Comparison of the effects of the GPIIb-IIIa antagonist Zalunfiban and the P2Y12 antagonist Selatogrel on Platelet Aggregation.

Understanding the pharmacodynamic effects of platelet inhibitors is standard for developing more effective antithrombotic therapies. An example is the antithrombotic treatment of acute coronary syndrome (ACS), in particular ST-elevated myocardial infarction (STEMI) patients who are in need for rapid acting strong antithrombotic therapy despite the use of aspirin and oral P2Y12-inhibitors. In this study, we evaluated two injectable platelet inhibitors under clinical development (the P2Y12 antagonist selatogrel and the GPIIb-IIIa antagonist zalunfiban) that may be amenable to pre-hospital treatment of STEMI patients.

Switching from Dual Antiplatelet Therapy with Aspirin Plus a P2Y12 Inhibitor to Dual Pathway Inhibition with Aspirin Plus Vascular-Dose Rivaroxaban: The Switching Anti-Platelet and Anti-Coagulant Therapy (SWAP-AC) Study.

Background:  To date, there are no data on switching to dual pathway inhibition (DPI) patients who have completed a guideline-recommended dual antiplatelet therapy (DAPT) regimen.

Objectives:  To assess the feasibility of switching from DAPT to DPI and to compare the pharmacodynamic (PD) profiles of these treatments.

Methods:  This was a prospective, randomized, PD study conducted in 90 patients with chronic coronary syndrome (CCS) on DAPT with aspirin (81 mg/qd) plus a P2Y inhibitor (clopidogrel [75 mg/qd;  = 30], ticagrelor [90 mg/bid;  = 30], or prasugrel [10 mg/qd;  = 30]).

Platelet P2Y12 inhibiting therapy in adjunct to vascular dose of rivaroxaban or aspirin: a pharmacodynamic study of dual pathway inhibition vs. dual antiplatelet therapy.

Aims: Dual pathway inhibition (DPI) by adding a vascular dose of rivaroxaban to a single antiplatelet agent has emerged as a promising antithrombotic strategy. However, in most studies the antiplatelet agent of choice used in adjunct to a vascular dose of rivaroxaban was aspirin, and data on a P2Y12 inhibitor and how this DPI regimen compares with standard dual antiplatelet therapy (DAPT) are limited.

Methods And Results: This investigation was a substudy analysis conducted in selected cohorts of patients with stable atherosclerotic disease enrolled from a larger prospective, open-label, parallel-group pharmacodynamic (PD) study.

Bentracimab for Ticagrelor Reversal in Patients Undergoing Urgent Surgery.

BACKGROUND: Ticagrelor is a reversible oral P2Y12 platelet inhibitor used to treat patients with acute coronary syndromes, prior myocardial infarction, high-risk coronary artery disease, transient ischemic attack, or ischemic stroke. A healthy volunteer study showed that the intravenous monoclonal antibody bentracimab rapidly reverses ticagrelor, but the effect in patients was unknown. METHODS: In a prespecified interim analysis of a single-arm, prospective study, bentracimab was evaluated in ticagrelor-treated patients who required urgent surgery or had major hemorrhage.

Pharmacodynamic Profiles of Dual-Pathway Inhibition with or without Clopidogrel versus Dual Antiplatelet Therapy in Patients with Atherosclerotic Disease.

Aim:  Inhibition of thrombin-mediated signaling processes using a vascular dose of rivaroxaban in adjunct to antiplatelet therapy, known as dual-pathway inhibition (DPI), reduces atherothrombotic events in patients with stable atherosclerotic disease. However, there are limited data on the pharmacodynamic (PD) effects of this strategy and how it compares to standard dual antiplatelet therapy (DAPT).

Methods And Results:  This investigation was conducted in selected cohorts of patients ( = 40) with stable atherosclerotic disease-enrolled within a larger prospective, open-label, parallel-group PD study-who were treated with either aspirin plus clopidogrel (DAPT), aspirin plus rivaroxaban 2.

Pharmacodynamic Effects of Vorapaxar in Prior Myocardial Infarction Patients Treated With Potent Oral P2Y Receptor Inhibitors With and Without Aspirin: Results of the VORA-PRATIC Study.

Background Vorapaxar as an adjunct to dual antiplatelet therapy (DAPT) reduces thrombotic events in patients with prior myocardial infarction at the expense of increased bleeding. Withdrawal of aspirin has emerged as a bleeding reduction strategy. The pharmacodynamic effects of vorapaxar with potent P2Y inhibitors as well as the impact of dropping aspirin is unexplored and represented the aim of the VORA-PRATIC (Vorapaxar Therapy in Patients With Prior Myocardial Infarction Treated With Newer Generation P2Y Receptor Inhibitors Prasugrel and Ticagrelor) study.

Thrombo-Inflammation in Cardiovascular Disease: An Expert Consensus Document from the Third Maastricht Consensus Conference on Thrombosis.

