A large national study suggests that children with Down syndrome — the most common chromosomal disorder — do not face additional risks when undergoing heart surgery. In addition, the children may actually have a better chance of survival while hospitalized compared with other pediatric heart patients.

Researchers at the University of California Davis Children’s Hospital in Sacramento looked at a national database and, surprisingly, found that deaths among patients with Down syndrome after a heart surgery were significantly lower when compared with patients who did not have Down syndrome, 1.9 percent versus 4.3 percent, respectively. This lower risk held true even after researchers accounted for the child’s age, whether the child was born premature and the type of heart defect. The findings are based on more than 51,000 patients, from infants to young adults, who underwent surgery to correct congenital heart defects. Among these patients, 2,114 died while hospitalized.

However, the study leaves many questions, including: why children with Down syndrome may have better chances of surviving heart surgery during their hospital stay than other children; and what is the quality of life and long-term survival for the children after they leave the hospital.

The study published Tuesday in the latest issue of Circulation: Cardiovascular Quality and Outcomes, a journal of the American Heart Association.

“This is encouraging news for families with children of Down syndrome because this may help them when contemplating heart surgery,” said Michael Gewitz, MD, who is physician-in-chief and executive director and chief of Pediatric Cardiology at Maria Fareri Children’s Hospital at Westchester Medical Center in Hawthorne, N.Y. “There was concern complications related to Down syndrome would increase the risk of surgery-related complications, but this study indicates that is not the case.”

Down syndrome is a chromosomal abnormality that occurs when an infant is born with an extra chromosome. The condition occurs in one to two of 1,000 live births, and has been on the rise as more women wait until they are older to start families. According to the study, infant death among babies born with Down syndrome is five to eight times higher than average. Moreover, up to 50 percent of children with Down syndrome have some form of congenital heart disease, the most common type, atrioventricular septal defects. Children with Down syndrome also face related complications, including lung disease, a compromised immune system making them prone to infection, and gastrointestinal disorders, all of which could deter some families from considering surgery to treat congenital heart defects.

Dr. Gewitz said that one of the strengths of this study is that it looked at a large group of children across all age groups and who were undergoing a range of procedures, from low- to high-risk, to treat a congenital heart defect. However, he adds, the findings are based on a national database.

“We need to confirm these findings with prospective trials that look deeper into how the children are doing,” he said.