Combination Antithrombotic Therapies

Antithrombotic therapy-A simple algorithm for the interventional pathologist: A case series

We can safely manage patients on antithrombotic therapy in the interventional pathology practice with this practical algorithm based on the new Antithrombotic Therapy Management Guidelines. This new algorithm helps ensure safe care for patients on antithrombotic therapy undergoing interventional pathology procedures. #interventionalpathology.

Rivaroxaban plus aspirin vs. dual antiplatelet therapy in endovascular treatment in peripheral artery disease and analysis of medication utilization of different lesioned vascular regions

Background

In the management of Peripheral Arterial Disease (PAD), the administration of anticoagulant or antiplatelet agents is imperative. The use of Dual Antiplatelet Therapy (DAPT) in conjunction with rivaroxaban has shown potential in mitigating adverse outcomes. Given the heterogeneity in the pathology of lower limb arteries, there is a compelling case for individualized treatment strategies.

Methods

In a single-center retrospective study on pharmacotherapy for peripheral artery disease, patients were treated with either aspirin combined with rivaroxaban or aspirin coupled with clopidogrel. The primary efficacy outcome encompassed a composite of increases in the Rutherford classification, acute limb ischemia, amputations due to vascular causes, target lesion revascularization, myocardial infarction, ischemic stroke, and cardiovascular death. The primary safety outcome was major bleeding, as defined by the Thrombolysis in Myocardial Infarction (TIMI) criteria; meanwhile, major bleeding as categorized by the International Society on Thrombosis and Haemostasis (ISTH) served as a secondary safety outcome. The study differentiated between two subgroups: patients with only above-the-knee and below-the-knee arterial lesions.

Results

From January 2016 to December 2021, 455 patients received either clopidogrel plus aspirin or rivaroxaban plus aspirin following endovascular treatment (EVT). The rivaroxaban group (n = 220) exhibited a lower incidence of primary efficacy outcomes [49.1% vs. 60.4%, hazard ratio (HR) 0.77, P = 0.006] but had more TIMI major bleeding events (5.9% vs. 2.1%, HR 2.6, P = 0.04). ISTH major bleeding events did not show a significant difference, though a higher percentage of rivaroxaban patients discontinued medication due to bleeding (10% vs. 4.7%, HR 2.2, P = 0.03). In the above-the-knee arterial disease subgroup, the rivaroxaban group demonstrated a lower incidence of primary efficacy outcomes (28.2% vs. 45.2%, HR 0.55, P = 0.02). In the below-the-knee arterial disease subgroup, no significant difference was observed in the occurrence of primary efficacy events between the two groups (58.7% vs. 64.8%, HR 0.76, P = 0.14).

Conclusion

Rivaroxaban plus aspirin improved outcomes compared to DAPT in patients with lower extremity artery disease. Similar findings were observed in the above-the-knee artery lesion-only group. However, in the below-the-knee artery lesion-only group, rivaroxaban plus aspirin did not surpass DAPT in efficacy. Regarding safety, rivaroxaban plus aspirin exhibited higher bleeding risks and more frequent treatment discontinuation than aspirin combined with clopidogrel.

An update on novel therapies for treating patients with arterial thrombosis

INTRODUCTION

Antithrombotic therapy field is undergoing rapid and significant changes during the past decade. In addition to new therapeutic strategies with existing targets, investigators are exploring the potential use of new targets to address unmet needs to treat patients with arterial diseases.

AREAS COVERED

We aim to provide an update on and a comprehensive review of the antithrombic agents that are being explored in patients with arterial diseases. We discuss latest developments with respect to upstream antiplatelet agents, and collagen and thrombin pathway inhibitors. We searched PubMed databases for English language articles using keywords: antiplatelet agents, thrombin pathway inhibitors, collagen receptors, arterial disease.

EXPERT OPINION

Despite implementation of potent P2Y12 inhibitors, there are numerous unmet needs in the treatment of arterial diseases including ceiling effect of currently available antiplatelet agents along with and an elevated risk of bleeding. The latter observations encouraged investigators to explore new targets that can attenuate the generation of platelet-fibrin clot formation and subsequent ischemic event occurrences with minimal effect on bleeding. These targets include collagen receptors on platelets and thrombin generation including FXa, FXIa, and FXIIa. In addition, investigators are studying novel antiplatelet agents/strategies to facilitate upstream therapy in high-risk patients.

