Cryptogenic Stroke, Patent Foramen Ovale, and ASD Closure

Atrial septal defect (ASD) is the most common congenital defect first recognized in adulthood while a patent foramen ovale (PFO) is found in between 20–30% of normal adults. Hemodynamically significant ASDs are those with a shunt fraction ≥1.5:1 and should be closed to treat symptoms and to prevent the sequale of long-term left-to-right shunt. Most ASDs are of the secundum type and 80–90% may be closed percutaneously. There is an association between PFO closure and stroke especially in young patients with absence of traditional stroke risk factors. Three large, randomized trials published in 2017 showed benefit to PFO closure over medical therapy in prevention of recurrent stroke in patients between 16 and 60 years of age where other stroke mechanisms were excluded. The relative risk reduction of PFO closure in those trials was between 50 and 70%. The presence of an atrial septal aneurysm in association with a PFO makes the PFO more likely to be culpable in the stroke etiology and closure seems to confer even more benefit for recurrent stroke prevention. In addition to fluoroscopy, intraprocedureal transesophageal echocardiography (TEE) or intracardiac echocardiography (ICE) are needed to guide device selection and closure.