The aim of the present study is to prospectively evaluate the safety of Edoxaban.

The aim of the present study is to prospectively evaluate the safety of Edoxaban in daily clinical practice in Spain in elderly patients with nonvalvular atrial fibrillation who meet the criteria for frailty and who have been prescribed the drug recently (<6 months prior to inclusion).

The study will provide us with a clear and real-life picture of bleeding and ischemic complications and possible treatment interruptions with Edoxaban in real life and in a large subgroup, although underrepresented in the studies.

Inclusion Criteria:

• Patients 75 years of age or older with a diagnosis of NVAF.
• Patients in whom treatment had been started in the 6 months prior to enrollment in the study with Edoxaban for prevention of stroke and systemic embolism after diagnosis of NVAF and according to the drug's technical data sheet.
• Frailty criteria according to the FRAIL scale (score of 3 to 5 points).
• Written informed consent to participate in the study prior to any intervention.

Exclusion Criteria:

• Creatinine clearance according to the CKD-EPI formula less than 15 ml/min/m2
• Moderate or severe hepatic insufficiency (Defined as grade B or C of the Child-Pugh classification.
• Contraindication to receive Edoxaban according to the Technical Data Sheet.
• Participation in any clinical drug trial in the 2 months prior to the initial visit.
• Absence of recorded patient or treatment information.
• Surgical or percutaneous occlusion of the left atrial appendage or intention to perform such intervention at the time of inclusion.
• Any circumstance that, in the opinion of the investigator, affects patient follow-up (including life expectancy of less than two years or inability to perform follow-up).
• Persons who are legally incapacitated or unable to understand informed consent.

The study population will consist of patients ≥75 years diagnosed with NVAF who meet frailty criteria and who have been receiving anticoagulation therapy with Edoxaban for no more than 6 months prior to study inclusion according to AEMPS recommendations and the summary of product characteristics.