ABSTRACT NUMBER: ESOC2026A54 CIRCULATING MICROPLASTICS IN ACUTE ISCHEMIC STROKE: FEASIBILITY, VARIABILITY, AND EXPLORATORY COMPARISONS WITH HEALTHY INDIVIDUALS

Abstract Background and aims Microplastics (MPs) are found in human tissues and are increasingly discussed as a potential cardiovascular risk factor. Methods We conducted a prospective pilot study applying a contamination-controlled, plastic-free protocol to quantify MPs in whole blood. Thirty-five participants were enrolled: 20 with ischemic stroke and 15 healthy controls. Samples were analyzed by micro-Fourier transform infrared spectroscopy to determine particle counts, polymer types, and size distributions. To contextualize findings, we performed an exploratory pooled comparison with a reference of healthy individuals derived from two published datasets using weighted combination of reported means and standard deviations. Results MPs were detected in 94% of participants (median 11.0 MPs/mL; IQR 4-22; mean ± SD,12.6 ± 9.7; range 0-35). Median MP counts were numerically higher in stroke [13.5MPs/mL (IQR 6-23)] than in healthy controls [7.0 MPs/mL (IQR 2-18)]; group differences were not statistically significant in within-study comparisons (p=0.21, Mann-Whitney U). In an exploratory analysis, stroke patients exhibited significantly higher mean MP concentrations than a pooled healthy reference derived from external datasets (13.95±8.73 vs 5.11±7.31 MPs/mL; Welch’s t=3.69, p=0.0016). Polyethylene, polypropylene, and polyethylene terephthalate were the most abundant polymers, and smaller particles (20-100μm) predominated. Conclusions This proof-of-concept study demonstrates the feasibility of blood-based MP quantification under clinical conditions and provides preliminary, hypothesis-generating evidence that circulating MP levels may be elevated in acute ischemic stroke. Because the apparent difference relied on an exploratory pooled comparison across heterogeneous datasets, confirmation in larger, harmonized studies is essential before any inference about disease-specific elevation or clinical relevance. Conflict of interest nothing to disclose