Letter by Bhindi and Ormerod Regarding Article, “Lack of Association Between Migraine Headache and Patent Foramen Ovale: Results of a Case-Control Study”
To the Editor:
Garg and colleagues1 demonstrate no association between migraines and patent foramen ovale (PFO) in their recent case control study. Although their observations are interesting, the implications of this, another small case control study, must be considered carefully when adding to the already murky association data linking migraine with PFOs.
Notwithstanding methodological issues highlighted by the authors themselves, the study is considerably underpowered in detecting differences between patients with more/less severe migraine, those with/without aura, and shunt severity. The baseline characteristics of the patient's including ethnicity are different, and 10% of all patients are on aspirin. It is also possible that the exclusion of patients with previous stroke may confound the issue, as patients with clinically significant prior paradoxical embolization events may have a more “malignant” PFO phenotype more likely to be associated with migraine.
Although this study argues against an association between migraines and PFOs, it has significant limitations, and its conclusions should be kept in perspective. Larger, more inclusive studies need to be performed before this matter can be put to rest.
- © 2010 American Heart Association, Inc.