Original Article

Vorapaxar in the Secondary Prevention of Atherothrombotic Events

David A. Morrow, M.D., M.P.H., Eugene Braunwald, M.D., Marc P. Bonaca, M.D., Sebastian F. Ameriso, M.D., Anthony J. Dalby, M.B., Ch.B., Mary Polly Fish, B.A., Keith A.A. Fox, M.B., Ch.B., Leslie J. Lipka, M.D., Ph.D., Xuan Liu, Ph.D., José Carlos Nicolau, M.D., Ph.D., A.J. Oude Ophuis, M.D., Ph.D., Ernesto Paolasso, M.D., Benjamin M. Scirica, M.D., M.P.H., Jindrich Spinar, M.D., Ph.D., Pierre Theroux, C.M., M.D., Stephen D. Wiviott, M.D., John Strony, M.D., and Sabina A. Murphy, M.P.H. for the TRA 2P–TIMI 50 Steering Committee and Investigators

N Engl J Med 2012; 366:1404-1413April 12, 2012DOI: 10.1056/NEJMoa1200933

Abstract

Background

Thrombin potently activates platelets through the protease-activated receptor PAR-1. Vorapaxar is a novel antiplatelet agent that selectively inhibits the cellular actions of thrombin through antagonism of PAR-1.

Methods

We randomly assigned 26,449 patients who had a history of myocardial infarction, ischemic stroke, or peripheral arterial disease to receive vorapaxar (2.5 mg daily) or matching placebo and followed them for a median of 30 months. The primary efficacy end point was the composite of death from cardiovascular causes, myocardial infarction, or stroke. After 2 years, the data and safety monitoring board recommended discontinuation of the study treatment in patients with a history of stroke owing to the risk of intracranial hemorrhage.

Results

At 3 years, the primary end point had occurred in 1028 patients (9.3%) in the vorapaxar group and in 1176 patients (10.5%) in the placebo group (hazard ratio for the vorapaxar group, 0.87; 95% confidence interval [CI], 0.80 to 0.94; P<0.001). Cardiovascular death, myocardial infarction, stroke, or recurrent ischemia leading to revascularization occurred in 1259 patients (11.2%) in the vorapaxar group and 1417 patients (12.4%) in the placebo group (hazard ratio, 0.88; 95% CI, 0.82 to 0.95; P=0.001). Moderate or severe bleeding occurred in 4.2% of patients who received vorapaxar and 2.5% of those who received placebo (hazard ratio, 1.66; 95% CI, 1.43 to 1.93; P<0.001). There was an increase in the rate of intracranial hemorrhage in the vorapaxar group (1.0%, vs. 0.5% in the placebo group; P<0.001).

Conclusions

Inhibition of PAR-1 with vorapaxar reduced the risk of cardiovascular death or ischemic events in patients with stable atherosclerosis who were receiving standard therapy. However, it increased the risk of moderate or severe bleeding, including intracranial hemorrhage. (Funded by Merck; TRA 2P–TIMI 50 ClinicalTrials.gov number, NCT00526474.)

Media in This Article

Figure 1Kaplan–Meier Rates of Cardiovascular Events.
Figure 2Kaplan–Meier Rates of Bleeding.
Article

Platelets play a central role in atherothrombosis and are an important target for pharmacotherapy. In patients with acute coronary syndromes, the use of potent platelet inhibitors has been shown to reduce the rate of thrombotic events at the cost of increased bleeding.1-3 In contrast, among patients with stable atherosclerosis, a reduced rate of thrombotic events with antiplatelet therapy in addition to aspirin therapy has not been established.4

Thrombin is a serine protease that is critical in thrombosis. In addition to generating fibrin, thrombin is a potent agonist of platelets through interaction with protease-activated receptors (PARs).5 Vorapaxar (SCH 530348, Merck) is a competitive and selective antagonist of PAR-1, the major thrombin receptor on human platelets. Vorapaxar potently inhibits thrombin-induced platelet aggregation.6,7 This study, called the Thrombin Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events (TRA 2P)–Thrombolysis in Myocardial Infarction (TIMI) 50 trial, was designed to evaluate the efficacy and safety of vorapaxar in reducing atherothrombotic events in patients with established atherosclerosis who were receiving standard therapy. In addition to investigating vorapaxar specifically, the trial more broadly tested the hypothesis that the intensification of antiplatelet therapy by adding an agent with a different pharmacologic target is beneficial for secondary prevention in patients with stable disease and a history of myocardial infarction, ischemic stroke, or peripheral arterial disease.

Methods

Study Design and Oversight

The TRA 2P–TIMI 50 trial was a multinational, double-blind, placebo-controlled trial8 that was conducted at 1032 sites in 32 countries (see the Supplementary Appendix, available with the full text of this article at NEJM.org). The trial was sponsored by Merck and was designed by the TIMI Study Group in conjunction with the steering committee and trial sponsor. The protocol was approved by the relevant ethics committees at all participating centers. The raw database was provided to the TIMI Study Group, which carried out the data analyses independently of the sponsor, prepared this report, and made the decision to submit the manuscript for publication. The members of the TIMI Study Group assume responsibility for the accuracy and completeness of the data and all analyses and for the fidelity of this report to the study protocol, which is available at NEJM.org.

Study Population

Eligible patients had a history of atherosclerosis, which was defined as a spontaneous myocardial infarction or ischemic stroke within the previous 2 weeks to 12 months or peripheral arterial disease associated with a history of intermittent claudication in conjunction with either an ankle–brachial index of less than 0.85 or previous revascularization for limb ischemia. By design, enrollment of patients with a qualifying diagnosis of either stroke or peripheral arterial disease was to end when the number enrolled reached approximately 15% of the total anticipated sample size.

