Few even get cardiac checkups, apparently believing they were cured as children — although a surgical repair isn't a cure. Worse, few cardiologists outside of children's hospitals have any idea how to care for these special hearts.
"The disease as an adult is completely different than the other kinds of heart disease adults get," warns Dr. Karen Kuehl, a pediatric cardiologist at Children's National Medical Center in Washington, who recently helped open one of the nation's few specialty clinics for adults with congenital heart disease.
"Here are people in their early young adulthood who have thought that they went through this (childhood surgery) ... and they were going to be fine. In fact, we don't know that," Kuehl adds. "Now we're seeing things nobody would have predicted."
Open-heart surgery for babies and young children didn't become common until the 1970s. Before then, only a quarter of "blue babies" and other infants born with complex heart defects lived beyond a year. Now, more than 95 percent of these "miracle babies" will grow up, living near-normal lives for many years.
Only recently have enough of the early survivors reached adulthood for doctors to notice a disturbing trend: Starting about 20 years after childhood surgery, the risk for some serious problems — irregular heartbeats, enlarged hearts, heart failure, occasionally even sudden death — begins to rise among people who had complex defects repaired.
Caught early, many such problems are treatable or, better, preventable. Too often, patients have serious damage or even need a heart transplant by the time someone links their survived birth defect to the new illness, says Dr. Roberta Williams of the American College of Cardiology.
How big is the risk, and who most needs preventive care? Doctors don't yet know, although pregnancy does demand extra caution. There have been no large-scale studies of survivors' long-term health, partly because so many disappear once they outgrow the pediatric cardiologist. Less than half of adults with congenital heart disease are thought to receive any regular cardiac care.
Denial plays a role. Young adults who feel well, and no longer are on a parent's insurance policy, desperately want to be normal and may not see a need for checkups.
Even if they want ongoing care, there are only about 100 cardiologists nationwide specially trained in adult congenital heart disease. Considering one in 150 babies is born with a heart defect, a soon-to-skyrocket new population of adult patients will compete for limited specialists.
"There's a setup for people to fall between the cracks," says Dr. George Ruiz of the Washington Hospital Center, who with Kuehl runs the new Washington Adult Congenital Heart Center — and is combing through boxes of dusty surgical records dating to the '70s, hoping to track down now-grown "miracle babies" who don't know their repairs may not last for life.
There are new moves to help:
"I don't mean to say we're going to die or do poorly," stresses Amy Verstappen of the Adult Congenital Heart Association, the advocacy group. "But we are likely to need reoperations, likely to develop things like heart arrhythmias where we're going to need additional care. Better to get it sooner than later."
For now, symptoms are what send many patients back for heart care, but they can be subtle, easy to dismiss.
Deepa Sinha of Herndon, Va., is a classic example. She had a complex but common defect called tetralogy of Fallot repaired at age 8, a final checkup around 21, and "went on with my life." Then weakness hit in her mid-30s.
Tetralogy repair frequently spurs a leak in the pulmonary valve that over time damages the heart's right ventricle, making it hard to exercise and risking a fatal irregular heartbeat. Sinha didn't know that. For a year she attributed worsening fatigue to being out of shape and the demands of two kids and a career — until the day she couldn't lift her 4-year-old.
"Life has totally changed," she says after getting a new valve last year. "I should have gotten this done years ago, if I had known."