thromboplastin and Angina--Stable

The knowledge of circadian variation of microparticles (MPs) in stable coronary artery disease (SCAD) is limited. The aim of this study was to evaluate the daily variation of platelet-, endothelial- and monocyte-derived MPs in whole blood and their tissue factor expression (TF) in SCAD and whether these MPs were related to other endothelial and coagulation markers.. Serial blood samples from patients with SCAD were collected during one day. Flow cytometry was used to evaluate the amount of large MPs 0.5-1.0 μm, positive for annexin, and their expression of CD41, CD62P, CD144, CD14 and TF. The lag time and endogenous thrombin potential (ETP) was calculated by Calibrated Automated Thrombogram and soluble (s)P-selectin, sTF and vWF by ELISA.. The majority of MPs in whole blood consisted of CD41 + MPs with no significant daily variation. In contrast, the concentration of CD62P + MPs described a daily variation with the lowest concentrations found in the evening (p = 0.031). CD62P + and CD144 + MPs had the highest expression of TF, 52.6% and 42.9%, respectively, and correlated to the endothelial activity evaluated by vWF. There was a circadian rhythm of lag time (p < 0.001) and ETP (p = 0.001). The CD62P+, CD14 + and CD144 + MPs correlated to the lag time.. The different subsets of platelet-, endothelial- and monocyte-derived MPs do not present the same circadian variation and they differ in TF expression in SCAD. The MPs from activated platelets, endothelial cells and monocytes exist in low concentrations in whole blood but are related to the endothelial and coagulation activity found in SCAD.

Topics: Aged; Angina, Stable; Antigens, CD; Blood Platelets; Cadherins; Case-Control Studies; Cell-Derived Microparticles; Circadian Rhythm; Coronary Artery Disease; Female; Humans; Male; Middle Aged; Monocytes; P-Selectin; Platelet Membrane Glycoprotein IIb; Thrombin; Thromboplastin

The aim of this study was to investigate the tissue factor (TF) expression of platelets and leukocytes in patients with acute coronary syndrome (ACS), patients with stable angina (SA) and healthy subjects (as controls). 26 patients with ACS, 29 patients with SA, and 25 controls were enrolled in this study. The peripheral blood samples of above-mentioned subjects were collected and isolated to obtain the monocytes and platelet-rich plasma, the TF-mRNA expression of monocytes, and platelets among 3 groups was detected by RT-PCR, the TF expression ratio of platelets, platelet-leukocyte aggregates (PLA) and platelet-monocyte aggregates (PMP) was detected by flow cytometry among 3 groups. The results showed that the TF mRNA expression level of platelets in ACS group were significantly higher (3.11 ± 0.51 relative expression) as compared with SA and control groups (1.88 ± 0.78 and 0.7 ± 0.1, respectively) (P = 0.03). Expression of TF mRNA of monocytes was higher in ACS group (P = 0.05 versus controls) too. ACS group had a significantly higher amount of TF-positive platelets (8.8 ± 2.6) than SA (2.6 ± 0.5, P = 0.02) or control groups (2.5 ± 0.4, P = 0.02). A significantly greater number of TF positive platelet-leukocyte aggregates and platelet-monocyte aggregates were also found by flow cytometry in blood of ACS patients than in either SA patients or controls. It is concluded that the high TF expression of platelets and leukocytes in ACS patients strengthens the platelet activation, blood coagulation, and thrombus formation and may further contribute to the hypercoagulability associated with the disease. The present study further extends the proinflammatory/prothrombotic phenotype of ACS patients showing that new players on the scene.

