vorapaxar and Atherosclerosis

In spite of treatment with the current standard of care antiplatelet regimens including dual antiplatelet therapy, recurrence rates of ischemic events remain elevated for high-risk patients with atherosclerotic disease. This may be in part attributed to the fact that other key platelet activation pathways remain uninhibited and can thus continue to trigger platelet activation and lead to thrombotic complications. Thrombin is a powerful inducer of platelet activation and mediates its effects directly on platelets through protease activator receptors (PARs), particularly the PAR-1 subtype, making PAR-1 inhibition an attractive approach for reducing atherothrombotic events. These observations have led to the development of several PAR-1 antagonists. Vorapaxar is a direct inhibitor of PAR-1 and the only agent of this class approved for the prevention of recurrent ischemic events in patients with prior myocardial infarction or peripheral artery disease. In the present manuscript, we present a review of the pathophysiologic role of thrombin on thrombotic complications, the impact of vorapaxar on outcomes, including the most recent updates deriving from clinical trials, as well as future perspectives in the field.

Topics: Atherosclerosis; Humans; Lactones; Myocardial Infarction; Myocardial Ischemia; Peripheral Arterial Disease; Platelet Aggregation Inhibitors; Pyridines; Receptor, PAR-1; Secondary Prevention; Thrombin; Thrombosis

To study the cumulative evidence for vorapaxar use in patients with atherosclerotic cardiovascular disease.. A systematic review of randomized control trials in MEDLINE, EMBASE, EBSCO, CINAHL, Web of Science and Cochrane databases comparing vorapaxar with placebo was performed. Pre-specified efficacy endpoints were all-cause mortality, CV mortality, myocardial infarction (MI), ischemic stroke and repeat revascularization. The pre-specified safety endpoint was intracranial hemorrhage (ICH) and a composite of TIMI major and minor bleeding. Risk ratios were used as the metric of choice by applying random effects models.. Five randomized controlled trials with 40,630 patients were included in final analysis. Compared with placebo, vorapaxar led to a statistically non-significant reduction in risk of MI [RR 0.86; 95% CI 0.80-0.93, p=0.427] and ischemic stroke [RR 0.84; 95% CI 0.72-0.97, p=0.920]. No differences were observed between vorapaxar and placebo with respect to all-cause mortality [RR 0.99; 95% CI 0.90-1.08, p=0.620], cardiovascular mortality [RR 0.94; 95% CI 0.83-1.06, p=0.351], repeat revascularization [RR 0.97; 95% CI 0.82-1.15, p=0.236], and TIMI bleeding [RR 1.29; 95% CI 0.98-1.69, p=0.126]. Vorapaxar was associated with a statistically non-significant higher risk of ICH [RR 2.36; 95% CI 1.40-3.96, p=0.137] compared with placebo.. Addition of Vorapaxar to standard medical therapy in in patients with atherosclerotic disease led to a statistically non-significant reduction in the risk of MI and ischemic stroke at the cost of statistically non-significant increase in risk of ICH.

Topics: Atherosclerosis; Clinical Trials, Phase III as Topic; Humans; Lactones; Multicenter Studies as Topic; Platelet Aggregation Inhibitors; Pyridines; Randomized Controlled Trials as Topic; Secondary Prevention; Treatment Outcome

