See below. It is not a matter of what age you have to be. The disease tends to be more likely to be present in older people. So as you get older you are more likely to need it. If necessary, the surgery can even be done in very old patients so that age is not really a limiting factor. A child would very rarely need this type of surgery.
Usually adult. It is treatment for angina-chest pain so one has to have coronary vessels blocked. It is not an operation done without specific indications of disease some very aged, frail, high risk persons may not be candidates.