by LAURAN NEERGAARD, AP Medical Writer
2 hours, 50 minutes ago



WASHINGTON - One in five adults has a little hole in the heart. Most
will never know it. But the defect may play a role in certain
strokes and severe migraines, leading thousands to get devices
implanted to seal it shut.

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The problem: Doctors haven't yet proved when the hole is harmful,
and whether fixing the heart in turn helps the head.

It's a controversy dividing cardiologists, even as use of the
umbrella-shaped implants steadily rises. Now the Food and
Drug Administration has taken an unusual step to push manufacturers
to settle the issue, stopping promotion of the expensive implants.

"What's really incumbent upon us now is proving these relationships
and proving that closing the hole is beneficial," says Dr. Robert
Sommer of Columbia University Medical Center, who implants the
devices and is helping to study them.

Everyone is born with a tiny flap-like opening between the heart's
two upper chambers. Usually, it grows shut during infancy. But in at
least 20 percent of the population, the opening doesn't heal over, a
defect called "patent foramen ovale" or PFO.

When blood returns to the heart, it's supposed to go to the lungs to
pick up more oxygen and be filtered clean. A PFO can allow some
blood to seep back into circulation without that filtering step. The
theory: That could allow small blood clots or other substances into
the bloodstream, traveling straight to the brain.

What's the evidence? It's mostly circumstantial. Among people who
have strokes at a young age — 55 or under — with no apparent risk
factors, up to 60 percent also have a hole in the heart. By some
estimates, that could equal 30,000 to 60,000 strokes a year.

In the late 1990s, cardiologists started aggressively sealing PFOs
in stroke survivors, in hopes of lowering their risk for further
strokes. They threaded tiny implants into the heart through a hole
in the groin, pulling them against the PFO's flap to seal it shut.

Then some implant recipients started reporting an odd side effect:
Their migraine headaches went away. Subsequent research suggested at
least 40 percent of people who suffer a severe type of migraine —
the kind that comes with an "aura" or visual disturbance — have
fairly large PFOs.

None of that research proves a PFO actually causes the ailments,
cautioned Dr. Joseph Carrozza of Boston's Beth Israel