Patients were ineligible if they were planning to undergo a revascularization procedure, had a history of bleeding diathesis, had recent active abnormal bleeding, were receiving ongoing treatment with warfarin, or had active hepatobiliary disease. The full eligibility criteria have been reported previously.8 Written informed consent was obtained from all patients.

Randomization and Study Treatment

Eligible patients were randomly assigned in a 1:1 ratio to receive either vorapaxar (2.5 mg daily) or matched placebo by a central computerized system with hierarchical stratification according to the qualifying diagnosis (myocardial infarction, stroke, or peripheral arterial disease) and the responsible physician's intent to administer a thienopyridine (see the Methods section in the Supplementary Appendix). Vorapaxar and placebo were administered orally in a blinded fashion once daily until the end of follow-up. Study therapy was to be interrupted if the patient required treatment with either a potent inhibitor of the cytochrome P-450 3A4 (CYP3A4) enzyme system or warfarin in conjunction with a thienopyridine. All concomitant medical therapy, including the use of other antiplatelet agents, was managed by the clinicians at the study sites who were responsible for the care of the patients, according to local standards of care.

In January 2011, after completion of enrollment and a median of 24 months of follow-up, the data and safety monitoring board reported an excess of intracranial hemorrhage in patients with a history of stroke in the vorapaxar group and recommended discontinuation of the drug in all patients with previous stroke, including those with a new stroke during the trial. The board also recommended continuation of the trial in patients without a history of stroke. The protocol was amended accordingly (see the Methods section in the Supplementary Appendix).

End Points

The protocol-defined primary efficacy end point was a composite of cardiovascular death, myocardial infarction, stroke, or recurrent ischemia leading to urgent coronary revascularization. The major secondary end point was a composite of cardiovascular death, myocardial infarction, or stroke. Before the database was locked and during blinded treatment, the investigators reviewed data from the newly completed Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) trial (ClinicalTrials.gov number, NCT00527943).9 On the basis of data from that trial, the steering committee amended the main data-analysis plan to reorder the hierarchy of efficacy analyses, defining as the primary end point the composite of cardiovascular death, myocardial infarction, or stroke. The composite of cardiovascular death, myocardial infarction, stroke, or urgent coronary revascularization became the major secondary end point. Definitions of the components of these composite end points are provided in the Supplementary Appendix.

We assessed bleeding using the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) classification system and the TIMI classification system, with GUSTO moderate or severe bleeding defined as the safety end point of primary interest. A clinical-events committee whose members were unaware of the study-group assignments adjudicated all components of the primary and major secondary efficacy end points and bleeding episodes.

Statistical Analysis

We calculated that 2279 events would be required to provide a power of at least 90% to detect a 15% relative risk reduction in the composite end point of cardiovascular death, myocardial infarction, stroke, or urgent coronary revascularization in the vorapaxar group, as compared with the placebo group. We estimated that 1400 events would be required to provide a power of at least 85% to detect the same relative treatment effect with respect to the composite end point of cardiovascular death, myocardial infarction, or stroke.

The primary efficacy analysis was conducted on an intention-to-treat basis among all patients who underwent randomization. After the data and safety monitoring board recommended discontinuation of vorapaxar in all patients with previous stroke, the protocol was amended to include supplementary evaluation of efficacy in patients who qualified for the trial with a diagnosis of myocardial infarction or peripheral arterial disease without a history of stroke before randomization. In addition, an analysis of efficacy that was restricted to patients with the qualifying diagnosis of myocardial infarction alone was specified in the original analysis plan before the board's recommendation.

The efficacy analyses were performed with the use of a Cox proportional-hazards model, with the study group and stratification factors at randomization as covariates. Cumulative event rates were calculated with the use of the Kaplan–Meier method at 3 years. Safety analyses were performed among patients who received one or more doses of a study drug and included events through 60 days after premature cessation of study therapy or 30 days after a final visit at the conclusion of the trial. On the basis of one planned interim analysis of efficacy, a P value of less than 0.049 was considered to indicate statistical significance for the final analysis,8 and a P value of less than 0.05 was deemed to indicate a significant interaction. All reported P values are two-sided.

Results

Study Patients and Follow-up

From September 26, 2007, through November 13, 2009, a total of 26,449 patients were enrolled in the trial. Of these, 13,225 were randomly assigned to receive vorapaxar, and 13,244 to receive placebo (Figure S1 in the Supplementary Appendix).

Baseline characteristics of the patients are shown in Table 1Table 1Baseline Characteristics of the Patients.. The qualifying diagnosis for enrollment was myocardial infarction in two thirds of the patients, stroke in 18%, and peripheral arterial disease in 14%. A total of 94% of the patients were treated with aspirin. At baseline, a thienopyridine was being administered in a majority of patients with a qualifying diagnosis of myocardial infarction but in only a minority of patients with a qualifying diagnosis of stroke or peripheral arterial disease. Only 177 patients (0.7%) received prasugrel during the study.

The longest duration of follow-up was 49 months, with a median follow-up of 30 months (interquartile range, 24 to 36). Details of follow-up and loss to follow-up are provided in the Supplementary Appendix. The last date of patient contact was December 23, 2011, and the trial database was locked on January 9, 2012.

