PFO and Cryptogenic Stroke—What Shall We Do?
PFO and Cryptogenic Stroke—What Shall We Do?
Abstract & Commentary
By Matthew E. Fink, MD, Vice Chairman, Professor of Clinical Neurology, Weill-Cornell Medical College, Chief, Division of Stroke and Critical Care Neurology, NewYork-Presbyterian Hospital. Dr. Fink reports no consultant, stockholder, speaker's bureau, research, or other financial relationship with any company related to this field of study.
Synopsis: Patent foramen ovale is commonly associated with cryptogenic stroke, but there is inadequate evidence in the medical literature to support the use of transcatheter closure devices for either primary or secondary prevention.
Source: Kizer JR, Devereux RB. Clinical Practice. Patent Foramen Ovale in Young Adults with Unexplained Stroke. N Engl J Med. 2005;353:2361-2372.
In our search for modifiable risk factors for ischemic stroke, PFO has become a popular topic for discussion and disagreement. Kizer and Devereux have given us an excellent review of the available literature with sound criticisms and insights.
At least one-third of young adults with stroke do not have a definable cause ("cryptogenic"), and more than half of such persons will have a PFO diagnosed by transesophageal echocardiography. It has been proposed that the PFO can serve as a gateway to the arterial circulation for venous thromboemboli that have formed in the legs or pelvis. Therefore, logic suggests that treatment with warfarin anticoagulation or closure of the defect via surgery or a transcatheter device might reduce the risk of recurrent stroke. To counter this theory, there is a large body of evidence that demonstrates equal rates of recurrent stroke in patients with PFO who are treated with aspirin or warfarin. And, there is no data from a randomized, prospective, clinical trial that demonstrates superiority of transcatheter closure over antiplatelet or anticoagulation therapy.
Potentially, more than 500,000 patients annually may be candidates for a closure procedure, worldwide, with a potential market value of $2 billion, and procedural costs exceeding $10,000 for each device placed. The FDA has provided a Humanitarian Device Exemption which allows usage of the closure devices for "closure of a PFO in patients with a recurrent cryptogenic stroke due to presumed paradoxical embolus… who have failed conventional drug therapy… conventional drug therapy is defined as a therapeutic international normalized ratio using oral anticoagulants" (JAMA. 2005;294:366-369).
At the present time, there are 4 different randomized trials comparing transcatheter closure with medical therapy, and all of them are having difficulty with patient enrollment. There are strong opinions on either side of this argument, and we will never know what is best for our patients until we answer the question with appropriate clinical trials. We should refer our patients to these trials, rather than continuing the off-label insertion of closure devices, contrary to the guidelines that have been issued by the FDA and our own professional societies.
Patent foramen ovale is commonly associated with cryptogenic stroke, but there is inadequate evidence in the medical literature to support the use of transcatheter closure devices ...Subscribe Now for Access
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