Background and Purpose—Carotid angioplasty and stenting (CAS) has not been shown to be as safe as carotid endarterectomy (CEA) with regard to the risks of periprocedural complications, but beyond the perioperative period, the risks are comparable, suggesting that CAS may be an acceptable option in selected patients. However, risk factors for perioperative stroke and death have not been clearly established. We aimed to estimate the 30-day absolute risks of stroke or death after CAS and investigate sources of heterogeneity.

Methods—We sought articles published between January 1990 and June 2008 by using MEDLINE, EMBASE, the COCHRANE databases, hand-searching, abstract books from conferences, and official websites. Two reviewers independently and in duplicate selected articles on the risks of CAS, irrespective of the type of treatment, study design, setting, or language. The 2 reviewers abstracted data and assessed the quality of the studies.

Results—Two hundred six independent studies (with 54 713 patients) were included. The overall 30-day risk of stroke or death was 4.7% (95% CI, 4.1 to 5.2) with substantial heterogeneity across studies. Symptomatic patients were about twice as likely as those with asymptomatic stenoses to have complications. The 30-day risk of stroke or death was 7.6% (3.6 to 9.1) in symptomatic and 3.3% (2.6 to 4.1) in asymptomatic patients. Risks increased with age, hypertension, and history of coronary artery disease; were unrelated to sex and the presence of contralateral carotid occlusion; and were lower in patients who had carotid restenosis after CEA and in those treated with the use of a cerebral protection device. Risks have also decreased over time.

Conclusions—Risks of CAS vary substantially across studies. Risks are overall higher than those of CEA in symptomatic patients. Some factors are likely to help select good candidates for CAS.