Effect of Clopidogrel and Aspirin vs Aspirin Alone on Migraine Headaches After Transcatheter Atrial Septal Defect Closure: One-Year Results of the CANOA Randomized Clinical Trial.

Importance Adding clopidogrel to aspirin for 3 months after transcatheter atrial septal defect (ASD) closure results in a lower incidence of new-onset migraine attacks. However, the outcomes at 6- to 12-month follow-up (after clopidogrel cessation at 3 months) remain largely unknown. Objective To assess the incidence of migraine attacks at 6- and 12-month follow-up after transcatheter ASD closure. Design, Setting, and Participants This prespecified analysis of a randomized, double-blind clinical trial included patients with no prior history of migraine undergoing ASD closure from 6 university hospitals in Canada from December 2008 to November 2014. Patients were followed up at 3, 6, and 12 months, and a migraine headache questionnaire was administered at each time. Analysis began June 2019. Interventions Patients were randomized (1:1) to receive dual antiplatelet therapy (aspirin plus clopidogrel; n = 84) vs single antiplatelet therapy (aspirin plus placebo; n = 87) for 3 months following transcatheter ASD closure. After 3 months, only single antiplatelet therapy (aspirin) was pursued. Main Outcomes and Measures Incidence and severity of migraine attacks at 6- and 12-month follow-up. Results The mean (SD) age of the study population was 38 (12) years, with 106 women (62%). A total of 27 patients (15.8%) had new-onset migraine attacks within the 3 months following ASD closure (8 of 84 [9.5%] vs 19 of 87 [21.8%] in the initial clopidogrel and placebo groups, respectively;P = .03). After cessation of clopidogrel and aspirin monotherapy, the percentage of patients with migraine attacks decreased over time, with 8 (4.7%) and 4 patients (2.3%) continuing to have migraine attacks at 6 and 12 months, respectively (vs 3 months:P  Conclusions and Relevance New-onset migraine attacks after ASD closure improved or resolved spontaneously within 6 to 12 months in most patients. No significant rebound effect was observed after clopidogrel cessation at 3 months. These results demonstrate a low rate of migraine events beyond 3 months following transcatheter ASD closure and support the early discontinuation of clopidogrel therapy if administered. Trial Registration ClinicalTrials.gov Identifier:NCT00799045