November 15th, 2010
Let’s Bring CLOSURE to This Debate About PFO Treatment
Richard A. Lange, MD, MBA
In this blog, Rick Lange tells us how he would answer FAQs about PFO closure to prevent stroke.
The controversy:
Based on retrospective and nonrandomized studies, many physicians are convinced that percutaneous patent foramen ovale closure can reduce rates of cryptogenic stroke and transient ischemic attack. Although PFO closure devices are approved for stroke prevention in Europe and Canada, the FDA has not approved them for this indication in the U.S. Despite the lack of trial evidence, the number of percutaneous PFO/atrial septal defect closures in the U.S. increased almost 50-fold from 1998 to 2004, according to a recent study, while the number of surgical PFO/ASD closures was unchanged. The estimated percentage of PFO/ASD closures performed percutaneously in the U.S. increased from 18.5% to 92.5%.
In about 100 sites in the U.S. and Canada, 909 patients with a stroke and/or TIA due to presumed paradoxical embolism through a PFO were randomized to receive medical therapy alone or PFO closure with the STARFlex Septal Closure System followed by medical therapy. The rate of the primary endpoint — stroke or TIA at 2 years — did not differ significantly between the two groups (5.5% in the PFO-treatment group vs. 7.7% in the control group). Stroke recurrence at 2 years was 3% in both groups.
Was there a problem with the device?
Not likely, since the rate of adverse events with the closure device was low, and it was used successfully to close more than 85% of PFOs.
Why wasn’t PFO closure more effective than medical therapy?
Although PFOs are present in as many as 30% of individuals, paradoxical embolism through a PFO is rarely the cause of cryptogenic stroke. Furthermore, medical therapy can be quite effective at preventing paradoxical emboli.
Does this bring closure to the issue?
It does for me. However, individuals who are convinced that PFO closure is important will likely want corroborative studies. Several ongoing trials using other closure devices are in progress: the Helex septal occluder (Gore Medical) is under investigation in the multinational REDUCE study; the Amplatzer closure device (AGA Medical) is under investigation in the North American RESPECT trial and the European and Australian PC Trial; and the CLOSE study , which does not specify a particular device, is underway in France.
Where do you stand? For which, if any, patients with PFO would you recommend percutaneous closure?
10 Responses to “Let’s Bring CLOSURE to This Debate About PFO Treatment”
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None.
Although a negative trial, should percutaneous PFO closure remain an alternative to chronic anticoagulation in patients with cryptogenic stroke who would like to avoid warfarin?
Also did the CHADS2 score correlate with the population with PFO?
in terms of their stroke risk…
My only question would be the adequacy of a two-year follow-up period; will be interesting to see longer-term results. Certainly the study helps in counseling patients, some of whom in my experience have been very interested in pursuing this therapy, on the current lack of evidence.
A big thank you to the investigators for sorting this out. What is shocking to me is how many interventional cardiologists performed this invasive procedure over the last several years based on no data. How many patients now have a useless foreign body stuck in their heart for the rest of their lives? Just because you can do something doesn’t mean you should.
Also interesting was that in 60% of these patients with “cryptogenic” stroke, a cause of the stroke was identified after the closure device was placed. This study in my mind reveals how little we understand about cryptogenic strokes in general
I can’t find the full publication. Where?
Competing interests pertaining specifically to this post, comment, or both:
none
I am curious how the other trials mentioned and the subgroup analysis for different patient populations will play out. I looked up some articles on the topic, and there a few reports that suggest using the Starflex devices for closure seems to be related to a higher rate of device dislocation and embolization when compared to ASDOS or Amplatzer devices (citations below). There haven’t been very many head-to-head comparisons of these devices that I’m aware of. I have virtually no experience with these devices (yet), but I’m curious if anyone feels that the finding of no difference may be related to the device used? There was a slight non-significant difference in the primary outcome, so would usage of a different device push the findings towards statistical significance?
I would definitely prefer a medical therapy based approach patients with ASD who had a cryptogenic stroke, especially after this trial. The major vascular complication rate of the procedure in this trial was 3.2% and atrial fibrillation also was much more prevalent, 5.7% vs 0.7%.
I do feel there is a role for these devices in a certain population though… prevalence of patent foramen ovale has been shown to be significantly greater among patients with cryptogenic stroke than among those with stroke of known cause, for both younger patients (43.9% vs. 14.3%; odds ratio, 4.70; P<0.001 in the NEJM study). Studies have shown that there are certain factors, such as older patients, septal excursion distance or smaller PFO size without the presence of atrial septal aneurysm correlates with stroke.
– Post, M. C. et al., Comparison of outcome and complications using different types of devices for percutaneous closure of a secundum atrial septal defect in adults: A single-center experience. Catheterization and Cardiovascular Interventions, [2006] 67:438–443
– Butera, G et al., CardioSEAL/STARflex versus Amplatzer devices for percutaneous closure of small to moderate (up to 18 mm) atrial septal defects. American Heart Journal [September 2004] 148(3):507-510
– Akhondi A., et al., The association of patent foramen ovale morphology and stroke size in patients with paradoxical embolism. Circ Cardiovasc Interv. [2010 Oct];3(5):506-10.
– Handke M., et al.,Patent foramen ovale and cryptogenic stroke in older patients. N Engl J Med.[Nov 29 2007] 357(22):2262-8.
Dr. Powell,
I could only find the description of the trial design in a peer-reviewed journal: http://stroke.ahajournals.org/cgi/content/short/41/12/2872 . I believe the full study results haven’t been published yet. The results that all the news sites are abuzz with were presented by Dr. Anthony Furtan at AHA 2010.
In addendum to my earlier post, I meant to write that prevalence of stoke with PFO occurs in both younger and older patients…. I don’t know how to edit posts on this site yet!