Believe it or not, a “hole in the heart” from a condition called patent foramen ovale (PFO) is mostly harmless and doesn’t need treatment. That is, until a person develops problems with blood clots. Then, stroke is a serious concern, and the risk only increases after a person’s first stroke. Scientists from the University of California, Los Angeles want to lower that risk by closing the hole in the heart.
PFO is characterized by a hole in the layer of tissue separating the left and right atria - the foramen ovale - which is supposed to close naturally after birth. When it doesn’t, problems can arise later in life for people with other risk factors for stroke. PFO is thought to be the cause of 10 percent of the United States’ strokes; other causes include high blood pressure, narrowed arteries, and blood clots from arrhythmia.
Strokes that have no known cause are called cryptogenic strokes, and these cases combined with people who also have PFO means a drastic increase in their risk of having a second stroke. Traditional treatment for these at-risk patients is anti-clotting drugs, but UCLA scientists think there might be another option, at least to be used alongside anti-clotting drugs.
The RESPECT study (for Recurrent Stroke Comparing PFO Closure to Established Current Standard of Care Treatment) recruited 980 participants between the ages of 18 and 60, all who had experienced a stroke in their lives, to determine the effectiveness of procedures that fix PFOs to reduce the risk fo stroke.
Participants were randomly assigned into two groups who received different treatments: half underwent a procedure to close the hole in their heart, and half received anti-clotting drugs. Follow-up results after approximately six years showed that for people with cryptogenic strokes, receiving the procedure to close the PFO led to better outcomes than standard anti-clotting medication, specifically a 45 percent reduction in stroke recurrence.
"People on medical therapy have fairly low risk, but people on the device have even lower risk," explained lead author Jeffrey Saver.
Some concerns that still exist suggest that surgery to repair PFOs may not be sufficient for preventing all types of circulatory conditions. Participants in the RESPECT group that had the repair procedure were slightly more likely to develop deep vein thrombosis, a blood clot often occurring in the legs.
“Certain patients, those who have had a definite deep venous thrombosis in the past, may need lifelong strong anti-clotting medications, whether or not they receive the device," Saver said.
In the future, Saver and his team want to learn in more detail how to determine which stroke patients are the best candidates for PFO repair, and which patients would fare better with anti-clotting drugs alone.
The present study was published in the New England Journal of Medicine.