ABSTRACT NUMBER: ESOC2026A1917 INFLUENCE OF INFARCT VOLUME ON CIRCULATING INFLAMMATORY MARKER LEVELS AFTER ACUTE ISCHEMIC STROKE AND TIA

Abstract Background and aims Routine measurement of circulating inflammatory markers after ischemic stroke/TIA identifies patients at risk of recurrence and could guide patient selection for anti-inflammatory therapies for prevention. However, the influence of brain infarction on circulating markers is poorly understood and the optimal timing of measurement for risk prediction is unknown. Methods We performed a prospective multi-centred cohort study which included patients with recent (0-14 days) non-severe ischemic stroke (mRS≤3) or TIA. We measured MCP-1, IL-6, IL-8, IL-10, IL-12, hsCRP and TNFa and measured infarct volume using manual quantification on DWI sequence. We performed multivariate linear regression to explore the relationship between inflammatory markers and infarct volume after adjustment for confounding factors. Results MRI and inflammatory marker data was available for 365 patients; median infarct volume 0.81cm3 (IQR 0.29 – 3.68cm3) median time to phlebotomy 48hrs (IQR 25-73hrs), 74% non-severe stroke/26% TIA. Following adjustment for age, sex, cholesterol, smoking and atrial fibrillation, infarct volume was modestly associated with IL-6 (ß 0.0084, 95% CI -0.0002 – 0.017) (Figure 1). HsCRP was not associated with infarct volume (ß 0.011, 95% CI -0.0035 – 0.025) (Figure 2). No association was found for the other markers analysed. Conclusions Our findings demonstrate that infarct volume has a modest, clinically insignificant effect on circulating IL-6 in the days following a non-severe stroke/TIA, with no effect on the remaining inflammatory markers analysed. These data suggest that inflammatory marker measurement for risk stratification and patient selection for anti-inflammatory prevention strategies should be performed approximately 24hours after stroke. Conflict of interest Jane Buckley: nothing to disclose Figure 1 - belongs to Methods Figure 2 - belongs to Results