What were the outcomes of the Asymptomatic Carotid Surgery Trial (ACST)?
The Asymptomatic Carotid Surgery Trial (ACST) included 3120 patients with asymptomatic carotid stenoses of 70%, as measured by duplex ultrasonography. Subjects were randomized to immediate CEA versus indefinite deferral of the operation. The trial used end points that were different from those used in ACAS (perioperative stroke, MI or death, and nonperioperative stroke). The net 5-year risks were 6.4% in the immediate surgery group and 11.8% in the deferred surgery group for any stroke or perioperative death (net gain, 5.4%; 95% CI, 3.0 7.8; P<0.0001). In subgroup analysis, the benefits of CEA were confined to patients <75 years of age. 