The risk of stroke in patients with asymptomatic carotid stenosis undergoing cardiac surgery: a follow-up study.

During a 7-year period, 4047 patients underwent a battery of noninvasive carotid tests before cardiac surgery. Two thirds of the patients with abnormal studies underwent carotid angiography. One hundred fifty-three patients (3.8%) had significant carotid disease, narrowing the luminal diameter by greater than 50%. The incidence of transient ischemic attack or cerebrovascular accident following cardiac surgery was 1.9% in those patients with no carotid disease and 9.2% in those patients with carotid lesions. The incidence of transient ischemic attack or cerebrovascular accident in 32 patients with inoperable (occluded) carotid vessels was 15.6% and in 121 patients with operable (stenotic) lesions was 7.4%. In the group of patients with stenosis, 57 patients underwent carotid operation with an 8.8% incidence of neurologic deficit. During the last 1 1/2 years, no patient with asymptomatic carotid stenosis underwent simultaneous carotid and coronary surgery. Four of 64 patients with combined lesions but no carotid surgery (6.3%) had a neurologic deficit, one of which was severe and permanent. The highest incidence of neurologic dysfunction occurred in patients with unilateral occlusions and contralateral stenosis. Four of 12 patients in this group had a deficit (three of seven patients underwent operation; one of five did not), one of which was permanent. The operative mortality rate after cardiac surgery was three times higher in patients with carotid disease than in those patients with normal carotid arteries. Combined carotid and coronary surgery is currently reserved for patients with neurologic symptoms and severe cardiac disease.