Common heart defect identified as stroke risk in elderly: Cleveland Clinic expert hopes new finding will lead to screening for patent foramen ovale in older adults with unexplained strokes, because effective treatments exist.
But among people under 55 who suffer a stroke with no obvious cause (called a cryptogenic stroke), a PFO is often considered the prime suspect. For older adults, a PFO has been largely ignored as a contributor to strokes because seniors often have other stroke risks as well, such as high blood pressure and cholesterol, diabetes, and atrial fibrillation, according to Cleveland Clinic cardiologist Richard Krasuski, MD.
"The thinking was that if you had an unexplained stroke and you were older with a patent foramen ovale, it's more likely that it [PFO] was an innocent bystander," Dr. Krasuski says.
However, a study reported in the Nov. 29 issue of the New England Journal of Medicine shows that PFO is an important cause of stroke in older patients, too. A PFO was present in more than 28 percent of the cryptogenic stroke patients age 55 and older who participated in the study.
Dr. Krasuski says he hopes the study will prompt more doctors to consider screening older unexplained stroke patients for a PFO and treating them with medication or, if deemed appropriate, a procedure to close the opening.
"Here's a study now that shows we shouldn't discount patent foramen ovale if we can't find other causes," Dr. Krasuski says.
Discovering a PFO
Diagnosing a PFO is relatively easy, but treatment decisions are more complicated, Dr. Krasuski explains.
A PFO forms when the opening in the septum between the right and left atria fails to close up after birth. While in the womb, a baby needs that opening so blood can circulate from the right side of the heart to the left, without the blood traveling through still-developing lungs, Dr. Krasuski says.
But soon after birth, the foramen ovale closes up on its own in most people.
Usually, someone with a PFO will never know it unless he or she has a stroke or a transient ischemic attack (TIA), a condition in which a person suffers stroke-like symptoms for less than 24 hours.
If a PFO is suspected, a patient can expect to have an echocardiogram, which uses sound waves to create a moving picture of the heart's internal structure and activity.
And to get a good ultrasound view of a potential PFO, a patient is given an IV of saline, into which bubbles are introduced. If the bubbles can be seen crossing to the left side of the heart, it's likely to be a PFO, Dr. Krasuski says.
To help prevent a PFO from contributing to a stroke, the first choice is blood-thinning medications such as aspirin, warfarin (Coumadin) or clopidogrel (Plavix); Dr. Krasuski says warfarin is usually the most effective choice.
A catheter-based procedure to close a PFO is also an option, but Dr. Krasuski says he can rarely justify putting a device in a person's heart when there's no guarantee that it could stop a second stroke.
"There's very little evidence available at all that it will prevent a future stroke in someone who suffers a first stroke and was not previously on a blood thinner," he says. "There's no proof that a device in that situation would be any better than medical therapy though studies are currently trying to answer that question."
However, a patient on drug therapy who has a second event would be considered a candidate for PFO closure, Dr. Krasuski adds.
With any patient, young or old, Dr. Krasuski explains the advantages and potential risks of drug therapy alone, as well as the combination of medications and the procedure to repair the defect. The closure device is a small, umbrella-like occluder that can be collapsed inside a catheter and then opened at the PFO site.
Just how effective the catheter-based procedure is in preventing future strokes among PFO patients is currently being studied in the CLOSURE I trial at Cleveland Clinic and other hospitals around the country.
Dr. Krasuski says that based on the NEJM study and his own experience, he hopes older patients are well represented in the research to help improve treatment plans in the future.
"This should open people's eyes," Dr. Krasuski says. "We shouldn't be excluding people from PFO research just because they're older."
WHAT YOU SHOULD KNOW
* Migraine headaches appear to be more common among people with a PFO and early research suggests that PFO closure can reduce headache symptoms.
* If a PFO closure device is implanted, heart tissue will eventually grow over the device, further securing the closure.
* Because a temporary irregular heartbeat may develop after a PFO closure procedure, report those symptoms and other problems such as chest pain or fatigue to your doctor.
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|Article Type:||Clinical report|
|Date:||Apr 1, 2008|
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