Earlier studies have indicated that there may be a link between a particular congenital heart anomaly, a patent foramen ovale (PFO), and migraine. Some patients - particularly those suffering from migraine with aura- have had reductions in the frequency and severity of migraines following closure of their PFO.
In the Rush study, interventional cardiologists will close the PFO in the catheterization lab using an implant that acts like an umbrella, crossing over the chambers in attempt to occlude or close the flaps together.
Principal investigator Dr. Clifford Kavinsky and his team have started enrolling patients for the clinical trial, called MIST II (Migraine Intervention with BioSTAR). The team is looking for individuals with severe migraines to see if they may have a patent foramen ovale.
A PFO is a small opening between two overlapping sections of tissue, which form a division between the upper chambers of the heart, the right atrium and the left atrium. In the womb, this opening is present since it makes circulation more efficient for the developing fetus. After birth, the flaps normally fuse together to form a solid wall, called a septum, between the chambers. However, in about 25 percent of the population, the flaps do not fuse together.
The PFO then works like a valve, staying closed most of the time but opening when certain activities cause a build up of pressure inside the chest. When opened, the PFO may permit unfiltered venous blood to cross from the right atrium to the left atrium rather than passing through the lungs. The unfiltered venous blood may contain elements that can trigger migraines in some patients.
"In a smaller predicate trial of similar design conducted in the United Kingdom , headache specialists observed a significant treatment effect with 42 percent of patients experiencing a 50 percent reduction in migraine headache days and 37 percent reduction in frequency and duration of migraine attacks," says Kavinsky.
"The combination of the bioabsorbable septal repair implant and the longer duration of the MIST II Trial are expected to provide even more positive outcomes. Finding an effective therapy for this group of patients who are refractory to medical therapy would be an important advance in the treatment of migraine."
Rush is one of the first centers in the world to employ the bioabsorbable septal repair technology which provides biological repair of structural heart defects using the patient's natural healing response as a part of this study.
"Recently completed trials of the implant, published in Circulation (the Journal of the American Heart Association), reflect a high rate of early and complete defect closure, and since 90 to 95 percent of the implant is absorbed during the natural healing process, future left atrial access is preserved."
The trial is a prospective, randomized, multi-center, controlled study. The double-blinded trial is designed to randomize approximately 600 migraine patients with a PFO to either PFO closure with the bioabsorbable technology or a control arm.