Multicenter Non-Interventional Real-World Clinical Practice Registry of Patients with Atrial Fibrillation. The primary objective of the registry is an epidemiological assessment of the characteristics, clinical outcomes, and therapeutic approaches in patients with atrial fibrillation and a CHA₂DS₂-VASc score of no more than 2 for men and no more than 3 for women.

Multicenter Non-Interventional Real-World Clinical Practice Registry of Patients with Atrial Fibrillation. The primary objective of the registry is an epidemiological assessment of the characteristics, clinical outcomes, and therapeutic approaches in patients with atrial fibrillation and a CHA₂DS₂-VASc score of no more than 2 for men and no more than 3 for women.

The registry comprises both a retrospective and a prospective component. Patient enrollment in the retrospective part will be conducted through the review of medical records of individuals who were followed up for atrial fibrillation at the participating centers during the preceding three years. For inclusion in the prospective part, screening of all patients meeting the predefined inclusion and non-inclusion criteria will be performed during routine outpatient and inpatient care, followed by prospective follow-up over a three-year period.

Data derived from the retrospective and prospective phases of the registry will enable an epidemiological assessment of the demographic and clinical characteristics, outcomes, and therapeutic approaches employed in real-world clinical practice among patients with atrial fibrillation. These findings may provide important insights to advance the understanding of diagnostic and management strategies, and to inform efforts aimed at optimizing healthcare delivery within this patient cohort.

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).

Anonymized male and female patients aged 18 to 64 years suffering from atrial fibrillation confirmed by a specialist, with a CHA₂DS₂-VASc score ranging from 0 to 2 for men and from 1 to 3 for women.