Exactly what do you mean?
Oh, dear. You must, starting now, eat no fat, no oil at all, no added fat in your diet, period. But this is only a start.
Now, by "failed," you mean the bypass grafts have become blocked by atherosclerotic plaques?
How old are you? What is your lipid profile? What medications are you taking? What is the condition of your heart? Do you have CHF? What does your doctor say?
Without this kind of information I'm afraid that we can only guess.
If there is nothing (nothing at all?) that can be done, you might, indeed be a candidate for a transplant.
If, however, your doctor is not that worried about you at the moment even though your grafts are reoccluding, you might be able to control the progression of your atherosclerosis--if that's what you mean by "failed"--by statin
drugs and a no-fat-at-all diet. An Ornish diet, in other words.
Dietary changes work slowly, now, so don't expect great things next week, but you can do something about the fast progress of what sounds like fat buildup in your arteries.
What information and guidelines did you get when you had your bypasses? When did you have them? What are you doing now to control your atherosclerosis?
Can it be that nothing can be done? Or just nothing can be done with and about those bypass grafts?
Six grafts is quite a lot. What were you doing before, and what are you doing now? My guess would be that after the bypasses you didn't change much in your lifestyle. Is that right? Then perhps you should start changing as much as you can immediately?
Dean Ornish has had success in reversing some blockages in his patients through diet--the no-fat-at-all diet I mentioned at the beginning--and if there is indeed "nothing" else that you can do, then you should, you must do this.
Get his books and follow their directions, immediately and exactly. Consult with your doctor and take whatever medications he prescribes, exactly as he tells you to.
Begin an exercise and weight-loss program. Walk much more and eat much less than you do now. Walk for an hour a day. Eat no junk, eat lots of fruits and vegetables, eat or drink no empty calories. No chips, no french fries, no burgers, no cheese. For the next six months, do not go to a restaurant to eat, eat only at home and eat only what you fix without any fat at all. Ornish, remember.