Pre-procedural Risk Quantification for Carotid Stenting Using the CAS Score : A Report From the NCDR CARE Registry

ObjectivesWe developed and internally validated a risk score to predict in-hospital stroke or death after carotid artery stenting (CAS).BackgroundA tool that accurately assesses CAS risk could aid clinical decision making and improve patient selection.MethodsPatients undergoing CAS without acute evolving stroke from April 2005 through June 2011 as part of the NCDR Carotid Artery Revascularization and Endarterectomy (CARE) Registry were included. In-hospital stroke or death was modeled using logistic regression with 35 candidate variables. Internal validation was achieved with bootstrapping, and model discrimination and calibration were assessed.ResultsA total of 271 (2.4%) primary endpoint events occurred during 11,122 procedures. Independent predictors of stroke or death included impending major surgery, previous stroke, age, symptomatic lesion, atrial fibrillation, and absence of previous ipsilateral carotid endarterectomy. The model was well calibrated with moderate discriminatory ability (C-statistic: 0.71) overall, and within symptomatic (C-statistic: 0.68) and asymptomatic (C-statistic: 0.72) subgroups. The inclusion of available angiographic variables did not improve model performance (C-statistic: 0.72, integrated discrimination improvement 0.001; p = 0.21). The NCDR CAS score was developed to support prospective risk quantification.ConclusionsThe NCDR CAS score, comprising 6 clinical variables, predicts in-hospital S/D after CAS. This tool may be useful to assist clinicians in evaluating optimal management, share more accurate pre-procedural risks with patients, and improve patient selection for CAS.