AHA News: Even 'Mild' Congenital Heart Disease Poses Risk Later in Life

THURSDAY, Feb. 28, 2019 (American Heart Association News) -- For many people born with mild heart defects, successful surgery early in life seemed like the happy end of their story.

"Doctors told them, 'You're fixed, go enjoy the rest of your life,'" said Dr. James Priest, a pediatric cardiologist and assistant professor at the Stanford University School of Medicine. "They weren't generally followed up long-term."

A new study published Thursday in the American Heart Association journal Circulation suggests the situation is not so simple.

Researchers analyzed more than 2,000 people in the United Kingdom with less serious forms of adult congenital heart disease and concluded they were at far higher risk of heart attack, stroke, heart failure and atrial fibrillation than the general population. The heightened risk ranged from twofold for heart attack to thirteenfold for heart failure, even after adjusting for traditional risk factors.

The people studied came from a database known as the UK Biobank that has tracked the health of more than 500,000 adults in Great Britain since 2005.

"People have suspected this is a problem," said Priest, the study's senior author. "But nobody had access before to such a large control population where we had all the information for all the other risk factors. It's not because they're more obese or smoke a lot more or have bad exercise habits. We have to find out why."

Thanks to medical advances, Priest said, most children born with heart defects now survive to adulthood. But the lives they live depend on the severity of the condition.

Complex forms of congenital heart disease involve malformations in the heart and defective valves that may not be easily fixed.

"They get surgery to allow them to grow and develop, but it's well recognized they'll need lifelong care and additional surgeries throughout their lives," Priest said.

In less serious cases, known as simple or noncomplex congenital heart disease, treatment can seemingly make the problem go away.

"It's a hole that can be closed surgically, or a blood vessel or a valve that can be repaired," Priest said. "Otherwise all the plumbing of the heart is connected as it should be and the heart is working reasonably well."

That can lead to complacency in later life.

"Most of the time these patients don't know they're at risk, and their physicians don't know they're at risk," Priest said. "People are going to be surprised by this study."

Dr. Ari Cedars, an associate professor at UT Southwestern Medical Center in Dallas who specializes in adult congenital heart disease, said the results should prompt doctors to be more vigilant in treating patients with congenital heart disease.

"If all these findings are true, this would be a truly remarkable study," said Cedars, who was not involved in the research. "It suggests that there is some overlay of risk from congenital heart disease on top of traditional cardiovascular risk factors."

The cardiologist said existing data has shown that adult congenital heart disease patients "are less likely to have statin cholesterol therapy compared to the general population, and their blood pressure may be less aggressively controlled. This study would suggest that those are mistakes, and if anything, we need to be more aggressive in controlling risk factors for cardiovascular disease."

Priest agreed. "Despite not knowing what is causing this, we can do a much better job treating the risk factors we know about, like treating hypertension and high lipid levels," he said. "Then we have to figure out what's so special about these patients so we can figure out what to do about it."

Several possible factors could link noncomplex congenital heart disease to cardiovascular problems later in life, Priest said, including the repercussions of childhood surgery, radiation used in diagnosis, long-term effects of medication and genetic anomalies.

"I've got lots of theories," he said. "I hope I can get some grant money to explore them."