Abstract TMP94: Association of Acute Carotid Stenting With Functional Outcome Mediated by Excellent Reperfusion in Tandem Lesions: Analysis of a Multicenter Registry

Abstract

Introduction: Current evidence suggests that acute carotid artery stenting (CAS) for cervical lesions is associated with better functional outcomes in patients with acute stroke with tandem lesions (TLs) treated with endovascular treatment (EVT). However, a gap in understanding persists regarding the underlying causal pathophysiological mechanism of this relationship when compared to angioplasty alone. We aimed to determine whether, and to what degree, excellent reperfusion (mTICI 2c-3) mediates the relationship between acute CAS and functional outcome in patients with TLs. Methods: This sub-analysis stems from a multicenter cohort study of patients with anterior circulation TLs who underwent EVT across 16 stroke centers spanning from January 2015 to December 2020. Mediation analysis was conducted to examine the potential causal pathway in which the relationship between acute CAS and favorable functional outcome (90-day mRS 0-2) is mediated by excellent reperfusion. Results: A total of 512 patients were included, out of whom 319 (62.3%) underwent acute CAS, and 243 (47.5%) had a favorable functional outcome. Excellent reperfusion was a predictor of favorable functional outcome (adjusted OR [aOR]: 2.27, 95% CI 1.57-3.28, p =<0.001). Excellent reperfusion partially mediated the relationship between acute CAS and functional outcome ( Figure ), as acute CAS was still significantly associated with functional outcome after adjustment for excellent reperfusion (aOR: 1.56, 95% CI 1.07-2.28, p =0.022). Excellent reperfusion explained 53% (95% CI 24-87) of the relationship between acute CAS and functional outcome. Conclusions: In TL patients undergoing EVT, excellent reperfusion predicted favorable functional outcome when CAS was performed as compared to angioplasty alone. A significant proportion (53%) of the treatment effect of acute CAS on functional outcome was found to be mediated through the improvement of excellent reperfusion rates.