Inclusion Criteria- All patients included in the study will have TIA or minor stroke (defined as NIHSS score = 3).
- Patients must be treated within 24 hours of symptom 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.
- All patients will be 18 years or older.
- All patients will have an MRI, with evidence of at least one DWI lesion, consistent with ischemia, prior to randomization.
Exclusion Criteria- Patients with stroke mimics (such as seizures, migraine etc.) will be excluded from the study.
- Patients with contraindications to MRI will also be excluded, including metallic implants.
- Patients with any past sensitivity to gadolinium contrast media will be eligible, but will not undergo PWI.
- Patients with renal failure, defined as Glomerular Filtration Rate (GFR) <30 ml/min, will be excluded as well.
- 93 Patients deemed to have any ongoing bleeding risks or unsuitable for dabigatran therapy by the attending stroke clinician will be ineligible.
- Patients in whom the MRI demonstrates additional pathology including arteriovenous malformations, intracranial aneurysms, tumours, or abscess will be excluded.
Additional Exclusion Criteria:
- Age <18 years
- Planned thrombolysis or endovascular intervention for the index event
- Thrombolysis for ischemic stroke within preceding 7 days
- Planned carotid endarterectomy/carotid artery stent within 30 days
- Any history of spontaneous intracranial bleeding
- Clear indication for anticoagulation, including atrial fibrillation, mechanical cardiac valves, deep venous thrombosis, pulmonary embolism or known hypercoagulable state
- Co-morbid illness with expected life expectancy of <30 days