ABSTRACT NUMBER: ESOC2026YS30 PROGNOSTIC VALUE OF THE PSOAS MUSCLE MASS INDEX IN PATIENTS WHO UNDERWENT ENDOVASCULAR THROMBECTOMY

Abstract Background and aims The psoas muscle mass index (PMI) is recognized as a reliable indicator of sarcopenia. This study aimed to determine whether PMI can predict outcomes in patients undergoing endovascular thrombectomy. Methods Among 323 patients who underwent endovascular thrombectomy between January 2021 and March 2024, we included 161 who underwent contrast-enhanced trunk CT on admission, had premorbid mRS 0–3, achieved successful recanalization (TICI ≥2b), and had recorded height. PMI was calculated by normalizing the bilateral psoas muscle area at the L3 level by height squared. The primary outcome was mRS 0–3 at 90 days, and the secondary outcome was 90-day mortality (mRS 6). Multivariable logistic regression was performed using premorbid mRS, baseline NIHSS, ASPECTS, PMI, and age as covariates. Results: Median age was 77 years (IQR 69–85), 45% were women, and 20% had M2 occlusions. Onset-to-reperfusion time was 214 minutes (149–430), and baseline NIHSS was 17 (11–23). Good outcome occurred in 98 patients (61%). A 0.1-unit increase in PMI was independently associated with good outcome (adjusted OR 1.26, P=0.044). An interaction trend between PMI and age (OR 0.99, P=0.05) suggested a stronger impact in younger patients. Mortality occurred in 17 patients (11%), and PMI showed no association (adjusted OR 1.0, P=0.983). Among patients <70 years(n=42), PMI demonstrated good predictive ability (AUC 0.771), with an optimal cutoff value of 5.99 (sensitivity 48.6%, specificity 100%). Conclusion PMI is a simple and practical indicator of sarcopenia and may help predict functional outcomes before endovascular thrombectomy. Conflict of interest Noriko Nomura: nothing to disclose