To identify patients undergoing carotid endarterectomy who are at high risk for cardiac events and death, we studied the course of 614 patients with known risk factors who were entered into our carotid follow-up registry. Patients were divided into two groups, group I with overt coronary disease (prior myocardial infarction, angina, significant electrocardiographic abnormalities) (N = 324) and group II without overt coronary disease (N = 290). Group II patients were subdivided into groups with (IIA) (N = 206) and without (IIB) (N = 84) coronary risk factors (cigarettes, diabetes, or hyperlipidemias). Thirty-day, 5-, 10-, and 15-year life-table survival for the groups was: I = 98.5%, 68.6%, 44.9%, 36.4%, respectively; II = 100%, 86.4%, 72.3%, 54.3%, respectively; IIA = 100%, 84.8%, 66.9%, 41.5%, respectively; IIB = 100%, 90.5%, 87.9%, 87.9%, respectively. Overt coronary disease was associated with diminished 30-day (p = 0.03) and late (p less than 0.0001) survival. Risk factors in the absence of overt disease were not associated with diminished 30-day survival. Late survival up to 3 years from endarterectomy was similar in groups IIA and IIB, but later survival was diminished in group IIA. Myocardial infarction was the most frequent cause of death in all groups. Patients with overt coronary disease are at high risk for late cardiac events and death. Patients without overt disease are at less risk than those with overt disease, and in the absence of overt disease, those without are at less risk than those with risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)