Three months of clopidogrel plus aspirin was associated with a reduced frequency of migraine in patients who had undergone transcatheter closure of an atrial septal defect (ASD) in the CANOA study.

Josep Rodes-Cabau, M.D., of Laval University, Quebec City, Canada, and colleagues randomly assigned 171 patients with an indication for ASD closure and no history of migraine to receive dual antiplatelet therapy (aspirin + clopidogrel [the clopidogrel group], n = 84) or single antiplatelet therapy (aspirin + placebo [the placebo group], n = 87) for 3 months following transcatheter ASD closure. This JAMA study is being released to coincide with its presentation at the American Heart Association's Scientific Sessions 2015.

Occurrence of new-onset migraine attacks has been reported in approximately 15 percent of patients following transcatheter ASD closure, with the majority of initial episodes occurring within the days to weeks following the procedure. Aspirin is often prescribed for 6 months following the procedure. Preliminary studies have suggested an association with a lower incidence and severity of migraine headaches following ASD closure when ticlopidine or clopidogrel is added to aspirin treatment.

The CANOA researchers found that patients in the clopidogrel group had a reduced average number of monthly migraine days within the 3 months following the procedure (0.4 days) vs. the placebo group (1.4 days) and a lower incidence of migraine attacks (9.5 percent for the clopidogrel group vs. 22 percent for the placebo group). Among patients with migraines, those in the clopidogrel group had less-severe migraine attacks (zero patients with moderately or severely disabling migraine attacks vs. 37 percent [7 patients] in the placebo group). No significant increase in adverse events was observed with the use of dual vs. single antiplatelet therapy.

"Further studies are needed to assess generalizability and durability of this effect," the authors write.

This study was funded by unrestricted grants from Sanofi and St. Jude Medical and a grant from the Foundation of the Quebec Heart and Lung Institute.