This is a prospective clinical study designed to evaluate biomarkers of brain injury and dementia incidence and moderate cognitive decline rates in moderate- to high-risk atrial fibrillation patients that undergo standard of care atrial fibrillation management.

A written informed consent will be obtained from atrial fibrillation patients seen at Intermountain Medical Center who meet the study eligibility criteria. Following the baseline visit for obtaining informed consent and conduct of baseline procedures, subjects will be required to return to clinic at 6, 12, 18 and 24 months after enrollment. Cognitive testing will be performed at baseline and repeated at 24 months. As much as possible, the study follow-up visits will be scheduled at the same time as the patients' regular visits for clinical care.

Six questionnaires will be administered at the baseline visit and repeated at the 24-month visit. At the time of cognitive assessment, the following will be completed, if not already performed as part of usual standard of care: complete blood count, protime/INR, basic metabolic profile, review of cardiac medications, and review of adverse events and hospitalizations. Additional serum tests will be performed on all subjects at enrollment and at the 24-month visit. Biomarkers will be drawn at specific intervals (baseline, 6, 12, 18, and 24 months) then on an as needed basis (within 7 days) when treatments for atrial fibrillation that may increase brain injury risk occur.

Inclusion Criteria:

1. Male or female 65 to ≤ 95 years of age
2. Ability to understand and sign a written informed consent form, which must be obtained prior to initiation of any study procedures
3. AF documented by electrocardiogram, ambulatory event monitor, telemetry, or medical records within 12 months of enrollment
4. Ability to complete a mini-mental status evaluation
5. Ability to independently comprehend and complete a quality of life and dementia questionnaires
6. Willing and able to comply with the follow-up visits, tests, and schedule of evaluations

Exclusion Criteria:

1. Have a history of any form of dementia
2. Have a life expectancy less than 24 months
3. Participation in any other clinical trials involving investigational or marketed products within 30 days prior to entry in the study
4. Other conditions that in the opinion of the Principal Investigator and/or Sub-Investigator(s) may increase risk to the subject and/or compromise the quality of the clinical trial
5. The Principal Investigator and/or Sub-Investigator(s) determine(s) that the subject is not eligible for participation in this research study

Moderate- to high-risk atrial fibrillation patients that undergo standard of care atrial fibrillation management at Intermountain Medical Center.