Graft Failure and Open Heart Surgery
(Technically speaking, an open heart surgery is any procedure where the chest is opened, which certainly includes procedures beyond a heart bypass (a valve replacement, for example). However, because a heart bypass is the most common type of open heart surgery, for the purposes of this article, we will be using the terms "bypass" and "open heart surgery" interchangeably.)
It is important to realize that bypass grafts can close over time. Graft closure is more frequent in those people who continue to smoke or have untreated high cholesterol (hypercholesterolemia). If the graft does close, your symptoms will return. Unfortunately, a repeat bypass surgery is more difficult and often less successful than the initial surgery.