aMAZE Study: LAA Ligation Adjunctive to PVI for Persistent or Longstanding Persistent Atrial Fibrillation

Inclusion Criteria: * Documented diagnosis of symptomatic continuous persistent or longstanding persistent non-valvular atrial fibrillation * Failed at least one Class I or III Antiarrythmic drug (AAD) and therefore, eligible and intended for standard of care catheter ablation; * Life expectancy ≥ 1 year; * Willing and able to return to and comply with scheduled follow-up visits and tests; and * Willing and able to provide written informed consent Exclusion Criteria: * Prior procedure involving opening of the pericardium or entering the pericardial space (e.g., coronary artery bypass graft, heart transplantation, valve surgery) where adhesions are suspected; * Any prior epicardial ablation or any type of left-sided atrial ablation procedure; * LA diameter \> 6 cm as measured by computerized tomography and confirmed by the imaging core laboratory; * Documented embolic stroke, transient ischemic attach or suspected neurologic event within 3 months prior to the planned study intervention; * Currently exhibits New York Heart Association Class IV heart failure symptoms; * Documented history of right heart failure specifically when right ventricle exceeds the left ventricular size; * Documented history of myocardial infarction (MI) within 3 months prior to the planned study intervention; * Documented history of unstable angina within 3 months prior to the planned study intervention; * Documented history of cardiogenic shock, hemodynamic instability or any medical condition in which intra-aortic balloon pump (IABP) therapy is clinically indicated within 3 months prior to the planned study intervention; * Documented symptomatic carotid disease, defined as \> 70% stenosis or \> 50% stenosis with symptoms; * Diagnosed active local or systemic infection, septicemia or fever of unknown origin at tme of baseline screening; * Chronic renal insufficiency defined as eGFR \< 30 mL/min/1.73m2 within 3 months prior to planned study intervention; * End Stage Renal Disease (ESRD) or documented history of renal replacement / dialysis; * Current documented history of clinically significant liver disease which predisposes the subject to significant bleeding risk (clinically defined by the treating physician); * Any history of thoracic radiation with the exception of localized radiation treatment for breast cancer; * Current documented use of long-term treatment with oral corticoid steroids, not including use of inhaled steroids for respiratory diseases; * Active pericarditis; * Active endocarditis; * Any documented history or autoimmune disease associated with pericarditis; * Evidence of Pectus Excavatum (documented and clinically defined by the treating physician); * Untreated severe scoliosis (documented and clinically defined by treating physician); * Documented Left Ventricular Ejection Fraction (LVEF) \< 30% within 30 days prior to planned intervention; * Documented presence of implanted congenital defect closure devices, (e.g., atrial septal defect, patent foramen ovale or ventricular septal defect device); * Previously attempted occlusion of the left atrial appendage (by any surgical or percutaneous method); * Inability, or unwillingness or contraindication to undergo TEE or CTA imaging or 24-hour Holter monitoring; * Body Mass Index (BMI) \> 40; * Evidence of active Graves disease; * Current untreated hypothyroidism; * Any contraindication to suture, endovascular device, or other minimally invasive techniques including percutaneous, transseptal, and/or sub-xiphoid access; * Subject is pregnant or plans / desires to get pregnant within next 12 months; * Current enrollment in an investigation or study of an investigational device or investigational drug that would interfere with this study and the required follow up; * Mental impairment or other psychiatric conditions which may not allow patient to understand the nature, significance and scope of the study; * Any other criteria, medical illness or comorbidity which would make the subject unsuitable to participate in this study as determined by the clinical site Primary Investigator; Additional Exclusion Criteria: Based on Screening / Pre-procedure Imaging Subjects will also be excluded if they meet any of the following: * Based on screening computed tomography angiography performed within 90 days prior to study intervention as confirmed by the core lab: * Left atrial appendage morphology: Superior-posterior oriented left atrial appendage (i.e. superior C shape), that has Left atrial appendage distal apex extending posterior to the ostium of the appendage. * Left atrial appendage positioned behind the pulmonary artery; or * All other left atrial morphology: Left atrial appendage LARIAT approach width \> 50 mm. * Based on a peri-procedural imaging (transesophageal echocardiography) at time of LARIAT or catheter ablation) and confirmed by institution's designated LARIAT echocardiographer: * Intracardiac thrombus; or * Significant mitral valve stenosis (i.e., mitral valve stenosis \< 1.5cm2) NOTE: It is anticipated that a majority of subjects enrolled in the aMAZE Trial will be elderly US Medicare beneficiaries. Therefore, the results from the aMAZE Trial are expected to be generalizable to the Medicare population.