High-risk PFO is defined by a moderate-to-large shunt combined with an atrial septal aneurysm. The Amplatz PFO occluder has demonstrated clear superiority over medical therapy; other device types have not. Post-closure AF is typically transient, resolving within approximately 45 days. ESUS accounts for 80-90% of cryptogenic ischemic strokes; optimal treatment (anticoagulation vs. antiplatelet) remains unestablished.

High-risk PFO: moderate-to-large shunt combined with atrial septal aneurysm.Amplatz PFO occluder has demonstrated clear superiority over medical therapy; other devices have not.PFO closure does not increase mortality or myocardial infarction risk.Post-closure AF is typically transient, resolving within approximately 45 days.Cryptogenic stroke generally carries a lower recurrence risk than stroke with an identified cause.MRI showing infarcts of different ages within a single vascular territory suggests artery-to-artery embolism.ESUS: non-lacunar infarct without identifiable major cardiac embolic source; accounts for 80-90% of cryptogenic strokes.Superficial or large deep infarcts in cryptogenic stroke are almost always embolic in origin.Presumed ESUS sources: mild LV dysfunction, mitral annular calcification, PFO, low-burden AF, aortic arch atherosclerosis, non-stenotic unstable plaques.Optimal ESUS treatment (anticoagulation vs. antiplatelet) remains unestablished.