The addition of clopidogrel on top of aspirin may reduce the occurrence of new-onset migraine headache episodes following transcatheter ASD closure.

The objective is to evaluate the incidence and severity of new-onset migraine headache episodes following transcatheter ASD closure in patients treated with aspirin alone compared to those on aspirin + clopidogrel therapy as antithrombotic treatment after the procedure.

This is a prospective, randomized, double blind, multicenter study, including patients with no previous history of migraine attacks who have been diagnosed with an ASD and for whom transcatheter ASD closure has been clinically indicated. Patients will be randomized either to aspirin (80 mg/day) or aspirin (80 mg/day) + clopidogrel (75 mg/day) for 3 months following ASD closure. The occurrence and severity of migraine headaches will be evaluated by a neurologist using a structured headache questionnaire at 1 month and 3 months following ASD closure. An additional 6 month and 1 year follow-up evaluation will be exploratory according to local feasibility.

Inclusion Criteria:

• Patients ≥ 18 year old undergoing transcatheter ASD closure with the Amplatzer Septal Occluder device (AGA medical Corp., MN, USA).
• Female subjects must be post-menopausal, surgically sterile, or using an effective method of birth control.
• Signed an informed consent document.

Exclusion Criteria:

• Allergy or intolerance to any of the antithrombotic drugs (aspirin, clopidogrel) used in the study.
• Need for anticoagulation therapy.
• Use of ASD closure devices other than the Amplatzer Septal Occluder device.
• History of migraine headaches (based on migraine headache questionnaire).
• Refusal to sign the informed consent.
• Pregnancy or breast-feeding or planning to become pregnant during the study.
• Previous stroke.