Efficacy End Points

At 3 years, the primary end point of cardiovascular death, myocardial infarction, or stroke had occurred in 1028 patients (9.3%) in the vorapaxar group, as compared with 1176 patients (10.5%) in the placebo group (hazard ratio, 0.87; 95% confidence interval [CI], 0.80 to 0.94; P<0.001) (Table 2Table 2Efficacy and Bleeding End Points at 3 Years. and Figure 1AFigure 1Kaplan–Meier Rates of Cardiovascular Events.). The major secondary end point of cardiovascular death, myocardial infarction, stroke, or urgent coronary revascularization occurred in 1259 patients (11.2%) in the vorapaxar group, as compared with 1417 patients (12.4%) in the placebo group (hazard ratio, 0.88; 95% CI, 0.82 to 0.95; P=0.001) (Table 2 and Figure 1B). The rate of cardiovascular death or myocardial infarction was reduced from 8.2% among patients in the placebo group to 7.3% among patients in the vorapaxar group (P=0.002) (Table 2, and Figure S2 in the Supplementary Appendix). Individual components of these composite end points are also shown in Table 2. The rate of death from any cause did not differ significantly between the vorapaxar group and the placebo group (5.0% and 5.3%, respectively; hazard ratio, 0.95; 95% CI, 0.85 to 1.07; P=0.41). (Additional prespecified efficacy end points are shown in Tables S1 and S2 in the Supplementary Appendix.)

Among patients with no history of stroke, the primary end point occurred in 8.3% of patients in the vorapaxar group, as compared with 9.6% of those in the placebo group (hazard ratio, 0.84; 95% CI, 0.76 to 0.93; P<0.001) (Table S3 in the Supplementary Appendix). There was no significant heterogeneity for the benefit of vorapaxar on the rate of cardiovascular death, myocardial infarction, or stroke across most of the major subgroups examined, including those defined according to the use or nonuse of a thienopyridine (Figure S3 in the Supplementary Appendix). However, among patients who weighed less than 60 kg, the use of vorapaxar did not have a favorable influence on this outcome (P=0.03 for interaction). Additional analyses of efficacy in subgroups that were defined according to the qualifying diagnosis of atherosclerosis (myocardial infarction, stroke, or peripheral arterial disease) and the presence or absence of a history of stroke are provided in Table S3 and Figure S3 in the Supplementary Appendix.

Safety End Points

The major safety end point of moderate or severe bleeding (according to GUSTO criteria) occurred in 438 patients (4.2%) in the vorapaxar group, as compared with 267 patients (2.5%) in the placebo group (hazard ratio, 1.66; 95% CI, 1.43 to 1.93; P<0.001) (Table 2 and Figure 2AFigure 2Kaplan–Meier Rates of Bleeding.). There was no evidence of heterogeneity in the effect of vorapaxar on moderate or severe bleeding in major subgroups (Figure S4 in the Supplementary Appendix). Rates of TIMI clinically significant bleeding (Figure 2B) and rates of TIMI major bleeding not related to coronary-artery bypass grafting were also both significantly increased in the vorapaxar group as compared with the placebo group (P<0.001) (Table 2).

Overall, intracranial hemorrhage occurred in 102 patients (1.0%) in the vorapaxar group, as compared with 53 patients (0.5%) in the placebo group (hazard ratio, 1.94; 95% CI, 1.39 to 2.70; P<0.001) (Table 2, and Figure S5 in the Supplementary Appendix). Fatal bleeding occurred in 29 patients (0.3%) in the vorapaxar group, as compared with 20 patients (0.2%) in the placebo group (hazard ratio, 1.46; 95% CI, 0.82 to 2.58; P=0.19). Among patients with a history of stroke, the rate of intracranial hemorrhage in the vorapaxar group was 2.4%, as compared with 0.9% in the placebo group (P<0.001), with corresponding rates of fatal bleeding of 0.5% and 0.3% (P=0.46) (Table S3 in the Supplementary Appendix). Among patients without a history of stroke, the rates of intracranial hemorrhage were lower in the two study groups (0.6% in the vorapaxar group and 0.4% in the placebo group, P=0.049), as were the rates of fatal bleeding (0.3% and 0.2%, respectively; P=0.30). Additional safety analyses are shown in Tables S3 and S4 in the Supplementary Appendix.

Net Clinical Outcome

A composite end point termed net clinical outcome, comprising the primary efficacy and safety end points, was prespecified (Table 2). The composite of cardiovascular death, myocardial infarction, stroke, or GUSTO moderate or severe bleeding occurred in 1315 patients (11.7%) in the vorapaxar group and in 1358 patients (12.1%) in the placebo group (hazard ratio, 0.97; 95% CI, 0.90 to 1.04; P=0.40). Other net clinical outcomes in all patients and in patients without stroke are reported in Table 2, and Table S4 in the Supplementary Appendix.

Discussion

In previous studies, it has not been established whether the addition of another antiplatelet agent to aspirin therapy would reduce the rate of thrombotic events in patients with stable atherosclerotic disease.4 In our large randomized trial, the PAR-1 antagonist vorapaxar significantly reduced the rate of cardiovascular death, myocardial infarction, or stroke in patients with a history of atherothrombosis who were receiving standard therapy. However, the reduction in cardiovascular events came at the cost of increased bleeding. This benefit and risk emerged early and continued to accrue throughout follow-up. Our findings show that inhibition of another platelet pathway in addition to that targeted by standard antiplatelet therapy for secondary prevention reduces the risk of recurrent thrombotic events in patients with previous atherothrombosis. This benefit was evident particularly in those whose qualifying diagnosis for participation in the trial was myocardial infarction.

