AF-CARD Registry (Real-World Clinical Practice Registry of Patients With Atrial Fibrillation)

Retrospective Part The retrospective part will include patients who attended a physician consultation for atrial fibrillation three years ago and who met the inclusion criteria at that time. Inclusion criteria for the retrospective part: * Male or female patients aged 18 to 64 years at the time of data registration; * Presence of a specialist-confirmed diagnosis of atrial fibrillation; * CHA₂DS₂-VASc score ranging from 0 to 2 for men and from 1 to 3 for women. Non-inclusion criteria for the retrospective part: * Age under 18 years; * Age over 64 years; * CHA₂DS₂-VASc score greater than 2 for men and greater than 3 for women; * Inability to undergo screening examination and follow-up; * Organ or tissue transplantation less than 5 years prior to study enrollment; * Open heart surgery (coronary artery bypass grafting, valve replacement, reconstructive aortic surgery) within 6 months prior to study enrollment; * Established diagnosis of dementia of any severity and/or established diagnosis of moderate or severe encephalopathy, as well as other conditions precluding independent regular medication intake. Prospective Part Inclusion criteria for the prospective part: * Male or female patients aged 18 to 64 years at the time of data registration; * Presence of a specialist-confirmed diagnosis of atrial fibrillation; * CHA₂DS₂-VASc score ranging from 0 to 2 for men and from 1 to 3 for women at the time of screening. Non-inclusion criteria for the prospective part: * Age under 18 years; * Age over 64 years; * CHA₂DS₂-VASc score greater than 2 for men and greater than 3 for women; * Inability to undergo screening examination and follow-up; * Organ or tissue transplantation less than 5 years prior to study enrollment; * Open heart surgery (coronary artery bypass grafting, valve replacement, reconstructive aortic surgery) within 6 months prior to study enrollment; * Established diagnosis of dementia of any severity and/or established diagnosis of moderate or severe encephalopathy, as well as other conditions precluding independent regular medication intake. Exclusion criteria: * Patient withdrawal of consent for further participation in the study; * Identification of factors precluding further patient participation in the study (at the physician's discretion).