Better size matches for donor hearts will help more people on waiting list

12th November 2015

Researchers say that creating three-dimensional reconstructions of donor hearts could save more people, especially children, on heart transplant waiting lists.

They say fewer well-functioning hearts would need to be discarded and patients would get a better sized heart for them.

Cardiomyopathy is one of the main reasons people, including children, need a heart transplant.

Researchers, led by Jonathan Plasencia, a PhD student at Arizona State University in America, used CT and MRI images to create three-dimensional reconstruction of donor hearts for a "virtual transplant" to see if the size matched.

They then created a "healthy heart library" where virtual reconstructions of healthy hearts were catalogued by size, and doctors could see if a prospective donor was a size match for their patient.

Currently, size-matching for donor hearts is done by the weight of the recipient, but this does not take into account if the donor is overweight or underweight, or if the measurements of the donor heart will actually fit into the thoracic cavity of the patient. So potential size mismatch was an issue particularly in children, but also in adults.

Details were given at an American Heart Association meeting.

Dr Janet Scheel medical director of transplantation at the Children's National Health System in Washington, told MedPage Today that about 40 per cent of hearts in America do not get used because of worries about a size mismatch, and a third of patients die waiting for a heart.

"This kind of a library may allow us to say: “OK, we have a kid with a 7-cm heart but we could safely take a much bigger donor,'" she said. "The ultimate goal would be to maximize the use of our donors, because there's definitely viable donors that we don't use because we can't match them. So this could be one more way to do it."

Mr Plasencia said the library is currently small with only about 50 data sets and a patient weight range of 22.5-100 kg (about 50-200 lbs), but they hope to continue expanding it.

He said the team wanted to minimize discarding well-functioning organs to reduce the transplant waiting list and improve survival.