Despite the current standard of care, patients with cardiovascular disease remain at a high risk for recurrent events. Inhibition of thrombin-mediated platelet activation through protease-activated receptor-1 antagonism may provide reductions in atherosclerotic disease beyond those achievable with the current standard of care.. Our primary objective is to evaluate the clinical literature regarding the role of vorapaxar (Zontivity™) in the reduction of cardiovascular events in patients with a history of myocardial infarction and peripheral artery disease. In particular, we focus on the potential future directions for protease-activating receptor antagonists in the treatment of a broad range of atherosclerotic diseases.. A literature search of PubMed and EBSCO was conducted to identify randomized clinical trials from August 2005 to June 2016 using the search terms: 'vorapaxar', 'SCH 530348', 'protease-activated receptor-1 antagonist', and 'Zontivity™'. Bibliographies were searched and additional resources were obtained.. Vorapaxar is a first-in-class, protease-activated receptor-1 antagonist. The Thrombin Receptor Antagonist for Clinical Event Reduction (TRACER) trial did not demonstrate a significant reduction in a broad primary composite endpoint. However, the Thrombin-Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events (TRA 2°P-TIMI 50) trial examined a more traditional composite endpoint and found a significant benefit with vorapaxar. Vorapaxar significantly increased bleeding compared with standard care. Ongoing trials will help define the role of vorapaxar in patients with peripheral arterial disease, patients with diabetes mellitus, and other important subgroups. The use of multivariate modeling may enable the identification of subgroups with maximal benefit and minimal harm from vorapaxar.. Vorapaxar provides clinicians with a novel mechanism of action to further reduce the burden of ischemic heart disease. Identification of patients with a high ischemic risk and low bleeding risk would enable clinicians to maximize the utility of this unique agent.

Topics: Atherosclerosis; Humans; Lactones; Platelet Aggregation Inhibitors; Pyridines; Receptors, Proteinase-Activated; Risk Reduction Behavior

To review the pharmacology, efficacy, and safety of vorapaxar, a protease activator receptor-1 (PAR-1) antagonist, in the management of atherosclerotic diseases.. Peer-reviewed clinical trials and review articles were identified from MEDLINE and Current Content database (both 1966 to December 31, 2014) using the search terms vorapaxar and protease activator receptor antagonist.. A total of 30 clinical studies were identified (16 clinical trials, including subanalyses, 14 related to pharmacology, pharmacokinetics, and pharmacodynamics and drug interactions).. Two phase III clinical trials with vorapaxar have been published. In patients with non-ST segment elevation myocardial infarction (MI), vorapaxar failed to significantly reduce the primary efficacy end point (composite of cardiovascular death, MI, stroke, recurrent ischemia with hospitalization, and urgent coronary revascularization). Conversely, in a study of secondary prevention for patients with cardiovascular disease, the composite end point of cardiovascular death, MI, or stroke was significantly reduced. In both trials, the safety end points of major/minor bleeding were increased compared with placebo. In the secondary prevention trial, an increased incidence of intracranial hemorrhage led to the exclusion of patients with a prior history of stroke.. Vorapaxar is approved for use with aspirin and/or clopidogrel in the secondary prevention of cardiovascular events in stable patients with peripheral arterial disease or a history of MI. However, the addition of vorapaxar to other antiplatelets can significantly increase the risk of bleeding. It is, therefore, essential to balance the need for further reduction of risk of thrombotic event with patient's individual bleeding risk.

Topics: Atherosclerosis; Cardiovascular Diseases; Clinical Trials, Phase III as Topic; Hemorrhage; Humans; Lactones; Myocardial Infarction; Peripheral Arterial Disease; Platelet Aggregation Inhibitors; Pyridines; Receptor, PAR-1; Risk; Secondary Prevention; Stroke; Treatment Outcome

Oral antiplatelet therapies for secondary prevention of ischemic recurrences in patients with atherosclerotic disease manifestations include aspirin and P2Y12 receptor antagonists. Despite the use of these therapies, patients remain at risk for recurrent ischemic events, which may be attributed to other platelet signaling pathways which continue to be activated. More intense antithrombotic strategies have been investigated, including identifying additional targets to modulate platelet activation. Among these, thrombin-mediated platelet activation through PAR-1 has been subject to broad clinical investigation. Vorapaxar is the only PAR-1 receptor antagonists that completed large-scale clinical investigations and is approved for clinical use. This manuscript provides an overview of the pharmacology and clinical trial development of vorapaxar as well as its role in clinical practice.

