Stroke survivors who also have patent foramen ovale (PFO), a hole in the heart, could benefit from a device that closes the PFO to help prevent future strokes, according to research presented at the American Stroke Association's International Stroke Conference 2016.

Researchers studied 980 stroke survivors, ages 18 to 60, who had strokes that were determined to be of unknown cause (cryptogenic) but had a PFO. A PFO results when a hole between the heart's chambers does not close at birth. It is thought that blood clots from a vein may travel through the PFO, block an artery in the brain and cause a stroke. Researchers implanted a PFO closure device in half the patients and prescribed blood thinning medications to the other half to determine which treatment might be better for preventing subsequent strokes.

In a long-term follow-up, researchers found:

  • Forty-two patients had recurrent strokes, including 18 in the group that received the device and 24 in the medicine group.
  • 56 percent of the device group's recurrent strokes were cryptogenic and the remainder were unrelated to their PFO.
  • 79 percent of the medication group's recurrent strokes were cryptogenic.
  • The size and location of the recurrent strokes also tended to be different. Those without the device tended to have large strokes more often than those with the device, and they were more often on the edges of the brain than deep inside.

Researchers said the device can only prevent strokes related to PFO. PFO-related strokes tend not to have another cause, are larger and on the edge of the brain. There were fewer such strokes in the device group than in the medical group, lending support to the probability that the PFO device prevents PFO recurrences.