Presence of Contralateral Carotid Occlusion Is Associated With Increased Periprocedural Stroke Risk Following CEA but Not CAS: A Meta-analysis and Meta-regression Analysis of 43 Studies and 96,658 Patients

Purpose: To investigate the prognostic role of contralateral carotid artery occlusion (CCO) in perioperative outcomes of patients undergoing carotid artery endarterectomy (CEA) vs carotid artery stenting (CAS). Materials and Methods: The PubMed, Scopus, and Cochrane databases were searched up to September 2018 to identify observational or randomized studies that compared outcomes of carotid revascularization in patients with vs without CCO. Forty-three studies (46 arms) comprising 96,658 patients were selected (75,857 CEA and 20,801 CAS). The CCO group included 9258 patients. Heterogeneity was assessed with the Higgins I 2 test. I 2 >75% indicated significant heterogeneity. A random effects model was used to account for heterogeneity among studies. The results were reported as the odds ratios (ORs) with the 95% confidence intervals (CIs). Meta-regression analysis examined potential confounders. Publication bias was quantified by the Egger method. Results: Carotid revascularization in patients with CCO was associated with an increased risk of 30-day mortality (OR 1.75, 95% CI 1.38 to 2.23, p<0.001; I 2 =0%), stroke (OR 1.77, 95% CI 1.41 to 2.22, p<0.001; I 2 =46%), transient ischemic attack (TIA) (OR 2.10, 95% CI 1.34 to 3.27, p=0.001; I 2 =15%), and the composite endpoint of stroke/death (OR 1.78, 95% CI 1.54 to 2.05, p<0.001; I 2 =0%). No difference was noted in the risk of perioperative myocardial infarction (OR 0.81, 95% CI 0.50 to 1.31; p=0.388; I 2 =0%). Subgroup analysis demonstrated that CEA in patients with CCO was associated with an increased risk of stroke (OR 2.07, 95% CI 1.72 to 2.49, p<0.001; I 2 =14%), death (OR 1.80, 95% CI 1.55 to 2.10, p<0.001; I 2 =0%), TIA (OR 2.18, 95% CI 1.38 to 3.45, p<0.001; I 2 =13%), and stroke/death (OR 1.80, 95% CI 1.55 to 2.10, p<0.001; I 2 =0%), whereas CCO patients who were treated with CAS were at an increased risk for death (OR 1.65, 95% CI 1.07 to 2.60, p=0.023; I 2 =0%) but not stroke (OR 0.94, 95% CI 0.61 to 1.47; p=0.080; I 2 =31%) or TIA (OR 1.18, 95% CI 0.18 to 7.55; p=0.861; I 2 =43%). The meta-regression analysis did not find any significant association for any of the outcomes, and there was no evidence of publication bias. Conclusion: Carotid revascularization outcomes are adversely affected by the presence of CCO. Patients with CCO have a significantly higher risk of periprocedural stroke, death, and TIA. CEA in patients with CCO is associated with an increased risk of perioperative stroke, death, TIA, and death/stroke, while CAS in the presence of a CCO is associated with an increased risk of periprocedural death but not stroke or TIA.