Regarding “Rapid progression of carotid stenosis is rare in a large integrated healthcare system over an eight-year period”

Abstract

I read with interest the article written by Chan et al entitled “Rapid progression of carotid stenosis is rare in a large integrated healthcare system over an eight-year period.”1Chan C. Fort D. Velasco-Gonzalez C. Hawken T.N. Leithead C.C. Brinster C.J. et al.Rapid progression of carotid stenosis is rare in a large integrated healthcare system over an eight-year period.J Vasc Surg. 2020 Oct 17; ([E-pub ahead of print])Abstract Full Text Full Text PDF Google Scholar However, I have some reserve about the methodology employed. Indeed, Chan et al used an algorithm to extract the data on carotid stenosis and recoded it into five levels: level 1, 20%-39%; level 2, 40%-59%; level 3, 60%-79%; level 4, 80%-99%; and level 5, complete occlusion. However, they do not precise the ultrasound criteria used to quantify carotid stenosis. Indeed, different criteria exist, mainly North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial criteria, which differ from each other (eg, a 65% European Carotid Surgery Trial stenosis is equivalent to a 30% NASCET stenosis). There are now well-defined guidelines2Von Reutern G.M. Goertler M.W. Bornstein N.M. Del Sette M. Evans D.H. Hetzel A. et al.Grading carotid stenosis using ultrasonic methods.Stroke. 2012; 43: 916-921Crossref PubMed Scopus (178) Google Scholar recommending that hemodynamic criteria should be used, and the result is given in the form of a percentage in the NASCET system to guide the management of carotid stenosis. As this quantification starts at 50% and above, I have a serious doubt that Chan et al followed these guidelines. These differences in the quantification method could explain in part the difference observed between studies concerning the percentage of rapidly progressive stenosis among the population (4.5% for Chan et al to 25% for Diomedi et al3Diomedi M. Scacciatelli D. Misaggi G. Balestrini S. Balucani C. Sallustio F. et al.5 Increased common carotid artery wall thickness is associated with rapid progression of 6 asymptomatic carotid stenosis.J Neuroimaging. 2014; 24: 473-478Crossref PubMed Scopus (6) Google Scholar). It could then be interesting to know how the degree of carotid stenosis was measured in this study and how the authors think it could have influenced their results. Rapid progression of carotid stenosis was rare in a large integrated healthcare system during an eight-year periodJournal of Vascular SurgeryVol. 73Issue 5PreviewFew studies have evaluated the rapid progression of carotid stenosis on a large scale. We created a custom software algorithm to analyze an electronic medical record database to examine the natural progression of carotid stenosis, identify a subset of patients with rapid progression, and evaluate the specific patient risk factors associated with this rapid progression. Full-Text PDF Open AccessReplyJournal of Vascular SurgeryVol. 73Issue 6PreviewWe thank Dr Auboire for his question on the methodology we applied for determining carotid stenosis and appreciate the care and detail with which he read the article. In the integrated health system in which this study was based, we used an Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL)-accredited vascular lab. This vascular lab reports carotid stenosis in ranges of 1%-39%, 40%-59%, 60%-79%, and 80%-99%. As a result, we used the same ranges for carotid stenosis levels in this study. Full-Text PDF