OBJECTIVES: To determine whether a long-term treatment with beta-blockers influences the inflammatory activity in carotid artery disease by reducing the carotid plaque levels of lipoprotein-associated phospholipase A2 (Lp-PLA2), its enzymatic products lysophosphatidylcholine (lysoPCs), and of soluble urokinase plasminogen activator receptor (suPAR). MATERIALS AND METHODS: One hundred and thirty-four patients with significant symptomatic or asymptomatic carotid stenosis undergoing surgery were prospectively included and divided into two groups (Group A or B) based on the absence or presence of an on-going long-term oral treatment with beta-blockers. The harvested carotid plaques were analyzed for the levels of lysoPCs using mass spectrometry and Lp-PLA2 and suPAR by Enzyme-linked immunosorbent assay (ELISA). RESULTS: Plaques of patients on long-term treatment with beta-blockers revealed lower levels of Lp-PLA2 (Group A 0.752±0.393 ug/g vs. Group B 0.644±0.445 ug/g, P=.049) as well as suPAR (Group A 0.044±0.024 μg/g vs. Group B 0.036±0.025 μg/g, P=.028). Levels of Lp-PLA2 and suPAR were positively correlated (r=.637, P