Topics: Atherosclerosis; Blood Platelets; Clinical Trials as Topic; Humans; Ischemia; Lactones; Platelet Activation; Platelet Aggregation Inhibitors; Pyridines; Receptors, Thrombin; Secondary Prevention

Atherosclerosis is frequently caused by clot blockage of the coronary or peripheral arteries, and may lead to myocardial infarction (MI) or peripheral arterial disease (PAD). Despite advancements in management of atherosclerosis, mortality and ischemic rates remain high. Vorapaxar is a protease activated receptor-1 (PAR-1) antagonist, and prevents thrombin activation of PAR-1 receptors on platelets.. Vorapaxar was studied in 2 landmark trials in patients with acute coronary syndrome (ACS) and in those with history of atherosclerosis. For patients with ACS, vorapaxar did not significantly reduce rates of the primary efficacy outcome as compared to placebo. For patients with a history of atherosclerosis, vorapaxar significantly reduced rates of primacy outcome. However, in both landmark trials, vorapaxar significantly increased risks of bleeding, and significantly increases risks of intracranial hemorrhage in patients with a history of stroke. Vorapaxar was approved in 2014 in the US for patients with a history of MI or PAD, and in the European Union for patients with a history of MI.. Use of vorapaxar may be limited due to its high potential for causing bleeding. Efficacy of vorapaxar in addition to aspirin and prasugrel or ticagrelor for the management of ACS should be studied in the future.

Topics: Acute Coronary Syndrome; Animals; Atherosclerosis; Hemorrhage; Humans; Lactones; Platelet Aggregation Inhibitors; Pyridines; Randomized Controlled Trials as Topic; Receptor, PAR-1; Risk; Stroke; Thrombosis

Platelet activation, achieved through a variety of surface receptors and biochemical mediators, represents a key event in the pathogenesis of atherothrombosis and its clinical manifestations. The major pathways involved in platelet activation are triggered by thromboxane A(2), adenosine diphosphate and thrombin, with the latter being the most potent of these agonists. Despite the effective inhibition of the first two pathways with aspirin and several generations of P2Y(12) receptor antagonists, respectively, the recurrence of ischaemic events in patients with atherothrombosis remains high. In addition, there is a growing concern over the safety profile of increasingly powerful antiplatelet drugs in terms of bleeding, which has tempered expectations of newly developed compounds. Thrombin receptor antagonists are a novel class of antiplatelet agents that inhibit thrombin-mediated platelet activation. Preliminary data indicate that these compounds may have the potential to improve ischaemic outcomes without significantly increasing the bleeding liability. Currently, two agents of this class are under clinical development: vorapaxar (previously known as SCH 530348) and E-5555. In this review we discuss this novel class of antiplatelet agents, focusing in particular on their therapeutic potential.

Topics: Atherosclerosis; Humans; Imines; Lactones; Platelet Activation; Platelet Aggregation Inhibitors; Pyridines; Receptors, Thrombin; Thrombosis

Aspirin, an irreversible inhibitor of thromboxane A(2) production, in combination with clopidogrel, an inhibitor of PY(12) ADP platelet receptors, represents the current standard-of-care of antiplatelet therapy for patients with acute coronary syndrome and those undergoing percutaneous coronary intervention. Although these agents have demonstrated significant clinical benefit, the increased risk of bleeding and the recurrence of thrombotic events represent substantial limitations.. The inhibition of protease-activated receptors (PAR)-1, is the target for novel antiplatelet drugs, which showed a good safety profile in preclinical studies. The drugs most developed are vorapaxar (SCH530348) and atopaxar (E5555), which will be further evaluated in ongoing Phase III and II clinical trials respectively.. This review is focused on the current knowledge of PAR-1 antagonists, analyzing the pharmacological and early phase clinical investigation findings on these new drugs.. The PAR-1 receptor offers a new target for the inhibition of platelet activation and aggregation. Preliminary results showed the good safety profile of these new agents. The results of the Phase III ongoing trials will provide important clinical insight into the blockade of thrombin-induced platelet activation.