The results of our study establish that interruption of the platelet-directed cellular actions of thrombin, suggested in preclinical studies to be pivotal to thrombosis,10 translates into a clinical effect on major thrombotic events. In our study, antagonism of PAR-1 was complementary to inhibition of the thromboxane A2 and P2Y12-receptor pathways with aspirin and thienopyridines, with respect to the protective effect against recurrent thrombosis. We did not find evidence of significant heterogeneity of the effect of vorapaxar on the basis of treatment with clopidogrel. When vorapaxar was studied in the TRACER trial for the management of acute coronary syndromes, there was a nonsignificant trend toward a reduction in the rate of cardiovascular death, myocardial infarction, stroke, recurrent ischemia with hospitalization, or urgent coronary revascularization and an exploratory finding of a reduction in the rate of cardiovascular death, myocardial infarction, or stroke, along with a significant increase in the risk of intracranial hemorrhage.9 Previous smaller phase 2 trials of vorapaxar11,12 and of atopaxar,13,14 another PAR-1 antagonist, have also revealed trends toward reductions in recurrent thrombotic events but without evidence of an increased risk of intracranial hemorrhage.

During the trial, the data and safety monitoring board recommended the discontinuation of vorapaxar in patients with a history of stroke on the basis of an excess of intracranial hemorrhage in such patients. We therefore carried out a separate analysis that was confined to patients without a history of stroke and found a significant benefit in this subgroup. In addition, in a prespecified analysis involving patients with a qualifying diagnosis of myocardial infarction, vorapaxar reduced the relative risk of the primary end point by 20%. In the largest previous placebo-controlled trial of antiplatelet therapy for secondary prevention in patients with stable atherothrombosis or at high risk for vascular disease, clopidogrel plus aspirin was no better than aspirin alone in the overall cohort.4 Nevertheless, in an exploratory analysis involving 3846 patients with previous myocardial infarction in that trial, the addition of clopidogrel reduced the risk of cardiovascular death, myocardial infarction, or stroke by 23%.15 Our trial involving a substantially larger number of patients with a history of myocardial infarction shows that the addition of another antiplatelet agent to aspirin therapy over the long term can achieve further reductions in recurrent atherothrombotic events in this population.

The reduction in thrombotic events with vorapaxar came with significant increases in bleeding. Although our findings show that additional reductions in atherothrombosis can be achieved, this benefit must be weighed against the increase in bleeding risk. In the overall trial cohort, there was no significant between-group difference in the prespecified net clinical outcome (including both thrombotic end points and moderate or severe bleeding). However, weighed against the risk of severe bleeding, particularly in patients without a history of stroke, the net clinical outcome was improved in patients receiving vorapaxar.

The results of our study also add to the accumulating evidence of a heightened risk of intracranial hemorrhage among patients with a history of stroke who are treated with potent antiplatelet therapy.2,16,17 As with the use of third-generation P2Y12 inhibitors, such as prasugrel, any clinical use of vorapaxar would have to be based on an appropriate selection of patients, with the risk of bleeding balanced against that of recurrent thrombotic events. We have previously identified criteria for selecting patients who are more likely to have improved net clinical outcomes with potent antiplatelet therapy.2,18 In our study, the relative risk of bleeding, including intracranial hemorrhage, showed a similar significant increase in the vorapaxar group among patients with and those without a history of stroke. However, the absolute rate of intracranial hemorrhage (0.2% per year) among patients without a history of stroke was substantially lower than that among patients with such a history (0.8% per year). The rate of fatal bleeding was not significantly increased in the vorapaxar group.

In conclusion, the addition of vorapaxar to standard therapy reduced the risk of cardiovascular death, myocardial infarction, or stroke among patients with stable atherosclerosis, a benefit that was most apparent in patients with a history of myocardial infarction. Vorapaxar also increased the risk of moderate or severe bleeding, including intracranial hemorrhage, with the latter occurring most frequently in patients with a history of stroke.

Supported by Merck.

Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.

This article (10.1056/NEJMoa1200933) was published on March 24, 2012, at NEJM.org.

Source Information

The authors' affiliations are listed in the Appendix.

Address reprint requests to Dr. Morrow at the TIMI Study Group, Cardiovascular Division, Brigham and Women's Hospital, 75 Francis St., Boston, MA 02115, or at .

Members of the Thrombin Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events (TRA 2P)–Thrombolysis in Myocardial Infarction (TIMI) 50 steering committee, as well as other committee members and investigators, are listed in the Supplementary Appendix, available at NEJM.org.

Appendix

The authors' affiliations are as follows: the Thrombolysis in Myocardial Infarction (TIMI) Study Group, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston (D.A.M., E.B., M.P.B., M.P.F., B.M.S., S.D.W., S.A.M.); the Institute for Neurological Research, FLENI, Buenos Aires (S.F.A.); Milpark Hospital, Johannesburg (A.J.D.); the Division of Cardiovascular Research, University of Edinburgh, Edinburgh (K.A.A.F.); Merck Research Laboratories, Rahway, NJ (L.J.L., X.L., J. Strony); the Heart Institute (InCor)–University of São Paulo Medical School, São Paulo (J.C.N.); Canisius–Wilhelmina Hospital, Nijmegen, the Netherlands (A.J.O.O.); Instituto de Investigaciones Clínicas Rosario, Rosario, Argentina (E.P.); University Hospital Brno, Masaryk University, Brno, Czech Republic (J. Spinar); and Montreal Heart Institute and University of Montreal, Montreal (P.T.).

