Published On: 1.28.2014 Charlotte, NC
Potentially Fatal Complication Found In Heart Valve Replacement
On behalf of Charles G. Monnett III & Associates
Boston Children’s Hospital is warning its patients and the medical community about a potentially fatal problem in children and young adults who received a Mitroflow bioprosthetic valve manufactured by Sorin.
Surgeons recently became concerned when an 8 year-old patient died suddenly after her valve underwent rapid calcification, just 7 months after a routine follow-up echocardiogram that found no signs of blockage.
“Congenital aortic valve diseases are one of the more common heart defects that we see,” said Pedro J. del Nido, the chair of cardiac surgery at BCH. Surgeons prefer whenever possible to repair the native valve in the hope that by the time it needs replacement the children will be old enough to receive an adult valve.” Valve replacement is never ideal. Mechanical valves are highly durable but require lifelong anticoagulation medication. Bioprosthetic valves, which are made from animal tissue, don’t require anticoagulation, but are less durable and eventually need to be replaced. BCH performs about 60-80 aortic valve surgeries each year, said del Nido.
In recent years surgeons at BCH and elsewhere started using Sorin’s Mitroflow valve, which is made from bovine tissue, in the aortic position. Following the death last year of the patient, who received the Mitroflow in 2011, doctors at BCH began an intense surveillance of all 18 patients at their institution who had received the Mitroflow valve in the aortic position. They found four additional cases of rapid calcification. Three of these patients had their valves replaced with a mechanical valve; the other is being watched closely.
“The rapid failures that we’re reporting have only been reported with the Mitroflow,” said del Nido. “We expect all bioprosthetic valves to fail eventually. The difference now is the speed of the deterioration, in two to three years instead of the 6 years that we would expect.” Typically, he said, patients are followed on a yearly basis. “But the speed of deterioration is so rapid that you won’t catch this problem early on.” BCH is now recommending that children with the Mitroflow valve be followed every 4 to 6 months so they can be caught before a problem occurs.
After the girl’s death, the hospital reached out to all of its patients under the age of 30 who had the valve implanted in a similar position. The American Society of Echocardiography forwarded a letter to its members from del Nido and James Lock, the chair of the cardiology department at BCH. The BCH doctors have also notified the FDA and the Sorin Group, the manufacturer of Mitroflow.