Researchers at Evanston Northwestern Healthcare are studying whether closing a tiny hole in the heart will reduce or cure migraine headaches, a chronic and disabling condition that affects about 10 percent of the population.

The common heart defect is called a patent foramen ovale (PFO). During fetal development, a small, flap-like opening develops in the wall between the right and left upper chambers of the heart. This flap usually closes at birth. But in about 25 percent of people, the opening remains throughout life.

When a person with this defect creates pressure inside their chest - such as when they cough or sneeze - the flap can open, and blood can flow through the PFO from the upper right chamber to the upper left chamber without first being filtered by the lungs.

The vast majority of people with PFO don’t have any problems, said Dr. Ted Feldman, director of cardiac catheterization at Evanston Northwestern Healthcare and principal investigator of the ESCAPE Migraine clinical trial. But for a small percentage, a small blood clot can pass through the hole, lodge in the brain and cause a stroke.

Discovery of the possible link between migraine headaches and PFO happened by chance. We’ve been closing PFO defects in patients who had stroke for a few years, said Feldman. Patients who suffered from migraines started telling us that after their PFO was fixed, their migraines were reduced or completely eliminated. Recent studies show that 40-50 percent of migraine sufferers have a PFO.

Feldman, along with Dr. Susan Rubin, are co-principal investigators of the ESCAPE Migraine clinical trial which is studying whether treating PFO in migraine sufferers without stroke will reduce the frequency of migraine attacks. The clinical trial expects to enroll 500 patients in the U.S. who have not found relief from migraines with preventive medicine, have experienced unwanted side effects from drug therapy or have been advised by a doctor against medications due to another condition.

Two-thirds of patients will have their PFO closed, while the other third will have a tube placed in their heart to measure the size of their PFO. The risk of migraine is related to the size of the PFO. Patients will not know until the end of the trial if they were assigned to receive PFO closure.

To close the PFO, physicians will guide a small device through a vein in the leg to the heart. Once inside the heart, the device will unfold to cover and close the PFO. The PFO procedure will use the Premere™ PFO Closure System, designed by St. Jude Medical, which is only available through this clinical trial and not currently approved by the FDA.

Trial participants meet with a cardiologist for a heart evaluation and a neurologist to evaluate and monitor their migraines after intervention. They will be asked to maintain an electronic journal of their migraines for one year.

The most positive result of this trial would be that a high number of migraine patients are cured, said Feldman. We’ll learn which types of headache patients respond best to therapy so we can better identify responders. A realistic expectation is there will be some patients who have complete relief, the majority of patients will have a spectrum of relief and some for whom it won’t work.

My greatest hope is that the need to take these very potent and sometimes side-effect ridden drugs with marginal success will become history, said Feldman. Nothing would please me more than to have that type of revolution in migraine therapy.

For more information on the ESCAPE Migraine clinical trial, visit www.ESCAPEmigraine.com.

By Terri Yablonsky Stat

Special to the Tribune