NASCET is an acronym associated with carotid stenosis at what threshold?

NASCET is an acronym associated with carotid stenosis at what threshold?

• A. 80% stenosis
• B. 70% stenosis
• C. 50% stenosis
• D. 30% stenosis

Answer: (B)

NASCET defines significant carotid stenosis using a specific measurement method that compares the narrowed segment to a normal distal portion of the internal carotid artery. According to this approach, severe stenosis is 70% to 99%. This 70% threshold became the criterion for recommending carotid endarterectomy in symptomatic patients because trials showed clear benefit when stenosis reached at least this level. The NASCET calculation uses the residual lumen at the stenosis compared to the normal distal artery lumen to derive the percent narrowing, which is why this threshold is tied to NASCET measurements. It's helpful to note that other measurement methods, like ECST, reference a different diagram and can yield different percentages for the same anatomy, so the 70% cutoff specifically applies to NASCET.

NASCET defines significant carotid stenosis using a specific measurement method that compares the narrowed segment to a normal distal portion of the internal carotid artery. According to this approach, severe stenosis is 70% to 99%. This 70% threshold became the criterion for recommending carotid endarterectomy in symptomatic patients because trials showed clear benefit when stenosis reached at least this level. The NASCET calculation uses the residual lumen at the stenosis compared to the normal distal artery lumen to derive the percent narrowing, which is why this threshold is tied to NASCET measurements. It's helpful to note that other measurement methods, like ECST, reference a different diagram and can yield different percentages for the same anatomy, so the 70% cutoff specifically applies to NASCET.