How to Understand Patent Foramen Ovale Clinical Significance - Part II: Therapeutic Strategies in Cryptogenic Stroke

In the first part of this review, we reminded that patent foramen ovale (PFO) is a slit or tunnel-like passage in the interatrial septum occurring in approximately 25% of the population and that a number of conditions have been linked to its presence, the most important being cryptogenic stroke (CS) and migraine. We have also shown how, in the setting of neurological events, it is not often clear whether the PFO is pathogenically-related to the index event or an incidental finding, and therefore we thought to provide some useful key points for understanding PFO clinical significance in a case by case evaluation. The controversy about PFO pathogenicity has consequently prompted a paradigm shift of research interest from medical therapy with antiplatelets or anticoagulants to percutaneous transcatheter closure, in secondary prevention. Observational data and meta-analysis of observational studies previously suggested that PFO closure with a device was a safe procedure with a low recurrence rate of stroke, as compared to medical therapy. However, so far, published randomized controlled trials (CLOSURE I, RESPECT and PC Trial) have not shown the superiority of PFO closure over medical therapy. Thus, the optimal strategy for secondary prevention of paradoxical embolism in patients with a PFO remains unclear. Moreover, the latest guidelines for the prevention on stroke restricted indications for PFO closure to patients with deep vein thrombosis and high-risk of its recurrence. Given these recent data, in the second part of the present review, we aim to discuss today treatment options in patients with PFO and CS, providing an updating on patients' management.