Efficacy and safety outcomes of long-term anti-thrombotic treatment of chronic coronary artery disease: A systematic review and network meta-analysis

Background

Clopidogrel, prasugrel, ticagrelor, and low-dose rivaroxaban are all optional strategies in conjunction with aspirin for long-term treatment of chronic coronary artery disease. The aim of this research was to assess the efficacy and safety of long-term anti-thrombotic treatment of chronic coronary heart disease.

Methods

PubMed (MEDLINE), Embase, Clinical Trials Registry ClinicalTrials.gov, and The Cochrane Library were searched through November 2021, to identify randomized controlled trials that compared long term anti-thrombotic therapy for coronary heart disease. Data were extracted to assess eligibility by two independent reviewers. Random-effects meta-analysis was used to pool results.

Results

Eleven randomized controlled trials were included (88,462 patients). In a network meta-analysis, the rivaroxaban compared to the clopidogrel regimen showed lower relative risks (RRs) for death of any cause (0.71; 95% confidence interval [CI], 0.52-0.96), major adverse cardiac events (MACE) (0.73; 95% CI, 0.57-0.93), and cerebrovascular events (0.48; 95% CI, 0.30-0.78). The RR of cerebrovascular events was also lower for the rivaroxaban compared to the ticagrelor 60 mg regimen (0.72; 95% CI, 0.52-0.99). For the prasugrel regimen, the RRs were lower of myocardial infarction incidence versus all extended strategies: clopidogrel plus aspirin (0.76; 95% CI, 0.58-0.99), rivaroxaban (0.60; 95% CI, 0.38-0.93), ticagrelor 60 mg (0.61; 95% CI, 0.42-0.89), and ticagrelor 90 mg (0.63; 95% CI, 0.41-0.97). None of the dual strategies were associated with differences in major bleeding compared to the prasugrel regimen.

Conclusions and relevance

The rivaroxaban regimen appeared to be the preferred long-term anti-thrombotic regimen in preventing all-cause mortality. Our available results tend to support the efficacy of extended anti-thrombotic therapy consisting of prasugrel in lowering MI incidence compared to the other strategies, without increased risk of bleeding. However, additional large-scale direct clinical trials are needed to further determine the adequate long-term anti-thrombotic regimens for treating chronic coronary syndrome.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020186583, identifier CRD42020186583.

Role of platelet function testing in acute coronary syndromes: a meta-analysis

OBJECTIVE

This meta-analysis aimed to evaluate whether using platelet function testing (PFT) in acute coronary syndromes (ACS) to personalise antiplatelet therapy including a P2Y₁₂ antagonist offers any clinical benefits to indicate incorporation into routine practice.

METHODS

A search was conducted on five databases for randomised controlled trials (RCTs) conducted between 1 January 2000 and 17 July 2022, which included an ADP-specific platelet function assays and P2Y₁₂ antagonists as part of dual antiplatelet therapy (DAPT) and have reported the efficacy and/or safety outcomes. The reported event frequencies were used to calculate the risk ratios (RRs) with a 95% CI. The χ² heterogeneity statistical test and sensitivity analysis were used for heterogeneity assessment.

RESULTS

Five RCTs with 7691 patients were included in the analysis. No significant risk reduction was seen in major adverse cardiovascular events (RR=0.95, p=0.42), individual cardiac events (cardiovascular death: RR=0.76, p=0.26; myocardial infarction: RR=0.96, p=0.74; stent thrombosis: RR=0.92, p=0.83; stroke: RR=0.91, p=0.72; target vessel revascularisation: RR=1.06, p=0.47) and overall clinical outcome (RR=0.90, p=0.22). There was also no difference in the rate of bleeding between PFT-guided and standard therapies (major bleeding: RR=0.97, p=0.78, minor bleeding: RR=0.89, p=0.19 and any bleeding: RR=1.04, p=0.33).

CONCLUSION

Compared with standard DAPT with P2Y₁₂ antagonists, using PFT to adjust antiplatelet therapy does not improve clinical outcomes. Therefore, the positions of key guidelines on routine testing in ACS should remain unchanged. In addition, the study highlights the need for well-designed and powered RCTs and standardised testing methodologies to provide reliable findings and definitive conclusions.

