Bridging Evidence Gaps in Severe Carotid Stenosis: A Systematic Review of Pre-Revascularization Risk Stratification, Clinical Predictors, and High-Risk Subgroups.

OBJECTIVE

Severe carotid artery stenosis (CAS) impairs cerebral blood flow and cognitive function. Revascularization may improve outcomes, but patient selection and timing remain challenging. This review synthesizes evidence on pre-revascularization risk factors. This systematic review synthesizes pre-revascularization evidence on CAS-related cognitive decline and evaluates timing, restenosis, high-risk subgroups (dialysis, radiation-induced, and sex), bilateral stenosis, hyperperfusion, and risk for stroke/death/MI outcomes.

METHOD: A systematic search of PubMed, Scopus, EBSCO, Web of Science, SciFinder, and Emerald databases identified 22 published studies that reported quantitative pre-revascularization data between 2013 and 2026. The search was restricted to English-language studies.

RESULTS

Severe CAS (≥70%) impairs memory, attention, and executive function (MMSE +0.9 post-revascularization, p = 0.019; MoCA R = -0.359, p < 0.001). Modern medical therapy reduced 120-day stroke risk to 1.97% (vs. historical 5%); large carotid internal lumen (CIL) volume (≥4,000 mm3) predicts stroke (OR 4.6); urgent TFCAS riskier than carotid endarterectomy (CEA) (6.5% vs. 4.0%); restenosis higher after CAS (40% vs. 18% CEA). High-risk subgroups: dialysis (4.7% 30-day mortality; 43.4% 3-year survival), radiation-induced (86% vulnerable plaques), female TFCAS (OR 2.85 stroke/death), contralateral occlusion (CAS OR 2.90), octogenarians (TF-CAS 6.6% vs. CEA 2.5%). Bilateral stenosis requires carotid vascular reserve (CVR)-guided staging.

CONCLUSION

Pre-revascularization cognitive assessment identifies treatment-responsive deficits. Timing should be individualized (delay large CIL); CEA preferred for high-risk anatomy. Novel risk stratification (dialysis, radiation, female sex, and bilateral CVR) guides patient selection beyond traditional stenosis degree.