The U.S. Food and Drug Administration (FDA) on October 1 approved the Autus Size-Adjustable Valve, a surgically implanted pulmonary heart valve for children with congenital pulmonary valve disease that can be widened with a balloon catheter as the child grows. The agency said it is the first heart valve designed to be expanded after surgery to keep pace with growth, and that it may reduce the number of repeat open-heart operations some children need.
The valve was developed by Autus Valve Technologies Inc., and the approval was granted to Edwards Lifesciences, according to the FDA’s press release. It is implanted at a diameter of about 13 mm, a size the agency said suits a toddler or preschool-aged child, and can later be enlarged in a minimally invasive catheter procedure up to 22 mm, roughly the size of an adult pulmonary valve.
Its inner leaflets, the flaps that open and close with each heartbeat, are made of a polymeric material rather than animal tissue, which the FDA said can wear down faster in children. The agency said it is the first valve approved in the United States with polymeric leaflets for any indication.
What the study showed
The approval rests on a study of 62 pediatric patients enrolled at 12 U.S. sites. At six months, the first 60 patients showed acceptable hemodynamic performance, meaning blood flow through the valve was within acceptable limits, with no more than mild regurgitation, or backward leakage, the FDA said. All implant procedures were successful, and there were no deaths, no clot-related complications requiring treatment and no strokes.
Three patients had fractures in the valve frame and two had reduced leaflet movement, but none had symptoms, according to the agency. In two patients who had begun to outgrow their valves, performance started to decline; both valves were then expanded without open surgery. One-year follow-up data suggest the synthetic leaflets are holding up well, the FDA said, while noting that longer-term studies are under way.
The device went through premarket approval, the FDA’s most stringent review pathway, which is used for Class III devices. It had previously received Breakthrough Device designation, and the agency said it is the first pediatric approval to come out of its Total Product Life Cycle Advisory Program, known as TAP.
Children with congenital heart defects “have had very limited surgical options,” Acting FDA Commissioner Kyle Diamantas said in the release. Michelle Tarver, director of the FDA’s Center for Devices and Radiological Health, said: “The Autus Size-Adjustable Valve gives doctors the option of far fewer trips to the operating room.”
Why it matters
Congenital heart defects affect about one in 100 births in the United States, and pulmonary valve atresia and stenosis together affect about 4,200 U.S. babies each year, according to Centers for Disease Control and Prevention figures cited by Medical Dialogues, which reported on the approval. A fixed-size valve cannot keep pace with a growing child, and the FDA said the new device may reduce the number of repeat open-heart surgeries these patients need.
For surgeons and pediatric cardiologists, the approval adds a device whose later enlargement is done through a catheter rather than by reopening the chest. For families, the practical change the agency highlighted is fewer operations over a childhood, although the release did not estimate how many procedures might be avoided or over what period.
What to watch
The FDA said longer-term studies are under way to better understand the risks and to show that expansion can keep the valve functional and reduce surgeries. Results from those studies, and from the first years of routine use, will show whether the six-month and one-year findings hold as more children reach the point at which their valves need to be enlarged.
The caveats
The evidence base is small and short. The pivotal study enrolled 62 children, the headline results are at six months, and only two valves have so far been expanded in patients, which the FDA itself described as limited experience. Three frame fractures and two cases of reduced leaflet motion were recorded, even though none caused symptoms. The findings come from the FDA’s summary of the data submitted for approval, not from a peer-reviewed publication.
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