What you need to know: The recommendations apply to patients under 60 years old with patent foramen ovale (PFO) who have had a cryptogenic ischaemic stroke, when extensive workup for other aetiologies of stroke is negative; For patients who are open to all options, we make a weak recommendation for PFO closure plus antiplatelet therapy rather than anticoagulant therapy; For patients in whom anticoagulation is contraindicated or declined, we make a strong recommendation for PFO closure plus antiplatelet therapy versus antiplatelet therapy alone; For patients in whom closure is contraindicated or declined, we make a weak recommendation for anticoagulant therapy rather than antiplatelet therapy; Further research may alter the recommendations that involve anticoagulant therapy. Options for the secondary prevention of stroke in patients younger than 60 years who have had a cryptogenic ischaemic stroke thought to be secondary to patent foramen ovale (PFO) include PFO closure (with antiplatelet therapy), antiplatelet therapy alone, or anticoagulants. International guidance and practice differ on which option is preferable. The BMJ Rapid Recommendations panel used a linked systematic review1 triggered by three large randomised trials published in September 2017 that suggested PFO closure might reduce the risk of ischaemic stroke more than alternatives.234 The panel felt that the studies, when considered in the context of the full body of evidence, might change current clinical practice.5 The linked systematic review finds that PFO closure prevents recurrent stroke relative to antiplatelet therapy, but possibly not relative to anticoagulants, and is associated with procedural complications and persistent atrial fibrillation.1 The review also presents evidence regarding the role of anticoagulants or antiplatelet therapy when PFO closure is not acceptable or is contraindicated.