Impact of Anticoagulation Therapy on the Cognitive Decline and Dementia in Patients With Non-Valvular Atrial Fibrillation

Inclusion Criteria: 1. Male or female \>65 years of age. 2. Non-valvular atrial fibrillation documented by electrocardiogram, ambulatory event monitor, or telemetry within 12 months of enrollment. 3. Moderate risk of thromboembolism based upon a CHADS score or CHADS2 Vasc score of ≥2. 4. Ability to complete a mini-mental status evaluation. 5. Ability to independently comprehend and complete a quality of life and dementia questionnaires. 6. Ability to provide informed consent for study participation. 7. Willing and able to comply with the prescribed follow-up tests and schedule of evaluations. Exclusion Criteria: 1. Inability to take an anticoagulant due to known or perceived bleeding risk. 2. Known coagulopathy that may impact the choice, duration, efficacy and safety of anticoagulation therapy. 3. Atrial Fibrillation in the setting of valvular heart disease. Valvular heart disease defined as any surgical valve, mitral stenosis, or moderate-severe valvular heart disease. 4. Severe renal dysfunction, defined as a creatinine clearance rate \<15 mL/min (documented within the last 3 months). 5. History of any form of dementia. 6. A life expectancy less than 24 months. 7. Inability to comply with the follow-up schedule. 8. Current participation in a clinical investigation that includes an active pharmacologic treatment arm. 9. An upper age limit not to be used if participation inclusion criteria are met. 10. Participation in any other clinical trials involving investigational or marketed products within 30 days prior to entry in the study. 11. Other conditions that in the opinion of the Principal Investigator(s) may increase risk to the subject and/or compromise the quality of the clinical trial. 12. Concurrent pharmacologic treatment that is required to treat a condition long-term in which concurrent use of dabigatran etexilate is contraindicated. 13. Treatment with any anticoagulant drug for stroke prevention for more than 30 days. * Aspirin and P2Y12 inhibitors (e.g. clopidogrel (Plavix), or prasugrel (Effient)) are not considered anticoagulant drugs. * If the subject has received any anticoagulant drug for stroke prevention for less than 30 days, the Principal Investigator(s) or a Co-Investigator will decide whether or not the subject is eligible for this study 14. The Principal Investigator(s) determine(s) that the subject is not eligible for participation in this research study.