We sought to investigate whether levels of matrix metalloproteinases (MMPs) and their inhibitors predict coronary atherosclerotic plaque instability, as assessed by intravascular ultrasound (IVUS) virtual histology during coronary angiography. Blood samples were collected before angiography in 32 subjects (mean age 56 ± 8 years) with stable coronary heart disease (CHD) and elevated lipoprotein(a) (Lp(a), 94 ± 35 mg/dL). Levels of high-sensitivity C-reactive protein (hsCRP), apolipoprotein B100 (apoB100), MMP-7, MMP-9, tissue inhibitor of metalloproteinases (TIMP)-1, and TIMP-2 were determined using commercially available enzyme-linked immunosorbent assay kits. Results. The morphology of a total of sixty coronary lesions was assessed by virtual histology IVUS imaging. Eleven (18%) plaques in nine (28%) patients were classified as plaques with an unstable phenotype or a thin-cap fibroatheroma. Age, low-density lipoprotein cholesterol, apoB100, MMP-7, and MMP-9 levels were positively associated with necrotic core volume. Conversely, there was a negative relationship between MMP-7 and -9 levels and fibrous and fibro-fatty tissue volume. Multivariate regression analysis revealed that MMP-9 is a strong independent predictor of atherosclerotic plaque instability in stable CHD patients. In stable CHD patients with elevated Lp(a), MMP-9 levels are positively associated with the size of the necrotic core of coronary atherosclerotic plaques.

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This study is aimed at investigating the relationship between inflammation, the number of vasa vasorum, and the presence of lipoprotein (a) [Lp(a)] in the aortic aneurysm wall, as well as the relationships of these pathological processes with the development of aneurysm wall dissection. To that end, we examined segments of aortic aneurysm wall, consisting of intima, media, and adventitia, collected from patients during aneurysm prosthetics intervention. The material was collected from 23 men and eight women aged from 33 to 69 years. Monoclonal antibodies to Lp(a), markers of monocytes and macrophages (CD68), T cells (CD3, CD4, and CD8), von Willebrand factor, endothelium NO synthase, and smooth muscle α-actin were used for morphological and morphometric investigation. The present study demonstrated that Lp(a) is not often found in biopsies of patients with thoracic aortic aneurysm. Morphological and morphometric investigation shows the connection of aortic dissection with the process of damage to its wall caused by inflammatory infiltrates, medianecroses, and the appearance of newly formed vasa vasorum in media.