One-year-old Angelica Moreno-Roman had already survived two major heart surgeries before she could walk. In April, she became the first patient in Oklahoma to receive a partial heart transplant, a rare procedure that replaced her failing heart valves with living donor tissue that doctors expect will grow with her.

Dr. Harold Burkhart, director of the Pediatric Cardiothoracic Surgical Program at OU Health Oklahoma Children's Hospital, performed the approximately four-hour operation, according to OU Health. Fewer than 50 partial heart transplants have been performed in the United States.

"We've put two valves in a baby that typically would require multiple heart surgeries through life as that child grew, and I'm hoping that she won't have these anymore," Burkhart told KOCO.

Angelica was born with truncus arteriosus, a rare congenital heart defect in which only one large artery forms instead of the usual two. She underwent her first heart surgery at 2 days old. At 4 months, she contracted rhinovirus, and doctors discovered one of her heart valves was severely leaking. A traditional replacement valve would not grow with her, meaning she would face repeated open-heart surgeries as she got bigger. Her medical team determined a partial heart transplant offered the best path forward.

The donor heart used in the procedure could not support a full transplant because it did not pump well enough, but its valves were healthy. Burkhart and his team removed those valves and placed them inside Angelica's heart, according to News9. Because no formal training program exists for partial heart transplantation, the surgical team adapted techniques from other complex pediatric heart operations and held several planning sessions before the procedure.

The surgery took about four hours.

The family knew they were charting new territory. Jeneliz Moreno-Roman, Angelica's mother, said doctors told them in advance that their daughter would be the first patient in Oklahoma to undergo the surgery. She told KOCO that Angelica has always been a happy girl and that most people wouldn't know she'd had heart surgery.

Angelica has celebrated her first birthday. Her mother describes her as curious and active, fond of Elmo, Miss Rachel and rolling around with her favorite toy. She receives nutrition through a feeding tube while working with a speech therapist because her early surgeries prevented her from fully developing the muscles needed to eat and drink safely.

Oklahoma Children's OU Health operates the state's only pediatric heart transplant program. Burkhart said four or five other children are already listed for partial heart transplants at the hospital. Dr. R. Erik Edens, medical director of pediatric heart failure and transplant at Oklahoma Children's, is participating in a national study group collecting outcomes data on the procedure.

The hospital is also exploring "domino transplants," in which valves from a child receiving a full heart transplant could be used to help another child who needs only valve replacement.

What's ahead: OU Health plans to break ground on the Oklahoma Children's OU Health Presbyterian Health Foundation Heart Center later in 2026. The seven-story, 200,000-square-foot facility will open to patients in early 2030, according to OU Health, centralizing and expanding pediatric cardiac care in Oklahoma.