Patent foramen ovale and cardiac embolism
Prof. Jean-Louis Mas
22 slide(s) – 00:24:53– English –2010-09-27
Over the past 15 years, there has been an increasing number of papers dealing with PFO and stroke, but the nature of the relationship between this common cardiac abnormality and stroke is still a matter of controversy. Case-control studies have established a statistical association between PFO and cryptogenic stroke and this association appears to be stronger in patients who have an atrial septal aneurysm (ASA) in addition to a PFO and in those with large PFO or massive right-to-left shunt, but longitudinal studies failed to show an increased risk of first or recurrent stroke in patients with a PFO. The combination of PFO and ASA may confer an increased risk of subsequent stroke in medically treated patients who are less than 55 years of age. Strategies for distinguishing incidental PFOs from pathogenic ones in cryptogenic stroke patients and for identifying patients at high risk of recurrence are needed. The actual mechanisms by which PFO could cause stroke must be more fully elucidated. Paradoxical embolism may not be the predominant mechanism of stroke. It should be kept in mind that PFO is a common finding in the normal population and may coexist by chance alone in patients with cryptogenic stroke. There is insufficient evidence regarding the effectiveness of antiplatelet drugs, oral anticoagulants and PFO closure in preventing recurrent stroke. Until randomized clinical trials can define who should be treated by what and for how long, we risk ending up exposing some patients to unnecessary complications of treatment. PFO closure is not without risk and leaves an implant behind with potential long-term complications. Off-protocol closure of PFO limit enrolment of patients in ongoing randomized controlled trials and could undermine their validity.