Equivalence of measurements of carotid stenosis. A comparison of three methods on 1001 angiograms. European Carotid Surgery Trialists' Collaborative Group.

Abstract

There is confusion about how carotid stenosis should be measured on angiograms. If the results of research based on different methods of measurement of stenosis are to be discussed and the results of clinical trials properly applied to routine clinical practice, measurements made by the different methods must be formally compared.The method of measurement of stenosis used in the European Carotid Surgery Trial (ECST), that used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET), and a method based on measurement of the common carotid (CC) artery lumen diameter were compared. Carotid stenosis was measured by two observers, working independently and using the three different methods of measurement, on the angiographic view of the symptomatic carotid stenosis that showed the most severe disease in 1001 patients from the ECST.The results of using the ECST and CC methods differed from those of using the NASCET method in the classification of stenoses as mild (0% to 29%), moderate (30% to 69...