Stephen J.LurieMD, PhD, Contributing EditorIndividualAuthor
In Reply: Dr Bluth correctly notes that the
degree of stenosis is not the only variable that increases the risk of stroke.
He cites studies showing that modern ultrasound done in well-equipped and
closely supervised laboratories can distinguish between echodense and echolucent
carotid lesions. Echolucency (corresponding to soft and friable plaques) along
with the degree of stenosis led to an increased risk of stroke. However, such
sophisticated ultrasound technology did not exist when NASCET was launched
in 1987. At that time it was an inadequate method to evaluate either the severity
of stenosis or the nature of the carotid lesion causing the symptoms. A major
study contemporaneous with NASCET could not conduct risk and benefit analyses
based on the degree of stenosis as evaluated by ultrasound.1
Thus, the NASCET protocol appropriately required conventional angiography.
Fontanarosa PB, Barnett HJM, Eliasziw M, Meldrum H. Plaque Morphology as a Risk Factor for Stroke—Reply. JAMA. 2000;284(2):177. doi:10.1001/jama.284.2.175