An Insight into Recent Advances on Platelet Function in Health and Disease

Platelets play a variety of roles in vascular biology and are best recognized as primary hemostasis and thrombosis mediators. Platelets have a large number of receptors and secretory molecules that are required for platelet functionality. Upon activation, platelets release multiple substances that have the ability to influence both physiological and pathophysiological processes including inflammation, tissue regeneration and repair, cancer progression, and spreading. The involvement of platelets in the progression and seriousness of a variety of disorders other than thrombosis is still being discovered, especially in the areas of inflammation and the immunological response. This review represents an integrated summary of recent advances on the function of platelets in pathophysiology that connects hemostasis, inflammation, and immunological response in health and disease and suggests that antiplatelet treatment might be used for more than only thrombosis.

Prevention of arterial and venous thrombotic events in symptomatic peripheral arterial disease patients after lower extremity revascularization in the VOYAGER PAD trial: Dual anticoagulant/antiplatelet regimen vs antiplatelet therapy alone

BACKGROUND

Vascular disease burden after lower extremity revascularization (LER) comprises more than the first event, more vascular beds than the local arteries, and more than one clinical event type.

OBJECTIVES

Assess total arterial and venous thrombotic burden after LER for symptomatic peripheral artery disease (PAD) and effect of low-dose anticoagulation added to low-dose antiplatelet therapy.

PATIENTS/METHODS

VOYAGER PAD randomized 6564 symptomatic PAD patients undergoing LER to rivaroxaban 2.5 mg twice-daily or placebo on aspirin background. Marginal proportional-hazards models used to generate treatment hazard ratios and associated 95% CIs for first and total events; non-thrombotic deaths treated as competing terminal events. Incidence rates calculated as number of events per 100 patient-years follow-up.

RESULTS

Over 2.5 years (median), first and total thrombotic event rates: 7.1 and 10.3 events/100 patient-years, respectively, in placebo group. Two-thirds (925/1372) of total thrombotic events (arterial 95%, venous 5%) were nonfatal first events. Nearly one-third of patients with first event had a second arterial or venous thrombotic event. Rivaroxaban plus aspirin reduced first and total arterial and venous thrombotic events to 5.4 and 7.9 events/100 patient-years, respectively, a reduction in total thrombotic events over aspirin of 23% (HR: 0.77, 95%CI: 0.67-0.89, p = .0005), preventing 6.1 total arterial and venous thrombotic events at 3 years.

CONCLUSIONS

Assessing total arterial and venous thrombotic events, not just first events, provides more complete information about disease burden and absolute on-treatment impact. Following LER, judicious modulation of more than one coagulation pathway can provide broader benefit than intensifying inhibition of one hemostatic system component.

Role of Membrane Lipid Rafts in MRP4 (ABCC4) Dependent Regulation of the cAMP Pathway in Blood Platelets

BACKGROUND

Platelet cytosolic cyclic adenosine monophosphate (cAMP) levels are balanced by synthesis, degradation, and efflux. Efflux can occur via multidrug resistant protein-4 (MRP4; ABCC4) present on dense granule and/or plasma membranes. As lipid rafts have been shown to interfere on cAMP homeostasis, we evaluated the relationships between the distribution and activity of MRP4 in lipid rafts and cAMP efflux.

METHODS

Platelet activation and cAMP homeostasis were analyzed in human and wild-type or MRP4-deleted mouse platelets in the presence of methyl-β-cyclodextrin (MßCD) to disrupt lipid rafts, and of activators of the cAMP signalling pathways. Human platelet MRP4 and effector proteins of the cAMP pathway were analyzed by immunoblots in lipid rafts isolated by differential centrifugation.

RESULTS

MßCD dose dependently inhibited human and mouse platelet aggregation without affecting per se cAMP levels. An additive inhibitory effect existed between the adenylate cyclase (AC) activator forskolin and MßCD that was accompanied by an overincrease of cAMP, and which was significantly enhanced upon MRP4 deletion. Finally, an efflux of cAMP out of resting platelets incubated with prostaglandin E1 (PGE1) was observed that was partly dependent on MRP4. Lipid rafts contained a small fraction (≈15%) of MRP4 and most of the inhibitory G-protein Gi, whereas Gs protein, AC3, and phosphodiesterases PDE2 and PDE3A were all present as only trace amounts.

CONCLUSION

Our results are in favour of part of MRP4 present at the platelet surface, including in lipid rafts. Lipid raft integrity is necessary for cAMP signalling regulation, although MRP4 and most players of cAMP homeostasis are essentially located outside rafts.

