ABSTRACT NUMBER: ESOC2026A272 COLLATERAL STATUS MEDIATES THE LINK BETWEEN ESTIMATED ARTERIAL STIFFNESS AND FUNCTIONAL OUTCOME IN LARGE VESSEL OCCLUSION STROKE: A SECONDARY ANALYSIS OF THE OPTIMAL-BP TRIAL

Abstract Background and aims Estimated pulse wave velocity (ePWV), a surrogate marker of arterial stiffness derived from age and blood pressure, may influence stroke outcomes by affecting collateral circulation. This study investigated whether ePWV is associated with poor collaterals and if collateral status mediates the relationship between ePWV and functional outcome in patients with acute ischemic stroke due to large vessel occlusion (LVO) who underwent successful endovascular thrombectomy. Methods We analyzed 285 patients from the OPTIMAL-BP trial. Collateral status was assessed using the Tan scale and categorized as poor (grades 0–1) or good (grades 2–3). Functional outcome was defined by the modified Rankin Scale (mRS) at 3 months, dichotomized into poor (mRS 3–6) or good (mRS 0–2). Multivariable logistic regression and mediation analysis were performed. Results The mean age was 73.3±11.3 years; 40.4% were women. Poor collaterals and poor outcomes were observed in 32.6% and 53.0%, respectively. Higher ePWV was associated with older age, more severe stroke, and increased rates of poor collaterals and outcomes. Each 1 m/s increase in ePWV was independently associated with poor collaterals (adjusted odds ratio [OR] 1.308, 95% confidence interval [CI] 1.103–1.552) and poor outcomes (adjusted OR 1.277, 95% CI 1.072–1.521). Mediation analysis showed that collateral status mediated the ePWV-outcome relationship (indirect effect β=0.0266, 95% CI 0.0027–0.0581). Conclusions Elevated ePWV is independently associated with poor collateral circulation and unfavorable outcomes in LVO stroke. Collateral status mediates this link, suggesting a mechanistic pathway between arterial stiffness and stroke prognosis. Conflict of interest All authors: nothing to disclose