Ge. Mead et al., Can simple clinical features be used to identify patients with severe carotid stenosis on Doppler ultrasound?, J NE NE PSY, 66(1), 1999, pp. 16-19
Objectives-Carotid endarterectomy reduces the risk of stroke in symptomatic
patients with severe ipsilateral carotid stenosis. Symptomatic patients sh
ould therefore undergo carotid Doppler imaging, but in some centres access
to imaging is limited. It was therefore investigated whether simple clinica
l features alone or in combination could be used to identify patients with
severe carotid stenosis, so that they could be referred preferentially for
carotid imaging.
Methods-1041 patients with acute stroke, cerebral or retinal transient isch
aemic attacks, and retinal strokes admitted to Western General Hospital or
seen in neurovascular clinics were assessed by a stroke physician. Their ca
rotid arteries were investigated using colour Doppler imaging by a consulta
nt neuroradiologist. Patients with primary intracerebral haemorrhage, total
anterior circulation strokes, posterior circulation strokes, or posterior
circulation transient ischaemic attacks were excluded because carotid surge
ry would be inappropriate.
Results-726 patients were used in the analysis. Stepwise logistic regressio
n showed that there were significant positive associations between severe c
arotid stenosis and an ipsilateral bruit, diabetes mellitus, and previous t
ransient ischaemic attacks; and a negative association with lacunar events.
The strategy with the highest specificity (97%) was "any three of these fo
ur features" but sensitivity was only 17%. The strategy with the highest se
nsitivity (99%) was to use one or more of the four features, but specificit
y was only 22%.
Conclusion-None of the strategies identified all patients with severe carot
id stenosis with a reasonable specificity. When access to carotid imaging i
s severely Limited, simple clinical features are of some use in prioritisin
g patients for imaging, but access to carotid imaging should be improved.