Overview of Primary and Secondary Analyses From 20 Randomised Controlled Trials Comparing Carotid Artery Stenting With Carotid Endarterectomy

Objectives

Overview of primary and secondary outcomes from 20 randomised controlled trials (RCTs) comparing carotid endarterectomy (CEA) with carotid artery stenting (CAS).

Methods

Systematic review and meta-analysis of data from 20 RCTs (126 publications).

Results

Peri-operative death/stroke was significantly higher after CAS. Excluding procedural risks, ipsilateral stroke was about 4% at 9-years for CEA/CAS, ie CAS was durable. To improve 10-year survival; peri-operative stroke/myocardial infarction must be prevented, mandating greater emphasis on risk factor control and best medical therapy (BMT). Reducing procedural death/stroke after CAS may be achieved through emerging CAS technologies, but better case selection is essential; eg perhaps preferentially performing CEA in; (i) symptomatic patients aged >70yrs; (ii) interventions <14 days of symptom onset and (iii) situations where stroke risk after CAS is higher (segmental/remote plaques, plaque length >13mm, heavy burden of white matter lesions (WML), avoiding situations where 2 or more stents need to be deployed). New WMLs are significantly more common after CAS and may be associated with higher rates of late stroke/TIA, requiring better risk factor control and BMT in patients with new, post-operative WMLs. There is no evidence that new WMLs predispose to cognitive impairment. Restenoses are more common after CAS, but do not increase late ipsilateral stroke. CEA is associated with a small, but significant increase in stroke ipsilateral to 70-99% restenoses, but procedural risks need to be <2% for redo CEA/CAS to be beneficial.

Conclusions

Questions to be answered include; (i) can CAS be undertaken <14 days of symptom-onset with outcomes similar to CEA; (ii) will emerging stent technologies and improved cerebral protection

prevent stroke after CAS; (iii) what is the optimal volume of CAS procedures to maintain competency; (iv) how to deliver better risk factor control and BMT, and (v) is there a role for CEA/CAS in preventing/reversing cognitive impairment?

What this paper adds to the literature?

This is the first paper to provide a comprehensive overview of primary and secondary outcome data from 20 RCTs comparing CEA with CAS. It includes separate meta-analyses for peri-operative risks and late ipsilateral stroke. Secondary analyses include risk factors for stroke after CEA/CAS and its prevention; the effect of peri-operative stroke or myocardial infarction on long-term

survival; non-stroke complications after CEA/CAS (cranial nerve injury, haematoma, arrhythmias and hypertension/hypotension); the significance of new white matter lesions on late stroke and

cognitive impairment and whether asymptomatic 70-99% restenoses increase the risk of ipsilateral

stroke after CEA and CAS.