Migraine and Patent Foramen Ovale (PFO)

Probably no real association between the two

Migraine
Migraine. BSIP/UIG/Getty Images

For years, many experts postulated a cause-and-effect relationship between migraine headaches and patent foramen ovale (PFO).

This idea was based on early studies reporting that PFOs appear to be more common in migraine sufferers. This apparent association between PFOs and migraines subsequently led to a lot of enthusiasm in the cardiology community for using PFO closure devices to treat migraine patients who have PFOs.

As a result, hundreds or perhaps thousands of migraine patients have had their PFOs closed.

However, it now appears that not only does PFO closure fail to improve migraines, but also the original observation that PFOs are more prevalent in migraine sufferers may itself have been spurious.

The Data On Migraine and PFOs

Several lines of evidence have now thrown a wet blanket on the idea that PFOs somehow cause migraines, and that closing PFOs can treat migraines.

First, it turns out that patients with migraine probably do not have an increased incidence of PFO. The only carefully-done population-based study to look at the association concluded that migraine sufferers have the same incidence of PFO as non-migraine sufferers.

Second, those who postulate that PFOs can cause migraines have been unable to offer a compelling theory as to how PFOs might produce migraine headaches in the first place. Without a statistically demonstrated association between the two conditions, and without a plausible theory as to why there might be one, it is difficult to say why the idea of a cause-and-effect relationship between the two ever gained any currency whatsoever.

And finally, the large, prospective, randomized clinical trial (the MIST trial), designed to prove that PFO closure improves migraines, failed to show any benefit. While earlier observational trials claimed to show a benefit, a subsequent systematic review of these earlier trials concluded that they constituted low-quality evidence, and should not be used to guide clinical practice.

Complications of PFO Closure

Furthermore, PFO closure devices are not without significant complications. These devices have caused atrial fibrillation, large left atrial thrombus, actual worsening of the PFO, and even death. PFO closure is not a technique to be taken lightly, or one to be used “in case” it might be helpful.

The Bottom Line

At this point there is little reason to suppose that PFO closure for treating migraine headaches ought to work in the first place, and no data of any quality suggesting that it does work. Especially in light of the invasive nature of the PFO closure procedure, its complications, and its expense, at this time PFO closure should not be used in treating migraines.

As a migraine sufferer myself, this is disappointing. I fully understand that there are more than a few migraine sufferers who have compelling stories about how PFO closure miraculously diminished their headaches, and I have nothing to say to them except that I am glad for it. I will only add that in the MIST trial, patients who had a sham catheter procedure were just as likely to experience this type of striking benefit as those who had the actual PFO closure.

In my view, this whole episode is another instance where a group of doctors in possession of a cool new procedure were desperately looking for an indication to use it. As happens all too often, they allowed themselves to be carried away by a spurious association between their cool new procedure and a common medical condition whose sufferers are just as desperate as they are.

This kind of medicine-by-wishful thinking is not limited to the alternative medicine universe. It is also common in “real” medicine, and will persist as long as human nature does.

It’s why clinical trials will always be necessary.

Sources:

Dowson A, Mullen MJ, Peatfield R, et al. Migraine Intervention With STARFlex Technology (MIST) trial: a prospective, multicenter, double-blind, sham-controlled trial to evaluate the effectiveness of patent foramen ovale closure with STARFlex septal repair implant to resolve refractory migraine headache. Circulation 2008; 117:1397.

Schwedt TJ, Demaerschalk BM, Dodick DW. Patent foramen ovale and migraine: a quantitative systematic review. Cephalalgia 2008; 28:531.

Kurth T, Tzourio C, Bousser MG. Migraine: a matter of the heart? Circulation 2008; 118:1405.

Continue Reading