This study of 1,718 men with bypass surgery from 1970 to 1974 in Milwaukee has indicated that the following factors are significantly associated with five-year survival: left ventricular end-diastolic pressure (LVEDP), plasma cholesterol level, coronary occlusion score, age, and left ventricular function (LVF). The 31 men with a previous stroke had a high risk (five-year survival was 32%). To serve as a guide to patient risk, a logistic model is used to predict five-year survival. These probabilities are tabulated for all combinations of LVEDP, age, LVF, occlusion score, and plasma cholesterol level.