(Stroke. 2006;37:577.)
These are the latest guidelines from the American Stroke Association and American Heart Association on how to treat a PFO. I’ve included the summary, authors and abstract and pulled out only the PFO treatment guidelines here.

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(You can also click any of the citations in the article to go to the Stroke website for reference)

AHA/ASA Guidelines

Guidelines for Prevention of Stroke in Patients With Ischemic Stroke or Transient Ischemic Attack

A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association Council on Stroke: Co-Sponsored by the Council on Cardiovascular Radiology and Intervention: The American Academy of Neurology affirms the value of this guideline.

Ralph L. Sacco, MD, MS, FAHA, FAAN, Chair; Robert Adams, MD, FAHA, Vice Chair; Greg Albers, MD; Mark J. Alberts, MD, FAHA; Oscar Benavente, MD; Karen Furie, MD, MPH, FAHA; Larry B. Goldstein, MD, FAHA, FAAN; Philip Gorelick, MD, MPH, FAHA, FAAN; Jonathan Halperin, MD, FAHA; Robert Harbaugh, MD, FACS, FAHA; S. Claiborne Johnston, MD, PhD; Irene Katzan, MD, FAHA; Margaret Kelly-Hayes, RN, EdD, FAHA; Edgar J. Kenton, MD, FAHA, FAAN; Michael Marks, MD; Lee H. Schwamm, MD, FAHA Thomas Tomsick, MD, FAHA
Abstract The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches for the implementation of guidelines and their use in high-risk populations. (Stroke. 2006;37:577-617.)
Key Words: AHA Scientific Statements • ischemia • ischemia attack, transient • stroke
Survivors of a transient ischemic attack (TIA) or stroke have an increased risk of another stroke, which is a major source of increased mortality and morbidity. Among the estimated 700 000 people with stroke in the United States each year, 200 000 of them are among persons with a recurrent stroke. The number of people with TIA, and therefore at risk for stroke, is estimated to be much greater. Epidemiological studies have helped to identify the risk and determinants of recurrent stroke, and clinical trials have provided the data to generate evidence-based recommendations to reduce this risk. Prior statements from the American Heart Association (AHA) have dealt with primary1 and secondary stroke prevention.2,3 Because most strokes are cerebral infarcts, these recommendations focus primarily on the prevention of stroke among the ischemic stroke or TIA group. Other statements from the AHA have dealt with acute ischemic stroke,4 subarachnoid hemorrhage (SAH),5 and intracerebral hemorrhage (ICH).6 Recommendations follow the AHA and the American College of Cardiology (ACC) methods of classifying the level of certainty of the treatment effect and the class of evidence (see Table 1).7

B. Patent Foramen Ovale

Patent foramen ovale (PFO), a persistence of an embryonic defect in the interatrial septum, is present in up to 27% of the general population. Atrial septal aneurysms, defined as >10-mm excursions of the interatrial septum, are less common, affecting {approx}2% of the population. The prevalence of PFOs and atrial septal aneurysms does not appear to vary by race/ethnicity.313 The presence of an atrial septal aneurysm or a large right-to-left shunt has been reported to increase the risk of stroke in patients with PFO.314–322

Studies have found an association between PFO and cryptogenic stroke.323–327 In a study of 581 patients <55 years of age with cryptogenic stroke, the prevalence of PFO was reported to be 46%.328 In the Patent Foramen Ovale in Cryptogenic Stroke Study (PICSS), a substudy of WARSS, which randomized patients between 30 and 85 years of age with noncardioembolic stroke to either warfarin or aspirin, the prevalence of PFO was 34%.327 PFOs were identified in 39% of patients with cryptogenic stroke compared with 29% in those with a defined mechanism (P<0.02).327

Estimates for the rate of annual stroke recurrence in cryptogenic stroke patients with PFO vary widely, ranging from 1.5% to 12%, depending on the study population.314,315,317,323,327,329 In the Lausanne Study, 140 patients representing 41% of a population-based cohort with stroke or TIA were found to have a PFO (mean age, 44±14 years) and were followed up for an average of 3 years. Venous thrombus was detected in 5.5%. An alternative cause of stroke was identified in 16%. PFO was not a significant predictor of 2-year risk of stroke recurrence in PICSS.

