Squeals of delight and the lively patter of little feet fill a playroom at NewYork-Presbyterian Morgan Stanley Children’s Hospital of Children’s Hospital of New York as two toddlers race around the room before pausing to embrace a girl whom they’ve never met, as their parents look on.

Seven months before, the children and their families were strangers. Now, they are forever bonded thanks to a pioneering procedure in which one heart saved the lives of three children. On July 25, 2024, 10-year-old Hend Almesafri, 2-year-old Thomas “Teddy” Carter, and 18-month-old John Catoliato, were part of one of the first split-root domino partial heart transplants in the United States. A “domino” transplant is a procedure where the recipient of a new organ also becomes an organ donor.

In a span of 24 hours, Hend received a full heart transplant from a deceased donor, then became a living heart donor when she donated two healthy valves from her old heart to Teddy and John, who each received partial heart transplants. The three operations involved a multidisciplinary team including cardiac surgeons, perfusionists, heart failure clinicians, ICU staff, and nurses, who precisely executed a tightly coordinated plan.

“The living valves used have growth potential, which means patients may not require multiple re-operations down the road. This is a game-changer for these children,” says Dr. David Kalfa, pediatric cardiothoracic surgeon at NewYork-Presbyterian Morgan Stanley Children’s Hospital. “Seeing them now all together with their families is an incredible feeling, and reminds us why we do this every day.”

A Cascade of Events
In 2023, NewYork-Presbyterian performed the first-ever domino heart valve transplant between two infants — Mia Skaats, then 8 months old, received a full heart transplant and healthy valves from her old heart were donated to Brooklyn Civil, who was 2 months old. The team has since performed several domino partial heart transplants. With this experience and expertise, they were well positioned to perform a domino procedure that would help not just two, but three patients.

Hend was diagnosed with a genetic cardiomyopathy, meaning her heart muscles were too weak to pump enough blood to the rest of her body. Though she required a mechanical heart pump to treat her heart failure until she received a transplant, her valves worked well, making her an ideal living donor for this innovative procedure. She had been in the hospital for 7 weeks when her family received the life-changing news: a donor heart was available.  

“To offer this opportunity to treat valvular heart disease is very exciting,” says Dr. Andrew Goldstone, pediatric cardiothoracic surgeon at NewYork-Presbyterian Morgan Stanley Children’s Hospital. “The idea of a partial heart transplant, or valve transplant, came to be since there’s currently no living valve substitute for patients. We now have a successful program where we evaluate heart transplant recipients as potential donors for valves, receive their consent, and match them to other patients in case a potential domino situation may arise.”

Hend’s valves, the pulmonary and aortic, were the right size for two potential recipients: John and Teddy.

The Possibility of a New Life
John and Teddy were born with different congenital heart conditions that required them to undergo several operations in the short span of their lives.

Before birth, John was diagnosed with truncus arteriosus, a condition where instead of having two exits from the heart — one going to the body and one going to the lungs — he only had one, and a hole in his heart.

“Dr. Goldstone met us with so much compassion, and we had full trust in him,” says John’s mom, Joanne Dowling. “We knew John was in the hands of a surgeon who truly cared about each patient.”

Dr. Goldstone performed surgery on John when he was just five days old to repair his artery and close the hole. John underwent another open-heart surgery a day later to connect the circulation between his heart and lungs using an artificial valve with a tube, then three additional stent placements over the course of the year, to keep the narrowed artery open.

“Throughout a year and a half, John went into heart failure twice. He got so sick that he almost died. He had been through way too much and it was a long road,” says John’s dad, Thomas Catoliato.

“Without a growing valve, John faced the potential of multiple re-operations into adulthood,” says Dr. Goldstone. Other treatment options included a valve from a cow or pig, which tend to fail quickly in children; cryopreserved valves from a deceased human donor, which do not grow; or a mechanical valve, which carry the risk of blood clots and need medication to prevent clotting over time.

“When doctors told us John wasn’t going to benefit much from another stent and Dr. Goldstone presented the option of a living valve, we thought this could be a new life for him,” says Joanne.

At 2 months old, Teddy was diagnosed with aortic stenosis.

The congenital malformation of his aortic valve blocked blood flow from his heart to the rest of his body and also caused blood to leak backward. An initial procedure to widen the blocked area was unsuccessful, so the family turned to Dr. Kalfa to perform open-heart surgery to open up the valve. Two years after his first surgery, leakage of the valve had progressed and needed to be addressed.

The Carters considered a Ross procedure, where his aortic valve would be replaced with his own pulmonary valve. Another option: the split-root domino partial heart transplant.  

“With the Ross procedure, we were going to have to go through multiple surgeries with him, which no parent wants to put their child through. We knew it was going to be tough,” says Teddy’s dad, John Carter.

“The team at NewYork-Presbyterian, including our cardiologist, our transplant team, our surgeon, they were all so generous with their time,” said Teddy’s mom, Katie Carter. “The more we talked to them about a potential split-root domino, the more we thought it was our destiny and a solve for Teddy to have a more normal childhood. That’s all we wanted.”

