ABSTRACT NUMBER: ESOC2026A1572 SYMMETRIC DIMETHYLARGININE FOR RISK STRATIFICATION OF CARDIOEMBOLIC STROKE

Abstract Background and aims A significant proportion of ischemic strokes are classified as embolic stroke of undetermined source (ESUS), complicating secondary prevention. Nitric oxide metabolism is regulated by L-arginine (Arg), asymmetric (ADMA) and symmetric dimethylarginine (SDMA), contributing to increased cardiovascular risk. Previous studies suggest that SDMA and the ratio of Arg/SDMA help to detect atrial fibrillation (AF). We hypothesized that SDMA and Arg/SDMA improve diagnosis of cardioembolic stroke (CES), which may enable more accurate secondary prevention. Methods This prospective nested case-control study included ischemic stroke patients (CES or ESUS) at Hannover Medical School between January 2022 and July 2023. Blood samples were collected after 24h of stroke onset. ADMA, SDMA, and Arg concentrations were measured and relevant biomarker ratios were calculated. Logistic regression and receiver operating curve analyses examined discriminatory biomarker performances for CES versus ESUS, alongside established clinical risk scores. Results 235 patients (107 CES, 128 ESUS) were analyzed. Arg/SDMA ratio and SDMA values showed comparable or better discriminatory power between CES and ESUS than clinical AF scores (AUC SDMA=0.71 (95%CI: 0.64-0.77, p<0.001); AUC Arg/SDMA=0.74 (95%CI: 0.67-0.80, p<0.001)). The same was true for AF detected after stroke (AFDAS) vs. ESUS. Combining Arg/SDMA-ratio and AS5F diagnostic accuracy is modestly improved compared to AS5F alone (Delta-AUC=0.03 (95%CI: -0.06-0.11). Conclusions SDMA and Arg/SDMA ratio can serve as biomarkers for AF and AFDAS. While the additional predictive value in combination with clinical scores may be limited, these findings support the pathogenic role of the Arg/SDMA pathway in stroke pathophysiology. Conflict of interest Johanna Ernst: nothing to disclose, Ilai Kaulbarsch: nothing to disclose, Anika Grosshennig: nothing to disclose, Svenja Jochmann: nothing to disclose, Jens Martens-Lobenhoffer: nothing to disclose, Stefanie Bode-Boeger: nothing to disclose, Ralf Lichtinghagen: nothing to disclose, Karin Weissenborn: nothing to disclose, Rieke Ringlstetter: nothing to disclose, Gerrit M Grosse: nothing to disclose