Prevalence of asymptomatic CT infarcts in the ongoing Asymptomatic Carotid Surgery Trial (ACST).

BACKGROUND: The ACST has randomised over 1670 patients to determine if carotid endarterectomy (CEA) prolongs stroke free survival when compared with best medical treatment alone. This study aims to assess the prevalence of asymptomatic cerebral infarcts in patients grouped by sex, age, mean blood pressure (MBP), total cholesterol, diabetes and coronary artery disease (CAD). METHODS: The type of study was retrospective. Patients with preoperative CT scans were included. In those with previous stroke, only the contralateral cerebral hemisphere was studied for presence of infarcts. One thousand one hundred and forty-two patients were studied. RESULTS: The proportion of patients with CT infarcts was 19% (211/1142). Men (155/777) had a higher incidence of CT infarction (20% vs 15%, p = 0.01). Mean age was 68 years and mean MBP was 107 mmHg. The incidence of CT infarcts was not associated with age or MBP. Diabetics or those with definite CAD had no difference in the incidence of cerebral infarction. Diabetics with definite CAD (51/796) had a greater incidence of CT infarcts (33% vs 21%, p = 0.03) compared with those without evidence of CAD and diabetes together (745/796). CONCLUSIONS: In ACST, CT infarcts are more prevalent in men compared to women, and in diabetics with CAD. There was no difference in the incidence of CT infarction by age, mean BP, or by the presence of diabetes or CAD alone.