Topics: Acute Coronary Syndrome; Aged; Angina, Stable; Blood Platelets; Case-Control Studies; Cell Adhesion; Female; Humans; Leukocytes; Male; Middle Aged; Platelet Aggregation; RNA, Messenger; Thromboplastin

Stent implantation into atherosclerotic coronary arteries releases particulate debris and soluble substances that contribute to impaired microvascular perfusion. Here we addressed the potential for microvascular obstruction in patients with stenotic native right coronary arteries (nRCA) compared with saphenous vein grafts on right coronary arteries (SVG-RCA). We enrolled symptomatic, male patients with stable angina pectoris and a flow-limiting stenosis in their nRCA or SVG-RCA (n = 18/18). Plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Coronary aspirate was retrieved during stent implantation under protection with a distal occlusion/aspiration device and divided into particulate debris and plasma. The release of catecholamines, endothelin, serotonin, thromboxane B2, and tumor necrosis factor-α was measured. The response of rat mesenteric arteries with intact (+E) and denuded (-E) endothelium to aspirate plasma (without and with selective endothelin receptor blockade) was normalized to that by potassium chloride (KClmax = 100%). Plaque volume and composition were not different between nRCA and SVG-RCA. There was less particulate debris (65 ± 8 vs. 146 ± 23 mg; P < 0.05) and more endothelin release (5.8 ± 0.8 vs. 1.3 ± 0.7 pg/ml; P < 0.05) in nRCA than in SVG-RCA, whereas the release of the other mediators was not different. Aspirate from nRCA induced stronger vasoconstriction than that from SVG-RCA [nRCA, 78 ± 6% (+E)/84 ± 5% (-E); SVG-RCA, 59 ± 6% (+E)/68 ± 3% (-E); P < 0.05 nRCA vs. SVG-RCA], which was attenuated by a nonspecific endothelin and a specific endothelin receptor A antagonist. Thus coronary aspirate from stented nRCA is characterized by less debris but more endothelin and stronger vasoconstrictor response than that from SVG-RCA.

Topics: Aged; Angina, Stable; Animals; Coronary Stenosis; Endothelins; Epinephrine; Graft Occlusion, Vascular; Humans; Male; Mesenteric Arteries; Middle Aged; Norepinephrine; Rats; Saphenous Vein; Serotonin; Stents; Thromboplastin; Thromboxane B2; Tumor Necrosis Factor-alpha; Vasoconstriction

Tissue factor (TF), the major procoagulant in vivo, is usually absent from blood cells. However, since both monocyte TF (MoTF) expression and platelet activation are present in acute coronary syndrome we hypothesized that MoTF expression may in part depend on monocyte platelet aggregate (MPA) formation in coronary artery disease (CAD). Patients with unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI, n = 20) had significantly higher levels of MoTF (17.4 ± 3.1MFI) and MPAs (CD42b:273 ± 183MFI; CD62P:256.3 ± 48.5MFI) than patients with stable angina (SA, n = 40; MoTF:13.2 ± 2.2MFI, p = 0.001; CD42b:160 ± 113MFI, p = 0.025; CD62P:118.7 ± 24.5MFI, p = 0.018) as measured by whole blood flow cytometry on CD14+-cells. TF-activity of isolated mononuclear cells (MNC) was elevated in UA/NSTEMI (75 ± 27 pg/mL) in comparison to SA (47 ± 17 pg/mL, p = 0.001) as determined by chromogenic assay, and TF mRNA expression in isolated MNC was more frequent in UA/NSTEMI than in SA (50% vs. 18.2%; p = 0.017). MoTF expression significantly correlated with the constitutive platelet marker CD42b (r = 0.69, p < 0.001) and the platelet activation marker CD62P (r = 0.47, p = 0.001) on CD14+-cells suggesting its association with MPAs in UA/NSTEMI. In addition, MoTF expression correlated with MoTF activity of isolated MNC (r = 0.41, p = 0.01) and plasma levels of the F1.2 prothrombin fragment (r = 0.35, p = 0.02). In conclusion, MoTF and MPAs are elevated in UA/NSTEMI compared with SA. MoTF expression correlates with platelet mass and activity attached to monocytes.

Topics: Adult; Aged; Aged, 80 and over; Angina, Stable; Angina, Unstable; Blood Platelets; Cell Communication; Female; Humans; Male; Middle Aged; Monocytes; Myocardial Infarction; RNA, Messenger; Thromboplastin