DEBATE continues on whether aortocoronary bypass 1 is an appropriate procedure for treatment of obstructive coronary artery disease. On the one extreme, enthusiasts indicate that the coronary bypass concept already appears to be the most important contribution of the decade, because it seems not only to give prompt relief of disabling symptoms, but also to extend life in certain subgroups. On the other extreme, pessimists contend that because new occlusive lesions often develop in the intrinsic coronary arteries or the saphenous vein forming the bypass, the obstructive disease process actually progresses and may accelerate. Taking an intermediate position, the majority of investigators agree that it is a procedure that improves the quality of life by relieving symptoms, but that the evidence that it may lengthen life is not yet convincing. Even though still debatable, coronary bypass surgery continues to attain increasing popularity because it is capable of providing an immediate