Abstract 3677: Prospective, Multicenter, Randomized, Double Blind, Placebo-Controlled Trial to Evaluate the Efficacy of Patent Foramen Ovale Closure with the STARFlex® Septal Repair Implant to Prevent Refractory Migraine Headaches: The MIST Trial
Background: Observational studies demonstrated that patent foramen ovale (PFO) closure in stroke and decompression sickness patients led to improvement or resolution of migraine in 65–90% of patients.
Hypothesis:The MIST (Migraine Intervention with STARFlex® Technology) Trial is the first prospective, placebo-controlled trial designed to assess the hypothesis that: - There is a higher prevalence of moderate to large PFO in migraine with aura patients than in the general population - PFO closure with STARFlex® will improve or resolve migraine in these patients
Methods: Patients with frequent migraine (and some aura) that was not controlled with prophylactic medications were recruited. Transthoracic contrast echocardiography was used to detect right-to-left shunts and to semi-quantitatively assess their size. Patients with a large or medium size PFO were randomized to PFO closure with the STARFlex® implant or to a sham procedure. Patients and their headache specialist were blind to randomization during the 180-day follow-up period.
Results: 432 patients were recruited and screened. 260 (60.2%) had a shunt, of which 163 (37.7% of total and 62.7% of those with shunts) had a large PFO. The mean diameter of the PFOs was 9.21mm (±3.27mm). 73 patients were randomized to the sham procedure and 74 to the closure procedure with. 42% of patients who had their PFOs closed with STARFlex had a 50% reduction in migraine compared to 23% in the control arm. The difference between the two arms may increase over time - further results and analysis will be available for first presentation at AHA
Conclusion: Large right-to-left shunts (mostly PFOs) are 6 times more common in migraine with aura patients than in the general population. The average diameter of the PFO in these patients is similar to that seen in patients with paradoxical embolism. While the aggressive primary end point of 40% complete resolution was not achieved, MIST has demonstrated that closure of PFO with STARFlex® provides a significant treatment effect in some patients. Longer follow up of this patient population and future trials will improve our understanding.