Associations of local release of inflammatory biomarkers during carotid artery stenting with plaque echogenicity and calcification.

BACKGROUND AND PURPOSE

The purpose of this study is to evaluate whether release of inflammatory markers locally from an atherosclerotic plaque after carotid artery stenting (CAS) is associated with plaque echogenicity and calcification.

METHODS

The study consisted of 36 patients with 42 severely stenotic carotid arteries who underwent CAS with the distal balloon occlusion. Before CAS, the plaque echogenicity was evaluated by acoustic densitometry and the distribution of calcification was investigated. Systemic blood samples were obtained from the aorta before CAS and local blood samples under distal balloon occlusion just after CAS.

RESULTS

The interleukin (IL)-6 and osteopontin (OPN) levels markedly increased at the plaque site in comparison to the systemic values (p < 0.001). Moreover, the local IL-18 level slightly increased compared to the systemic values. In contrast, the local high-sensitive C-reactive protein level slightly decreased. The local matrix metalloproteinase (MMP)-2, tissue inhibitor of MMP-1 and soluble intercellular adhesion molecule 1 levels were not changed. The levels of local IL-6 release were associated with lower echogenicity and less calcification (p < 0.05), while those of local OPN release were independent of plaque characteristics.

CONCLUSIONS

Our observations show that IL-6 and OPN were released from carotid stenotic lesions after CAS. The association between high levels of IL-6 release and lower plaque echogenicity and less plaque calcification suggests that IL-6 is prone to be released from vulnerable carotid plaques after CAS.