In another study from France, recurrent stroke risks were evaluated among patients 18 to 55 years of age with ischemic cryptogenic stroke and PFO on transesophageal echocardiography treated with aspirin.315 After 4 years, the rates of recurrent stroke were 2.3% for PFO alone, 15.2% for PFO with atrial septal aneurysm, and 4.2% with neither. Although the increased risk associated with PFO and atrial septal aneurysms is supported by some studies, this finding remains controversial because other studies have failed to show a higher risk.314,316,323,327

1. Medical Therapy
In the Lausanne Study, the annual infarction rate on conventional therapies (66% aspirin, 26% anticoagulation, 8% PFO closure) was 1.9%. The rate of stroke and death was 2.4%. There were no ICHs.323 Cujec et al329 analyzed a cohort of 90 cryptogenic stroke patients <60 years of age, more than one half of whom had a PFO, and reported that warfarin was more effective than antiplatelet therapy for secondary stroke prevention. PICSS provides the only randomized comparison of warfarin and aspirin in patients with PFO. Because this was a substudy of WARSS, it was not designed to evaluate the superiority of an antithrombotic strategy among those with stroke and a PFO.327 In PICSS, 33.8% of 630 patients found to have a PFO on transesophageal echocardiography and randomized to either aspirin 325 mg or warfarin (target INR range, 1.4 to 2.8) were followed up for 2 years. There was no significant difference in rates of recurrent stroke or death in patients with PFO versus those with no PFO. Event rates among the cryptogenic stroke patients with PFO treated with aspirin (17.9%, n=56) and warfarin (9.5%, n=42) were not statistically significant (HR, 0.52; 95%CI, 0.16 to 1.67; P=0.28) and similar to those cryptogenic stroke patients without PFO (HR, 0.50; 95% CI, 0.19 to 1.31; P=0.16).

2. Surgical Closure
There are conflicting reports concerning the safety and efficacy of surgical PFO closure. After 19 months of follow-up, there were no major complications or recurrent vascular events found among a series of 32 young patients with PFO and cryptogenic embolism or TIA and PFO who underwent surgical closure.330 Similar results were reported in another independent series of 30 patients.331 In a 2-year follow-up of a cohort of 91 patients with cryptogenic stroke or TIA who underwent surgical closure, 7 TIAs but no major complications were reported.332 Another series found poorer outcomes, with a recurrence rate of 19.5% at 13 months after surgical closure.333

3. Transcatheter Closure
A recent review of 10 nonrandomized unblinded transcatheter closure studies for secondary prevention reported a 1-year rate of recurrent neurological events of 0% to 4.9% in patients undergoing transcatheter closure compared with 3.8% to 12.0% in medically treated patients.334 The incidence of major and minor procedural complications was 1.45% and 7.9%, respectively.334 Other randomized trials evaluating the efficacy of transcatheter closure devices are ongoing.

Our recommendations are consistent with those of other organizations that have also published recommendations with regard to the management of stroke and TIA patients with PFO.335


  1. For patients with an ischemic stroke or TIA and a PFO, antiplatelet therapy is reasonable to prevent a recurrent event (Class IIa, Level of Evidence B). Warfarin is reasonable for high-risk patients who have other indications for oral anticoagulation such as those with an underlying hypercoagulable state or evidence of venous thrombosis (Class IIa, Level of Evidence C).
  2. Insufficient data exist to make a recommendation about PFO closure in patients with a first stroke and a PFO. PFO closure may be considered for patients with recurrent cryptogenic stroke despite optimal medical therapy (Class IIb, Level of Evidence C) (Table 7 Up).