Topics: Animals; Atherosclerosis; Clinical Trials as Topic; Humans; Imines; Lactones; Pyridines; Receptor, PAR-1; Thrombosis; Treatment Outcome

Patients with renal disease are often undertreated with antiplatelet therapy due to concerns about bleeding. Vorapaxar blocks platelet activation via the PAR-1 receptor and reduces cardiovascular events in patients with stable atherosclerosis, but with increased bleeding. We examined the efficacy and safety of vorapaxar in patients with impaired renal function. TRA2°P-TIMI 50 randomized patients with stable atherosclerosis to vorapaxar or. We analyzed patients with eGFR assessed who qualified with a history of MI or PAD (without stroke or TIA) (n = 19,932). Cox models assessed the risk of CV events and bleeding by quartile of baseline eGFR in the placebo arm and then by randomized assignment. Net clinical outcome (NCO) was predefined as CV death, MI, stroke, or GUSTO severe bleeding. Patients with lower eGFR tended to be older, female, have hypertension, hyperlipidemia or prior PAD. In the placebo arm, baseline eGFR in the lowest quartile was associated with a 26% higher risk of CV death, MI or stroke (Q1:Q4 HR

Topics: Aged; Atherosclerosis; Cardiovascular Diseases; Female; Glomerular Filtration Rate; Hemorrhage; Humans; Kidney Diseases; Lactones; Male; Middle Aged; Platelet Aggregation Inhibitors; Pyridines; Receptor, PAR-1; Risk; Secondary Prevention; Treatment Outcome

Patients with peripheral artery disease (PAD) are at heightened risk of acute limb ischemia (ALI), a morbid event that may result in limb loss. We investigated the causes, sequelae, and predictors of ALI in a contemporary population with symptomatic PAD and whether protease-activated receptor 1 antagonism with vorapaxar reduced ALI overall and by type.. The Trial to Assess the Effects of Vorapaxar in Preventing Heart Attack and Stroke in Patients With Atherosclerosis-Thrombolysis in Myocardial Infarction 50 (TRA2°P-TIMI 50) was a randomized, double-blind, placebo-controlled trial of vorapaxar in stable patients, including 3787 with symptomatic PAD. ALI was a prespecified adjudicated end point using a formal definition. A total of 150 ALI events occurred in 108 patients during follow-up (placebo 3-year rate, 3.9%; 1.3% annualized). For patients with symptomatic PAD, previous peripheral revascularization, smoking, and the ankle-brachial index were predictive of ALI. The majority of ALI events occurred as a result of surgical graft thrombosis (56%), followed by native vessel in situ thrombosis (27%). Stent thrombosis and thromboembolism caused ALI in 13% and 5%, respectively. Amputation occurred in 17.6% presenting with ALI. Vorapaxar reduced first ALI events by 41% (hazard ratio, 0.58; 95% confidence interval, 0.39-0.86; P=0.006) and total ALI events by 41% (94 versus 56 events; risk ratio, 0.59; 95% confidence interval, 0.38-0.93; P=0.022). The efficacy of vorapaxar was consistent across types of ALI.. In selected patients with symptomatic PAD and without atrial fibrillation, ALI occurs at a rate of 1.3%/y, is most frequently caused by acute bypass graft thrombosis or in situ thrombosis of a diseased vessel, and often results in limb loss. Vorapaxar reduces ALI in patients with symptomatic PAD with consistency across type, including PAD resulting from surgical graft thrombosis and in-situ thrombosis.. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00526474.

