Selective digital angiography of the index carotid artery was performed with an
Axiom Artis Zee angiograph (Siemens) in multiple (4-7, median 4) angulated projections to identify the narrowest lumen diameter while minimizing foreshortening and avoiding overlap of side branches. The view where the stenosis was tightest was used for quantitative measurements (
Quantcor QA v5.0, Siemens). Stenosis severity measurements were performed by agreement of 2 angiographic core lab analysts and were verified by an angiographic corelab supervisor. The %DS was computed as [(RD-DS)/RD]*100% according to NASCET (North American Symptomatic Carotid Endarterectomy Trial) method [7 (
link)], where DS is diameter stenosis and RD is reference diameter. In the projection showing the narrowest lumen diameter 3 measurements were performed and the average %DS was taken for further analysis.
The CTA and cQA analyses were blinded against each other. The study protocol was approved by the local Ethics Committee, and all patients provided written informed consent.
Treatment decisions were based on cQA-DS and guideline criteria other than stenosis severity.
Tekieli L., Mazurek A., Dzierwa K., Stefaniak J., Kablak-Ziembicka A., Knapik M., Moczulski Z., Banys R.P., Urbanczyk-Zawadzka M., Dabrowski W., Krupinski M., Paluszek P., Weglarz E., Wiewiórka Ł., Trystula M., Przewlocki T., Pieniazek P, & Musialek P. (2023). Misclassification of carotid stenosis severity with area stenosis-based evaluation by computed tomography angiography: impact on erroneous indication to revascularization or patient (lesion) migration to a higher guideline recommendation class as per ESC/ESVS/ESO/SVS and CMS-FDA thresholds. Postępy w Kardiologii Interwencyjnej = Advances in Interventional Cardiology, 18(4), 500-513.