Patent foramen ovale and stroke

A patent foramen ovale (PFO) is a highly prevalent finding in cryptogenic ischaemic stroke, particularly in young adults. A common challenge in clinical practice is to distinguish between incidental and pathogenic PFO. Some clinical features and tools such as the Risk of Paradoxical Embolism score may help determining the probability of a stroke-related PFO. Nonetheless, the best therapeutic option to reduce stroke recurrence after a cryptogenic stroke with PFO has been a matter of debate for a long time. We review the mechanisms of stroke-related PFO, together with its clinical features and diagnostic criteria. In addition, we focus on the methodological details and results from new studies in the field of secondary prevention. In contrast to prior evidence, the data from three recent clinical trials and an updated meta-analysis favour PFO closure over medical treatment after cryptogenic stroke/TIA for the prevention of stroke recurrence. The PFO closure device procedure is not associated with higher mortality or cardiovascular events, except for a small increase in the occurrence of transient atrial fibrillation. Furthermore, the benefit of PFO closure was higher among those with atrial septal aneurysm and PFO with large right-to-left shunt. Future studies should address pending issues such as the option for anticoagulants or antiplatelet in patients not undergoing closure, the duration of antiplatelet treatment after PFO closure and the role of PFO closure in patients older than 60.