By AMERICAN HEART ASSOCIATION NEWS
Many people with neuromuscular disorders that begin in childhood are living longer thanks to advances in treating the disease and its complications, such as breathing problems.
That trend, however, has not applied to the potentially deadly heart complications associated with many of these disorders. Experts don’t know how heart problems develop in the different types of muscle disorders, but an American Heart Association scientific statement issued Thursday offers new guidance to doctors designed to improve patient care.
The statement urges collaboration between cardiologists and the neurologists who treat a vast number of neuromuscular diseases – which often complicate breathing, movement and heart function. Such collaboration can be complicated by the fact that many heart doctors are not familiar with rare muscle disorders, said Brian Feingold, M.D., the statement’s lead author.
“We need to be able to care for all of these patients,” said Feingold, medical director of the heart failure and heart transplant programs at Children’s Hospital of Pittsburgh of UPMC and associate professor at the University of Pittsburgh School of Medicine in Pennsylvania.
The most common heart conditions in people with neuromuscular diseases are cardiomyopathy and irregular heart rhythms. Cardiomyopathy, which can lead to heart failure, occurs as an enlarged heart struggles to pump blood through the body.
“The heart is often overlooked in neuromuscular disorders and it shouldn’t be,” said Linda Cripe, M.D., a pediatric cardiologist at Nationwide Children’s Hospital and professor of pediatrics at The Ohio State University in Columbus, who was not a statement author.
There are more than 90 neuromuscular disorders, according to the Muscular Dystrophy Association, although researchers involved in the statement said many of these diseases are not well understood. The statement detailed heart complications associated with six categories of neuromuscular diseases.
Among the most common is Duchenne muscular dystrophy, which affects one in every 3,600 to 9,300 male births, according to the statement. Duchenne weakens muscles over time, and evidence of heart disease often appears before age 14. Death generally comes by age 30, usually due to heart or breathing problems. A milder form of the disorder is known as Becker muscular dystrophy. Both conditions occur in boys due to a gene mutation on the X chromosome. Girls can be carriers of the mutation and can pass the disease to their sons.
Because neuromuscular diseases are complex and impact numerous organs, they are difficult to manage, Cripe said.
“There are many things about these diseases that we don’t currently understand. Even within families who carry the same genetic mutation there can be tremendous differences in how a person progresses through the disease,” she said.
Despite the challenges, the statement is a step in the right direction, said Kathi Kinnett, senior vice president of clinical care for Parent Project Muscular Dystrophy. The nonprofit organization supports people with the disease and their families, and advocates for optimal care for Duchenne patients.
“Anything that raises awareness of the need for lifelong cardiac care and management is a win for the Duchenne community,” Kinnett said.
The statement also notes the lack of research about cardiomyopathy related to neuromuscular disorders, Cripe said. For example, there’s not a specific treatment for Duchenne cardiomyopathy, she said. The only available treatments are traditional heart failure therapies.
The statement points out that many Duchenne patients don’t get basic heart tests and treatments.
One study reported that more than 30 percent of patients with Duchenne muscular dystrophy had not received an echocardiogram as recommended. Only 43 percent took heart medication after being diagnosed with cardiomyopathy.
“The heart is a muscle, too” has been Cripe’s catchphrase over the decades as she speaks to families and other doctors about the heart in neuromuscular diseases. Heart disease can easily be missed in patients, because it’s less obvious than the inability to walk or get out of a chair, she said.
Getting the statement to more cardiologists is important because more patients are surviving to adulthood, Kinnett said.
Certifying neuromuscular centers that follow guidelines-based quality standards is one way to get medical professionals working together, Kinnett said. She has led her organization’s program to certify 16 centers that treat Duchenne patients in the United States.
Feingold hopes the statement will lead to more consistent and better heart care for people with neuromuscular diseases.
“If you can get this information to cardiologists caring for these patients, ultimately that will bring up to par what the care should be,” Feingold said.