Volkers, Eline J.

Background and Purpose— We investigated whether procedural stroke or death risk of carotid artery stenting (CAS) compared with carotid endarterectomy (CEA) is different in patients with and without history of coronary heart disease (CHD) and whether the treatment-specific impact of age differs. Methods— We combined individual patient data of 4754 patients with symptomatic carotid stenosis from 4 randomized trials (EVA-3S [Endarterectomy Versus Angioplasty in Patients With Symptomatic Severe Carotid Stenosis], SPACE [Stent-Protected Angioplasty Versus Carotid Endarterectomy], ICSS [International Carotid Stenting Study], and CREST [Carotid Revascularization Endarterectomy Versus Stenting Trial]). Procedural risk was defined as any stroke or death ≤30 days after treatment. We compared procedural risk between both treatments with Cox regression analysis, stratified by history of CHD and age (<70, 70–74, ≥75 years). History of CHD included myocardial infarction, angina, or coronary revascularization. Results— One thousand two hundred ninety-three (28%) patients had history of CHD. Procedural stroke or death risk was higher in patients with history of CHD. Procedural risk in patients treated with CAS compared with CEA was consistent in patients with history of CHD (8.3% versus 4.6%; hazard ratio [HR], 1.96; 95% CI, 0.67–5.73) and in those without (6.9% versus 3.6%; HR, 1.93; 95% CI, 1.40–2.65; P interaction =0.89). In patients with history of CHD, procedural risk was significantly higher after CAS compared with CEA in patients aged ≥75 (CAS-to-CEA HR, 2.78; 95% CI, 1.32–5.85), but not in patients aged <70 (HR, 1.71; 95% CI, 0.79–3.71) and 70 to 74 years (HR, 1.09; 95% CI, 0.45–2.65). In contrast, in patients without history of CHD, procedural risk after CAS was higher in patients aged 70 to 74 (HR, 3.62; 95% CI, 1.80–7.29) and ≥75 years (HR, 2.64; 95% CI, 1.52–4.59), but equal in patients aged <70 years (HR, 1.05; 95% CI, 0.63–1.73; 3-way P interaction =0.09). Conclusions— History of CHD does not modify procedural stroke or death risk of CAS compared with CEA. CAS might be as safe as CEA in patients with history of CHD aged <75 years, whereas for patients without history of CHD, risk after CAS compared with CEA was only equal in those aged <70 years.

Background and Purpose— Prediction models may help physicians to stratify patients with high and low risk for periprocedural complications or long-term stroke risk after carotid artery stenting or carotid endarterectomy. We aimed to evaluate external performance of previously published prediction models for short- and long-term outcome after carotid revascularization in patients with symptomatic carotid artery stenosis. Methods— From a literature review, we selected all prediction models that used only readily available patient characteristics known before procedure initiation. Follow-up data from 2184 carotid artery stenting and 2261 carotid endarterectomy patients from 4 randomized trials (EVA-3S [Endarterectomy Versus Angioplasty in Patients With Symptomatic Severe Carotid Stenosis], SPACE [Stent-Protected Angioplasty Versus Carotid Endarterectomy], ICSS [International Carotid Stenting Study], and CREST [Carotid Revascularization Endarterectomy Versus Stenting Trial]) were used to validate 23 short-term outcome models to estimate stroke or death risk ≤30 days after the procedure and the original outcome measure for which the model was developed. Additionally, we validated 7 long-term outcome models for the original outcome measure. Predictive performance of the models was assessed with C statistics and calibration plots. Results— Stroke or death ≤30 days after the procedure occurred in 158 (7.2%) patients after carotid artery stenting and in 84 (3.7%) patients after carotid endarterectomy. Most models for short-term outcome after carotid artery stenting (n=4) or carotid endarterectomy (n=19) had poor discriminative performance (C statistics ranging from 0.49–0.64) and poor calibration with small absolute risk differences between the lowest and highest risk groups and overestimation of risk in the highest risk groups. Long-term outcome models (n=7) had a slightly better performance with C statistics ranging from 0.59 to 0.67 and reasonable calibration. Conclusions— Current models did not reliably predict outcome after carotid revascularization in a trial population of patients with symptomatic carotid stenosis. In particular, prediction of short-term outcome seemed to be difficult. Further external validation of existing prediction models or development of new prediction models is needed before such models can be used to support treatment decisions in individual patients.