Asymptomatic carotid endarterectomy. Patient and surgeon selection

The applicability of prospective carotid endarterectomy protocols to the general population has been questioned. Outcomes for asymptomatic patients undergoing carotid endarterectomy were compared with the results of the Asymptomatic Carotid Atherosclerosis Study (ACAS) patients treated concurrently at our institution.

Asymptomatic patients undergoing carotid endarterectomies (n = 277) from 1987 to 1993 (ACAS enrollment period) were reviewed. Primary end points were mortality, myocardial infarction, and stroke. Five subgroups were studied: (1) ACAS surgical patients; (2) ACAS-eligible patients not enrolled and ACAS surgeons; (3) ACAS-eligible patients not enrolled and non-ACAS surgeons; (4) ACAS-ineligible patients and ACAS surgeons; and (5) ACAS-ineligible patients and non-ACAS surgeons.

ACAS-eligible patients were younger (P = .014), had more severe carotid stenosis (P = .001), and had lower incidences of pulmonary (P = .015) and renal (P = .008) diseases compared with ineligible patients. Patient selection (ACAS eligibility) significantly improved outcomes for mortality (P = .014) and myocardial infarction (P = .006). Length of stay favored ACAS-eligible patients (P = .004). ACAS surgeons operated on more severely stenotic carotid lesions (P = .005) and on patients with a lower incidence of coronary artery disease (P = .007). There was no difference in outcomes between ACAS and non-ACAS surgeons.

Patient selection was a significant factor in determining outcome. With strict adherence to ACAS enrollment guidelines, the conclusions of ACAS appear applicable to patients seen at our institution with asymptomatic carotid stenosis.