Background—Transplant vasculopathy is the main limiting factor of the long-term success of heart transplantation. We sought to establish the role of platelets in the development and progression of transplant vasculopathy. Methods and Results—Platelet analysis and intracoronary ultrasound examination were performed in 78 heart transplant recipients. Quantitative intracoronary ultrasound was used to define the severity of disease at baseline (48.8±4.5 months after transplantation) and at 1-year follow-up. Platelet activation was assessed with the use of immunological surface markers of activation (ligand-induced binding site 1 [LIBS-1], P-selectin, GPIIb-IIIa) and flow cytometry. We found that LIBS-1 immunoreactivity was significantly increased in patients with diffuse disease when compared with focal transplant disease (median [quartile], 27[14, 64] versus 18[7.9, 47], P=0.04). In a logistic regression model, we found that LIBS-1 was an independent predictor for the presence and progression of diffuse tran...
Abstract Platelets and alterations of chemotactic and adhesive properties of endothelium play an important role in the pathophysiology of atherosclerosis. We investigated the effect of platelets on secretion of monocyte chemotactic protein-1 (MCP-1) and on surface expression of intercellular adhesion molecule-1 (ICAM-1) of cultured endothelium. Pretreatment of cultured monolayers of endothelial cells with α-thrombin-activated platelets significantly enhanced secretion of MCP-1 and ICAM-1 surface...
Last. Albert Schömig(TUM: Technische Universität München)H-Index: 100
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Platelet membrane glycoproteins play a crucial role in ischemic complications after coronary stenting. Glycoprotein IIb-IIIa blockade reduces adverse clinical events after angioplasty but is associated with rare but profound thrombocytopenia that might increase hemorrhagic complications. Changes in platelet membrane glycoproteins of patients with angina who underwent coronary stenting and were treated with the GPIIb-IIIa antagonist abciximab (n = 20) or with heparin (n = 23) were studied. GPIIb-...
CD40 ligand (CD40L, CD154), a transmembrane protein structurally related to the cytokine TNF-alpha, was originally identified on stimulated CD4+ T cells, and later on stimulated mast cells and basophils. Interaction of CD40L on T cells with CD40 on B cells is of paramount importance for the development and function of the humoral immune system. CD40 is not only constitutively present on B cells, but it is also found on monocytes, macrophages and endothelial cells, suggesting that CD40L has a bro...
Last. John M. Harlan(UW: University of Washington)H-Index: 86
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Although it has been reported that activated platelets can adhere to intact endothelium, the receptors involved have not been fully characterized. Also, it is not clear whether activated platelets bind primarily to matrix proteins at sites of endothelial cell denudation or directly to endothelial cells. Thus, this study was designed to further clarify the mechanisms of activated platelet adhesion to endothelium. Unstimulated human umbilical vein endothelial cell (HUVEC) monolayers were incubated...
Objectives. This study evaluates the feasibility, reliability and reproducibility of electrocardiogram (ECG)-gated intravascular ultrasound (IVUS) image acquisition during automated transducer withdrawal and automated three-dimensional (3D) boundary detection for assessing on-line the result of coronary stenting. Background. Systolic-diastolic image artifacts frequently limit the clinical applicability of such automated analysis systems. Methods. In 30 patients, after successful angiography-guid...
Last. Amiram Eldor(TAU: Tel Aviv University)H-Index: 13
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Several clinical and laboratory findings suggest the presence of a chronic hypercoagulable state in patients with β-thalassaemia major (TM). We have previously shown that isolated TM red blood cells (RBC) strongly enhance prothrombin activation, suggesting an increased membrane exposure of procoagulant phospholipids (i.e. phosphatidyl-serine). In this study we quantitated the procoagulant activity of RBC in TM and thalassaemia intermedia (TI) patients. We also determined the fraction of activate...
The integrin GPIIbIIIa is known to be crucial to the formation of platelet aggregates and potentiates adhesion to subendothelial matrices via fibrin(ogen), von Willebrand factor, and vitronectin. Given the demonstration by us and others of widespread platelet aggregation during xenograft rejection, we hypothesized that platelet thrombi might contribute to graft dysfunction during development of hyperacute rejection (HAR), as well as during what we have termed delayed xenograft rejection (DXR), e...
Cardiac allograft vasculopathy (CAV) is a pathologic immune-mediated remodeling of the vasculature in transplanted hearts and, by impairing perfusion, is the major cause of late graft loss. Although best understood following cardiac transplantation, similar forms of allograft vasculopathy occur in other vascularized organ grafts and some features of CAV may be shared with other immune-mediated vasculopathies. Here we describe the incidence and diagnosis, the nature of the vascular remodeling, im...