Topics: Acute Disease; Aged; Atherosclerosis; Coronary Artery Bypass; Double-Blind Method; Extremities; Female; Follow-Up Studies; Humans; Ischemia; Lactones; Male; Middle Aged; Myocardial Infarction; Peripheral Arterial Disease; Platelet Aggregation Inhibitors; Prospective Studies; Pyridines; Stroke; Thrombolytic Therapy; Treatment Outcome

Patients with stable ischemic heart disease and previous myocardial infarction (MI) vary in their risk for recurrent cardiovascular events. Atherothrombotic risk assessment may be useful to identify high-risk patients who have the greatest potential to benefit from more intensive secondary preventive therapy such as treatment with vorapaxar.. We identified independent clinical indicators of atherothrombotic risk among 8598 stable, placebo-treated patients with a previous MI followed up for 2.5 years (median) in TRA 2°P-TIMI 50 [Thrombin Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events-TIMI 50]. The efficacy and safety of vorapaxar (SCH 530348; MK-5348) were assessed by baseline risk among patients with previous MI without prior stroke or transient ischemic attack for whom there is a clinical indication for vorapaxar. End points were cardiovascular death, MI, or ischemic stroke and GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) severe bleeding.. The 9 independent risk predictors were age, diabetes mellitus, hypertension, smoking, peripheral arterial disease, previous stroke, previous coronary bypass grafting, heart failure, and renal dysfunction. A simple integer-based scheme using these predictors showed a strong graded relationship with the rate of cardiovascular death/MI/ischemic stroke and the individual components (P for trend <0.001 for all). High-risk patients (≥3 risk indicators; 20% of population) had a 3.2% absolute risk reduction in cardiovascular disease/MI/ischemic stroke with vorapaxar, and intermediate-risk patients (1-2 risk indicators; 61%) had a 2.1% absolute risk reduction (P<0.001 each), translating to a number needed to treat of 31 and 48. Bleeding increased across risk groups (P for trend<0.01); however, net clinical outcome was increasingly favorable with vorapaxar across risk groups. Fatal bleeding or intracranial hemorrhage was 0.9% with both treatments in high-risk patients.. Stratification of baseline atherothrombotic risk can assist with therapeutic decision making for vorapaxar use for secondary prevention after MI.. URL: https://www.clinicaltrials.gov. Unique identifier: NCT00526474.

Topics: Aged; Atherosclerosis; Double-Blind Method; Female; Hemorrhage; Humans; Kaplan-Meier Estimate; Lactones; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Platelet Aggregation Inhibitors; Proportional Hazards Models; Pyridines; Recurrence; Risk Assessment; Secondary Prevention; Treatment Outcome

Vorapaxar, a novel thrombin receptor antagonist, reduces cardiovascular death and recurrent thrombotic events when added to standard antiplatelet therapy in patients with stable atherosclerotic vascular disease.. The goal of this study was to test the hypothesis that treatment with vorapaxar reduces the rate of coronary stent thrombosis (ST) in stable patients with a history of coronary stenting.. TRA 2° P-TIMI 50 (Trial to Assess the Effects of Vorapaxar in Preventing Heart Attack and Stroke in Patients With Atherosclerosis-Thrombolysis In Myocardial Infarction 50) was a multinational, randomized, double-blind, placebo-controlled trial of vorapaxar in stable patients with prior myocardial infarction, peripheral arterial disease, or stroke. We evaluated the rates of definite ST as adjudicated by a central events committee using Academic Research Consortium (ARC) criteria.. A total of 26,449 patients were randomized, with 14,042 (53%) having a history of a coronary stent implantation before randomization, and an additional 449 patients receiving a coronary stent during the trial (total 14,491). During follow-up (median 2.5 years), there were 152 definite ST events, with the majority (92%) occurring late or very late. Vorapaxar reduced ARC definite ST (1.1% vs. 1.4%, hazard ratio [HR]: 0.71, 95% confidence interval [CI]: 0.51 to 0.98; p = 0.037). The reduction was consistent, regardless of time from percutaneous coronary intervention, history of diabetes, use of drug-eluting stents, and use of dual antiplatelet therapy (DAPT) at randomization. Vorapaxar increased GUSTO moderate/severe bleeding (HR: 1.57, 95% CI: 1.26 to 1.94; p < 0.001).. The rate of ARC definite ST in stable patients, the majority of whom were receiving DAPT, was approximately 1.4% at 3 years. In stable patients with coronary stenting receiving standard antiplatelet therapy, vorapaxar administered for long-term secondary prevention significantly reduced ARC definite ST, including very late ST. (Trial to Assess the Effects of Vorapaxar [SCH 530348; MK-5348] in Preventing Heart Attack and Stroke in Patients With Atherosclerosis [TRA 2° P-TIMI 50] [P04737]; NCT00526474).

