For patients undergoing transcatheter atrial septal defect (ASD) closure, the use of dual antiplatelet therapy consisting of clopidogrel and aspirin led to fewer migraine headaches and less severe migraine episodes compared with taking aspirin alone, according to a randomized, double-blind trial.

Lead researcher Josep Rodés-Cabau, MD, of the Quebec Heart and Lung Institute, presented the results on Nov. 9 at the American Heart Association Scientific Sessions. The findings were simultaneously published online in JAMA.

“These results have an important clinical impact on the management of patients undergoing transcatheter ASD closure and may be considered when analyzing the results of studies assessing the efficacy of interatrial shunt closure for the treatment of migraines,” Rodés-Cabau said. “This study provides also further insight into the mechanisms of migraine, suggesting that a potential role of prothrombotic status on the pathogenesis of migraines in certain groups of patients can be established.”

The CANOA (Clopidogrel for the Prevention of New-Onset Migraine Head- ache Following Transcatheter Closure of Atrial Septal Defects) 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.

Previous studies found approximately 15 percent of patients had new-onset migraine attacks following transcatheter ASD closure. Rodés-Cabau noted physicians typically prescribe aspirin for six months after the procedure.

In the CANOA study, Rodés-Cabau and his colleagues randomized 171 patients at six centers in Canada to receive 75 mg of clopidogrel and 80 mg of aspirin per day or 80 mg of aspirin per day plus placebo.

Treatment began 24 hours before the ASD closure procedure and continued for three months following the procedure. The first patient enrolled in December 2008, and the final follow-up visit occurred in February 2015.

All patients completed a migraine headache questionnaire within 60 days of undergoing transcatheter ASD closure with the Amplatzer Septal Occluder device (St. Jude Medical). A neurologist then evaluated the questionnaire to determine if patients had a history of migraines. Patients who had migraines were excluded from the trial. They were also excluded if they had a previous stroke, needed anticoagulation therapy, had an allergy or could not tolerate aspirin or clopidogrel, used an ASD closure device other than the Amplatzer Septal Occluder or refused to sign the informed consent form.

Physicians performed transcatheter ASD closure through the transfemoral venous approach and used echocardiography. During the procedure, patients received intravenous heparin. They also underwent transthoracic echocardiography at discharge and at three months following randomization.

At baseline, the mean age was 49, and 62 percent of patients were women. During the study, 91 percent of patients were adherent to the medications.

Within three months of the procedure, 15.8 percent of patients had a diagnosis of new-onset migraine attacks. The incidence of new-onset migraine attacks was 9.5 percent in the clopidogrel group and 21.8 percent in the placebo group.

The mean number of monthly migraine days was 0.4 in the clopidogrel group and 1.6 in the placebo group. After three months, the mean total number of migraine days was 0.9 and 4.2, respectively.

Of the patients with migraines, those in the clopidogrel group had reduced migraine severity as assessed by the Migraine Disability Assessment questionnaire. The researchers found 36.8 percent of patients in the clopidogrel group and no patients in the placebo group had moderate to severe disabling migraine attack. However, there was no significant difference between the groups in the number of migraine days per month or migraine duration.