MICRO- AND NANOPLASTIC CONTAMINATION IN HUMAN ATHEROSCLEROTIC PLAQUES AND ITS IMPACT ON CARDIOVASCULAR EVENTS

Raffaele MARFELLA | Department of Advanced clinical and surgical sciences, University of Campania “L. Vanvitelli”, Naples, Italy

Micro- and nanoplastics (MNPs) are emerging environmental pollutants with potential health implications. While the link between air pollution and cardiovascular diseases (CVDs) is established, limited data exist on the direct role of plastic contaminants in human vascular pathology. In this study, we evaluated the presence of MNPs in human carotid atherosclerotic plaques collected from patients undergoing endarterectomy for asymptomatic stenosis >70%. Advanced techniques including electron microscopy, pyrolysis, and mass spectrometry were used to detect 11 common plastic polymers (e.g., polyethylene, PVC, polycarbonate). Our findings reveal that approximately 60% of plaques were contaminated with MNPs, primarily polyethylene. Patients with contaminated plaques were significantly younger and showed fewer classical risk factors such as hypertension or diabetes, suggesting that MNP exposure may accelerate atherosclerosis independently of traditional risk profiles. Microscopy demonstrated intracellular plastic particles within macrophages and associated pro-inflammatory changes, including increased cytokine expression, macrophage and T cell infiltration, and reduced collagen, indicating plaque vulnerability. A 3-year follow-up of 257 patients showed a 4.5-fold increased risk of major adverse cardiovascular events (MACE: MI, stroke, death) in individuals with MNP-contaminated plaques, independent of confounders. These data provide the first human evidence of MNP accumulation in atherosclerotic tissue and its association with systemic cardiovascular risk. Our results highlight the need to address plastic pollution as a novel and modifiable risk factor in cardiovascular prevention strategies.