NASCET & ECST Calculator for Carotid Artery Stenosis Grading
Reference:
- North American Symptomatic Carotid Endarterectomy Trial Collaborators, Barnett, H. J. M., Taylor, D. W., Haynes, R. B., Sackett, D. L., Peerless, S. J., Ferguson, G. G., Fox, A. J., Rankin, R. N., Hachinski, V. C., Wiebers, D. O., & Eliasziw, M. (1991). Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. The New England journal of medicine, 325(7), 445–453. https://doi.org/10.1056/NEJM199108153250701
- Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST). (1998). Lancet (London, England), 351(9113), 1379–1387.
More about this calculator:
The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) have provided critical insights into the management of carotid stenosis, especially in symptomatic patients. These landmark studies have established that carotid endarterectomy significantly reduces the risk of stroke in patients with high-grade carotid stenosis, highlighting the importance of accurate assessment and timely intervention.
NASCET demonstrated that carotid endarterectomy offers substantial benefits for patients with recent hemispheric or retinal transient ischemic attacks or nondisabling strokes who have 70-99% stenosis of the internal carotid artery. The trial showed a remarkable reduction in the two-year cumulative risk of any ipsilateral stroke from 26% in medically treated patients to 9% in surgically treated patients, with a significant absolute risk reduction of 17%. The benefit was even more pronounced for major or fatal ipsilateral strokes, with an absolute risk reduction of 10.6% .
Similarly, ECST findings reinforced the value of carotid endarterectomy in preventing major strokes in patients with symptomatic carotid stenosis. The trial revealed that the risk of major ischemic stroke ipsilateral to the unoperated symptomatic carotid artery increased with the severity of stenosis. For patients with stenosis greater than about 80% of the original luminal diameter, the three-year risk of major stroke or death was significantly lower in the surgery group (14.9%) compared to the control group (26.5%), resulting in an absolute benefit of 11.6% .
Incorporating these findings into clinical practice, calculators that determine NASCET and ECST scores based on CT angiography (CTA) and magnetic resonance angiography (MRA) findings have been developed. These calculators enhance the utility of the NASCET and ECST protocols by providing clinicians with an objective, numerical risk assessment, aiding in the decision-making process for carotid endarterectomy. By automating the calculation of stenosis severity and associated stroke risk, these tools streamline clinical workflow, ensure consistent application of trial findings, and ultimately improve patient outcomes. The integration of such calculators into routine practice not only facilitates precise risk stratification but also supports the formulation of individualized treatment plans, optimizing the management of patients with symptomatic carotid stenosis.