CYP2C19 genotype has prognostic value in specific populations following coronary stenting

Background

The prognostic value of the CYP2C19 genotype in post-percutaneous coronary intervention (PCI) patients remains controversial. The recently-published, limited-sample PHARMCLO trial indicates a personalized pharmacogenomic approach may reduce adverse events. This study aimed to determine the prognostic value of CYP2C19 genotypes.

Methods

The original cohort consisted of 10,724 PCI patients in 2013. 756 patients with genotyped CYP2C19 were included in our analysis. The CYP2C19 genotype prognostic value was tested based on different clinical factors. The primary endpoint was major adverse cardio- and cerebro-vascular event (MACCE).

Results

MACCE 2-years post-PCI occurred in 19 patients (17.4%) in poor metabolizers (PM, CYP2C19 *2/*2, *2/*3, *3/*3), 43 patients (12.2%) in intermediate metabolizers (IM, CYP2C19 *1/*2 or *1/*3) and 27 patients (9.2%) in extensive metabolizers (EM, CYP2C19 *1/*1). PM was an independent MACCE predictor compared with EM (HR: 1.960, 95% CI: 1.139–3.372), but the difference between IM and PM was not significant (HR: 1.314, 95% CI: 0.843–2.048). Major bleeding (BARC grade ≥3) was not significantly different between the three groups (2.5% vs. 2.1% vs. 0.8%, P=0.133). Subgroup analysis showed that the CYP2C19 genotype prognostic value was present in the following subgroups: male, age >60 years, body mass index (BMI) >24 kg/m², SYNTAX score >15, current smokers, and patients without chronic kidney disease.

Conclusions

Utilizing CYP2C19 genotype to guide post-PCI antiplatelet therapy might be appropriate in patients with the following characteristics: male, age >60 years, BMI >24 kg/m², SYNTAX score >15, current smokers, and non-chronic kidney disease (CKD) patients.

Efficacy and safety of non-vitamin K antagonist oral anticoagulants combined with antiplatelet drugs for patients with peripheral artery disease: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) combined with antiplatelet drugs in patients with peripheral artery disease remain largely unknown.

OBJECTIVE

The aim of this meta-analysis was to explore the effects of NOACs combined with antiplatelet drugs versus antiplatelet drugs alone in this population.

METHODS

A comprehensive search of randomized controlled trials published in PubMed, EMBASE, Web of Science, and the Cochrane Library in 30 September 2020 and before. According to the I² statistic, a random or fixed-effect model was used to analyze the safety and effectiveness of NOACs combined with antiplatelet drugs in peripheral artery disease patients.

RESULTS

Three RCTs met the inclusion criteria, with a total sample size of 11,761 participants. Compared with antiplatelet drugs alone, NOACs combined with antiplatelet drugs resulted in lower risk of ischemic stroke events (OR = 0.75, 95%CI 0.57-0.98, p = 0.03), while other treatment effects were not worse than those of single antiplatelet drugs (p ≥ 0.05). In addition, although compared with single antiplatelet drugs alone, NOACs combined with antiplatelet drugs had a higher risk of major bleeding and clinically related nonmajor bleeding, their risk was not higher for intracranial hemorrhage, which may endanger the life of patients, or for fatal bleeding.

CONCLUSIONS

In summary, for peripheral artery disease patients, a combination of NOACs plus antiplatelet drugs may offer additional benefit in reducing ischemic stroke outcome, yet it may increase the risk of bleeding.

Low Dose Rivaroxaban for Atherosclerotic Cardiovascular Diseases: A Systematic Review and Meta-analysis

