Lisa Yue had a "mother's instinct" that something was wrong when her seemingly healthy 11-month-old, Bryan, just didn't get better after catching a cold in 1999.
"He wouldn't eat and he was lethargic -- he was like a rag doll," said Yue, a marketing director for Sony Pictures who was living in Hong Kong at the time.
But Yue's doctors dismissed her concerns and never recommended screening on Bryan, despite a family history. Her husband, Eddie Yu, had hypertrophic cardiomyopathy (HCM), a rare disease that affects the heart muscle.
"The pediatrician said everything was fine -- young kids don't get cardiomyopathy," said Yue, now 47 and living in Cresskill, N.J. "A month later Bryan was dead -- just weeks from his first birthday."
Bryan died in her arms en route to the hospital. Then, in 2001, tragedy struck again when the couple returned to the United States. Their son Kevin also died of cardiac arrest from cardiomyopathy waiting for a heart transplant at just 9 months old.
Searching for answers, Yue founded the Children's Cardiomyopathy Foundation (CCF), which over the last decade has contributed more than $2.1 million to research and treatment initiatives.
"I became obsessed, trying to find out what happened," said Yue. "At first, CCF started out as a tribute to my two sons. Every parent, when they lose a child, wants to justify their child's existence. But I was also hoping I could help other families with the knowledge gained."
And now, a North American population-based study, inspired by Yue's loss, has identified risk factors that explain why some children do well on medication while others die. Researchers analyzed more than 1,000 children with the disease from 98 medical centers in Canada and the United States from 1990 to 2009.
The study, published today in the medical journal Lancet, found that the worst outcomes for those diagnosed with HCM, were children less than a year old or those with metabolic disorders, malformation syndromes or a mixed form of the disease in combination with dilated or restrictive cardiomyopathy.
The risk of death jumped when two or more of these risk factors were present: decreased weight, congestive heart failure and abnormal electrocardiograms.
Such information might have saved Bryan or Kevin Yu, had cardiologists been able to identify their risk factors earlier in the course of the disease and listed them for a heart transplant sooner.
|"It gives us greater lead time if we can identify right at diagnosis who will be dead in the first two years and get them listed earlier so they have a better chance of getting a heart transplant. -- Dr. Steven E. Lipshultz, University of Miami|
The study provides a risk calculator that cardiologists can use to evaluate which children should be considered for heart transplant after diagnosis.
These guidelines for risk "can really make a difference," said lead researcher Dr. Steven E. Lipshultz, professor of pediatrics and director of the Batchelor Children's Research Center at the University of Miami. "This has the potential to save lives."
Lipshultz, who founded the Pediatric Cardiomyopathy Registry, sits on the CFF's medical advisory board. The study was funded by the National Heart, Lung, and Blood Institute and a grant from CCF.
"It gives us greater lead time if we can identify right at diagnosis who will be dead in the first two years and get them listed earlier so they have a better chance of getting a heart transplant," he said.
HCM damages the muscles of the heart and its ability to pump effectively. It can be inherited, as in the Yu family, or acquired through a viral infection or cancer chemotherapy in children.
For doctors, predicting the outcomes of children with HCM is challenging because its presentation is so variable.
The success rate for early childhood heart transplants is "quite good," Lipshultz said. "On average, they can live 15 years or more before they need another one. And of those, 90 percent or more go home alive."