Atrial septal abnormalities and cryptogenic stroke: a paradoxical science

Patent foramen ovale and/or atrial septal aneurysm occur in up to 20% of the general population, and have been linked to cryptogenic ischemic strokes in younger individuals. The pathophysiologic basis of this association remains unclear, with growing evidence suggesting a role for thrombosis and embolization. Aspirin and warfarin constitute the current mainstay of medical therapy, with a variety of secondary prevention studies assessing their impact on stroke recurrence. To date, the quality of published data preclude the development of strict recommendations, but a number of suggestions can be derived from available literature. Patients with isolated patent foramen ovale or atrial septal aneurysm and a first ischemic stroke respond well to either aspirin or warfarin therapy. On the other hand, oral anticoagulation seems to be the preferred medical therapy in higher-risk patients with both patent foramen ovale and atrial septal aneurysm or those with multiple strokes on aspirin. Percutaneous or surgical patent foramen ovale closures have been proposed as alternative therapies and seem effective in reducing stroke recurrence. In the absence of randomized, controlled trials comparing medical and invasive approaches, the adoption of a particular therapy should take into consideration the individual's preference, clinical presentation, risk profile, lifestyle, and the expertise of the local interventional and surgical teams.