Introduction: Demographics and vascular anatomy may play an important role in predicting periprocedural complications in symptomatic patients undergoing carotid artery stenting (CAS). In this study, we sought to predict factors associated with increased risk of complications in symptomatic patients undergoing CAS, as well as devise a CAS scoring system that predicts such complications.

Methods: A retrospective study was conducted of patients who underwent CAS for symptomatic carotid stenosis during a 3-year period. Demographics as well as anatomical characteristics were correlated with 30-day outcome measures. A CAS risk model was subsequently devised by developing a linear combination of dichotomized predictors to predict the various complications. Those predicting factors were initially selected based on the p-values in the multivariate logistic regression. The total score predicted patients who are low risk (CAS I), moderate risk (CAS II), or high risk (CAS III) for the various CAS complications.

Results: A total of 221 patients were included in the study. The cumulative rate of periprocedural complications was 7.2%, including stroke (3.2%), myocardial infarction (MI) (3.2%), and death (1.4%). Renal disease increased the risk of all complications. National Institute of Health Stroke Scale (NIHSS) score =10 at presentation, difficult femoral access, and diseased calcified aortic arch, increased the risk of stroke and all complications. Type III aortic arch correlated with increased risk of stroke. Pseudoocclusion and concentric calcification of the carotid artery increased the risk of MI, death, and all complications. Carotid tortuosity and anatomy hostile to the deployment of distal protection devices increased the risk of stroke, MI, death and all complications.

Conclusions: CAS should be avoided in patients with multiple anatomical risk factors. High presenting NIHSS score and renal disease also increase the complication risk. The CAS scoring system devised in this study is simple, reproducible, and clinically valuable in predicting complications risk in symptomatic patients undergoing CAS.

Patient Care: Our research provides guidance as to which patients with symptomatic carotid disease should undergo carotid artery stenting, based on their demographics and vascular anatomy. This will significantly decrease the rates of morbidity and mortality in this patient population, and will render carotid stenting for symptomatic carotid disease a much safer procedure.

Learning Objectives: - Understand the demographic and anatomic risk factors associated with poor outcome in patients undergoing carotid artery stenting for symptomatic carotid disease. - Understand and apply a scoring system that predicts increased risk of complications in symptomatic patients undergoing carotid stenting. - Avoid carotid stenting in symptomatic patients with multiple demographic and anatomic risk factors.

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