Patients with asymptomatic carotid stenosis (ACS) have severe atherosclerosis and, besides a moderate risk of stroke, are at high risk of myocardial infarction. Although screening for asymptomatic stenosis is not justified for the purpose of identifying patients for inappropriate intervention, ultrasound assessments of atherosclerosis severity may be useful in identifying patients at high risk, in whom intensive medical therapy would markedly reduce risk.1 Indeed, the risk of myocardial infarction in ACS is higher than the risk of stroke. It is thus immaterial that randomised controlled trials have not been carried out to test the efficacy of interventions such as antiplatelet therapy. In the Veteran's Administration trial of ACS,2 patients with no prior history of coronary disease had a 33% 4-year risk of myocardial infarction. Among patients with diabetes, intracranial stenosis and peripheral vascular disease, the 4-year risk of a coronary event was 69%. It is axiomatic, therefore, that all patients with ACS should receive intensive medical therapy. However, despite widespread belief that carotid endarterectomy (CEA) and stenting (CAS) are justified in ACS, most patients (∼90%) with ACS would be better treated with intensive medical therapy than with either stenting or endarterectomy.
Cognitive function is only preserved in a few patients with asymptomatic carotid artery stenosis. Mild cognitive impairment can be precisely detected by performing the discrepancy analysis between crystallized and fluid intelligence tests 1).