Like most people born with a hole in the heart called a patent foramen ovale (PFO), Phoebe Dow had no idea she was walking around with an increased risk for stroke – until the day she experienced one at just age 19. Stroke survivors such as Dow are educated by neurologists like Anjail Sharrief, M.D., M.P.H., of McGovern Medical School at UTHealth, about the prevalence of the recurrent stroke in persons with PFOs. Dow had the opportunity to enroll in what was then a new trial to assess a device to close the hole, led by cardiologist Richard Smalling, M.D., Ph.D., at McGovern Medical School and Memorial Hermann Heart & Vascular Institute-Texas Medical Center. A decade later, Dow remains stroke-free.

From Anjail Sharrief, M.D., M.P.H., assistant professor at McGovern Medical School and director of the Stroke, Transitions, Education and Prevention Clinic at UT Physicians, five things you need to know about the prevalence of recurrent stroke in patients with PFOs:

1. Up to 25 percent of the population has a PFO but may not know it until they suffer a stroke. Every year, approximately 100,000 Americans suffer PFO-related strokes, according to the National Stroke Association.
2. In patients with a stroke, an echocardiogram (ultrasound of the heart) should be ordered to help determine whether a stroke may have been related to a PFO.
3. Doctors will determine whether there are blood clots in the legs that could have passed through the PFO to cause a stroke, or whether a person has a genetic or hematologic condition that makes them more prone to blood clots.
4. Aspirin or a stronger blood thinner will need to be taken after a stroke, whether it is related to a PFO or not. Blood pressure control, diet and exercise will also help to prevent another stroke.
5. If PFO is likely the cause, the patient’s neurologist and cardiologist will work together to determine whether the patient is a candidate for a PFO closure procedure. Results of the study Dow was enrolled in were recently published in the New England Journal of Medicine and showed that patients who had the PFO closure procedure were 45 percent less likely to have a recurrent stroke than participants who received standard medical therapy.  Two additional studies evaluating this problem also published in the same issue of the New England Journal of Medicine had similar findings.