimated): May 31, 2029
• Study Completion (Estimated): March 31, 2030
• Last Updated: August 15, 2025

Record last verified: 2025-08

Locations

JP (21)