Investigator-initiated prospective multicentre hospital-based registry to uncover the proportion of self-reported anticoagulation in stroke patients with atrial fibrillation and assessing the proportion of stroke, intracranial bleeding and all-cause death in the short (at 3 months), mid-term (at 12 months) as well as long term (at 24 months) after ischemic stroke or transient ischemic attack in an unselected urban population in Germany. In addition, annual follow-up is planned yearly up to 5 years after enrollment.

Inclusion Criteria:

• Acute ischemic stroke or transient ischemic attack (with clinical deficit on admission or corresponding brain MRI lesion)
• Age ≥ 18 years
• Known atrial fibrillation or ECG recording documenting atrial fibrillation during the in-hospital stay for acute ischemic stroke or transient ischemic attack
• Written or oral informed consent
• Willingness to take part in the planned follow up examinations

Exclusion Criteria:

• Life expectancy < 1 year (before stroke)
• Assumed post-stroke life expectancy < 1 month according to stroke severity
• Chronic anticoagulation for reasons other than atrial fibrillation

Patients with known atrial fibrillation and acute ischemic stroke or transient ischemic attack