Implications of the finding of no significant carotid stenosis based on data from a regional Australian vascular unit

The aim of this study was to assess the long-term clinical outcomes in terms of vascular events in patients who showed no significant or mild carotid stenosis (<50%) and thus in whom surgical intervention was not planned. Patients were recruited through referrals to a vascular laboratory between January 2000 and June 2000. One hundred thirty-two of 316 (42%) patients referred for carotid duplex scan were identified to have mild carotid artery disease.

A retrospective observational study of patients identified to have mild carotid artery stenosis from a regional vascular unit in Australia was carried out. Patients were followed up over an 8-year period. Outcomes were assessed in relation to the patients' presenting complaint and risk factor profile. Outcomes included the following: (1) combined cardiovascular events (fatal and nonfatal strokes, fatal and nonfatal myocardial infarctions, and cardiac admissions, which included arrhythmias and angina), (2) strokes (both fatal and nonfatal strokes), and (3) all-cause mortality.

The patient sample included 75 men and 57 women. The median age of the patients was 69.9 (interquartile range: 63.4-76.7) years. There were a total of 49 vascular events in 46 of the 132 patients, including 16 nonfatal and 2 fatal myocardial infarctions, 19 admissions for cardiac reasons other than an acute coronary syndrome, and 12 nonfatal strokes. The cardiovascular and stroke rates were 33.9% and 13.0% at 7.7 years, respectively. The incidence of strokes was highest among those who presented with a previous stroke or a transient ischemic attack.

The long-term clinical outcomes of patients who were referred for duplex ultrasonography and found to have <50% stenosis were not benign. A significant number of vascular events were observed in this study group. Those who presented with a history of stroke or transient ischemic attack were at particular risk of another stroke.