When a donor heart became available for Hend on July 24, John and Teddy’s parents were each called with the news of a match. The split-root domino heart transplant would take place the next day, with new possibilities opening for the two toddlers’ futures and paving the way for countless other children.

A Marathon Surgery  
From the time they received the call accepting Hend’s donor heart to the start of her transplant surgery, the clinical teams had about 12 hours to execute the logistical preparations for simultaneous and back-to-back procedures.

They needed two open operating rooms, three intensive care unit beds for recovery, and all three patients available for their procedures on short notice, with the coordination of multiple teams to navigate the complexities of each case.

“We’re uniquely positioned to perform domino transplants and split-root dominos because of the surgical and team expertise in all aspects of cardiovascular disease and transplantation, and the resources necessary to make this all a reality,” says Dr. Goldstone, who is also assistant professor of surgery in the section of Pediatric and Congenital Cardiac Surgery at Columbia University Vagelos College of Physicians and Surgeons.

On the morning of Thursday, July 25, the Almesafri family, the Carters, and the Catoliatos readied their children for surgery.

Starting at 8 a.m., Dr. Kalfa led a team to begin Hend’s heart transplant. He removed the mechanical heart pump and explanted Hend’s heart, harvesting the pulmonary valve to hand off to Dr. Goldstone.

In the next room, Dr. Goldstone and his team prepped 18-month-old John to receive Hend’s pulmonary valve, then began the eight-hour valve transplant, as well as the stent removal from his pulmonary artery.

Simultaneously, Hend’s transplant continued, with her new heart implanted by mid-afternoon. When her procedure finished, Dr. Kalfa and his surgical team began preparing the room for 2-year-old Teddy.

Teddy entered the operating room at 7 p.m. for his aortic valve replacement. Dr. Kalfa detached Hend’s aortic valve from her explanted heart, which had since been placed on a device designed to preserve the organ for transplant, then began the Teddy’s eight-hour valve replacement.

At 4 a.m. on Friday, the teams completed three successful surgeries as part of NewYork-Presbyterian’s first split-root domino heart transplant.

“It really takes a village to accomplish a feat like this. It’s a multidisciplinary team working together, and a passion and will to innovate,” says Dr. Kalfa, who is also associate professor of surgery in the section of Pediatric and Congenital Cardiac Surgery at Columbia University Vagelos College of Physicians and Surgeons. 

“Heart Brothers”
The three patients recovered well, with John and Teddy discharged nine days later, and Hend leaving the hospital nearly three weeks after her transplant.

John’s parents saw an immediate change in him following his valve transplant as he ran down the hospital’s hallways five days post-operation.

“He is so full of life and the littlest things make him happy,” Joanne says, adding that John, who turned 2 in January 2025, fearlessly climbs the furniture around their home.

“A big weight has been lifted off our chest, and we see a brighter horizon,” says Teddy’s dad, John.

To celebrate Teddy’s milestone of being three months post-operation, the Carters took a family trip to Disney World.

“We had an incredible experience at NewYork-Presbyterian, you can’t even put into words how smart and kind these people are, from the nurses and the physical therapists to the surgeons and doctors, everyone is just top notch,” says Teddy’s mom, Katie.

Teddy, now 3, John, and Hend return to the hospital monthly for follow-up care, with the frequency decreasing as their recovery progresses.  

Connected by the gift of life, the three children met at NewYork-Presbyterian Morgan Stanley Children’s Hospital on February 12, seven months after their transformative procedures.

Hend, who turned 11 in January, offered presents to each of her heart valve recipients.

“I feel amazing to see them healthy,” says Hend. “It feels good to see the boys playing together.”

“To be able to meet the individual that saved our son’s life, we can’t thank her and her family enough,” Thomas says of Hend.

John and Teddy’s parents stay in touch, bonded by their experiences and affectionately calling the pair “heart brothers.”

“Last time we were together, we were in a scary situation. We had sick children in hospital beds and today, they’re just happy, playing kids. That’s the best thing in the world,” says Katie.

Their care team looks toward a near future where the use of new technologies and the allocation and donation of living valves can help more children.

“Seeing these children thrive is one of the most rewarding aspects of our job,” says Dr. Goldstone. “It’s amazing to see how innovation can really help someone in need.”

David Kalfa, M.D., Ph.D., is a Board-certified cardiothoracic surgeon with a subspecialization in pediatric cardiac surgery. He is also Director of the Pediatric Heart Valve Center, and Surgical Director for the Initiative for Pediatric Cardiac Innovation at NewYork-Presbyterian. Dr. Kalfa specializes in neonatal surgery and complex heart reconstructions in children, including minimally invasive congenital cardiac surgery and hybrid procedures.

Andrew B. Goldstone, M.D., Ph.D., is a pediatric cardiothoracic surgeon and Surgical Director of Pediatric Heart Transplantation, and Surgical Director of Pediatric Heart Valve Transplantation at NewYork-Presbyterian/Columbia University Irving Medical Center. With a focus on neonatal surgery, complex biventricular repair, pulmonary artery reconstruction, and the surgical management of heart failure, Dr. Goldstone treats the full spectrum of congenital heart disease, with patients spanning from birth through adulthood.