This is an early feasibility study is to evaluate the safety and effectiveness of the Laminar Left Atrial Appendage Closure System to treat patients with non-valvular atrial fibrillation that cannot take, or a have a reason to seek an alternative, to anticoagulant medications.

Left atrial appendage closure (LAAC) is an approved therapy for stroke prevention in atrial fibrillation patients who are recommended for chronic oral anticoagulation therapy (OAC), but are non-eligible or have an appropriate rationale to seek a non-pharmacologic alternative to chronic oral anticoagulants in accordance with evidence-based decision-making criteria and current scientific guidelines.

The objective of this study is to evaluate the safety and effectiveness of the Laminar Left Atrial Appendage Closure System to treat patients with non-valvular atrial fibrillation who are deemed appropriate for LAAC to reduce the risk of stroke and systemic embolism.

Patients will be followed for 5 years after the procedure.

Inclusion Criteria:

• Documented non-valvular atrial fibrillation (AF), defined as AF (paroxysmal, persistent, or permanent) in the absence of moderate-to-severe mitral stenosis or a mechanical heart valve
• Participant greater than or equal to (>=)18 years old
• CHA2DS2-VASc score >=2 in men and >= 3 in women
• Participant is recommended for chronic oral anticoagulation therapy (OAC) but is not eligible or has an appropriate rationale to seek a non-pharmacologic alternative to chronic OAC
• Participant deemed appropriate for LAA closure by the Site Heart Team using an evidenced based decision-making tool
• Participant eligible for the protocol-specified post-procedural antithrombotic regimen
• Participant or Legally Authorized Representative informed of the nature of the study, is willing and able to comply with the protocol, and has provided written informed consent per Institutional Review Board (IRB) requirements

Exclusion Criteria:

• Single episode, transient, or reversible AF (for example, secondary thyroid disorders, acute alcohol intoxication, trauma, recent major surgical procedures)
• Stroke or transient ischemic attack within 90 days before the index procedure
• Myocardial infarction or unstable angina within 90 days before the index procedure
• Renal insufficiency, defined as estimated glomerular filtration rate (eGFR) less than (<)30 milliliters per minute (mL/min)/1.73 sqaure meter (m^2), or dialysis at the time of screening
• Active infection with bacteremia
• Confirmed coronavirus disease 2019 (COVID-19) infection within 10 days before the index procedure Coexisting Cardiovascular Disease
• Cardiac tumor
• History of mitral valve or other severe cardiac valvular disease requiring intervention or presence of prosthetic mechanical valve
• Medical condition (other than AF) that mandates chronic oral anticoagulation (e.g., history of unprovoked deep vein thrombosis or pulmonary embolism, or mechanical heart valve)
• Severe heart failure (New York Heart Association Class IV)
• Symptomatic carotid artery disease (greater than [>] 50 percent [%] diameter reduction with prior ipsilateral stroke or transient ischemic attack [TIA]) or asymptomatic carotid artery disease (diameter reduction of >70%) Previous or Planned Interventions
• Previous AF ablation procedure in the 90 days before the index procedure date or need for AF ablation to be performed in less than 90 days after the index procedure
• Recent (within 30 days before the index procedure) or planned (within 60 days after the index procedure) cardiac or non-cardiac interventional or surgical procedure
• Intracardiac thrombus or dense spontaneous echo contrast visualized by transesophageal echocardiographic (TEE) within 2 days before the index procedure
• Left ventricular ejection fraction (LVEF) <30%
• Circumferential pericardial effusion >10 mm or symptomatic pericardial effusion, signs or symptoms of acute or chronic pericarditis, or evidence of tamponade physiology
• Complex atheroma with mobile plaque of the aorta
• Interatrial communication, atrial septal defect, or patent foramen ovale that warrants closure
• Vascular access precluding delivery of implant with catheter-based system
• Presence of inferior vena cava (IVC) filter that would interfere with Laminar sheath insertion
• Participant unable to undergo general anesthesia
• Participant with condition which precludes adequate TEE assessment
• Known allergy, hypersensitivity or contraindication to aspirin, heparin, or device materials (e.g., nickel, titanium)
• Contrast sensitivity that cannot be adequately pre-medicated
• Thrombocytopenia , thrombocytosis, or leukopenia values as specified in protocol
• Pregnant or nursing and those who plan pregnancy in the period up to 1 year following the index procedure. Participants of childbearing potential must have a negative pregnancy test (per site standard test) within 7 days before index procedure
• Known other medical illness or known history of substance abuse that may cause non-compliance with the protocol or protocol-specified medication regimen, confound the data interpretation, or is associated with a life expectancy of less than 1 year
• Current participation in another investigational drug or device study that in the opinion of the investigator could confound the data interpretation

The data sharing policy of Johnson & Johnson Innovative Medicine is available at www.innovativemedicine.jnj.com/our-innovation/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu.