To the Editor.
—Because the number of patients screened (42 000) greatly exceeded the number of patients randomized (1662), the generalizability of the ACAS1 results needs to be examined more closely. Although the ACAS authors were careful in their report, they failed to highlight the danger of applying their results to the general population. The public policy implication of the ACAS results will most likely affect truly asymptomatic patients (only 46% of ACAS study patients). Furthermore, primary care clinicians will wonder whether or not to screen these patients. What ACAS authors failed to emphasize is that screening truly asymptomatic patients with noninvasive tests, performing carotid angiography on all patients with positive tests, and finally performing carotid endarterectomy on patients with greater than 60% stenosis of any internal carotid artery will never prevent strokes in the long run.The problem arises because the prevalence of carotid artery stenosis (>60%) in
Oddone E, Waters K. Endarterectomy for Asymptomatic Carotid Artery Stenosis. JAMA. 1995;274(19):1506. doi:10.1001/jama.1995.03530190019016