Background: This study aims to explore the role of low-dose rivaroxaban (≤10 mg daily) for the treatment of atherosclerotic cardiovascular disease (ASCVD). Methods: PubMed, Embase and the Cochrane Library were searched for randomized controlled trials (RCTs) of low-dose rivaroxaban in patients with ASCVD including coronary artery disease (CAD) and peripheral artery disease (PAD). Literature screening, data extraction, and risk of bias assessment were carried out independently by two researchers. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using random-effect models to determine risks of outcomes in ASCVD patients treated with rivaroxaban and comparators, and meta-analysis was conducted via Review Manager 5.3.5 software. Results: 3,768 records were obtained through literature search, and 9 articles representing 6 RCTs ultimately qualified for this study. The meta-analysis indicated that for patients with CAD, the addition of rivaroxaban (5 mg daily) to aspirin could significantly reduce the risk of major adverse cardiovascular events (MACEs) compared with aspirin alone (HR 0.81, 95% CI, 0.72 to 0.91, p = 0.0004, I² = 60%, 4 studies). For PAD patients receiving rivaroxaban (5 mg daily) plus aspirin, there was no significant reduction in the risk of MACEs (HR 0.84, 95% CI, 0.63 to 1.13, p = 0.25, I² = 74%, 2 studies); however, there was significant reduction in major adverse limb events (MALEs) (HR 0.54, 95% CI, 0.35 to 0.83, p = 0.005, one studies) and in the composite of MACEs or MALEs (HR 0.78, 95% CI, 0.64 to 0.95, p = 0.02, I² = 66%, 2 studies) when compared with patients receiving aspirin alone. Meanwhile, rivaroxaban combined with aspirin significantly increased the risk of International Society on Thrombosis and Haemostasis (ISTH) major bleeding compared with aspirin alone in patients with CAD (HR 1.74, 95% CI, 1.43 to 2.13, p < 0.00001, I² = 0%, 2 studies) and PAD (HR 1.47, 95% CI, 1.19 to 1.83, p = 0.0004, I² = 0%, 2 studies). Conclusions: Compared with standard antiplatelet therapy, the addition of a 5 mg daily dose of rivaroxaban to standard antiplatelet therapy may improve cardiovascular or limb outcomes of patients with ASCVD, with an increase in major bleeding. Patients who would benefit from the addition of low-dose rivaroxaban to antiplatelet agents and appropriate dual-pathway antithrombotic strategies should be identified in clinical practice to individualize antithrombotic therapy.

Evolving Approaches to Antithrombotics in Stroke Prevention and Treatment

The optimization of antithrombotic therapy for acute stroke treatment and secondary prevention is an evolving process based on an increasing array of studies that provide an evidence-based approach. Options have increased dramatically with the release of the non-vitamin K oral anticoagulants and with the results of recent randomized clinical trials designed to assess potential benefits versus risks for patients in an individualized fashion. Recent studies have provided important information to guide choice and dosing of antiplatelet agents as well as the length of treatment. Anticoagulant use is particularly pertinent for stroke prevention in patients at higher risk of atrial fibrillation and may have a place in certain other stroke mechanisms. One important focus of study is the potential benefit of combined antiplatelet and anticoagulant therapy. Options for our patients, when the initial choice of therapy does not demonstrate benefit or is not well tolerated, clearly, are valuable. For example, short-term dual antiplatelet therapy for minor stroke and transient ischemic attack is being adopted, but with the recognition that longer-term combined therapy is not worth the increased risk of bleeding. Alternative antiplatelet choices, such as cilostazol and possibly ticagrelor, may be of benefit for refractory patients and this could affect the decision-making process. This review represents an effort to incorporate the information from more recent stroke prevention and treatment studies with information gleaned from prior studies.

Platelet Function in Cardiovascular Disease: Activation of Molecules and Activation by Molecules

Globally, one of the major causes of death is the cardiovascular disease (CVD), and platelets play an important role in thrombosis and atherosclerosis that led to death. Platelet activation can be done by different molecules, genes, pathways, and chemokines. Lipids activate platelets by inflammatory factors, and platelets are activated by receptors of peptide hormones, signaling and secreted proteins, microRNAs (miRNAs), and oxidative stress which also affect the platelet activation in older age. In addition, surface molecules on platelets can interact with other cells and chemokines in activated platelets and cause inflammation thrombosis events and CVD. However, these molecules activating platelets or being activated by platelets can be suggested as the markers to predict the clinical outcome of CVD and can be targeted to reduce thrombosis and atherosclerosis. However, hindering these molecules by other factors such as genes and receptors can reduce platelet activation and aggregation and targeting these molecules can control platelet interactions, thrombosis, and CVD. In addition, dual therapy with the receptor blockers and novel drugs results in better management of CVD patients. Overall, our review will emphasize on the molecules involved in the activation of platelets and on the molecules that are activated by platelets in CVD and discuss the molecules that can be blocked or targeted to reduce the thrombosis events and control CVD.

