Coronary artery bypass grafting for the reduction of mortality: An analysis of the trials

Abstract

None of the three studies of coronary artery bypass grafting is perfect, and we cannot be certain whether surgical treatment prolongs the life of patients with angina. Statistically, the CASS and the European results are compatible. However, the Coronary Artery Surgery Study was a better trial than the European study. Probably the patients admitted to the two studies were similar, but we cannot be certain because the severity of angina in the European patients was poorly defined. Allowing for the differences in operative mortality, the outcome in the patients treated surgically was similar in the two studies. The difference between the patients treated medically and surgically in the European study was probably due to the mortality among the patients treated medically being 'too high'. It seems reasonable to base our clinical practice on the results of CASS: patients whose angina is not adequately controlled should be considered for surgery, but those who can climb a flight of stairs without pain can be treated medically, for there is no good evidence that surgery will prolong their lives.