Unstable angina. A national cooperative study comparing medical and surgical therapy

Data presented in this communication are preliminary results of an ongoing study that is not yet concluded. At this point in the random trial, the incidence of myocardial infarction is greater with surgery than with medical therapy of patients with unstable angina. Secondly, there was no difference observed in the mortality rate in either group of patients followed for a period of time that averaged less than one year. Thirdly, a persistent anginal syndrome was observed more often in patients treated with medical therapy than with surgery. Thus, it would seem that successful surgery clearly decreases myocardial ischemia better than medical therapy if the relief of clinical angina pectoris is the measured end point. A logical correlation of these observations is that the indications for surgery in patients with unstable angina may be the same for patients with stable angina, that is, the relief of symptoms. Secondly, although the patients surviving surgical therapy clearly have less symptoms than patients surviving only medical therapy, there does not seem to be any evidence to suggest that it is necessary to operate upon patients on an emergency basis, since the early mortality and morbidity in the medically treated patients is quite low and since the authors were unable to demonstrate that myocardial infarction or death was prevented by surgery. Thus, a logical approach to the management of this problem might be as follows: First, admission to a coronary care unit; second, treatment with appropriate pharmacologic agents and bed rest; third, hemodynamic investigation to determine the presence or absence of coronary occlusive disease and the extent of the disease; fourth, continued pharmacologic therapy; fifth, urgent surgery in some instances, i.e., left main coronary artery disease or medical failure; and sixth, elective surgery at a time convenient to all concerned. The authors emphasize, however, that these guidelines should not be considered rigid since they are based on preliminary observations of the first 150 patients randomized in a trial that is still going on. Final conclusions must await results in more patients with a longer followup.