Supplemental Fibrinogen Restores Platelet Inhibitor-Induced Reduction in Thrombus Formation without Altering Platelet Function: An In Vitro Study

BACKGROUND

 For patients treated with dual antiplatelet therapy, standardized drug-specific 3-to-7 day cessation is recommended prior to major surgery to reach sufficient platelet function recovery. Here we investigated the hypothesis that supplemental fibrinogen might mitigate the inhibitory effects of antiplatelet therapy.

METHODS AND RESULTS

 To this end blood from healthy donors was treated in vitro with platelet inhibitors, and in vitro thrombus formation and platelet activation were assessed. Ticagrelor, acetylsalicylic acid, the combination of both, and tirofiban all markedly attenuated the formation of adherent thrombi, when whole blood was perfused through collagen-coated microchannels at physiological shear rates. Addition of fibrinogen restored in vitro thrombus formation in the presence of antiplatelet drugs and heparin. However, platelet activation, as investigated in assays of P-selectin expression and calcium flux, was not altered by fibrinogen supplementation. Most importantly, fibrinogen was able to restore in vitro thrombogenesis in patients on maintenance dual antiplatelet therapy after percutaneous coronary intervention.

CONCLUSION

 Thus, our in vitro data support the notion that supplementation of fibrinogen influences the perioperative hemostasis in patients undergoing surgery during antiplatelet therapy by promoting thrombogenesis without significantly interfering with platelet activation.

Associations of antithrombotic agent use with clinical outcomes in critically ill patients with troponin I elevation in the absence of acute coronary syndrome

Introduction

To evaluate efficacy of antithrombotic agents in critically ill patients with elevated troponin I level during intensive care unit (ICU) admission.

Methods and results

It was a retrospective observational study which was conducted in a tertiary teaching hospital in Taipei, Taiwan. All patients hospitalized in ICU for >3 days and with available serum troponin I data from December 2015 to July 2017 were included. Patients with definite diagnosis of acute myocardial infarction (AMI) were excluded. We divided patients with troponin I elevation into three groups; no prescription, chronic prescription and new prescription of antithrombotic agents during ICU admission. We defined new prescription when patients were on antithrombotic agents, including antiplatelet agents, direct oral anticoagulants, and warfarin after troponin I was found to be elevated at ICU admission and chronic prescription, if antithrombotic agents were on medication list more than 30 days before ICU admission. Primary outcomes were 30-day and one-year all-cause mortality. Of 597 subjects who met inclusion criteria, 407 (68%) patients had elevated troponin I (>0.1 ng/mL) on ICU admission. These patients had increased 30-day [hazard ratio (HR), 1.679; 95% confidence interval (CI), 1.132–2.491; p = 0.009] and one-year (HR, 1.568; 95% CI, 1.180–2.083; p = 0.002) all-cause mortality compared with those without elevated troponin I. In patients with elevated troponin I, there was no significant difference of 30-day all-cause mortality among three groups (p = 0.051) whereas patients on chronic prescription showed significant survival benefit in one-year all-cause mortality when compared to those without or with new prescription (p = 0.008).

Conclusions

In critically ill patients, elevated troponin I in the absence of AMI was associated with poor prognosis. Newly prescribed antithrombotic agents in ICU didn’t reveal the difference in short and long-term prognosis while chronic antithrombotic agent use was associated with better one-year survival rate, suggesting that these drugs play a protective role in this high-risk population.

Vorapaxar in the treatment of cardiovascular diseases

Vorapaxar specifically and effectively inhibits protease activated receptor-1 and may reduce thrombin-mediated ischemic events without interfering primary hemostasis. In the TRA-2P-TIMI 50 trial, vorapaxar reduced the risk of primary ischemic outcome but with increased bleeding risk. In the post hoc analysis, in patients with a history of myocardial infarction, peripheral artery disease, the net clinical outcome favored vorapaxar therapy with 10% reduction in cardiovascular death, myocardial infarction, stroke, urgent coronary revascularization and moderate or severe bleeding. Based on these favorable results, vorapaxar was approved for the reduction of thrombotic cardiovascular events in patients with prior myocardial infarction or with peripheral artery disease on top of standard antiplatelet therapy. A careful patient selection is needed to balance efficacy versus safety.

