Reducing risk of stroke in patients with acute coronary syndrome: is screening for asymptomatic carotid disease useful?

Stroke is a rare but severe event after acute coronary syndrome. Relations between both arterial territories are still discussed but prevalence of asymptomatic carotid stenosis potentially implicated in the mechanism of stroke is under-investigated. This study aimed to determine the prevalence of asymptomatic carotid stenosis in that population and review the value of screening in a view to potential surgical correction or other preventive therapies. Systematic carotid Doppler ultrasound screening was implemented on 152 consecutive patients admitted to the intensive care unit due to acute coronary syndrome. Fifty-two percent of patients had at least one carotid artery stenosis determined using the NASCET method. Forty-three percent had at least one carotid stenosis < 30%, 6% had mild (30-60%) stenosis, and 2.6% had high-grade (> 60%) stenosis. Existence of carotid stenosis was associated with age, diabetes mellitus, hypertension, and with the extent of the coronary atherosclerosis (left main artery stenosis). In multivariate analysis, age and diabetes were independently associated with existence of a carotid stenosis. When ultrasound screening was restricted to patients identified by multivariate analysis, the prevalence of carotid stenosis potentially requiring surgical treatment rose to 4.6%. The frequency of asymptomatic carotid atherosclerosis was high in this population but lesions were mild. While the small number of high-grade lesions indicates that systematic screening is not to be recommended, screening of patients aged > 65 years or with diabetes, or both, with a view to surgery may be envisaged, since the role of mild stenosis in the occurrence of stroke remains debatable.