Role of occlusive devices to prevent thromboembolism among persons with a patent foramen ovale and prior stroke.

Patent foramen ovale (PFO) has been linked to stroke, presumably through the mechanism of paradoxical embolism; however, data is confusing regarding the causal relationship between PFO and embolic stroke. What has come to light in the past decade of research is that PFO closure with devices that achieve a high rate of closure may reduce the risk of recurrent stroke compared with medical therapy, but this benefit has not been shown in the general population with a PFO and cryptogenic stroke. The important question now is which patient will benefit from PFO closure for stroke risk reduction. A validated risk prediction tool is needed to help physicians determine those patients who will derive benefit from closure of PFO to prevent recurrent stroke. It is clear that even in studies with a small number of individuals and a very small number of events, there is some benefit to closure. Furthermore, improvements in closure devices and techniques have made percutaneous device closure both safe and efficacious. As such, it is not necessary to wait for a patient to have two strokes prior to serious consideration of PFO closure. We would advocate that the decision to close a PFO in the setting of a cryptogenic stroke be made at an individual level, on a case-by-case basis. Patients with high-risk features may be more likely to benefit, though who exactly comprises this population is still being elucidated. The most difficult aspect of managing this disease is the substantial number of individuals with incidental PFOs, as well as the prevalence of stroke due to other etiologies. When treating this disease, the physician must be able to weigh the likelihood of benefit versus the risk of the procedure, as well as patient preference.