References

References

  1. 1

    Yusuf S, Zhao F, Mehta SR, Chrolavicius S, Tognoni G, Fox KK. Effects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation. N Engl J Med 2001;345:494-502[Erratum, N Engl J Med 2001;345:1506, 1716.]
    Free Full Text | Web of Science | Medline

  2. 2

    Wiviott SD, Braunwald E, McCabe CH, et al. Prasugrel versus clopidogrel in patients with acute coronary syndromes. N Engl J Med 2007;357:2001-2015
    Free Full Text | Web of Science | Medline

  3. 3

    Wallentin L, Becker RC, Budaj A, et al. Ticagrelor versus clopidogrel in patients with acute coronary syndromes. N Engl J Med 2009;361:1045-1057
    Free Full Text | Web of Science | Medline

  4. 4

    Bhatt DL, Fox KA, Hacke W, et al. Clopidogrel and aspirin versus aspirin alone for the prevention of atherothrombotic events. N Engl J Med 2006;354:1706-1717
    Free Full Text | Web of Science | Medline

  5. 5

    Leger AJ, Covic L, Kuliopulos A. Protease-activated receptors in cardiovascular diseases. Circulation 2006;114:1070-1077
    CrossRef | Web of Science | Medline

  6. 6

    Chackalamannil S, Xia Y, Greenlee WJ, et al. Discovery of potent orally active thrombin receptor (protease activated receptor 1) antagonists as novel antithrombotic agents. J Med Chem 2005;48:5884-5887
    CrossRef | Web of Science | Medline

  7. 7

    Chackalamannil S. Thrombin receptor (protease activated receptor-1) antagonists as potent antithrombotic agents with strong antiplatelet effects. J Med Chem 2006;49:5389-5403
    CrossRef | Web of Science | Medline

  8. 8

    Morrow DA, Scirica BM, Fox KA, et al. Evaluation of a novel antiplatelet agent for secondary prevention in patients with a history of atherosclerotic disease: design and rationale for the Thrombin-Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events (TRA 2P)-TIMI 50 trial. Am Heart J 2009;158(3):335.e3-341.e3.

  9. 9

    Tricoci P, Huang Z, Held C, et al. Thrombin-receptor antagonist vorapaxar in acute coronary syndromes. N Engl J Med 2012;366:20-33
    Free Full Text | Web of Science | Medline

  10. 10

    Coughlin SR. Thrombin signalling and protease-activated receptors. Nature 2000;407:258-264
    CrossRef | Web of Science | Medline

  11. 11

    Becker RC, Moliterno DJ, Jennings LK, et al. Safety and tolerability of SCH 530348 in patients undergoing non-urgent percutaneous coronary intervention: a randomised, double-blind, placebo-controlled phase II study. Lancet 2009;373:919-928
    CrossRef | Web of Science | Medline

  12. 12

    Goto S, Yamaguchi T, Ikeda Y, Kato K, Yamaguchi H, Jensen P. Safety and exploratory efficacy of the novel thrombin receptor (PAR-1) antagonist SCH530348 for non-ST-segment elevation acute coronary syndrome. J Atheroscler Thromb 2010;17:156-164
    CrossRef | Web of Science | Medline

  13. 13

    O'Donoghue ML, Bhatt DL, Wiviott SD, et al. Safety and tolerability of atopaxar in the treatment of patients with acute coronary syndromes: the Lessons From Antagonizing the Cellular Effects of Thrombin-Acute Coronary Syndromes trial. Circulation 2011;123:1843-1853
    CrossRef | Web of Science | Medline

  14. 14

    Wiviott SD, Flather MD, O'Donoghue ML, et al. Randomized trial of atopaxar in the treatment of patients with coronary artery disease: the Lessons From Antagonizing the Cellular Effect of Thrombin-Coronary Artery Disease trial. Circulation 2011;123:1854-1863
    CrossRef | Web of Science | Medline

  15. 15

    Bhatt DL, Flather MD, Hacke W, et al. Patients with prior myocardial infarction, stroke, or symptomatic peripheral arterial disease in the CHARISMA trial. J Am Coll Cardiol 2007;49:1982-1988
    CrossRef | Web of Science | Medline

  16. 16

    Sacco RL, Diener H-C, Yusuf S, et al. Aspirin and extended-release dipyridamole versus clopidogrel for recurrent stroke. N Engl J Med 2008;359:1238-1251
    Free Full Text | Web of Science | Medline

  17. 17

    Diener H-C, Bogousslavsky J, Brass LM, et al. Aspirin and clopidogrel compared with clopidogrel alone after recent ischaemic stroke or transient ischaemic attack in high-risk patients (MATCH): randomised, double-blind, placebo-controlled trial. Lancet 2004;364:331-337
    CrossRef | Web of Science | Medline

  18. 18

    Wiviott SD, Desai N, Murphy SA, et al. Efficacy and safety of intensive antiplatelet therapy with prasugrel from TRITON-TIMI 38 in a core clinical cohort defined by worldwide regulatory agencies. Am J Cardiol 2011;108:905-911
    CrossRef | Web of Science | Medline

Citing Articles (58)

Citing Articles

  1. 1

    Thomas Gremmel, Christoph W. Kopp, Daniela Seidinger, Renate Koppensteiner, Sabine Steiner, Simon Panzer. (2013) Preserved thrombin-inducible platelet activation in thienopyridine-treated patients. European Journal of Clinical Investigation 43:7, 689-697

  2. 2

    Renato D. Lopes, Richard C. Becker, L. Kristin Newby, Eric D. Peterson, Elaine M. Hylek, Robert Giugliano, Christopher B. Granger, Kenneth W. Mahaffey, Antonio C. Carvalho, Otavio Berwanger, Roberto R. Giraldez, Gilson Soares Feitosa-Filho, Marcia M. Barbosa, Maria da Consolacao V. Moreira, Renato A. K. Kalil, Marildes Freitas, Joao Carlos Campos Guerra, Marcio Vinicius Lins Barros, Thiago da Rocha Rodrigues, Antonio C. Lopes, David A. Garcia. (2013) Highlights from the fifth international symposium of thrombosis and anticoagulation (ISTA V), october 18–19, 2012, Belo Horizonte, Minas Gerais, Brazil. Journal of Thrombosis and Thrombolysis 36:1, 115-130

