Percutaneous patent foramen ovale closure for cryptogenic ischemic stroke: is it time for new guidelines?
Patent foramen ovale (PFO) mediated right-to-left shunting has been associated with a variety of medical syndromes including cryptogenic stroke, migraine headache, platypnea-orthodeoxia, sleep apnea and decompression sickness (1-7). Observational studies suggest that PFO occurs in 20–25% of the adult population, but up to 50% of patients with cryptogenic stroke have a PFO (8). While the etiology of PFO mediated stroke is attributed to paradoxical embolism, there is no increased benefit of anticoagulation with warfarin or newer oral anticoagulants for secondary prevention of cryptogenic stroke, in the absence of atrial fibrillation (9,10). Given the lack of a superior antithrombotic medication, non-randomized studies were performed to assess the efficacy of percutaneous PFO closure; these observational studies suggested that device closure reduces the rate of recurrent stroke compared with medical therapy in patients with cryptogenic ischemic stroke (1,8). Subsequently, five randomized controlled trials were completed in an effort to confirm these findings.