Blinded Randomized Trial of Anticoagulation to Prevent Ischemic Stroke and Neurocognitive Impairment in AF

For entry into the study, the following criteria must be met: Inclusion Criteria: * Age at consent ≥30 to ≤62 years; * Non-valvular atrial fibrillation (paroxysmal, persistent or permanent) documented by any electrical tracing or any device (i.e. routine 12-lead electrocardiogram, Holter monitor \[continuous ECG recording\] rhythm strip, intracardiac electrogram, or pacemaker or implantable cardiac defibrillator interrogation of at least 30 s, transcutaneous monitoring or other) in the last 2 years; * Low risk of stroke as defined by the absence of all of the following: i. Prior stroke or Transient Ischemic Attack, ii. Hypertension, iii. Diabetes mellitus, iv. Congestive heart failure (New York Heart Association class II or higher at the time of enrolment or a known left ventricular ejection fraction \<35%); * Signed informed consent For entry into the study, none of the following criteria MUST be met Exclusion Criteria: * Known diagnosis of dementia; * MMSE score \<25; * Valvular AF \[mechanical heart valve, moderate to severe mitral stenosis (rheumatic or non rheumatic), or hypertrophic cardiomyopathy\]; * Other indication for antiplatelet therapy or anticoagulation; * History of GI bleeding; * Conditions associated with an increased risk of bleeding described as follows: 1. Major surgery within the previous month; 2. Planned surgery or intervention within the next 3 months; 3. History of intracranial, intraocular, spinal, retroperitoneal or a traumatic intra-articular bleeding; 4. Symptomatic or endoscopically documented gastroduodenal ulcer disease in the previous 30 days; 5. Haemorrhagic disorder or bleeding diathesis; 6. Fibrinolytic agents within 48 hours of study entry; 7. Recent malignancy or radiation therapy (within 6 months from the time of enrolment) and not expected to survive 3 years; * Reversible cause of AF (e.g. cardiac surgery, pulmonary embolism, untreated hyperthyroidism); * Absence of recurrence of AF 3 months after AF ablation; * Severe renal impairment (creatinine clearance 30 mL/min or less); * Active infective endocarditis; * Active liver disease (e.g. acute clinical hepatitis, chronic active hepatitis, cirrhosis), or Alanine Transaminase (ALT) \>3 times the upper limit of normal; * Women who are pregnant or of childbearing potential not using a medically acceptable form of contraception throughout the study; * Women who are breastfeeding; * Anemia or thrombocytopenia (according to the normal range values of the local laboratory); * Participation in another study involving an investigational drug (under development) at the same time or within 30 days of randomization; * Subjects considered unreliable, or having a life expectancy of less than 3 years or having any condition which, in the opinion of the investigator, would not allow safe participation in the study (e.g. drug addiction, alcohol abuse); * History of allergic reaction to rivaroxaban. * History of allergic reaction, in the absence of desensitization to acetylsalicylic acid in patients with vascular disease.