Nonvalvular Atrial FibrillationPhase 4NCT07125417
Non-antithrombotic Versus. Single Antiplatelet Therapy Following Left Atrial Appendage Closure
A Phase 4 study testing Non-Antithrombotic Therapy in people with Nonvalvular Atrial Fibrillation and Aspirin, run by OCEAN-SHD Study Group at 21 sites in Japan.
Trial 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… Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Nonvalvular Atrial Fibrillation, Aspirin, Non-Antithrombotic Therapy
- What is being tested?
- Non-Antithrombotic Therapy
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 500 participants
- Where
- 21 sitesJapan
- Study dates
- 29 May 2025to 31 Mar 2030
- Phase
- Phase 4
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
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- 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
- Patients with active infection
- Individuals with NYHA class related IV congestive heart failure at enrollment
- Patients who are pregnant, breastfeeding, or wishing to become pregnant
- Patients with an expected life expectancy of less than 2 years
- Patients requiring emergency surgery for any reason
- 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
- Other patients whose investigator or subinvestigator judges their participation in the study to be inappropriate
Trial locations and contacts
21 sites in 1 country. Contact the study team or a site near you to ask about taking part.
21 sites in 1 country
Japan21 sites, 21 recruiting
- Recruiting
Juntendo University Hospital
Bunkyo-ku, Tokyo, 113-8431
Shinya Okazaki, +81-3-3813-3111
Shinya Okazaki
- Recruiting
Mitsui Memorial Hospital
Chiyoda-ku, Tokyo, 101-8643
Masahiko Asami, +81-3-3862-9111
Masahiko Asami
- Recruiting
Sakakibara Heart Institute
Fuchū, Tokyo, 183-0003
Yuki Izumi, +81-42-314-3111
Yuki Izumi
- Recruiting
Gifu Heart Center
Gifu, Gifu, 500-8384
Tetsuro Shimura, +81-58-277-2277
Tetsuro Shimura
- Recruiting
Tokai University Hospital
Isehara, Kanagawa, 259-1193
Yohei Ohno, +81-463-93-1121
Yohei Ohno
- Recruiting
Teikyo University Hospital
Itabashi-ku, Tokyo, 173-8606
Yusuke Watanabe, +81-3-3964-1211
Yusuke Watanabe
- Not yet recruiting
IMS Tokyo Katsushika General Hospital
Katsushika-ku, Tokyo, 124-0025
Hirofumi Hioki, +81-3-5670-9901
Hirofumi Hioki
- Recruiting
St.Marianna University Hospital
Kawasaki, Kanagawa, 216-8511
Masaki Izumo, +81-44-977-8111
Masaki Izumo
- Recruiting
Kokura Kinen Hospital
Kitakyushu, Fukuoka, 802-8555
Shinichi Shirai, +81-93-511-2000
Shinichi Shirai
- Recruiting
Kurashiki Central Hospital
Kurashiki, Okayama-ken, 710-8602
Shunsuke Kubo, +81-86-422-0210
Shunsuke Kubo
- Recruiting
New Tokyo Hospital
Matsudo, Chiba, 270-2232
Toru Naganuma, +81-47-711-8700
Toru Naganuma
- Recruiting
Nagoya Heart Center
Nagoya, Aichi-ken, 461-0045
Atsushi Sugiura, +81-52-719-0810
Atsushi Sugiura
- Recruiting
The Sakakibara Heart Institute of Okayama
Okayama, Okayama-ken, 700-0804
Takao Morikawa, +81-86-225-7111
Takao Morikawa
- Recruiting
Kindai University Hospital
Ōsaka-sayama, Osaka, 589-8511
Gaku Nakazawa, +81-72-366-0221
Gaku Nakazawa
- Recruiting
Toho University Omori Medical Center
Ōta-ku, Tokyo, 143-8541
Mike Saji, +81-3-3762-4151
Mike Saji
- Recruiting
Medical Corporation Sapporo Heart Center Sapporo Cardio Vascular Clinic
Sapporo, Hokkaido, 007-0849
Daisuke Hachinohe, +81-11-784-7847
Daisuke Hachinohe
- Recruiting
Sapporo Higashi Tokushukai Hospital
Sapporo, Hokkaido, 065-0033
Tomoyuki Tani, +81-11-722-1110
Tomoyuki Tani
- Recruiting
Sendai Kousei Hospital
Sendai, Miyagi, 981-0914
Masaki Nakashima, +81-22-728-8000
Masaki Nakashima
- Recruiting
Keio University Hospital
Shinjuku-ku, Tokyo, 160-8582
