Advances and Ongoing Controversies in Patent Foramen Ovale Closure and Cryptogenic Stroke.

Up to a third of strokes are cryptogenic. The prevalence of patent foramen ovale (PFO) in patients with cryptogenic stroke is higher than in individuals with stroke of known origin. It has been proposed that some cryptogenic strokes can be caused by paradoxic embolism across a PFO. The treatment of PFO includes medical treatment with antithrombotic agents and percutaneous PFO closure. There is limited evidence to support PFO closure in unselected cases of cryptogenic stroke. However, large randomized clinical trials confirmed the superiority of transcatheter PFO closure compared with medical treatment in young patients with cryptogenic stroke.