ABSTRACT NUMBER: ESOC2026A1278 BRAIN LESION PATTERNS AND OUTCOMES IN ACUTE ISCHEMIC STROKE WITH INFECTIVE ENDOCARDITIS: COMPARISONS BY CAUSATIVE MICROORGANISMS

Abstract Background and aims Infective endocarditis (IE) constitutes an important cause of embolic stroke. While patients with IE demonstrate pathogen-specific variations in clinical outcomes and disease characteristics, current understanding of the differences in IE-related stroke according to causative microorganisms remains limited. We investigated characteristics and outcomes in patients with IE-related acute ischemic stroke stratified by causative pathogens. Methods This retrospective observational study analyzed patients diagnosed with definite IE presenting with acute ischemic stroke. Pathogen-specific comparisons were conducted to examine clinical characteristics and outcomes across groups infected with Staphylococcus aureus, coagulase-negative Staphylococci (CoNS), streptococci, and enterococci. Multivariable logistic regression analysis was performed to investigate predictors of hemorrhagic transformation (HT) and mortality across the entire cohort. Results Among 170 patients with IE-related stroke, pathogen-specific analysis was conducted in 140 patients: S. aureus (n=55), CoNS (n=18), Streptococci (n=51), and Enterococci (n=16). S. aureus demonstrated the highest rates of HT (58.9% S. aureus, 50.0% CoNS, 29.4% streptococci, and 12.5% enterococci; P<0.001) and three-month mortality (28.6% S. aureus, 12.5% CoNS, 8.5% streptococci, and 6.7% enterococci; P=0.042). Multivariable analysis identified S. aureus (OR 6.68, 95% CI 1.46–30.58, P=0.014) and unknown pathogen (OR 11.31, 95% CI 1.40–91.35, P=0.023) as independent predictors of mortality. S. aureus (OR 4.20, 95% CI 1.50–11.75, P=0.006) were associated with an increased risk of HT. Conclusions S. aureus and unidentified pathogen were associated with increased mortality in IE-related stroke. S. aureus also demonstrated elevated HT risk and a tendency toward multiple embolic lesions. These microorganism-specific findings contribute to better understanding of the pathophysiology underlying IE-related stroke complications. Conflict of interest Kwanju Song: nothing to disclose, Bum Joon Kim: nothing to disclose Table 1 - belongs to Results Figure 1 - belongs to Results