Patent foramen ovale and cryptogenic stroke: many unanswered questions.

Patent foramen ovale (PFO) is associated with cryptogenic stroke, but uncertainty remains about the exact relationship and the best management. Percutaneous closure of PFO is safe and effective, but this procedure has yet to be definitely proven to be better than medical therapy. The scenario of PFO and cryptogenic stroke poses unique challenges to primary care physicians and subspecialists and requires an understanding of the relationship between cryptogenic stroke and PFO, and of current data on the safety, efficacy, and comparative effectiveness of management options.