Topics: Aged; Atherosclerosis; Coronary Thrombosis; Double-Blind Method; Drug-Eluting Stents; Female; Follow-Up Studies; Humans; Lactones; Male; Middle Aged; Myocardial Infarction; Pyridines; Receptors, Thrombin; Stroke

Vorapaxar, a novel antiplatelet therapy, reduces thrombotic events in patients with a history of myocardial infarction (MI) or peripheral artery disease (PAD); however, because of an increased risk of intracranial hemorrhage, it is contraindicated in patients with a history of stroke.. The aim of this study was to investigate the incidence of new ischemic stroke and subsequent death or intracerebral hemorrhage in patients with MI or PAD and no cerebrovascular disease (CVD) treated with vorapaxar.. The TRA 2 °P-TIMI 50 (Trial to Assess the Effects of Vorapaxar in Preventing Heart Attack and Stroke in Patients With Atherosclerosis-Thrombolysis In Myocardial Infarction 50) was a randomized, double-blind, placebo-controlled trial of vorapaxar 2.5 mg daily in 26,449 patients with atherosclerosis, stratified by qualifying disease (MI, PAD, or CVD). A total of 20,170 patients with MI/PAD, but no CVD, were enrolled.. In patients with MI/PAD and no prior stroke or transient ischemic attack, vorapaxar reduced first ischemic stroke (hazard ratio [HR]: 0.57, 95% confidence interval [CI]: 0.43 to 0.75; p < 0.001). The risk of hemorrhagic conversion after stroke (HR: 1.19, 95% CI: 0.49 to 2.91; p = 0.70) or death (HR: 1.09, 95% CI: 0.57 to 2.07; p = 0.79) during follow-up was not significantly increased with vorapaxar in patients who had a new ischemic stroke (n = 204). Although hemorrhagic stroke was increased (HR: 2.79, 95% CI: 1.00 to 7.73; p = 0.049), overall stroke was significantly reduced (HR: 0.67, 95% CI: 0.52 to 0.87; p = 0.002).. Vorapaxar reduces ischemic stroke in patients with MI or PAD and no known CVD. There does not appear to be a significant increase in the risk of hemorrhagic conversion or death in patients who experienced a first ischemic stroke on vorapaxar. Although primary hemorrhagic stroke is increased, vorapaxar reduces the total incidence of stroke. (Trial to Assess the Effects of Vorapaxar (SCH 530348; MK-5348) in Preventing Heart Attack and Stroke in Patients With Atherosclerosis [TRA 2 °P-TIMI 50]; NCT00526474).

Topics: Aged; Atherosclerosis; Brain Ischemia; Double-Blind Method; Female; Follow-Up Studies; Humans; Lactones; Male; Middle Aged; Myocardial Infarction; Pyridines; Receptors, Thrombin; Stroke; Treatment Outcome