  3. 3

    Fabiana Rollini, Francesco Franchi, Ana Muñiz-Lozano, Dominick J Angiolillo. (2013) Platelet Function Profiles in Patients with Diabetes Mellitus. Journal of Cardiovascular Translational Research 6:3, 329-345

  4. 4

    Giovanni Cimmino, Paolo Golino. (2013) Platelet Biology and Receptor Pathways. Journal of Cardiovascular Translational Research 6:3, 299-309

  5. 5

    C. Olivier, P. Diehl, C. Bode, M. Moser. (2013) Thrombin Receptor Antagonism in Antiplatelet Therapy. Cardiology and Therapy 2:1, 57-68

  6. 6

    Teddy Kosoglou, Paul Statkevich, Bharath Kumar, Fengjuan Xuan, James E. Schiller, Amy O. Johnson-Levonas, Sophia Young, David L. Cutler. (2013) The Effect of Multiple Doses of Ketoconazole or Rifampin on the Single- and Multiple-Dose Pharmacokinetics of Vorapaxar. The Journal of Clinical Pharmacology 53:5, 540-549

  7. 7

    William R. Hiatt. (2013) Vascular disease: Vorapaxar prevents progression of peripheral artery disease. Nature Reviews Cardiology

  8. 8

    Dominick J. Angiolillo, José Luis Ferreiro. (2013) Antiplatelet and Anticoagulant Therapy for Atherothrombotic Disease: The Role of Current and Emerging Agents. American Journal of Cardiovascular Drugs

  9. 9

    Nilusha Gukathasan, Roxana Mehran. (2013) Acute Coronary Syndromes: Advances in Antithrombotics. Current Atherosclerosis Reports 15:4,

  10. 10

    James J. DiNicolantonio, Mehmet Mustafa Can, Victor L. Serebruany. (2013) Lost in follow-up rates in TRACER, ATLAS ACS 2, TRITON and TRA 2P trials: Challenging PLATO mortality rates. International Journal of Cardiology 164:3, 255-258

  11. 11

    Marc P. Bonaca, Joshua Beckman. (2013) Management of Asymptomatic Carotid Artery Stenosis. Current Treatment Options in Cardiovascular Medicine 15:2, 252-263

  12. 12

    G. Rauch, J. Beyersmann. (2013) Planning and evaluating clinical trials with composite time-to-first-event endpoints in a competing risk framework. Statistics in Medicinen/a-n/a

  13. 13

    Thomas Gremmel, Simon Panzer, Sabine Steiner, Daniela Seidinger, Renate Koppensteiner, Ingrid Pabinger, Christoph W. Kopp, Cihan Ay. (2013) Response to antiplatelet therapy is independent of endogenous thrombin generation potential. Thrombosis Research

  14. 14

    Lawrence F. Brass, Maurizio Tomaiuolo, Timothy J. Stalker. (2013) Harnessing the Platelet Signaling Network to Produce an Optimal Hemostatic Response. Hematology/Oncology Clinics of North America

  15. 15

    S. Leonardi, P. Tricoci, H. D. White, P. W. Armstrong, Z. Huang, L. Wallentin, P. E. Aylward, D. J. Moliterno, F. Van de Werf, E. Chen, L. Providencia, J. E. Nordrehaug, C. Held, J. Strony, T. L. Rorick, R. A. Harrington, K. W. Mahaffey. (2013) Effect of vorapaxar on myocardial infarction in the thrombin receptor antagonist for clinical event reduction in acute coronary syndrome (TRA{middle dot}CER) trial. European Heart Journal

  16. 16

    S. Leonardi, P. W. Armstrong, P. J. Schulte, E. M. Ohman, L. K. Newby. (2013) Implementation of standardized assessment and reporting of myocardial infarction in contemporary randomized controlled trials: a systematic review. European Heart Journal 34:12, 894-902

  17. 17

    P.C. Manoria, Pankaj Manoria, Piyush Manoria, S.K. Parashar. (2013) The nuances of new antiplatelet drugs in acute coronary syndrome. Journal of Indian College of Cardiology 3:1, 16-23

  18. 18

    Rudolf Kirchmair, Peter Marschang. Medical therapy for peripheral vascular disease. In: Peripheral Vascular Disease: Basic & Clinical Perspectives. Future Medicine Ltd, 2013:48-59.

  19. 19

    Flavio Souza Brito, Pierluigi Tricoci. (2013) Novel Anti-platelet Agents: Focus on Thrombin Receptor Antagonists. Journal of Cardiovascular Translational Research

  20. 20

    Silvio Antoniak, A. Phillip Owens, Martin Baunacke, Julie C. Williams, Rebecca D. Lee, Alice Weithäuser, Patricia A. Sheridan, Ronny Malz, James P. Luyendyk, Denise A. Esserman, JoAnn Trejo, Daniel Kirchhofer, Burns C. Blaxall, Rafal Pawlinski, Melinda A. Beck, Ursula Rauch, Nigel Mackman. (2013) PAR-1 contributes to the innate immune response during viral infection. Journal of Clinical Investigation

  21. 21

    Freek W.A. Verheugt. (2013) Low-Dose Anticoagulation for Secondary Prevention in Acute Coronary Syndrome. The American Journal of Cardiology 111:4, 618-626

  22. 22

    Michael Holinstat, Nancy E. Colowick, Willie J. Hudson, Dana Blakemore, Qingxia Chen, Heidi E. Hamm, John H. Cleator. (2013) Dichotomous effects of exposure to bivalirudin in patients undergoing percutaneous coronary intervention on protease-activated receptor-mediated platelet activation. Journal of Thrombosis and Thrombolysis 35:2, 209-222

