New Device for Preventing Recurrent Strokes Approved by Food and Drug Administration
Although the device can lessen stroke risk, patients should still discuss treatment options with their medical team
The Food and Drug Administration (FDA) has approved a device known as the Amplatzer PFO Occluder, which may reduce the risk of a stroke for certain patients.
The device reduces the risk for patients who have already experienced a stroke that is believed to have been caused by a blood clot that went through a small hole in the heart—known as a patent foramen ovale (PFO)—and then journeyed to the brain.
Bram Zuckerman, M.D., is the director of the Division of Cardiovascular Devices in the FDA's Center for Devices and Radiological Health. "The Amplatzer PFO Occluder provides a non-surgical method for doctors to close a PFO," he said. "But as the device labeling clearly states, patients need to be evaluated carefully by a neurologist and cardiologist to rule out other known causes of stroke and help ensure that PFO closure with the device is likely to assist in reducing the risk of a recurrent stroke."
Roughly 25 to 30 percent of people in the U.S. have a PFO, which normally does not cause health problems and requires no treatment. The cause of the majority of strokes can be determined, such as high blood pressure that is poorly controlled, narrowed blood vessels caused by cholesterol deposits and scar tissue (known as atherosclerosis), or a blood clot from an abnormal heart rhythm (atrial fibrillation).
However, there are some patients for whom medical tests cannot identify a stroke's cause, and in these cases the stroke as referred to as a cryptogenic stroke. In a small percentage of such patients, doctors believe that the PFO provided a path through which the blood clot travelled to the brain, where the clot blocked a blood vessel and thereby caused the patient to have a stroke. Patients who experience such a stroke and who have a PFO may be at a higher risk for a second stroke.
The Amplatzer PFO Occluder is inserted into the patient's body through a catheter put into a leg vein and then pushed to the heart. The device is then implanted near the hole in the heart between the top right chamber (right atrium) and the top left chamber (left atrium). The Occulder had actually been on the market more than a decade ago under a humanitarian device exemption (HDE), but the manufacturer voluntarily withdrew it in 2006 after the FDA decided that the device's target population was greater than 4,000 patients and that it no longer qualified for an HDE approval. No heart occluder device approved by the FDA has been on the market for the past decade that is particularly indicated to close PFOs in the heart to lessen recurrent stroke risk in patients who have previously experienced a cryptogenic stroke.
When approving the device, the agency concluded that it showed a reasonable assurance of safety and effectiveness. It assessed these qualities through a randomized study evaluating 499 participants ages 18 to 60 who received treatment with the Amplatzer PFO Occluder as well as blood-thinning medicines in comparison with 481 participants treated solely with blood thinners. Although the rate of new strokes patients experienced in both groups was very low, there was a 50 percent reduction rate in new strokes experienced by the participants using the Occluder in addition to the medications compared to those using only the medications.
There are adverse effects associated with either the device or the procedure for implanting it, including injury to the heart; irregular and/or rapid heart rate; blood clots in the heart, leg, or lung; bleeding; and stroke.
Patients who have a heart valve infection or other untreated infections, as well as those who have a heart tumor or blood clot at the site of the implant, should not use the device. It should also not be used by patients who have other abnormal connections between the chambers of the heart or whose cardiovascular anatomy or blood clots would interfere with moving the catheter that is used for delivering the device to the heart.
Patients interested in having the device implanted are urged to discuss the risks and benefits of PFO closure as opposed to treatment with medications alone with their medical team (comprising a neurologist and a cardiologist).