Kentaro Hayashida, +81-3-5843-6702
Kentaro Hayashida
- Recruiting
Toyama University Hospital
Toyama, Toyama, 930-0194
Hiroshi Ueno, +81-76-434-7297
Hiroshi Ueno
- Recruiting
Toyohashi Heart Center
Toyohashi, Aichi-ken, 441-8530
Masanori Yamamoto, +81-532-37-3377
Masanori Yamamoto
About this study
Official title: Non-Antithrombotic Versus. Single antiPlatelet Therapy Following Left Atrial Appendage Closure：NAPT-LAAC Randomized Controlled Trial
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).
Read more
- 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
- Being tested
- Single Antiplatelet Therapy or No Therapy (Control), Non-Antithrombotic Therapy
- Keywords
- Left Atrial Appendage Closure, High bleeding risk, Non-Antithrombotic therapy, Aspirin, Nonvalvular Artial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
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.
Non-Antithrombotic TherapyOther
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.
| Study group | Role | What they receive |
|---|---|---|
| SAPT Arm (Single Antiplatelet Therapy Arm) | Active comparator | Not described Receives: Drug: Single Antiplatelet Therapy or No Therapy (Control) |
| NAPT Arm (Non-Antithrombotic Therapy Arm) | Experimental | Not described Receives: Other: Non-Antithrombotic Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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
Non-procedure-related was defined as occurring after 7 days after the LAAC procedure.
It will be assessed throughout the entire study period, as well as from the day following Visit 1 (occurring 46 to 60 days post-randomization) until the end of the study.
Measured: 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
Not related to the procedure refers to events occurring 7 days after the LAAC procedure.
It will be assessed throughout the entire study period, as well as from the day following Visit 1 (occurring 46 to 60 days post-randomization) until the end of the study.
Measured: 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)
Measured: 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
It will be assessed throughout the entire study period, as well as from the day following Visit 1 (occurring 46 to 60 days post-randomization) until the end of the study.
Measured: Through study completion, maximum of four years, with a minimum follow-up period of two years from the time of randomization.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Aug 2025
- Study start29 May 2025
- Primary completion31 May 2029 (estimated)
- Study completion31 Mar 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Nonvalvular Atrial FibrillationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- OCEAN-SHD Study Group
- Sponsor type
- University, hospital or other
- Collaborators
- Boston Scientific Corporation
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07125417
- Sponsor's protocol ID
- NAPT-LAAC trial
- Status last verified
- Aug 2025
- First submitted
- 24 Jul 2025
- Last updated
- 15 Aug 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Otsuka T, Yamamoto M, Asami M, Naganuma T, Ohno Y, Tani T, Nakazawa G, Izumo M, Saji M, Hachinohe D, Ueno H, Sugiura A, Shimura T, Okazaki S, Morikawa T, Izumi Y, Nakashima M, Kubo S, Shirai S, Watanabe Y, Hayashida K, Of The Ocean-Laac Investigators OB. No antithrombotic therapy versus single antiplatelet therapy after percutaneous left atrial appendage closure in non-valvular atrial fibrillation: rationale and design of the multicentre, randomised, non-inferiority NAPT-LAAC trial. EuroIntervention. 2026 Apr 20;22(8):e455-e462. doi: 10.4244/EIJ-D-25-01307.
PubMed 42003301