Researchers Find Hole in Heart Does Not Make Stroke Inevitable

Mayo Clinic researchers have found that - contrary to current thinking by some in the medical community - a patent foramen ovale (PFO), a small hole between the two upper chambers of the heart, does not predestine an individual to a stroke later in life. Findings will appear online on Friday, Dec. 9 in the Journal of the American College of Cardiology.

"In the general population, it does not appear there is a direct association between the detection of a PFO and having a stroke," says Irene Meissner, M.D., Mayo Clinic neurologist and lead study researcher. "Our study looked at the general population with PFO; if you detect PFO in someone who has already had a stroke, one cannot immediately assume that the PFO is causative."

Adds Bijoy Khandheria, M.D., chair of the Division of Cardiology at Mayo Clinic in Arizona and study author, "Our findings show that the hole is not always the guilty party in a stroke; it may be an innocent bystander.

If someone says you have a tiny hole in your heart, it's not doom and gloom. After following patients in our study with small holes in the heart for five years, their risk for stroke was no different than those who did not have the hole."

PFO is a common, benign, congenital condition occurring in one out of four people in which the partition between the upper right and left heart chambers fails to close shortly after birth. PFO also is often a stealth condition. "Most people don't know they have this - it's usually a silent condition," says Dr. Meissner.

According to the study researchers, PFOs are now detected more often, usually by chance, due to more frequent use of cardiovascular imaging. Physicians now send patients more often to have transesophageal echocardiograms - heart scans via a probe inserted into the esophagus - which are conducted to detect a variety of heart conditions. A transesophageal echocardiogram is considered the best test to detect a hole in the heart, indicates Dr. Meissner.

The current practice of closing PFOs derives from many observational research studies demonstrating higher incidence of PFO in stroke patients, according to the Mayo Clinic researchers. The methodologies for many of these studies were problematic, however, according to Dr. Meissner.

How Findings Apply to Patients with PFO

Due to the lack of association between PFO and later stroke found in this study, the Mayo Clinic investigators indicate that closure surgery should not be reflexive.

"We now see that a hole in the heart leading to stroke is not borne out in our study, the largest transesophageal echocardiogram-based study of the general population," says Dr. Khandheria. "Just because you have a hole, you don't automatically need to have it closed. You don't need to panic."

Dr. Meissner agrees. "More people are now getting PFOs repaired unnecessarily," she says. "Some don't need to be fixed. For patients who know they have a PFO and have not had neurologic symptoms, I'd advise them to sit tight. They don't need heart surgery to close the PFO."