"Left Atrial Appendage Occlusion and Biomarker Evaluation" (LABEL) is a single-center, prospective and observational study evaluating changes of the expression of biomarkers in eligible patients before and after percutaneous implantation of a left atrial appendage (LAA) occlusion device at mid-term follow-up.

This study will evaluate the changes of different types of biomarkers before and after successful percutaneous implantation of an LAA occlusion device.

Biomarker evaluation will focus on blood derived biomarkers including neurohormones, proteins, cytokines, microRNAs and metabolomics.

Inclusion Criteria:

• non valvular atrial fibrillation, that makes anticoagulation to prevent embolic stroke from the LAA
• contraindication for the therapy with oral anticoagulants:
• refusal to take oral anticoagulation
• HasBled-score more than 3
• prior bleedings under oral anticoagulation

Exclusion Criteria:

• under 18 years
• severely reduced left atrial function
• mechanical heart valve
• pulmonary embolism
• deep vein thrombosis
• myocardial infarction within the last 3 months
• electrical cardioversion within 30 days after potential occluder implantation
• atrial septum defect or interventional/surgical occlusion of ASD
• status after heart transplant
• symptomatic carotid artery stenosis
• transient ischemic attack (TIA) or stroke within last 30 days
• intracerebral bleeding within the last 2 months
• acute infection
• existing or planned pregnancy

Patients suffering from non valvular atrial fibrillation with a contraindication for oral anticoagulation (i.e. bleeding) being eligible of percutaneous implantation of LAA occlusion devices.