Collateral Circulation Outweighs Therapeutic Modality in Predicting Outcomes of Symptomatic MCA Stenosis: A Triple-Center Retrospective Cohort.

Abstract

This multicenter study investigated whether treatment outcomes for severe symptomatic middle cerebral artery (MCA) stenosis (≥90%) depend on collateral circulation status, given conflicting evidence on endovascular intervention versus medical therapy for intracranial atherosclerotic disease (ICAD). A retrospective cohort analysis was conducted across three Chinese tertiary centers (2017-2022), enrolling 192 patients with symptomatic MCA stenosis. Participants were stratified by ASITN/SIR collateral grades (good: 3-4; poor: 0-2) and treatment (medical vs. interventional), forming four cohorts. All received standardized medical therapy (dual antiplatelets+risk factor control); intervention groups underwent angioplasty±stenting. Primary outcomes were functional independence (mRS ≤2 at 1 year), with secondary endpoints of stroke/death at 1 year. Statistical analyses included multivariable logistic regression (adjusting for age, sex, hypertension, diabetes) and Kaplan-Meier survival analysis. Good collaterals independently predicted better outcomes: reduced adverse events (aOR 0.42, 95% CI 0.21-0.84; P = 0.014) and improved survival (HR 0.39, 95% CI 0.17-0.90; log-rank P = 0.027). Perioperative complications were comparable between intervention groups (good collaterals-intervention: 4.5% vs. poor collaterals-intervention: 7.3%; P = 0.935). At 1 year, pooled analysis showed lower event rates with good collaterals (7% vs. 17%, RR=2.49, P = 0.021), with no treatment-specific differences (good collaterals-intervention: 9.1% vs. good collaterals-medical: 5.4%, P = 0.696; poor collaterals-intervention: 15% vs. poor collaterals-medical: 20%, P = 0.590). In this multicenter retrospective cohort study, robust collateral circulation (ASITN/SIR grades 3-4) appears to be a more important independent predictor of functional independence and reduced stroke/death at 1 year than treatment modality in patients with severe symptomatic MCA stenosis.