Inclusion Criteria- All patients included must meet one of these two conditions:
- Patient presenting with an episode of transient ischemic attack (TIA) of cryptogenic origin with neurological symptoms of less than 24h of evolution and negative neuroimaging.
- First episode of ischaemic stroke with cryptogenic etiology following TOAST criteria
- All patients must meet all of the following:
- The patient has been implanted an ILR within 30 days after qualifying event
- Age between 45-85 years
- No stenosis >50% in any arterial vessel corresponding to the affected territory
- Normal Echocardiography
- Normal 24 hours EKG Holter recording
- Absence of Patent Foramen Ovale through transcranial doppler (or transesophageal echocardiography)
- Acceptance and signature of Patient Informed Consent.
Exclusion Criteria- All patients included cannot meet any of the following conditions:
- Recurrent stroke or TIA
- Stroke or TIA with determined etiology according to TOAST criteria.
- Anticoagulation indication at the time of enrollment in the study.
- Total contraindication for anticoagulation therapy
- Atrial fibrillation detection prior to enrollment
- Severe cognitive impairment or dementia
- Patient unable to be followed up
- Patients enrolled in another clinical trial
- Patients with life expectancy of less than 1 year