Migraine sufferers who want to know more about patent foramen ovale (PFO) and a possible connection to Migraine should be interested in the results of the MIST (Migraine Intervention with STARFlex® Technology) study. MIST was the British double-blind study designed to evaluate the effect of PFO (patent foramen ovale) closure on Migraine. (See: PFO and Migraine -: "Hole in the Heart and Migraine?.)
Doctors Peter Wilmshurst and Andrew Dowson, co-primary investigators of MIST, jointly presented the results on March 13, 2006, at the American College of Cardiology's 55th Annual Scientific, Late-Breaking Clinical Trials Sessions. Dr. Wilmshurst is Consultant Cardiologist at Royal Shrewsbury Hospital, Shrewsbury. Dr. Dowson is Director of the King's Headache Service, Kings College Hospital, London.
MIST, which was conducted in the United Kingdom, is the first prospective, randomized, double-blinded study to evaluate the effect of PFO (patent foramen ovale) closure on Migraine headaches. NMT 's proprietary PFO closure technology, STARFlex®, was exclusively used in the study. A PFO is a common heart defect that is a risk factor for Migraine headaches in some patients. The PFO allows venous blood, unfiltered and unmanaged by the lungs, to enter the arterial blood circulation. The unfiltered venous blood may contain elements that can trigger Migraines in some patients.
The study, screened 432 Migraine with aura patients for a PFO and enrolled 147 patients into the study. A significant finding in the MIST study is that over 60% of those screened had a right to left shunt, a heart defect, which allows blood to cross from the right to left chambers of the heart, bypassing the lungs. Of those patients, almost 40% had a moderate or large PFO, six times greater than the general population.
Dr. Wilmshurst said,
"With no prior randomized, double blind study to draw from, MIST was designed and primary endpoints were selected based upon a review and analysis of several previously reported device observational and Migraine drug studies. Consistent with what was reported in the observational studies, we selected a challenging primary endpoint of 40% elimination in Migraine headache at six months in the treatment group. Preliminary analysis of MIST data did not satisfy that endpoint, however, we are seeing a significant treatment effect and promising trend to support PFO closure with STARFlex® as a treatment option for certain types of Migraine."