  23. 23

    Khaled Khoufache, Fatma Berri, Wolfgang Nacken, Annette B. Vogel, Marie Delenne, Eric Camerer, Shaun R. Coughlin, Peter Carmeliet, Bruno Lina, Guus F. Rimmelzwaan, Oliver Planz, Stephan Ludwig, Béatrice Riteau. (2013) PAR1 contributes to influenza A virus pathogenicity in mice. Journal of Clinical Investigation 123:1, 206-214

  24. 24

    David E. Newby, Keith A.A. Fox. Stable Ischemic Heart Disease/Chronic Stable Angina. In: Cardiovascular Therapeutics: A Companion to Braunwald's Heart Disease. Elsevier, 2013:131-152.

  25. 25

    Roza Badr Eslam, Irene M. Lang, Alexandra Kaider, Simon Panzer. (2013) Human platelet protease-activated receptor-1 responsiveness to thrombin related to P2Y12 inhibition. Translational Research

  26. 26

    Thomas Gremmel, Sabine Steiner, Daniela Seidinger, Renate Koppensteiner, Simon Panzer, Christoph W. Kopp. (2013) Obesity is associated with poor response to clopidogrel and an increased susceptibility to protease activated receptor-1 mediated platelet activation. Translational Research

  27. 27

    R. De Caterina, S. Husted, L. Wallentin, F. Andreotti, H. Arnesen, F. Bachmann, C. Baigent, K. Huber, J. Jespersen, S. D. Kristensen, G. Y. H. Lip, J. Morais, L. H. Rasmussen, A. Siegbahn, F. W. A. Verheugt, J. I. Weitz. (2013) General mechanisms of coagulation and targets of anticoagulants (Section I). Thrombosis and Haemostasis 109:4, 569-579

  28. 28

    K. Huber, K. Schrör. (2013) High on-treatment platelet reactivity - why should we be concerned?. Thrombosis and Haemostasis 109:5, 789-791

  29. 29

    Lina Badimon, Gemma Vilahur. (2013) Mecanismos de acción de los diferentes agentes antiplaquetarios. Revista Española de Cardiología Suplementos 13, 8-15

  30. 30

    L. O. Mosnier, R. K. Sinha, L. Burnier, E. A. Bouwens, J. H. Griffin. (2012) Biased agonism of protease-activated receptor 1 by activated protein C caused by noncanonical cleavage at Arg46. Blood 120:26, 5237-5246

  31. 31

    Cheng Zhang, Yoga Srinivasan, Daniel H. Arlow, Juan Jose Fung, Daniel Palmer, Yaowu Zheng, Hillary F. Green, Anjali Pandey, Ron O. Dror, David E. Shaw, William I. Weis, Shaun R. Coughlin, Brian K. Kobilka. (2012) High-resolution crystal structure of human protease-activated receptor 1. Nature 492:7429, 387-392

  32. 32

    Yuri B. Pride, Bryan J. Piccirillo, C. Michael Gibson. (2012) Prevalence, Consequences, and Implications for Clinical Trials of Unrecognized Myocardial Infarction. The American Journal of Cardiology

  33. 33

    Claus Z Simonsen, Albert J Yoo. (2012) Antiplatelet therapy in ischemic stroke: does one size fit all?. Expert Review of Cardiovascular Therapy 10:12, 1455-1457

  34. 34

    Georgios J. Vlachojannis, Vijayalakshmi Kunadian, Joseph M. Sweeny, Roxana Mehran. Antithrombotic Therapy in Non-ST-Segment Elevation Acute Coronary Syndromes. In: Therapeutic Advances in Thrombosis. Blackwell Publishing Ltd., 2012:213-235.

  35. 35

    Matthew E. Wiisanen, David J. Moliterno. Interrelationship of Thrombin and Platelets: The Protease Activated Receptor-1. In: Therapeutic Advances in Thrombosis. Blackwell Publishing Ltd., 2012:71-86.

  36. 36

    Farzana Nawaz Ali, Teresa L. Carman. (2012) Medical Management for Chronic Atherosclerotic Peripheral Arterial Disease. Drugs 72:16, 2073-2085

  37. 37

    Arun Natarajan, Refai Showkathali, Kare Tang. (2012) PAR-1 inhibitor antiplatelet agents: Performance below par?. Indian Heart Journal 64:6, 594-597

  38. 38

    Dominick J. Angiolillo. (2012) The Evolution of Antiplatelet Therapy in the Treatment of Acute Coronary Syndromes. Drugs 72:16, 2087-2116

  39. 39

    Robert P. Giugliano, Eugene Braunwald. (2012) The Year in Non–ST-Segment Elevation Acute Coronary Syndrome. Journal of the American College of Cardiology 60:21, 2127-2139

  40. 40

    Christian Ukena, Michael Böhm, Stephan H. Schirmer. (2012) Hot topics in cardiology: data from IABP-SHOCK II, TRILOGY-ACS, WOEST, ALTIDUDE, FAME II and more. Clinical Research in Cardiology 101:11, 861-874

  41. 41

    Stefan James, Claes Held. (2012) Improving long-term outcome after myocardial infarction. The Lancet 380:9850, 1290-1291

  42. 42

    Eugene Braunwald, Marc S. Sabatine. (2012) The Thrombolysis in Myocardial Infarction (TIMI) Study Group experience. The Journal of Thoracic and Cardiovascular Surgery 144:4, 762-770