Synergistic influence of rivaroxaban on inflammation and coagulation biomarkers in patients with coronary artery disease and peripheral artery disease on aspirin therapy

COMPASS study demonstrated efficacy of dual pathway inhibition with 2.5 mg twice daily rivaroxaban and aspirin in patients with polyvascular disease (coronary artery disease, peripheral arterial disease or both), the underlying mechanism of which is not clearly understood. In this Phase IV, prospective, open-label and randomized study, we hypothesize that treatment with rivaroxaban is associated with a reduction in platelet activation and aggregation, inflammation and coagulation markers. 30 patients will be randomly treated with aspirin (81 mg q.d.) or aspirin plus rivaroxaban (2.5 mg b.i.d.) for 12 weeks. Platelet aggregation, platelet activation and inflammation markers, thrombin generation kinetics and tissue factor-induced platelet-fibrin clot strength will be measured at baseline, and 4 and 12 weeks after randomization. Trial registration number: NCT04059679.

Combination Antiplatelet and Oral Anticoagulant Therapy in Patients With Coronary and Peripheral Artery Disease

Antiplatelet therapy is the mainstay for the treatment of acute and chronic arterial disease involving the coronary and peripheral beds. However, questions remain about optimal antithrombotic therapy for long-term treatment of chronic vascular disease. The observation that dual antiplatelet therapy with acetylsalicylic acid and clopidogrel was associated with lower thrombotic event rates than acetylsalicylic acid monotherapy in patients with acute coronary syndromes and those undergoing percutaneous coronary intervention changed the treatment paradigm. Moreover, the demonstration that more pharmacodynamically potent P2Y₁₂ inhibitors than clopidogrel were associated with fewer thrombotic event occurrences further solidified the dual antiplatelet therapy approach. However, recurrent thrombotic events occur in ≈1 in 10 patients in the first year following an acute coronary syndrome event, despite treatment with the most potent P2Y₁₂ inhibitors, a limitation that has stimulated interest in exploring the efficacy and safety of approaches using anticoagulants on top of antiplatelet therapy. These investigations have included treatment with very-low-dose oral anticoagulation, and even its replacement of acetylsalicylic acid in the presence of a P2Y₁₂ inhibitor, in patients stabilized after an acute coronary syndrome event. Recent basic and translational studies have suggested noncanonical effects of coagulation factor inhibition that may further modulate clinical benefits. This in-depth review will discuss developments in our understanding of the roles that platelets and coagulation factors play in atherothrombosis and review the rationale and clinical evidence for combining antiplatelet and oral anticoagulant therapy in patients with coronary and peripheral artery disease.

Assessing platelet reactivity after drug eluting stent implantation: state of the art

Introduction: Platelets play a pivotal role in the occurrence of recurrent ischemic events in coronary artery disease patients who are treated with drug-eluting stents and are on dual antiplatelet therapy (DAPT).Areas covered: High platelet reactivity (HPR) to adenosine diphosphate during clopidogrel therapy is a strong predictor of post-stenting ischemic event occurrences. However, uniform use of potent P2Y₁₂ receptors blockers to overcome HPR is associated with elevated bleeding risk. Selective de-escalation of P2Y₁₂ receptor blocker therapy based on PFT in patients with acute coronary syndrome treated with stenting has been shown to be associated with a similar risk of ischemic event occurrence but with a reduced risk of bleeding. This review aims to discuss the role of PFT in guiding DAPT in patients treated with DES. We searched electronic databases from January 2000 to December 2019 for literatures evaluating the role of platelet function assessment after drug eluting stents.Expert opinion: Platelet function guided therapy improves patient outcomes by lessening bleeding and limiting the overuse of highly potent P2Y₁₂ inhibitors. Interest in this area of de-escalation of therapy will likely grow as the consequences of bleeding are better recognized and the cost of healthcare gains greater focus.

A Comparison Study of Cilostazol and Aspirin on Changes in Volume of Cerebral Small Vessel Disease White Matter Changes: Protocol of a Multicenter, Randomized Controlled Trial

Background and Purpose

Cerebral small vessel disease (CSVD) is the most common cause of vascular dementia and a major contributor to mixed dementia. CSVD is characterized by progressive cerebral white matter changes (WMC) due to chronic low perfusion and loss of autoregulation. In addition to its antiplatelet effect, cilostazol exerts a vasodilating effect and improves endothelial function. This study aims to compare the effects of cilostazol and aspirin on changes in WMC volume in CSVD.

