Risk Prediction for Adverse Events After Carotid Artery Stenting in Higher Surgical Risk Patients

BACKGROUND AND PURPOSE: The goal of carotid artery stenting is to decrease the risk of stroke or other adverse events from carotid artery disease. Choosing a treatment strategy requires patient-specific information regarding periprocedural risk of adverse neurologic events. The aim of this study was to predict individual patient risk after carotid artery stenting in patients at higher risk for carotid endarterectomy. METHODS: Subjects enrolled in the Stenting and Angioplasty with Protection in Patients at High-Risk for Endarterectomy (SAPPHIRE) worldwide study underwent carotid artery stenting with distal protection. Only patients with at least 1 anatomic or comorbid factor associated with elevated surgical risk were included. Preprocedural factors were used to develop a model and integer-based risk score predicting stroke or death within 30 days. The model was calibrated and internally validated using bootstrap resampling. RESULTS: Ten thousand one hundred eighty-six patients were included in the analysis. The overall rate of stroke or death was 3.6% at 30 days after carotid artery stenting. Independent predictors of adverse outcomes were increased age (P=0.006), history of stroke (P<0.001), history of transient ischemic attack presentation (P=0.001), recent (<4 weeks) myocardial infarction (P=0.006), dialysis treatment (P=0.007), need for cardiac surgery in addition to carotid revascularization (P=0.005), a right-sided carotid stenosis (P=0.006), a longer carotid plaque (P=0.012), the presence of a Type II or III aortic arch (P=0.035), and a tortuous carotid arterial system (P=0.004). The optimism-adjusted C-statistic was 0.691. CONCLUSIONS: Commonly collected clinical and anatomic variables can identify patients at high and low risk for stroke or death after carotid artery stenting.