Restenosis after Carotid Interventions and Its Relationship with Recurrent Ipsilateral Stroke: A Systematic Review and Meta-analysis.

OBJECTIVE: Do asymptomatic restenoses > 70% after carotid endarterectomy (CEA) and carotid stenting (CAS) increase the risk of late ipsilateral stroke? METHODS: Systematic review identified 11 randomised controlled trials (RCTs) reporting rates of restenosis > 70% (and/or occlusion) in patients who had undergone CEA/CAS for the treatment of primary atherosclerotic disease, and nine RCTs reported late ipsilateral stroke rates. Proportional meta-analyses and odds ratios (OR) at end of follow-up were performed. RESULTS: The weighted incidence of restenosis > 70% was 5.8% after "any" CEA, median 47 months (11 RCTs; 4249 patients); 4.1% after patched CEA, median 32 months (5 RCTs; 1078 patients), and 10% after CAS, median 62 months (5 RCTs; 2716 patients). In four RCTs (1964 patients), one of 125 (0.8%) with restenosis > 70% (or occlusion) after CAS suffered late ipsilateral stroke over a median 50 months, compared with 37 of 1839 (2.0%) in CAS patients with no significant restenosis (OR 0.87; 95% CI 0.24-3.21; p = .8339). In seven RCTs (2810 patients), 13 out of 141 (9.2%) with restenosis > 70% (or occlusion) after CEA suffered late ipsilateral stroke over a median 37 months, compared with 33 out of 2669 (1.2%) in patients with no significant restenoses (OR 9.02; 95% CI 4.70-17.28; p < .0001). Following data correction to exclude patients whose surveillance scan showed no evidence of restenosis > 70% before stroke onset, the prevalence of stroke ipsilateral to an untreated asymptomatic > 70% restenosis was seven out of 135 (5.2%) versus 40 out of 2704 (1.5%) in CEA patients with no significant restenosis (OR 4.77; 95% CI 2.29-9.92). CONCLUSIONS: CAS patients with untreated asymptomatic > 70% restenosis had an extremely low rate of late ipsilateral stroke (0.8% over 50 months). CEA patients with untreated, asymptomatic > 70% restenosis had a significantly higher risk of late ipsilateral stroke (compared with patients with no restenosis), but this was only 5% at 37 months. Overall, 97% of all late ipsilateral strokes after CAS and 85% after CEA occurred in patients without evidence of significant restenosis or occlusion.