Thirteen RCTs were included in the review (n=7,484 patients, range 20 to 2,502). Overall study quality was considered to be high. Allocation concealment was reported in eight trials. Blinding of outcome assessors was reported in four trials. There was no blinding of patients reported in any of the RCTs. Five RCTs were stopped prematurely for futility (two trials), harm (two trials), funding shortages (one trial), and slow enrolment (one trial). Follow-up ranged between one to 66 months.
Outcome data in asymptomatic patients were sparse and imprecise.
Stenting, compared with carotid endarterectomy, was associated with increased risk of any stroke (RR 1.45, 95% CI 1.06 to 1.99; 10 studies, I2=40%), decreased risk of periprocedural myocardial infarction (RR 0.43, 95% CI 0.26 to 0.71; 7 studies, I2=0%), and nonsignificant increase in mortality (8 studies, I2=5%).
For every 1000 patients choosing stenting rather than endarterectomy, 19 (95% CI 2 to 42) more patients would have strokes and 10 (95% CI 5 to 13) fewer would have MIs and would result in 3 (95% CI -1 to 11) more deaths.
Restricting the analysis to the most recent trials with the better methodology and more contemporary technique, stenting was associated with a significant increase in the risk of any stroke (RR 1.82, 95% CI 1.35 to 2.45; 2 studies) and mortality (RR 2.53, 95% CI 1.27 to 5.08; 2 studies) and a nonsignificant reduction of the risk of MI (2 studies).