‘Nothing short of remarkable.’ Heart transplant saves 18-year-old Gavin Nieters

Gavin Nieters never let his congenital heart defect slow him down.

He was born with pulmonary atresia, meaning the valve that would allow blood to flow from his heart to his lungs didn’t form. The condition can also affect blood flow to the heart, with the potential to lead to heart failure. Gavin went through two open-heart surgeries, one right after birth and another as a 1-year-old and grew up with no restrictions from his heart defect.

This spring, everything changed. Gavin, then 17 years old, began experiencing sudden and severe shortness of breath, making it hard to walk up the stairs at home. Gavin's family reached out to his cardiologist in St. Cloud, Minn., who advised them to come to the emergency department.

“In the emergency department, they did an echocardiogram and our cardiologist told Gavin, ‘Your heart’s not happy,’” said Gail Nieters, Gavin’s mother. The team in St. Cloud started Gavin on medication and referred him to the Pediatric Heart Center at M Health Fairview Masonic Children’s Hospital.

Gavin arrived at our hospital late on May 18, 2023 and, by the next morning, he had gone into sudden cardiac arrest due to an abnormal heart rhythm. It was clear that Gavin would eventually need a heart transplant to survive, but first he had to recover so that he was healthy enough to undergo major surgery.

Treating Gavin for cardiac arrest, preparing for transplant

“Gavin’s heart failure was so advanced that his heart wasn’t able to provide the blood flow that his heart and the rest of his body needed,” said Nathan Rodgers, MD, Gavin’s transplant cardiologist. Rodgers serves as medical director of our pediatric heart transplant program and an assistant professor at University of Minnesota Medical School. “This caused an irregular heart rhythm which sent him into cardiac arrest. Fortunately, Gavin was in our hospital and able to be treated right away.”

Doctors at our Pediatric Heart Center placed Gavin on extracorporeal membrane oxygenation (ECMO), an advanced life support system that helps the heart and lungs rest and recover by pumping oxygen-rich blood throughout the body. ECMO is a short-term support. Gavin’s team was focused on helping his heart and lungs recover after cardiac arrest, so Gavin was as healthy as possible going into surgery for heart transplantation.

While ECMO gave Gavin’s body a chance to rest and made sure he was getting oxygen-rich blood, it couldn’t keep his lungs completely healthy, due to pooling of blood from his heart. Doctors needed a way to drain this excess blood, or “decompress” Gavin’s heart, to prevent further damage to his lungs.

Our pediatric cardiology team had recently partnered with adult cardiologists at M Health Fairview University of Minnesota Medical Center to bring on the Impella CP® with SmartAssist®, a minimally invasive heart pump that can be inserted via a catheter. Primarily used in adults, it’s also possible to use the device in older children and teenagers whose leg arteries are large enough to support it.

Gurumurthy Hiremath, MD, director of the congenital interventional cardiology program with M Health Fairview and an associate professor at University of Minnesota Medical School, placed the pump and it began its work of both draining excess blood from Gavin’s heart and supporting circulation.

“The pump helped us transition Gavin off of ECMO while still supporting his heart and lungs, stabilizing him and making him a good candidate for transplant,” said Hiremath. “When a patient goes in for heart transplant, it’s important for the rest of their organs to be in as good of shape as possible.”

Given the state of Gavin’s heart, the Impella pump and ECMO would serve as a bridge to transplant, which Gavin would need at that point to survive. On May 24, 2023 – shortly before his 18^th birthday – Gavin was put on the transplant waiting list. Luckily, a matching heart became available only one day later. 

Plasmapheresis lowers chance of rejection

Gavin’s transplant surgery was complicated by both his age and by previous heart surgeries.

“When a patient has had a previous heart surgery, there’s scar tissue around the heart. It makes the surgery more challenging, and increases the risk of bleeding,” said Pranava Sinha, MD, surgical director of our pediatric heart transplant program and Division Chief of Pediatric Cardiac Surgery at University of Minnesota Medical School. “You have to plan your reoperations very carefully and be incredibly meticulous during surgery.”

Gavin’s immune system had also been sensitized to foreign antigens by his previous surgeries, as well as by the advanced cardiac support systems he needed after cardiac arrest. This meant it could have a stronger negative reaction to the donor heart. To prevent this, Sinha partnered with our plasmapheresis team led by Andrew Johnson, MD, to do a plasma exchange during surgery. This process filtered Gavin’s blood to remove antibodies that could cause him to reject the new heart.

“Having the opportunity to use plasmapheresis during transplant is something we’ve been laying the groundwork for since restarting our transplant program last year,” said Sinha. “Only a few centers are able to do the procedure, and it was another unique aspect of Gavin’s transplant. The combination of several therapies aimed at keeping Gavin and his vital organs healthy positioned him for success and maximized the chances of a successful transplant.”

Gavin’s transplant was the first performed by our team since Sinha arrived as surgical director of our pediatric transplant program last year.