Thrombin potently activates platelets via interaction with the protease-activated receptor 1. SCH 530348 is a novel antiplatelet agent that selectively inhibits the cellular actions of thrombin via antagonism of the protease-activated receptor 1. Because SCH 530348 does not interfere with other pathways for hemostasis, it is possible that SCH 530348 reduces thrombosis with less increase in bleeding than do other potent antiplatelet agents.. TRA 2 degrees P-TIMI 50 is a phase III, randomized, double-blind, placebo-controlled, multinational clinical trial designed to evaluate the efficacy and safety of SCH 530348 during long-term treatment of patients with established atherosclerotic disease receiving standard therapy (up to 27,000). Eligible patients with a history of myocardial infarction, ischemic stroke, or peripheral arterial disease are randomized 1:1 to SCH 530348 2.5 mg daily or matched placebo until the end of study. Randomization is stratified by the qualifying disease and planned use of a thienopyridine. The primary end point is the composite of cardiovascular death, myocardial infarction, stroke, or urgent coronary revascularization. The major secondary end point is the composite of cardiovascular death, myocardial infarction, or stroke. The evaluation of long-term safety includes bleeding defined by the GUSTO and TIMI criteria. Recruitment began in September 2007. The trial will continue until 2,279 primary end points and 1,400 secondary end points are recorded with expected completion in 36 to 44 months from first enrollment.. TRA 2 degrees P-TIMI 50 is evaluating whether a new approach to platelet inhibition via interruption of thrombin-mediated platelet activation reduces major cardiovascular events with a favorable safety profile in patients with established atherosclerosis.

Topics: Adult; Atherosclerosis; Double-Blind Method; Hemorrhage; Humans; Lactones; Platelet Activation; Platelet Aggregation Inhibitors; Pyridines; Receptor, PAR-1; Research Design; Treatment Outcome

Protease-activated receptor 1 (PAR1) and toll-like receptors (TLRs) are inflammatory mediators contributing to atherogenesis and atherothrombosis. Vorapaxar, which selectively antagonizes PAR1-signaling, is an approved, add-on antiplatelet therapy for secondary prevention. The non-hemostatic, platelet-independent, pleiotropic effects of vorapaxar have not yet been studied.. PAR1 inhibition with vorapaxar may be effective in reducing residual thrombo-inflammatory event risk in patients with atherosclerosis independent of its effect on platelets.

Topics: Animals; Apolipoproteins E; Atherosclerosis; Female; Humans; Inflammation; Intercellular Adhesion Molecule-1; Lactones; Male; Mice; Mice, Knockout; Myocardium; Platelet Aggregation; Pyridines; Receptor, PAR-1; Thrombin; Toll-Like Receptor 2; Toll-Like Receptor 4; Vascular Cell Adhesion Molecule-1; Vascular Diseases

Our dual aims were as follows: (1) to classify new or recurrent myocardial infarctions (MI) in patients with stable atherosclerosis using the Universal Definition of MI classification system; and (2) to characterize the effects of vorapaxar, a first-in-class platelet protease-activated receptor -1 antagonist, on new or recurrent MI.. We analyzed data from TRA 2°P-TIMI 50, a multinational, randomized, double-blind, placebo-controlled trial of vorapaxar. This analysis included 20 770 patients with previous MI or peripheral arterial disease without a history of transient ischemic attack or stroke. Each new or recurrent MI after randomization that met the trial end point definition was further categorized according to the European Society of Cardiology, American College of Cardiology, American Heart Association, World Heart Federation Universal Definition classification of type and size. Of 1095 incident MIs, 77% were spontaneous (Type 1), with a smaller number (9.8%) of secondary MIs (Type 2). Vorapaxar reduced Type 1 MI (hazard ratio [HR] 0.84, CI 0.73-0.98, P=0.024), with a similar pattern for Type 2 MI (HR 0.74, CI 0.49-1.10, P=0.13). Notably, vorapaxar showed a consistent pattern of reduction across size of MIs, including MIs in the highest Universal MI size class (≥10× upper reference limit, HR 0.83, CI 0.70-0.98, P=0.025). As such, there was a significant reduction in larger, spontaneous MIs (Type 1, ≥10× upper reference limit, HR 0.81, CI 0.67-0.99, P=0.036), and a consistent pattern with respect to fatal MI (HR 0.66, CI 0.39-1.11, P=0.12).. Among stable patients with established atherosclerosis, the most common type of incident MI is spontaneous MI, and the reduction in MI with vorapaxar was consistent across MIs of varying type and size, including spontaneous infarctions ≥10× upper reference limit.. URL: https://www.clinicaltrials.gov. Unique identifier: NCT00526474.

