Risk of Recurrent Stroke with Patent Foramen Ovale and Atrial Septal Aneurysm

The Quality Standards Subcommittee of the American Academy of Neurology has released a new guideline entitled, “Practice Parameter: Recurrent Stroke with Patent Foramen Ovale and Atrial Septal Aneurysm.” The guideline is available online athttp://www.neurology.org/cgi/content/full/62/7/1042.

A patent foramen ovale (PFO) is a small opening between the two upper chambers of the heart, or the atria. The opening normally closes shortly after birth, but does not close in up to 25 percent of people. Current thinking is that patients with a PFO who have had a stroke with no known cause and received treatment are at greater risk of having a second stroke than those patients who had a stroke and did not have a PFO. However, this is not true according to the guideline. Having a PFO does not place the patient at increased risk for a recurrent stroke.

There has been some debate within the medical community about whether PFOs should be closed or managed with medication. According to the guideline, there is no evidence to support or refute the role of closing a PFO for stroke prevention. More research is needed to answer this question.

Persons younger than 55 years with both a PFO and an atrial septal aneurysm (ASA) may have an increased risk of a second stroke. An ASA is a bulge in the wall between the atria and occurs in an estimated 5 percent of people. Up to 70 percent of people with an ASA also have a PFO.

Both aspirin and warfarin reduce the risk of blood clots that can cause stroke. According to the guideline, there is inadequate evidence to determine whether aspirin or warfarin is the better medication to prevent subsequent stroke and death. However, the side effect of minor bleeding is more common with warfarin than aspirin.

The authors of the guideline call for more research on the effects of an ASA on stroke risk and how ASAs should be managed. They also encourage physicians to communicate with patients who have had a stroke and are on aspirin or warfarin therapies about their future health risks. Patients should know that the presence of a PFO does not necessarily signify an increased risk for subsequent stroke, however these patients should consider participating in research studies to further address this condition.