A patient at Queen Mary Hospital who was given a heart of the wrong blood type was in a stable condition as of yesterday, almost three weeks after her transplant.
The 58-year-old woman can eat on her own and sit up, and is now out of the hospital's intensive care unit. Her body has so far not rejected the new organ.
She has not yet been told about the mistake.
Doctors had expected a 90 per cent chance of rejection after the heart from an AB-blood-type donor was mistakenly put into the blood-type-A patient on May 21. She is not yet out of danger.
Although it seems she may have been lucky, Professor Lo Chung-mau, the hospital's chief of surgery, said it does not make the mistake any less serious.
"We are happy that she is doing well," he said. "Without the transplant she may have died by now. The decision was wrong, but it seems to have helped her."
Doctors in charge of the transplant have apologised for the error. They said they could not explain why they had not realised that the two blood types were incompatible. An investigation is under way.
The patient was suffering from multiple organ failure when she was admitted to the hospital, and doctors expected her to live for just 10 more days before the transplant was carried out. No heart of blood type A has been donated since her transplant.
The hospital is arranging to have the whole medical team in charge of the transplant formally tell her about the blunder.
"If I were the patient, I can imagine that my feelings would be complicated," said Lo, an adviser to the team. "Someone made a mistake, but it has resulted in a benefit to me."
The Queen Mary patient's antibody level has been low since the transplant, which has reduced the likelihood of her body rejecting the new heart. Lo said her low antibody level may be related to the kidney dialysis she has been undergoing and to heredity factors.
The patient is also on immunosuppressant drugs.