SickKids teams came together to urgently perform an innovative procedure to bridge Mariam to a second heart transplant after she went into heart failure for a second time.  

By Sarah Warr

Last year, when Mariam Tannous’ first heart transplant started failing and other medical interventions were no longer working, her clinical team at The Hospital for Sick Children (SickKids) had to quickly think outside the box for an innovative treatment. With time ticking away and an urgent need to bridge Mariam to a second heart transplant, the team decided to try something that had never been done before at SickKids or in Canada – a total artificial heart implant for a paediatric patient.

Mariam’s team at SickKids consulted with colleagues in the United States and received training on the technology, and within two weeks, 11-year-old Mariam became the first paediatric patient in Canada to receive a total artificial heart. She was also one of the smallest, and youngest, patients in the world to have the device implanted.

Finding an urgent solution to Mariam’s failing heart transplant

Mariam, now 12, was born with two forms of congenital heart disease, Epstein’s Anomaly and cardiomyopathy, which meant her right heart ventricle was not well-formed and the valve was leaking. In 2017, she successfully underwent her first heart transplant at SickKids, and was able to go home and resume her favourite activities like swimming and soccer.

A few years later, Mariam unexpectedly started to go into heart failure again and was admitted to SickKids. Her doctors tried various heart failure medications but Mariam’s condition only got worse. She would need a second transplant and the clinical team had to buy her time until a heart became available. As both ventricles of Mariam’s transplanted heart were showing signs of failure, the only option was a total artificial heart – device that can effectively replace an entire human heart for a limited period of time to help bridge patients to a transplant.

“Total artificial hearts are rarely used in paediatric patients due to their size and limitations,” explains Mariam’s cardiologist, Dr. Aamir Jeewa, Medical Director of the Ventricular Assist Device Program at SickKids. “The device, intended for larger adults, has a large set of mechanical pumps that are surgically connected to vessels inside the chest and are driven by connections, outside of the body, to a large controller unit that is almost as tall as Mariam herself and runs 24 hours a day.”

The total artificial heart would provide Mariam with time until she could receive a second transplant, but she could not be connected to the device indefinitely. A number of factors such as potential infection risks, device failure and other health complications make the device a time-limited option, especially for a young person like Mariam.

Since this was a first-of-its-kind procedure at SickKids, Mariam’s parents had a difficult decision to make. “We had a meeting and they told us about the total artificial heart. They explained to us all the risks and what would happen in the surgery and after,” says Linda Antouan Adwar, Mariam’s mom. “It was a hard decision, but SickKids saved her life in the beginning, so we believed they would save her life again.”

SickKids team embarks on innovative surgical procedure

Jeewa and Dr. Osami Honjo, Mariam’s cardiovascular surgeon and Surgical Director of Heart Transplantation and Mechanical Circulatory Support at SickKids, quickly started to collaborate with American colleagues to train SickKids staff on the device, the surgical procedure and post-surgical care.

“Although we often manage other types of assistive devices, everything about the total artificial heart was new for the team. The fact that Mariam was one of the smallest patients in the world to have this device also presented a significant technical challenge,” explains Honjo.

On July 8, 2021, the surgery was successfully completed and Mariam began her recovery. With the support of her multidisciplinary team, she had to relearn how to walk, drink and eat while being attached to a large machine and tubes that kept her artificial heart pumping.

“Mariam always needs to do everything fast, and sometimes she would forget she has the machine attached to her. I would have to tell her ‘Wait, slow down, you have a machine with you’ and she just wanted to go,” recalls Linda.

A couple months later, Mariam received her second heart transplant and third surgery with Honjo. He says, “Mariam and her family have gone through a lot and it’s been my honour to join them on this journey. I’m so happy to see her thrive and go back to her life once again. It’s fantastic.”

While Mariam still faces ongoing challenges with her health, she is enjoying being at home, playing with her brother and returning to school with her friends. “I’m so happy and we are so proud of her,” says Linda. “Her journey is not easy, but day by day she shows us how strong she is now.”

About The Hospital for Sick Children (SickKids)

The Hospital for Sick Children (SickKids) is recognized as one of the world’s foremost paediatric health-care institutions and is Canada’s leading centre dedicated to advancing children’s health through the integration of patient care, research and education. Founded in 1875 and affiliated with the University of Toronto, SickKids is one of Canada’s most research-intensive hospitals and has generated discoveries that have helped children globally. Its mission is to provide the best in complex and specialized family-centred care; pioneer scientific and clinical advancements; share expertise; foster an academic environment that nurtures health-care professionals; and champion an accessible, comprehensive and sustainable child health system. SickKids is a founding member of Kids Health Alliance, a network of partners working to create a high quality, consistent and coordinated approach to paediatric health care that is centred around children, youth and their families. SickKids is proud of its vision for Healthier Children. A Better World.

Sarah Warr works in communications at The Hospital for Sick Children (SickKids).