About 25 to 30 percent of Americans have a PFO, which typically causes no health problems and does not require treatment. The cause of most strokes can be identified, such as poorly controlled high blood pressure, narrowed blood vessels due to cholesterol deposits and scar tissue (atherosclerosis), or a blood clot caused by an abnormal heart rhythm (atrial fibrillation). However, in some patients, medical tests cannot identify the cause of the stroke, which is referred to as a cryptogenic stroke. In a small percentage of these patients, it is believed that the PFO provided a path for a blood clot to travel to the brain where it blocked a blood vessel resulting in a stroke. Patients with a cryptogenic stroke and a PFO may be at an increased risk of having a second stroke.
The Amplatzer PFO Occluder is inserted through a catheter that is placed in a leg vein and advanced to the heart. It is then implanted close to the hole in the heart between the top right chamber (right atrium) and the top left chamber (left atrium). The device had been on the market more than a decade ago under a humanitarian device exemption (HDE), but was voluntarily withdrawn by the manufacturer in 2006 after the FDA concluded that the target population for this device was greater than 4,000 patients and that the device no longer qualified for an HDE approval. For the past 10 years, no FDA-approved heart occluder devices have been on the market specifically indicated to close PFOs to reduce the risk of a recurrent stroke in patients with a prior cryptogenic stroke.
In approving the Amplatzer PFO Occluder, the FDA concluded that the device demonstrated a reasonable assurance of safety and effectiveness. The safety and efficacy was assessed in a randomized study that evaluated 499 participants aged 18 to 60 years old who were treated with the Amplatzer PFO Occluder plus blood-thinning medications compared to 481 participants who were treated with blood-thinning medications alone. While the rate of new strokes in both treatment groups was very low, the study found a 50 percent reduction in the rate of new strokes in participants using the Amplatzer PFO Occluder plus blood-thinning medications compared to participants taking only blood-thinning medications.
Adverse effects associated with the device or the implantation procedure include injury to the heart, irregular and/or rapid heart rate (atrial fibrillation), blood clots in the heart, leg or lung, bleeding and stroke.
The Amplatzer PFO Occluder device should not be used in patients with a heart valve infection or other untreated infections, or a heart tumor or blood clot at the implant site. The device is also contraindicated in patients with other abnormal connections between the heart chambers or in whom the cardiovascular anatomy or blood clots would interfere with the ability to move the catheter used to deliver the device to the heart.
Patients should discuss with their medical team (consisting of a neurologist and a cardiologist) the risks and benefits of PFO closure in comparison to using medications alone.
The Amplatzer PFO Occluder device is manufactured by St. Jude Medical Inc. based in Plymouth, Minnesota.
The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.