Patent foramen ovale medical therapy


 * Associate Editors-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]; Assistant Editor-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Overview
There is a lack of consensus on the medical therapy for patent foramen ovale. Asymptomatic patent foramen ovale doesn't warrant any treatment. The incidence of recurrent stroke in patients with index episode of cryptogenic stroke and treated with aspirin or warfarin has been found similar in presence or absence of a patent foramen ovale. However, an increased risk of subsequent stroke has been seen in patent foramen ovale associated with atrial septal aneurysm. Thus, treatment with aspirin or warfarin could be considered in patients with patent foramen ovale associated with atrial septal abnormalities or other complicated patent foramen ovale. There are lack of studies to compare the efficacy of aspirin and warfarin in these conditions. However, aspirin's safety profile has been found to be better than warfarin (less bleeding). The benefit of PFO closure is not well established in the patient with a cryptogenic stroke. The benefit of Coumadin in the patient with PFO is not well established, and this therapy should be reserved for those patients with atrial fibrillation or venous thromboembolism.

Internatioanl guidelines for prevention of recurrent cerebral embolism in patent foramen ovale
===American Academy of Neurology Guidelines for prevention of recurrent cerebral embolism in patent foramen ovale (DO NOT EDIT) === Practice Recommendations

1) For patients who have had a cryptogenic stroke and have a patent foramen ovale (PFO), the evidence indicates that the risk of subsequent stroke or death is no different from other cryptogenic stroke patients without PFO when treated medically with antiplatelet agents or anticoagulants. Therefore, in persons with a cryptogenic stroke receiving such therapy, neurologists should communicate to patients and their families that presence of PFO does not confer an increased risk for subsequent stroke compared to other cryptogenic stroke patients without atrial abnormalities (Level A). However, it is possible that the combination of PFO and atrial septal aneurysm (ASA) confers an increased risk of subsequent stroke in medically treated patients who are less than 55 years of age. Therefore, in younger stroke patients, studies that can identify PFO or atrial septal aneurysm (ASA) may be considered for prognostic purposes (Level C).

2) Among patients with a cryptogenic stroke and atrial septal abnormalities, there is insufficient evidence to determine the superiority of aspirin or warfarin for prevention of recurrent stroke or death (Level U), but the risks of minor bleeding are possibly greater with warfarin (Level C) Rating of Recommendations

A = Established as effective, ineffective, or harmful for the given condition in the specified population.

B = Probably effective, ineffective, or harmful for the given condition in the specified population.

C = Possibly effective, ineffective, or harmful for the given condition in the specified population.

U = Data inadequate or conflicting. Given current knowledge, treatment (test, predictor) is unproven.

===American Academy of Chest Physicians Guidelines for prevention of recurrent cerebral embolism in patent foramen ovale (DO NOT EDIT) === 1) In patients with cryptogenic ischemic stroke and a PFO, we recommend antiplatelet therapy over no therapy (Grade 1A) and suggest antiplatelet therapy over warfarin (Grade 2A).

2) For patients with evidence of a DVT, anticoagulation therapy is recommended.

===American Heart Association/American Stroke Association guidelines for prevention of recurrent cerebral embolism in patent foramen ovale (DO NOT EDIT) ===

1 Antiplatelet therapy reasonable

2 Warfarin reasonable for high-risk patients with other indications such as hypercoagulable state or venous thrombosis

===European Stroke Organisation guidelines for prevention of recurrent cerebral embolism in patent foramen ovale (DO NOT EDIT) ===

1 Patients with cardioembolic stroke unrelated to atrial fibrillation should receive warfarin if the risk of recurrence is high.

Trial supportive data
A large randomized multicenter trial (42 centers) was done to compare the relative efficacy of aspirin and warfarin to prevent recurrent strokes in patients with patent foramen ovale. The study found an increased incidence of patent foramen ovale with cryptogenic stroke. This was similar to the results found in previous small scale trials, ,. Also, it was found in the study that cryptogenic strokes were commoner in larger  patent foramen ovale compared to the smaller. Nevertheless, the rate of recurrent stroke or death, in medically treated patients after index episode of cryptogenic stroke, was found to be similar between patients with and without patent foramen ovale. Also, the rate of adverse events after medical therapy was found to be the same in patent foramen ovale of different size.