Inclusion Criteria- All patients will be ≥ 18 years of age.
- All patients will have a diagnosis of minor ischemic stroke, defined as NIHSS score ≤ 8, or Transient Ischemic Attack (TIA), defined as acute focal neurological deficits, with complete resolution of symptoms within 24 h of onset. In cases where onset time cannot be established, it will be considered to be the time when the patient was last known to be well.
- Atrial Fibrillation (AF, paroxysmal or persistent). AF must be confirmed with ECG/Holter monitor, or by history (clinical documentation of previous AF must be provided).
- All included patients will be prescribed rivaroxaban following their stroke/TIA.
Exclusion Criteria- Acute or chronic renal failure, defined as eGFR <30 ml/min (Cockcroft Gault formula).
- Known hypersensitivity to rivaroxaban.
- Prior treatment with rivaroxaban or any other novel oral anticoagulant (including all Factor Xa antagonists). Treatment with warfarin prior to the stroke/TIA is acceptable, but enrolment cannot begin until the INR is ≤2.0.
- Any significant ongoing systemic bleeding risk, i.e. active GI/GU bleeding or recent major surgery.
- Any condition that, in the judgment of the investigator could impose hazards to the patient if study therapy is initiated or affect the participation of the patient in the study.
- Recent past history or clinical presentation of ICH, subarachnoid haemorrhage (SAH), arterio-venous (AV) malformation, aneurysm, or cerebral neoplasm. At the discretion of each Investigator.
- Hereditary or acquired haemorrhagic diathesis.
- Stroke mimics (such as seizures, migraine etc.)
- Contraindications to MRI will also be excluded, including metallic implants.