Why do you think there are fewer heart transplants performed each year than kidney transplants?

This is because, people, generally, have two kidneys and are also able to function properly with one functional kidney. Therefore it is easier to perform kidney surgery without putting the patient’s life at risk as compared to heart surgery. Everyone has one heart, a critical organ whose surgery has to be well planned and done only if the risk of not doing the surgery outweighs that of doing the surgery.