Thrombo-inflammation describes the complex interplay between blood coagulation and inflammation that plays a critical role in cardiovascular diseases. The third Maastricht Consensus Conference on Thrombosis assembled basic, translational, and clinical scientists to discuss the origin and potential consequences of thrombo-inflammation in the etiology, diagnostics, and management of patients with cardiovascular disease, including myocardial infarction, stroke, and peripheral artery disease. This article presents a state-of-the-art reflection of expert opinions and consensus recommendations regarding the following topics: (1) challenges of the endothelial cell barrier; (2) circulating cells and thrombo-inflammation, focused on platelets, neutrophils, and neutrophil extracellular traps; (3) procoagulant mechanisms; (4) arterial vascular changes in atherogenesis; attenuating atherosclerosis and ischemia/reperfusion injury; (5) management of patients with arterial vascular disease; and (6) pathogenesis of venous thrombosis and late consequences of venous thromboembolism.

Pharmacodynamic Effects of Vorapaxar in Patients With and Without Diabetes Mellitus: Results of the OPTIMUS-5 Study.

Vorapaxar reduces thrombotic cardiovascular events at the expense of increased bleeding. However, the differential pharmacodynamic (PD) effects of vorapaxar according to diabetes mellitus (DM) status are unknown. Moreover, although withdrawal of aspirin has emerged as a bleeding reduction strategy, the PD effects of stopping aspirin in patients treated with vorapaxar also are unknown.

Antibody-Based Ticagrelor Reversal Agent in Healthy Volunteers.

Background: Ticagrelor is an oral P2Y inhibitor that is used with aspirin to reduce the risk of ischemic events among patients with acute coronary syndromes or previous myocardial infarction. Spontaneous major bleeding and bleeding associated with urgent invasive procedures are concerns with ticagrelor, as with other antiplatelet drugs. The antiplatelet effects of ticagrelor cannot be reversed with platelet transfusion.

Effects of genetic variation in protease activated receptor 4 after an acute coronary syndrome: Analysis from the TRACER trial.

Variation in platelet response to thrombin may affect the safety and efficacy of PAR antagonism. The Thr120 variant of the common single nucleotide polymorphism (SNP) rs773902 in the protease-activated receptor (PAR) 4 gene is associated with higher platelet aggregation compared to the Ala120 variant. We investigated the relationship between the rs773902 SNP with major bleeding and ischemic events, safety, and efficacy of PAR1 inhibition in 6177 NSTE ACS patients in the TRACER trial.

Inhibitory mechanisms of very low-dose rivaroxaban in non-ST-elevation myocardial infarction.

Very low-dose (VLD) factor Xa (FXa) inhibition, in combination with acetylsalicylic acid (ASA) and clopidogrel, is associated with improved outcomes in patients with acute coronary syndrome (ACS) with a tolerable bleeding risk profile. To date, there are no data documenting platelet inhibition and the anticoagulatory effects of VLD FXa inhibition on top of guideline-adherent dual-antiplatelet therapy (DAPT) in patients with ACS. Patients with non-ST-elevation myocardial infarction (NSTEMI) receiving oral DAPT (ASA + clopidogrel, n = 20; or ASA + ticagrelor, n = 20) were prospectively enrolled in a nonrandomized study.

Association of D-dimer Levels with Clinical Event Rates and the Efficacy of Betrixaban versus Enoxaparin in the APEX Trial.

 Elevated D-dimer concentrations are associated with an increased risk of venous thromboembolism (VTE). However, they may also provide prognostic value. The present analysis sought to study the association of D-dimer levels with VTE event rates and the efficacy of betrixaban versus enoxaparin in the APEX trial.

A prospective study of platelet function in trauma patients.

Background: Exsanguination associated with acute traumatic coagulopathy is a leading cause of death following injury. While platelets occupy a pivotal role in clot formation, clinical research has been scant because of complexities resulting from the need for rapid handling and complex testing of platelet functions. While the thrombin pathway has been proposed as a mediator of platelet dysfunction in trauma, it has not been systematically investigated.

The utility of tetraspanin CD9 as a biomarker for metastatic clear cell renal cell carcinoma.

The use of tetraspanin CD9 as a biomarker for renal cell carcinomas (RCC) has been explored with minor conclusions. Identification of a biomarker that not only distinguishes between the different types of renal cell carcinomas, but also predicts the metastatic potential of these tumors would significantly advance diagnosis and prognosis of kidney cancers. We utilized established cell lines to better understand the contribution of CD9 to the metastatic potential of clear cell renal cell carcinomas, and then applied our findings to the TCGA database and immunohistochemical analysis of human samples based on tumor grading to determine the utility of CD9 as a biomarker for RCC.

Platelet function recovery following exposure to triple anti-platelet inhibitors using an in vitro transfusion model.

Introduction: Dual anti-platelet therapy (DAPT) with aspirin and a P2Y12 antagonist is standard of care to reduce risk of thrombosis, but does not directly target thrombin-dependent platelet activation. Therefore, PAR-1 antagonist addition to DAPT (i.e.

