Transplant Hope for Heart Patients

Friday, March 16th 2001, 12:00 am

By: News On 6

Doctors at the Hospital for Sick Children in Toronto are reporting a survival rate of 80 percent among infants who received transplanted hearts from donors with incompatible blood types, as good as the rate with compatible donors.

If confirmed by larger and longer studies, the findings could ease the shortage of donor hearts for thousands of desperately ill babies, doctors said.

Dr. Lori West performed the first such transplant at the Toronto hospital on Valentine's Day 1996. Though medical wisdom dictated that blood types should match, Dr. West's logic told her that the immature immune systems of babies should tolerate hearts from incompatible donors.

Her instincts appeared to be right.

In the five years since, the Canadian doctors have transplanted hearts of incompatible blood type into 10 children with failing hearts. The children, who were as old as 14 months, were almost all of type O blood, which is incompatible with other types. In most of the children, the immune systems did not yet produce antibodies against incompatible blood types.

"That's impressive," said Dr. Robert Morrow, who performs infant heart transplants at Arkansas Children's Hospital in Little Rock. "I think it'll stir a lot of debate."

In the study, even when the infants' immune systems began to make the blood antibodies, they did not attack the heart.

The findings were published in Thursday's New England Journal of Medicine.

At the time of the first such operation, the medical literature testified to the result of blood-type mistakes in adults: quick death as the new heart clotted over and seized up within minutes.

Eight of the 10 patients survived the study, which followed them for up to five years. Two died, but the causes appeared unrelated to blood compatibility, the researchers said.