Apixaban Safety and Therapy Adherence in Patients With Atrial Fibrillation

Inclusion Criteria: * Patients over 18 years of age. * Hemodynamically stable patients. * Patients with non-valvular atrial fibrillation. * Patients in whom the investigator, based on clinical assessment makes a decision to introduce apixaban therapy. * Patients who are on apixaban therapy for the first time Exclusion Criteria: * Positive history of angioneurotic edema. * Active, clinically significant bleeding. * Congenital or acquired bleeding disorder. * The presence of a malignant tumor. * Current or recent presence of gastrointestinal ulcer. * The presence of established or suspected esophageal varices. * Positive history of arteriovenous malformations, vascular aneurysms or intraspinal and intracerebral vascular anomalies. * Patients with artificial heart valves. * Liver cirrhosis and active liver disease associated with coagulopathy and clinically significant risk of bleeding. * Dialysis patients (GFR \<15 ml/min). * Simultaneous use of other anticoagulants. * Pregnancy and breastfeeding. * Patients who previously used apixaban in therapy. Withdrawal Criteria: * Deterioration of the clinical picture of the underlying disease that requires discontinuation of investigational therapy. * Development of serious adverse events that require discontinuation of therapy. * Occurrence of pregnancy. * Development of another disease that affects the course of research.