Patent foramen ovale (PFO) is associated with an increased risk of stroke. PFO-closure was effective in preventing stroke in young stroke patients less than age 60 presented as an embolic stroke of undetermined source (ESUS). However, the benefit of PFO-closure in elderly ESUS patients is not clear. The investigators designed this prospective register-based observational study to verify the efficacy of PFO-closure in elderly ESUS patients with high-risk PFO, older than 60 years

The COACH-ELDERLY ESUS study is a multicenter, prospective, registry-based, observational study in elderly ESUS patients with high-risk PFO treated with PFO-closure + standard antiplatelet treatment or standard antiplatelet treatment only in 20 centers in Korea.

Patients will receive an insertable loop recorder (ILR) to monitor paroxysmal atrial fibrillation. In cases, which are unavailable for ILR, recurrent EKG or Holter monitoring will be done based on the clinician's decision. Based on the attending physicians' decision with a multi-disciplinary approach, patients will receive PFO-closure with standard antiplatelet treatment or standard antiplatelet treatment only.

Inclusion Criteria:

1. Patients older than 60 years-old
2. Patients diagnosed as ESUS within 180 days from onset
3. PFO found from TTE or TEE, which attributed to the ischemic stroke
4. Patients or their legal representative agreed to participate

Exclusion Criteria:

1. Patients with transient ischemic attack
2. Patients with ischemic stroke at the vascular territory with significant stenosis
3. Patients with high risk cardioembolic stroke detected from EKG, Holter monitoring or echocardiography
4. Patients with other causes which may cause stroke (i.e. vasculitis, dissection, vasospasm, drug related or Moyamoya disease)
5. Patients with active cancer
6. Patients who need long term anticoagulation
7. Patients who have side effect on antiplatelet treatment
8. Patients with active internal bleeding
9. Patients who refuse to participate

Elderly ESUS patients