Amac: Trombositler ve ortalama trombosit hacmi ateroskleroz ile iliskilidir. Bu calismanin amaci, ortalama trombosit hacmi ile subklavyen arter darligi arasindaki iliskiyi arastirmakti. Materyal ve Metod: Sakarya Universitesi Egitim ve Arastirma Hastanesi kateter laboratuvarinda Eylul 2010 - Eylul 2015 tarihleri arasinda yapilan anjiyografi ile subklavyen arteriyel darlik tanisi alan hastalar retroolarak calismaya dahil edildi. Subklavyen arteriyel darlik hastalari ile anjiyografik acidan benzer...
BACKGROUND Enhanced platelet reactivity may play a role in cardiac allograft vasculopathy (CAV) progression. The use of antiplatelet agents after heart transplantation (HT) has been inconsistent and although aspirin (ASA) is often a part of the medication regimen after HT, limited evidence is available on its benefit. METHODS AND RESULTS CAV progression was assessed by measuring the difference in plaque volume and plaque index between the last follow-up and the baseline coronary intravascular ul...
#2Derek So(U of O: University of Ottawa)H-Index: 25
Last. Sharon Chih(U of O: University of Ottawa)H-Index: 7
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Abstract Background The role of antiplatelet therapy following heart transplantation (HT) is unclear. Ex-vivo studies suggest increased platelet hyperaggregability after HT. Recent studies suggest that early aspirin therapy is associated with improved survival and lower rates of cardiac allograft vasculopathy (CAV). We examined: (1) the prevalence of increased platelet reactivity on aspirin and clopidogrel post-HT, (2) platelet reactivity post-clopidogrel treatment in aspirin-resistant patients,...
#8Peter P. Liu(U of O: University of Ottawa)H-Index: 2
Cardiac allograft vasculopathy (CAV) limits long-term survival after heart transplantation. Non-invasive evaluation is challenging, and currently, there is no validated biomarker for CAV diagnosis or prognostication. To identify potential candidate CAV biomarkers, we utilized the Slow Off-rate Modified Aptamer (SOMAscan) assay, which evaluates over 1000 serum proteins, including many relevant to biological pathways in CAV. We evaluated three heart transplant patient groups according to angiograp...
Last. Meng Zhaohui(Kunming Medical University)H-Index: 5
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Background Acute coronary syndrome (ACS) occurs approximately every 40 seconds, and was an underlying cause of death in 1 out of every 7 deaths. More accurate indicators are needed to distinguish patients with ACS from patients manifesting negative changes in electrocardiogram (ECG) and myocardial enzymes. This study aimed to investigate whether the expression of platelet carcinoembryonic antigen cell adhesion molecule-5 (CEACAM5/CEA/CD66e) could help predict ACS.
: Cardiac allograft vasculopathy remains a major limiting factor in the long-term survival of the heart transplant recipient. Our understanding of its pathogenesis is continuously evolving as advances in imaging modalities have allowed a direct window into the natural history of the disease. Innovation in diagnostic modalities has spurred the proliferation of prognostic tools and biomarkers. And in parallel, pharmacological advances have emerged that have helped ameliorate the disease's progress...
Last. Dominik Rath(University of Tübingen)H-Index: 16
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: Recent guidelines suggest dual antiplatelet therapy (DAPT) after 'drug-eluting' stent (DES) implantation for 6 months in stable patients and for 12 months in patients after acute coronary syndrome. Serious complications after stent implantation include stent thrombosis, recurrent myocardial infarction, ischemic stroke, cardiovascular death and bleeding. These complications also occur beyond 1 year after coronary intervention. Thus, it is important to consider whether a prolonged DAPT (>12 mont...
AIM: Cardiac allograft vasculopathy (CAV) is a major cause of morbidity and mortality after heart transplantation (HT). Enhanced platelet reactivity is a contributing factor. We aimed to investigate the association between early initiation of aspirin therapy post-HT and the 15-year risk of the development of CAV. METHODS: We studied 206 patients who underwent HT between 1991 and 2016. Multivariate Cox proportional hazards regression modeling was employed to evaluate the association between early...
PURPOSE OF REVIEW Cardiac allograft vasculopathy (CAV) is a major limitation to long-term survival after heart transplantation. Innovative new techniques to diagnose CAV have been applied to detect disease. This review will examine the current diagnostic and treatment options available to clinicians for CAV. RECENT FINDINGS Diagnostic modalities addressing the pathophysiology underlying CAV (arterial wall thickening and decreased coronary blood flow) improve diagnostic sensitivity when compared ...