  43. 43

    Rachel F Power, Brian G Hynes, Darragh Moran, Hatim Yagoub, Gary Kiernan, Nicholas J Ruggiero, Thomas J Kiernan. (2012) Modern antiplatelet agents in coronary artery disease. Expert Review of Cardiovascular Therapy 10:10, 1261-1272

  44. 44

    D. CAPODANNO, D. L. BHATT, S. GOTO, M. L. O’DONOGHUE, D. J. MOLITERNO, C. TAMBURINO, D. J. ANGIOLILLO. (2012) Safety and efficacy of protease-activated receptor-1 antagonists in patients with coronary artery disease: a meta-analysis of randomized clinical trials. Journal of Thrombosis and Haemostasis 10:10, 2006-2015

  45. 45

    Benjamin M Scirica, Marc P Bonaca, Eugene Braunwald, Gaetano M De Ferrari, Daniel Isaza, Basil S Lewis, Felix Mehrhof, Piera A Merlini, Sabina A Murphy, Marc S Sabatine, Michal Tendera, Frans Van de Werf, Robert Wilcox, David A Morrow. (2012) Vorapaxar for secondary prevention of thrombotic events for patients with previous myocardial infarction: a prespecified subgroup analysis of the TRA 2°P-TIMI 50 trial. The Lancet 380:9850, 1317-1324

  46. 46

    Roza Badr Eslam, Irene M. Lang, Renate Koppensteiner, Andreas Calatzis, Simon Panzer, Thomas Gremmel. (2012) Residual platelet activation through protease-activated receptors (PAR)-1 and ‐4 in patients on P2Y12 inhibitors. International Journal of Cardiology

  47. 47

    Anjan K. Chakrabarti, Shalin J. Patel, Robert L. Salazar, Lakshmi Gopalakrishnan, Varun Kumar, Ujjwal Rastogi, Priyamvada Singh, Cafer Zorkun, C. Michael Gibson. (2012) Newer Pharmaceutical Agents for STEMI Interventions. Interventional Cardiology Clinics 1:4, 429-440

  48. 48

    David Tanne. (2012) Stroke: Secondary stroke prevention—personalized antiplatelet therapy. Nature Reviews Neurology 8:10, 536-537

  49. 49

    Raúl Carlos Rey, Sandra Marcela Lepera. (2012) Entre errores y aciertos de los nuevos antitrombóticos. Neurología Argentina 4:3, 107-111

  50. 50

    Michelle L. O’Donoghue, Deepak L. Bhatt, Marcus D. Flather, Shinya Goto, Dominick J. Angiolillo, Shaun G. Goodman, Uwe Zeymer, Philip E. Aylward, Gilles Montalescot, Rafal Ziecina, Hiroyuki Kobayashi, Fang Ren, Stephen D. Wiviott. (2012) Atopaxar and its effects on markers of platelet activation and inflammation: results from the LANCELOT CAD program. Journal of Thrombosis and Thrombolysis 34:1, 36-43

  51. 51

    Fabiana Rollini, Antonio Tello-Montoliu, Dominick J Angiolillo. (2012) Atopaxar: a review of its mechanism of action and role in patients with coronary artery disease. Future Cardiology 8:4, 503-511

  52. 52

    Hans-Christoph Diener. (2012) Neuer Plättchenhemmer im Fokus. InFo Neurologie & Psychiatrie 14:5, 35-35

  53. 53

    Kallirroi I Kalantzi, Maria E Tsoumani, Ioannis A Goudevenos, Alexandros D Tselepis. (2012) Pharmacodynamic properties of antiplatelet agents: current knowledge and future perspectives. Expert Review of Clinical Pharmacology 5:3, 319-336

  54. 54

    Kwon-Duk Seo, Kyung-Yul Lee. (2012) Stroke Update 2011: New Antithrombotics. Korean Journal of Stroke 14:2, 62

  55. 55

    Giuseppe Giugliano, Eugenio Laurenzano, Carlo Rengo, Giovanna De Rosa, Linda Brevetti, Anna Sannino, Cinzia Perrino, Lorenzo Chiariotti, Gabriele Giacomo Schiattarella, Federica Serino, Marco Ferrone, Fernando Scudiero, Andreina Carbone, Antonio Sorropago, Bruno Amato, Bruno Trimarco, Giovanni Esposito. (2012) Abdominal aortic aneurysm in patients affected by intermittent claudication: prevalence and clinical predictors. BMC Surgery 12:Suppl 1, S17

  56. 56

    D. Duerschmied, C. Bode. (2012) Vorapaxar expands antiplatelet options. Hämostaseologie 32:3, 221-227

  57. 57

    Anna Franzone, Marco Ferrone, Giuseppe Carotenuto, Andreina Carbone, Laura Scudiero, Federica Serino, Fernando Scudiero, Raffaele Izzo, Raffaele Piccolo, Savio Saviano, Bruno Amato, Cinzia Perrino, Bruno Trimarco, Giovanni Esposito. (2012) The role of atherectomy in the treatment of lower extremity peripheral artery disease. BMC Surgery 12:Suppl 1, S13

  58. 58

    Giuseppe Giugliano, Cinzia Perrino, Vittorio Schiano, Linda Brevetti, Anna Sannino, Gabriele Giacomo Schiattarella, Giuseppe Gargiulo, Federica Serino, Marco Ferrone, Fernando Scudiero, Andreina Carbone, Antonio Bruno, Bruno Amato, Bruno Trimarco, Giovanni Esposito. (2012) Endovascular treatment of lower extremity arteries is associated with an improved outcome in diabetic patients affected by intermittent claudication. BMC Surgery 12:Suppl 1, S19

Trends

Most Viewed (Last Week)