Abstract
Coronary by-pass surgery has been performed in hundreds of thousands of patients in the last 15 years with a high standard of technical and surgical perfection. The indications for this kind of surgery, however, are still controversial because in spite of many retrospective and several prospective studies it cannot be proven convincingly that in a given patient this surgical procedure will prolong life or prevent myocardial infarction. The present attempt to analyze the causes for this controversy shows that the main reasons for this uncertainty lie: (a) in the enigma of the underlying (ischemic heart) disease itself, which is supposed to lend itself to surgical therapy; (b) in the inadequate methods available up until now for characterizing the state of the disease, its probable course, and its pathogenesis; and (c) in the professional group interests which have a momentum of their own.