Left Atrial Appendage CLOSURE in Patients With Atrial Fibrillation Compared to Medical Therapy

Inclusion Criteria: * Signed written informed consent * Documented atrial fibrillation (paroxysmal, persistent, long-standing persistent or permanent) * CHA2DS2VASc-Score ≥2 * High risk of bleeding under oral anticoagulation or contraindication for (N)OAC therapy, in particular patients with at least one of the following conditions: * HAS-BLED-Score ≥3 * Prior intracranial/intraspinal bleed, intraocular bleed compromising vision (BARC: type 3c) * Hemorrhagic/bleeding complication fulfilling BARC type 3a or 3b: gastrointestinal tract, genitourinary tract or respiratory tract bleeding, where the patient is considered to be at a persistently increased risk of bleeding, e.g. the cause of bleeding cannot be successfully eliminated * Chronic kidney disease with eGFR 15-29 ml/min/1.73 m2 * Any recurrent bleeding making chronic anticoagulation not feasible * Subject eligible for an LAA occluder device * Age ≥18 years * Willing and capable of providing informed consent, participating in all associated study activities * negative SARS-CoV-2 PCR test (no longer than 48 hours prior to randomization in outpatients or not older than 14 days in continuously hospitalized patients without signs of COVID-19 infection) or negative SARS- CoV-2 rapid antigen test (no longer than 24 hours prior to randomization) Exclusion Criteria: * Absolute contraindication to acetylsalicylic acid * Comorbidities other than AF requiring chronic (N)OAC therapy, e.g. mechanical heart valve prosthesis * Symptomatic carotid disease (if not treated) * Complex aortic atheroma with mobile plaque (Kronzon classification grade V) * Heart transplant * Active infection or symptoms suggestive of COVID-19 infection or active endocarditis or other infections resulting in bacteremia * Cardiac tumor * Severe liver failure (Child-Pugh class C or liver failure with coagulopathy) * Severe renal failure (GFR \<15 ml/min/1.73m2 or current requirement for dialysis defined as current, regular renal replacement therapy performed at least weekly including hemodialysis and peritoneal dialysis within the last 30 days) * Pregnancy or breastfeeding * For female patients of reproductive potential: Unwilling to agree to use a highly effective method of contraception (Pearl index \<1) throughout the study period * Subject with participation in another interventional clinical trial during this study or within 30 days before entry into this trial. * Known terminating disease with life expectancy \<1 year (including those with end-stage heart failure) * Subjects, who are committed to an institution due to binding official or court order * Subject who is dependent on the Site, the Site Investigator, any sub- investigator, his/her representative and/or the sponsor * Persons who are not proficient in the German language * Unstable/not fully recompensated acute heart failure corresponding to NYHA class III and/or IV * Subjects with known antiphospholipid syndrome * Subjects with planned cardiac or non-cardiac surgery or intervention. (These subject can be included 30 days after such intervention / surgery.)