thromboplastin and Vascular-Calcification

Atherosclerotic coronary arteries are more calcified in patients with than without chronic kidney disease (CKD). We addressed the potential for coronary microvascular obstruction in patients with and without CKD during stenting for saphenous vein aorto-coronary graft (SVG) stenosis under protection with a distal occlusion/aspiration device. In patients with and without CKD (n = 20/20), SVG plaque composition was analyzed from virtual histology using intravascular ultrasound analysis before stent implantation. There was more dense calcium and more necrotic core in patients with than without CKD (14 ± 3 vs. 3 ± 1 % and 21 ± 3 vs. 12 ± 2 % of plaque volume, respectively). Coronary aspirate was retrieved during stent implantation and divided into particulate debris and plasma. Patients with CKD had more particulate debris and calcium release than patients without CKD. In contrast, the release of serotonin was less in patients with than without CKD (0.4 ± 0.1 vs. 1.2 ± 0.3 μmol/L), whereas that of catecholamines, endothelin, tissue factor, thromboxane, tumor necrosis factor α, and C reactive protein was not significantly different. Confirming the biochemical results, aspirate plasma from patients with CKD induced less vasoconstriction of rat mesenteric arteries than that from patients without CKD (with endothelium (+E), 26 ± 7 %; without endothelium (-E): 28 ± 7 % vs. +E, 68 ± 12 %; -E: 95 ± 16 % of maximum KCl-induced vasoconstriction). Graft atherosclerosis of patients with CKD is more degenerated and releases more particulate debris and calcium, but the aspirate has surprisingly less serotonin and vasoconstrictor potential.

Topics: Adult; Aged; Aged, 80 and over; alpha-2-HS-Glycoprotein; Animals; Atherosclerosis; Blood Vessel Prosthesis Implantation; C-Reactive Protein; Calcium; Coronary Artery Disease; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Necrosis; Plaque, Atherosclerotic; Rats; Renal Insufficiency, Chronic; Saphenous Vein; Stents; Thromboplastin; Tumor Necrosis Factor-alpha; Ultrasonography, Interventional; Vascular Calcification; Vasoconstriction

Morphology of atherosclerotic plaque is a major determinant of plaque thrombogenicity. Calcified atherosclerotic lesions are less prone to thrombosis and contain less tissue factor (TF) than lipid-rich plaques. Although bone morphogenetic protein (BMP)-2 is a known mediator of vascular calcification, the role of BMP-2 in the regulation of plaque thrombogenicity has not been established. We hypothesized that the expression of BMP-2 within highly calcified atherosclerotic plaques inhibits TF expression and reduces thrombogenicity of calcified lesions. In the present study, we measured levels of TF and BMP-2 in human calcified and lipid-rich carotid plaques and studied the effects of BMP-2 on TF expression in human monocytes in vitro. Quantitative immunohistochemical analysis of endarterectomy specimens for TF and BMP-2 revealed that calcified plaques contained nearly three-times less TF antigen than lipid-rich ones. In contrast, calcified plaques expressed two-times more BMP-2 antigen than lipid-rich lesions. BMP-2 markedly decreased protein expression and surface redistribution of TF in activated human monocytes in vitro. BMP-2-mediated inhibition of TF expression in monocytes/macrophages could contribute to reduced thrombogenicity of calcified atherosclerotic plaques.

Topics: Arteriosclerosis; Blotting, Western; Bone Morphogenetic Protein 2; Carotid Arteries; Cells, Cultured; Endarterectomy; Flow Cytometry; Gene Expression; Histocytochemistry; Humans; Lipids; Lipopolysaccharides; Macrophage Activation; Macrophages; Microscopy, Confocal; Monocytes; Plaque, Atherosclerotic; Thromboplastin; Thrombosis; Vascular Calcification