Polydopamine Integrated Nanomaterials and Their Biomedical Applications.

In the past few decades, the applications of nanomaterials in biologic systems have become one of the most studied areas. Many novel syntheses and processing methods have been developed to generate nanomaterials to enhance biomedical applications. Among those methods, polydopamine (PDA) integrated nanomaterials have attracted considerable interest for various types of biomedical applications.

The spectrum of thrombin in acute coronary syndromes.

The role of thrombin in vascular physiology and pathophysiology continues to impact our understanding of many cellular processes and systems including the function of platelets, endothelial cells, smooth muscle cells, leukocytes and the regulation of the coagulation cascade. Recent acute coronary syndrome clinical trial results that have compared the use of parenteral or oral anticoagulants versus or in combination with anti-platelet agents have forced a reexamination of the importance of thrombin activity in influencing patient outcomes, particularly in the area of secondary prevention. The debate of the need to include oral anticoagulation as a concomitant or replacement therapy to an antiplatelet regimen as a means to improve patient outcomes requires further examination and larger prospective clinical trials.

Self-compassion and life satisfaction in gay men.

Studies have shown that gay men are at increased risk for anxiety and depression due to social oppression; research suggests that self-compassion is positively associated with life-satisfaction and emotional resilience. In a sample of 68 gay men (M age = 39.7 yr.

Vorapaxar with or without clopidogrel after non-ST-segment elevation acute coronary syndromes: results from the thrombin receptor antagonist for clinical event reduction in acute coronary syndrome trial.

Background: Protease-activated receptor 1 antagonism with vorapaxar represents a novel strategy for platelet inhibition. In TRACER, vorapaxar was compared with placebo plus standard of care among 12,944 patients with non-ST-segment elevation acute coronary syndromes. We anticipated that most patients would have received clopidogrel as part of standard care.

Tetraspanin CD9 regulates cell contraction and actin arrangement via RhoA in human vascular smooth muscle cells.

The most prevalent cardiovascular diseases arise from alterations in vascular smooth muscle cell (VSMC) morphology and function. Tetraspanin CD9 has been previously implicated in regulating vascular pathologies; however, insight into how CD9 may regulate adverse VSMC phenotypes has not been provided. We utilized a human model of aortic smooth muscle cells to understand the consequences of CD9 deficiency on VSMC phenotypes.

Benzimidazole analogs as potent hypoxia inducible factor inhibitors: synthesis, biological evaluation, and profiling drug-like properties.

Aim: To develop potent HIF-1α inhibitors for potential treatment of cancer.

Materials And Methods: Chemical synthesis, HIF-luciferase assay, cytotoxic assay, platelet aggregation assay, western blot analysis, quantitative real-time PCR, aqueous solubility, protein binding, metabolic stability, and metabolic pathways.

Results: Thirteen novel benzimidazole analogs were synthesized.

PAR1 antagonists inhibit thrombin-induced platelet activation whilst leaving the PAR4-mediated response intact.

Thrombin-induced platelet activation is initiated by PAR1 and PAR4 receptors. Vorapaxar, a PAR1 antagonist, has been assessed in patients with acute coronary syndromes (ACS) and stable atherosclerotic disease in addition to standard-of-care treatment. In clinical trials, vorapaxar has been observed to reduce the frequency of ischaemic events in some subgroups though in others has increased the frequency of bleeding events.

Tetraspanin CD9 modulates human lymphoma cellular proliferation via histone deacetylase activity.

Non-Hodgkin Lymphoma (NHL) is a type of hematological malignancy that affects two percent of the overall population in the United States. Tetraspanin CD9 is a cell surface protein that has been thoroughly demonstrated to be a molecular facilitator of cellular phenotype. CD9 expression varies in two human lymphoma cell lines, Raji and BJAB.

The Utility of Platelet and Coagulation Testing of Antithrombotics: Fusing Science with Patient Care.

[Table: see text] There is an increasing need for the standardization of platelet function and coagulation testing for the assessment of antithrombotic therapies. Investigators continue to strive to identify ideal laboratory testing and monitoring procedures for acquired and inherited platelet function defects as well as for evaluating patient status when treated with existing or emerging antithrombotics. These therapies are used primarily in the treatment of ischemic complications.

Signaling via P2Y12 may be critical for early stabilization of platelet aggregates.

P2Y(12) receptor antagonism inhibits platelet aggregation by preventing adenosine diphosphate (ADP)-mediated amplification of activation pathways downstream of primary agonists, such as thrombin and collagen. However, the role of ADP signaling in maintaining aggregate stability and the effects of P2Y(12) antagonists on preestablished aggregates in vitro and arterial thrombus in vivo are not well understood. This study evaluated the impact of P2Y(12) signaling on platelet aggregate stability and early thrombotic occlusion using a reversible P2Y(12) antagonist, ticagrelor.