Cryptogenic Stroke and Patent Foramen Ovale

IN RESPONSE:

In our article, we do state that “warfarin therapy is generally not indicated for secondary stroke prevention except for patients with transient ischemic attack or stroke in the setting of persistent or paroxysmal atrial fibrillation and for some patients with a documented hypercoagulable state, left ventricular ejection fraction of 0.3 or less, carotid or vertebral artery dissection, or patent foramen ovale with an atrial septal defect.” We do not make this recommendation for patients with only a patent foramen ovale.

The American Academy of Neurology guideline states, “It is possible that the combination of a patent foramen ovale and atrial septal aneurysm confers an increased risk of subsequent stroke in medically treated patients who are less than 55 years of age” (1). The guideline concludes that there is insufficient evidence to determine the superiority of aspirin or warfarin for the prevention of stroke or death in this situation.

Given the increased risk and the lack of evidence to guide proper therapy, we do still conclude that warfarin may be considered in some patients with transient ischemic attack or stroke who have both a patent foramen ovale and an atrial septal aneurysm (for example, younger patients). We did not mean to imply that warfarin was “indicated,” but that it may be preferred and used after thoughtful estimations of the benefits and burdens of each therapy and incorporation of the preferences of the patient in terms of tolerance and acceptance of treatment and outcome risk.