Retrospective review of thienopyridine therapy in migraineurs with patent foramen ovale

OBJECTIVE: We retrospectively reviewed our clinical experience using off-label thienopyridine agents in patients with migraine headache (MHA) and patent foramen ovale (PFO). METHODS: Between 2011 and 2017, MHA/PFO patients referred to our practice were clinically treated with clopidogrel specifically for MHA. Those with ≥50% reduction in monthly MHA days compared with baseline were deemed MHA responders. MHA nonresponders with inadequate platelet inhibition by PRU testing were offered prasugrel. Thienopyridine-responsive patients were then offered PFO closure. RESULTS: Of 136 patients (86% female, mean age 37.9 years, mean MHA burden 14.7 days/month), 80 (59%) were MHA responders to clopidogrel. The clopidogrel responder rate was equivalent in episodic, chronic, aura, and nonaura subgroups. A total of 19/45 (40%) MHA nonresponders had inadequate platelet inhibition by PRU testing on clopidogrel. Sixteen of those patients received prasugrel, were adequately platelet inhibited by PRU, and 10/16 (62%) converted to MHA responders. A total of 56/90 thienopyridine-responsive patients underwent subsequent PFO closure with thienopyridine discontinuation after 3 months. Ninety-four percent had ongoing MHA relief. A total of 8/8 responders who stopped thienopyridine without PFO closure had resumption of MHA symptoms. CONCLUSION: Successful P2Y12 platelet inhibition seemed to reduce MHA symptoms in some patients with PFO, suggesting a platelet-based mechanism/trigger. The nearly parallel response to PFO closure may mechanistically link venous platelet activation with the right-to-left shunt of PFO. Thienopyridine responsiveness could be used to enrich the study population for a new MHA/PFO trial. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that in patients with PFO, P2Y12 inhibition improved MHA symptoms.