Post-authorization observational, prospective, follow-up study of a cohort of patients with non-valvular atrial fibrillation who are treated with direct oral anticoagulants (DOACs) to evaluate the clinical course (occurrence of stroke, major bleeding and mortality) and its correlation with clinical, pharmacokinetic (plasma concentrations), pharmacodynamic (haemostatic) and pharmacogenetic factors.

Post-authorization observational, prospective, follow-up study of a cohort of patients with non-valvular atrial fibrillation treated with direct oral anticoagulants (dabigatran, rivaroxaban, apixaban and edoxaban) to assess the clinical course (occurrence of stroke, other ischemic or bleeding events and mortality) and its correlation with clinical, pharmacokinetic (plasma concentrations), pharmacodynamic (haemostatic) and pharmacogenetic factors.

Patient selection and follow-up will be performed in 6 public Spanish hospitals: Hospital Universitario de la Princesa, Hospital Universitario La Paz, Hospital Universitario Ramón y Cajal, Fundación Jiménez Díaz, Hospital Gómez Ulla (Madrid) and Hospital Universitario de Burgos (Burgos). To reduce variability, the determination of anticoagulant activity will be performed in the Hematology Service of the Hospital Universitario de Burgos and the measurement of plasma concentrations and genotyping of all patients in the Clinical Pharmacology Service of the Hospital Universitario de la Princesa.

Patients who are to receive or are receiving one of the four DOACs currently available in Spain will be informed about the characteristics of this study and will be asked to sign the consent form for their participation. The treatment or clinical management of these patients at each centre will not be modified. They will be asked three blood samples, coinciding with other tests that will be carried out to monitor their pathology (one blood sample for the study of the effect on coagulation, another for drug quantification in plasma and another for genetic studies) with the only requirement that they must have been treated with the drug for at least one week so that they have spent more than 5 half-lives and are in steady state. The samples will be extracted in the morning, before medication intake (trough concentrations).

Inclusion Criteria:

1. Men or women over 18 years of age
2. Patients with non-valvular atrial fibrillation (NVAF).
3. Patients who are going to receive or are receiving treatment with any of the DOACs (dabigatran, rivaroxaban, apixaban or edoxaban) for the prevention of stroke and systemic embolism in adult patients with NVAF, according to the drug label.
4. Patients who agree to participate in the study and give their written consent.

Exclusion Criteria:

1. Patients on treatment with other anticoagulants.
2. Patients suffering from a malignant or terminal disease whose life expectancy is less than 6 months.

Men and women over 18 years of age with NVAF requiring anticoagulant treatment with a DOAC. The prescription of the treatment will be previous and independent to the inclusion of the patient in the study. Patients who will initiate treatment (which will only be evaluated prospectively) and patients already in treatment (which will also be evaluated retrospectively) will be included.