August 18, 2004
By Ashley
Starkweather, B.S. and Asher Kimchi M.D.
BETHESDA, MD –
Patients with a patent foramen ovale (PFO) have been found to
have higher incidences of cryptogenic stroke, and secondary
prevention has traditionally consisted of anticoagulant drug
therapy. However, a new study published by Dr. Stephan
Windecker, M.D., et al, at University Hospital in Bern,
Switzerland, in the August 18, 2004, issue of the Journal of
the American College of Cardiology compares the effectiveness
of percutaneous closure of the PFO with standard medical
treatment in the prevention of recurrent stroke in these
patients.
Windecker suggests that the cause of stroke in these patients
involves paradoxical embolism through the PFO, and therefore,
surgical closure of the PFO would reduce the incidence of
strokes in patients with PFO.
Patients who were admitted to University Hospital between
January 1994 and August 2000 with transient ischemic attack (TIA)
or ischemic stroke were identified, and presence of PFO was
determined. The cerebrovascular event was evaluated to
determine if paradoxical embolism was the likely cause. Two
treatment groups were then assigned, one using standard
medical treatment, such as Coumadin, acetylsalicylic acid, or
clopidogrel, and another group that underwent percutaneous PFO
closure.
The effectiveness of PFO closure versus drug therapy in these
patients appears to depend upon the degree to which complete
closure is achieved. In patients who did achieve complete
closure of the PFO, risk of recurrent stroke was lower than in
patients treated with drug therapy. However, in patients who
did not achieve complete closure according to post-operative
ultrasound, PFO closure was comparable to drug therapy in
prevention of recurrent stroke.
However, these results are preliminary and have yet to be
confirmed by a randomized trial. Furthermore, improvements in
PFO closure devices and technique may result in a positive
impact on clinical outcome in the future, and therefore
continued study regarding the link between PFO closure and
stroke prevention is needed.
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