Blood-Thinning Treatment for Migraine

Can antithrombotic treatment prevent migraines in people with a PFO?

The BMJ trial evaluated antithrombotic treatment in patients who had both migraine and a patent foramen ovale, or PFO. Antithrombotic medicines reduce blood-clot formation through effects on platelets or the coagulation system. Researchers have proposed that tiny emboli, activated platelets, or vasoactive substances crossing a PFO could contribute to migraine attacks, particularly migraine with aura, but these mechanisms remain unproven.

A randomised, active-controlled design can provide stronger evidence than an uncontrolled observational study because participants are assigned to competing treatment strategies. However, an open-label trial means participants and clinicians know which treatment is being used. That knowledge can influence symptom reporting, use of additional medication, and other migraine outcomes, so objective endpoints and blinded outcome assessment are especially important when interpreting the findings.

What is the connection between patent foramen ovale and migraine?

A PFO is a flap-like opening between the heart's upper chambers that persists after birth. It is found in approximately one-quarter of adults and usually causes no symptoms. Some studies have reported that PFO is more common among people with migraine with aura, prompting research into shared biological pathways and treatments directed at the heart-to-brain circulation.

The relationship is clinically complicated because both PFO and migraine are common. A person can therefore have both conditions without one causing the other. Trials of PFO closure for migraine have not established closure as routine migraine treatment, and Society for Cardiovascular Angiography & Interventions guidance suggests against routinely closing a PFO solely for migraine when there has been no PFO-associated stroke.

What should patients consider before taking aspirin or another blood thinner?

Antithrombotic drugs can cause clinically important bleeding, including gastrointestinal bleeding and, less commonly, intracranial bleeding. Risk varies according to the medicine, dose, treatment duration, age, previous bleeding, kidney or liver disease, and concurrent use of anticoagulants, antiplatelet drugs, corticosteroids, or nonsteroidal anti-inflammatory medicines.

The presence of a PFO alone does not establish an indication for aspirin, anticoagulation, or closure. Clinicians must distinguish migraine treatment from prevention of recurrent stroke, where PFO management follows a different evidence base. Established migraine care includes trigger management, acute medicines, and preventive treatments selected according to attack frequency, disability, cardiovascular history, pregnancy considerations, and patient preference.