Inclusion Criteria- Recent cerebral ischemia defined as stroke (sudden focal neurologic deficit lasting > 24h consistent with the territory of a major cerebral artery and categorised as ischemic) and/or a corresponding lesion on brain imaging.
- Stroke symptoms started ≤ 7 days ago.
- Age ≥ 60 years.
- Modified Rankin scale ≤ 2 (prior to index event).
Exclusion Criteria- Known history of atrial fibrillation/flutter or atrial fibrillation/flutter on admission ECG.
- Indication for oral anticoagulation at randomisation.
- Absolute contra-indication against oral anticoagulation at randomisation.
- Intracerebral bleeding in medical history.
- Patient scheduled for Holter-ECG or cardiac Event-Recording monitoring ≥ 48 hours.
- Significant carotid artery or vertebral artery stenosis > 50% (NASCET classification), significant intracranial artery stenosis suspicious of atherosclerotic origin or acute arterial dissection explanatory of stroke symptoms.
- Implanted pacemaker device or cardioverter/defibrillator.
- Life expectancy < 1 year for reasons other than stroke (e.g. metastatic cancer).
- Concomitant participation in other controlled randomised trial.