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

Study Questions:

What are the risk factors that predict occurrence of stroke or death in patients undergoing carotid stenting?

Methods:

The authors used data from the Stenting and Angioplasty with Protection in Patients at High-Risk for Endarterectomy (SAPPHIRE) worldwide study of patients undergoing carotid artery stenting with distal protection to assess predictors of procedural outcome. All patients had at least one anatomic or comorbid factor associated with elevated surgical risk. 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 validated using bootstrapping.

Results:

The study population was comprised of 10,186 patients and 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 (odds ratio [OR], 1.5; p = 0.006), history of stroke (OR, 2.0; p < 0.001), history of transient ischemic attack presentation (OR, 1.7; p = 0.001), recent (<4 weeks) myocardial infarction (OR, 2.8; p = 0.006), dialysis treatment (OR, 2.7; p = 0.007), need for cardiac surgery in addition to carotid revascularization (OR, 2.2; 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:

The authors concluded that the risk of stroke or death in patients undergoing carotid stenting can be predicted using commonly available clinical and anatomical variables.

Perspective:

The authors reported a bedside risk model that can be used to predict procedural outcome of patients undergoing carotid stenting. This model, like the model derived from the CARE registry, has a modest discrimination that limits bedside applicability of these models. Having said that, the model is easy to use, and the variables pass the clinical sniff test (other than perhaps the right side being associated with more complications in this study, see Zahn et al., Catheter Cardiovasc Interv 2009), and should be considered as part of clinical decision making and patient consent.

Keywords: Odds Ratio, Endarterectomy, Myocardial Infarction, Stroke, Ischemic Attack, Transient, Carotid Arteries, Risk Factors, Angioplasty, Stents, Registries, Vascular Malformations, Carotid Stenosis, Cardiac Surgical Procedures


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