Topics: Aged; Atherosclerosis; Coronary Artery Disease; Female; Humans; Lactones; Male; Middle Aged; Myocardial Infarction; Peripheral Arterial Disease; Platelet Aggregation Inhibitors; Proportional Hazards Models; Pyridines; Randomized Controlled Trials as Topic; Recurrence; Secondary Prevention

Morbidity and mortality in patients with atherothrombotic disease remain high despite the use of antiplatelet therapy with aspirin and an ADP receptor antagonist. Selective inhibition of the principal protease-activated receptor (PAR)-1 for thrombin, the most potent agonist for platelet activation, represents a promising novel strategy to reduce thrombosis and ischaemic events. SCH 530348, a potent thrombin receptor antagonist (TRA) selective for PAR-1, has been evaluated in preclinical studies, demonstrating complete and sustained inhibition of thrombin/TRAP-induced platelet aggregation without a concomitant increase in the risk of bleeding. Phase 2 studies in patients undergoing non-urgent or urgent PCI showed that treatment with SCH 530348 in addition to the standard of care (aspirin plus an ADP receptor antagonist) is not associated with an increased risk of TIMI bleeding and is well tolerated, with a rate of adverse events comparable to standard therapy alone. These studies also demonstrated that the use of SCH 530348 in combination with aspirin and an ADP receptor antagonist may reduce the incidence of major adverse cardiac events, specifically periprocedural myocardial infarction, vs aspirin plus an ADP receptor antagonist alone. On the basis of these encouraging results, 2 ongoing large phase 3 randomized trials are evaluating the efficacy and safety of SCH 530348 in combination with the standard-of-care therapy in approximately 35,000 patients with NSTE ACS or established atherosclerosis.

Topics: Administration, Oral; Antithrombins; Atherosclerosis; Clinical Trials as Topic; Hemorrhage; Humans; Lactones; Platelet Aggregation Inhibitors; Pyridines; Receptors, Thrombin; Safety; Thrombin

Atherothrombotic disease is a leading public health problem. Although current antiplatelet agents, such as aspirin and adenosine diphosphate (ADP)-receptor antagonists, reduce the morbidity and mortality associated with atherothrombotic disease, the residual risk for ischemic events remains substantial. The high residual risk despite dual antiplatelet therapy can be attributed to the fact that platelets possess multiple pathways of activation that are not all inhibited by aspirin and ADP-receptor antagonists. Among these, binding of thrombin to the proteinase-activated receptor 1 (PAR(1)) is the most potent platelet activation pathway. In addition, the PAR(1) pathway does not appear to be essential for initiating hemostasis. Inhibition of the PAR(1) receptor thus offers a possible new therapeutic approach with a potentially improved benefit-to-risk profile for treatment of patients with atherothrombotic disease. Preclinical and clinical studies have confirmed that SCH 530348, a potent, orally active thrombin-receptor antagonist selective for PAR(1), does not increase bleeding liability when added to dual antiplatelet therapy. Currently, two large ongoing phase 3 clinical trials are evaluating the efficacy and safety of SCH 530348 in combination with the standard of care in patients with acute coronary syndromes as well as for secondary prevention in patients with previous history of atherothrombotic disease.

Topics: Animals; Atherosclerosis; Clinical Trials as Topic; Disease Models, Animal; Drug Therapy, Combination; Hemorrhage; Humans; Lactones; Platelet Aggregation Inhibitors; Pyridines; Receptor, PAR-1; Risk Factors; Thrombosis