Benefits of coronary artery bypass surgery.

More than 150,000 Americans have undergone coronary artery bypass surgery since this operation was first available on a nationwide scale in 1968. From data now available, we can better evaluate the various mechanisms by which bypass surgery has been thought to relieve anginal symptoms, and whether or not this operation improves ventricular function and increases survival. Most individuals have substantial or complete relief of angina after surgery, no longer require nitroglycerin or beta blocking agents, and are able to return to full physical and sexual activity. A bypass graft restores the capacity of a proximally obstructed coronary artery to increase its blood flow level up to fourfold more than resting levels with exertion. Also, evidence is now appearing that bypass surgery can improve survival in patients with advanced coronary artery disease.