The death rate for congenital heart disease has dropped 39 percent in the last two decades -- an improvement medical experts call dramatic.
"But heart anomalies still remain a major cause of mortality among the young," says Dr. Lorenzo Botto, an epidemiologist with the National Center on Birth Defects and Developmental Disabilities and a member of the team at the Centers for Disease Control and Prevention (CDC) that conducted the research.Today, heart defects account for roughly one in 10 infant deaths, Botto says.
An estimated 30,000 babies, or one of every 125, are born each year with some type of heart defect, reports the American Heart Association. Sometimes the heart can't pump enough blood to the lungs because of a hole in the wall between the heart chambers, or the heart is enlarged, or its rhythm is disturbed in some way or the heart valves are blocked.
However, some 1 million adult Americans now live with congenital heart defects, the association says.
It's obviously good news that people are living longer, but that also holds serious implications for the health-care industry and society at large, says Dr. Kathy Jenkins, a pediatric cardiologist at Children's Hospital in Boston and an associate professor at Harvard Medical School.
"A growing number of children are surviving into adulthood with these defects," Jenkins says. "Some have minor defects, but some have significant problems that will affect them in day-to-day life, both in functional abilities and in the need for ongoing services."
She says problems range from "employability, insurability [and] providing enough caregivers for this growing population of people" to additional training needed by cardiologists to treat what once was the domain of pediatricians and children's specialists.
The drop in the death rate stems largely from "earlier identification of children, and especially infants, with congenital heart malformations by pediatricians and from markedly improved diagnostic techniques," Jenkins says.
For instance, the echocardiogram, which uses sound waves to examine the structure of a baby's heart and detect abnormalities before birth, was developed only 15 to 18 years ago but is now used routinely, Jenkins says.
But people, not just technology, share the credit, she says.
"The skills of surgeons, their technical expertise and ability to correct major malformations in small infants [has helped bring about] a really dramatic change in mortality rates," Jenkins says.
The CDC study reports a nearly 57 percent drop in deaths among children ages 1 to 4 years and nearly 40 percent among those younger than 1, the age group Botto says is most affected by heart anomalies. The findings, based on information culled from death certificates filed nationwide between 1979 and 1997, appear in the May 15 issue of Circulation: Journal of the American Heart Association.
Botto says the average age of death increased from 21 years to 41 years in the past two decades, based on what's called the 75th percentile method, meaning the age reached by 75 percent of a given population.
The median age at death for those born with heart defects also has gone up, from 6 months to 12 months, the study says. It's markedly lower because it's "essentially driven by the most severe cases," Botto says.
The report shows higher death rates for males than females, "perhaps due to the fact that some of the more severe heart anomalies tend to appear more frequently in boys than girls," Botto says.
Botto also calls the reported difference in mortality rates between blacks and whites "significant." The study found the death rate 19 percent higher among blacks.
Jenkins says that could stem from "obvious disparities in access to the highest quality care."
Jenkins says her own research on congenital heart defects has shown that children whose parents receive Medicaid "have worse outcomes than children without Medicaid, [and that] racial differences are regional."
"This suggests the problem is not purely related to biological differences but rather related to access to high-quality care," she says.
What causes heart defects at birth remains somewhat of a mystery.
A pregnant woman's use of certain medications, illegal drugs or alcohol and some illnesses have been linked to an increased risk of heart problems at birth. Researchers also presume that genes play a role, although few direct links yet have been proven.
"Part of the reason congenital heart defects are so frustrating is that really almost anyone is at risk for them. The next baby born in any family is equally at risk," Jenkins says.
A malformed heart "is still the No. 1 cause of death from congenital diseases of any sort, and [it] kills more children under 15 than all cancers," she says.
"The only way we're going to understand why particular individuals are at risk will be through more research," she says.
Medical science cannot yet prevent malformed hearts from developing. We're not quite there yet," Jenkins says.
"That's why it's so wonderful that we're having these outcomes," with more people living longer with heart defects, she says.
What To Do
To learn more about congenital heart defects, visit the March of Dimes Birth Defects Foundation online.
For more on the condition among adults, check information from the Mayo Clinic.
Or, read previous HealthScout articles on congenital heart defects.