A heart transplant removes a damaged or diseased heart and replaces it with a healthy one. The healthy heart comes from a donor who has died. It is the last resort for people with heart failure when all other treatments have failed. Heart transplants are now the third most common organ transplant operation in the U.S. Doctors may recommend a heart transplant for heart failure caused by Coronary artery disease Cardiomyopathy - disease of the heart muscle Heart valve disease In babies, multiple congenital heart defects that are too complex to repair