What Does Neurology Group's Recommendation on PFO Closure Mean for St. Jude?

The American Academy of Neurology has recommended against percutaneous closure of a congenital heart defect in patients who have had a stroke just as St. Jude Medical anticipates a device to treat the condition will gain FDA approval.

Nancy Crotti

St. Jude Medical doesn't even have FDA approval yet for a device purported to prevent stroke, and a major physicians' group is warning against implanting it in stroke survivors.

St. Jude's Amplatzer PFO Occluder would treat patent foramen ovale (PFO), a congenital defect that causes a hole in the wall between the heart's upper chambers. Study results show that 94% of patients who received the device had effective closure of the holes in their hearts six months after surgery. St. Jude CEO Michael Rousseau recently said he expects FDA approval later this year.

Meanwhile, the American Academy of Neurology updated its guidance to recommend against catheter-based PFO closure for patients who have had a stroke. The practice advisory was published in the July 27, 2016, online issue of Neurology, the academy's medical journal.

Percutaneous PFO closure with the Amplatzer PFO possibly decreases the risk of recurrent stroke while possibly increasing the risk of new-onset atrial fibrillation, "and is highly likely to be associated with a procedural complication risk of 3.4%," the study says.

In other words, one in 60 patients who had the implant might benefit from it, "which is not great," said study coauthor Gary Gronseth, MD, the academy's chief evidence-based-medicine methodologist. "When we meta-analyzed the data, the benefit seems to be small and that estimate is biased, and so great caution must be exercised."

One in four people has a PFO, and most people will have a blood clot in their leg that doesn't cause any symptoms, Gronseth noted. In people who do not have a PFO, these clots are harmlessly filtered by the lungs, but the presence of a PFO might allow clots to pass from the right side of the heart to the left side, which sends blood to the brain, he explained. It also might not. Doctors simply don't know how much of a difference having a PFO makes in terms of having a stroke, he added.

"Clinicians should not routinely offer percutaneous PFO closure to patients with cryptogenic ischemic stroke outside of a research setting," the study concludes. "In rare circumstances, such as recurrent strokes despite adequate medical therapy with no other mechanism identified, clinicians may offer the Amplatzer PFO Occluder if it is available."

The neurology group said its researchers reviewed all available scientific studies on people with PFO--a permanent implant--who had also had an ischemic stroke, which is a stroke caused by a blood clot, or a transient ischemic attack, which is an episode of temporary stroke symptoms.  

The Amplatzer PFO Occluder consists of two disks, a nitinol mesh, and polyester fabric, and can be recaptured and repositioned to ensure proper placement, according to St. Jude.  The product came to St. Jude by way of its 2010 acquisition of AGA Medical Corp.

In May, an FDA panel voted 15-1 that there was reasonable assurance that the device is safe for use, 11-5 that its benefits outweigh the risks, and 9-7 that it is effective for the intended use. St. Jude puts a lot of stock in the panel's recommendation, according to an emailed statement from the company.

"We believe Patent Foramen Ovale (PFO) closure represents an important treatment option for patients with a PFO who have experienced a cryptogenic stroke and is a therapy backed by compelling clinical evidence," the statement reads. "The positive discussion during the FDA meeting and resulting vote is an important step toward approval of the technology in the United States, and we look forward to additional discussions with the FDA in the coming months."

FDA's rules for device approval are not as stringent as those that physicians use to consider device efficacy and safety, according to Gronseth.

"Just because it's approved doesn't mean it's a good idea. Those two things don't equate," he said. "It's still an open question whether it makes any difference, whether it helps."

Nancy Crotti is a contributor to Qmed.