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.

pfo

Amplatzer device deployment. Adapted from http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/MedicalDevices/MedicalDevicesAdvisoryCommittee/CirculatorySystemDevicesPanel/UCM304944.pdf

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.

 

[Jim Siegler]


This episode was vetted and approved by Steven Messe.

REFERENCES

Wahl A, Juni P, Mono ML, Kalesan B, Praz F, Geister L, et al. Long-term propensity score-matched comparison of percutaneous closure of patent foramen ovale with medical treatment after paradoxical embolism. Circulation. 2012;125:803-812

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

Handke M, Harloff A, Olschewski M, Hetzel A, Geibel A. Patent foramen ovale and cryptogenic stroke in older patients. The New England journal of medicine. 2007;357:2262-2268

Carroll JD, Saver JL, Thaler DE, Smalling RW, Berry S, MacDonald LA, et al. Closure of patent foramen ovale versus medical therapy after cryptogenic stroke. The New England journal of medicine. 2013;368:1092-1100

Kent DM, Dahabreh IJ, Ruthazer R, Furlan AJ, Reisman M, Carroll JD, et al. Device closure of patent foramen ovale after stroke: Pooled analysis of completed randomized trials. Journal of the American College of Cardiology. 2016;67:907-917

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