There is SO MUCH more to consider with transplantation!! I really don't even know that they will consider this an issue for transplant. most transplants are considered when the heart muscle itself is diseased such as in a cardiomyopathy. (Either Hypertrophic or Dilated Cardiomyopathies) Normal EF% are from 50-70% and it is not the only thing they consider when talking about heart failure. Transplantation is the LAST thing you want to do, if you can avoid it, by all means do so! Right from the get-go, you are told this is not a cure for heart disease, you are still considered terminally ill and that it is there to give the family a bit more time with their sick child. The transplant team told us that if we had told them we wanted our daughter to live longer, they would not have accepted her for transplantation because no one knows how long transplanted hearts live for. From the get-go, coronary arteries are building up plague. Some people can live years, some don't make it out of the hospital alive. It's a risk you take. The drug schedule is absolutely RIGID!! Miss two doses and you are on IV antirejection drugs. You are having heart muscle biopsies all the time which can be very unpleasent and bloodwork all the time as well. There really is no deciding numbers as you have asked about. It is based on how well the child is/is not and the symptoms they are having. My daughter, right now is walking around with an EF% of 15! She's been in heart failure (enough to be hospitalized) 5-6 times so far and no one knows why that is happening. When you are talking about a transplanted heart, the treatments can be different because no one really knows enough about transplanted hearts yet. Another problem that can crop up is the development of cancers because the immune system is depressed. There are many adults walking around today with the same type of heart defects that your son was born with and are doing well. If your son is in need of a transplant, you will be sent to be evaluated by a transplant team and they will begin to follow your son from that point on. take care
You may also want to post your question in the doctor forum, where heart transplant specialists from the #1 children's hospital in the U.S. are answering questions for free.
Here's a link: http://www.medhelp.org/forums/Pediatric-Transplant/show/943