Closing the case on PFO closure
Cryptogenic stroke is the term neurologists use to describe patients with an unknown stroke etiology. (For a quick review, I’d refer you to our earlier episode on the topic.) In a large number of these patients, we find a patent foramen ovale (PFO) on echocardiography. Presumably, this aperture of the atrium permits passage of a venous thromboembolism into the arterial circulation, or a “paradoxical embolism.” The PFO itself may also have inherent thrombogenecity, and form a nidus for clot formation. So this begs the question, should we attempt to close the PFO in stroke patients? And for the last 2 decades, and for less than 20 minutes on BrainWaves, we have looked into this. Closing the PFO makes all too much sense, right?
Not quite. Of the 3 major randomized clinical trials that were published in 2013, only RESPECT found a benefit in closure over medical therapy for PFO. In their primary intention-to-treat analysis, there was a nominal 51% reduction in risk of recurrent cerebrovascular events with surgical closure, but this was not statistically significant. In the pre-specified per protocol and as-treated analyses, there was a 63% and 73% reduction in the primary endpoint of ischemic stroke or early death, and these were statistically significant.
What we are left with, given these available trial data, is still a relatively inconclusive answer. We can’t quite close the case on PFO closure just yet. Hopefully, in future trials with the Amplatzer or newer generation closure devices, in a particular patient population (meaning not just PFO), we may find an advantage to PFO closure for stroke prevention. Only time will tell.
This episode was vetted and approved by Steven Messe.
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Wolfrum M, Froehlich GM, Knapp G, Casaubon LK, DiNicolantonio JJ, Lansky AJ, et al. Stroke prevention by percutaneous closure of patent foramen ovale: A systematic review and meta-analysis. Heart. 2014;100:389-395
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