Methods

The comparison study of Cilostazol and aspirin on cHAnges in volume of cerebral smaLL vEssel disease white matter chaNGEs (CHALLENGE) is a double blind, randomized trial involving 19 hospitals across South Korea. Patients with moderate or severe WMC and ≥ 1 lacunar infarction detected on brain magnetic resonance imaging (MRI) are eligible; the projected sample size is 254. Participants are randomly assigned to a cilostazol or aspirin group at a 1:1 ratio. Cilostazol slow release 200 mg or aspirin 100 mg are taken once daily for 2 years. The primary outcome measure is the change in WMC volume on MRI from baseline to 104 weeks. Secondary imaging outcomes include changes in the number of lacunes and cerebral microbleeds, fractional anisotropy and mean diffusivity on diffusion tensor imaging, and brain atrophy. Secondary clinical outcomes include all ischemic strokes, all vascular events, and changes in cognition, motor function, mood, urinary symptoms, and disability.

Conclusions

CHALLENGE will provide evidence to support the selection of long-term antiplatelet therapy in CSVD.

Trial Registration

ClinicalTrials.gov Identifier: NCT01932203.

Effects of vorapaxar on clot characteristics, coagulation, inflammation, and platelet and endothelial function in patients treated with mono- and dual-antiplatelet therapy

BACKGROUND

Vorapaxar is indicated with standard antiplatelet therapy (APT) in patients with a history of myocardial infarction (MI) or peripheral arterial disease (PAD).

OBJECTIVES

To evaluate the comparative effects of vorapaxar on platelet-fibrin clot characteristics (PFCC), coagulation, inflammation, and platelet and endothelial function during treatment with daily 81 mg aspirin (A), 75 mg clopidogrel (C), both (C + A), or neither.

METHODS

Thrombelastography, conventional platelet aggregation (PA), ex vivo endothelial function by ENDOPAT, coagulation, platelet activation/inflammation marked by urinary 11-dehydrothromboxane B2 (UTxB2 ) and safety were determined in patients who were APT naïve (n = 21), on C (n = 8), on A (n = 29), and on A + C (n = 23) during 1 month of vorapaxar therapy and 1 month of offset.

RESULTS

Vorapaxar had no effect on PFCC, ADP- or collagen-induced PA, thrombin time, fibrinogen, PT, PTT, von Willebrand factor (vWF), D-dimer, or endothelial function (P > .05 in all groups). Inhibition of SFLLRN (PAR-1 activating peptide)-stimulated PA by vorapaxar was accelerated by A + C at 2 hours (P < .05 versus other groups) with nearly complete inhibition by 30 days that persisted through 30 days after discontinuation in all groups (P < .001). SFLLRN-induced PA during offset was lower in APT patients versus APT-naïve patients (P < .05). Inhibition of UTxB2 was observed in APT-naive patients treated with vorapaxar (P < .05). Minor bleeding was only observed in C-treated patients.

CONCLUSION

Vorapaxar had no influence on PFCC measured by thrombelastography, coagulation, or endothelial function irrespective of APT. Inhibition of protease activated receptor (PAR)-1 mediated platelet aggregation by vorapaxar was accelerated by A + C and offset was prolonged by concomitant APT. Vorapaxar-induced anti-inflammatory effects were observed in non-aspirin-treated patients.

A Multicenter, Randomized, Double-Blind, and Placebo-Controlled Study of the Effects of Tongxinluo Capsules in Acute Coronary Syndrome Patients with High On-Treatment Platelet Reactivity

Background

High platelet reactivity (HPR) during clopidogrel treatment predicts postpercutaneous coronary intervention (PCI) ischemic events strongly and independently. Tongxinluo capsules (TCs) are a traditional Chinese medicine formulation used as antiplatelet treatment. However, its efficacy against HPR is not known. The aim of the present study was to evaluate the effects of TCs in acute coronary syndrome (ACS) patients with HPR.

Methods

This multicenter, randomized, double-blind, placebo-controlled study prospectively analyzed 136 ACS patients with HPR who underwent PCI. The patients were enrolled from November 2013 to May 2014 and randomized to receive placebo or TCs in addition to standard dual antiplatelet therapy (DAPT) with aspirin and clopidogrel. The primary end points were the prevalence of HPR at 30 days and the mean change in P2Y₁₂reaction units (PRUs) between baseline and 30 days. Survival curves were constructed with Kaplan-Meier estimates and compared by log-rank tests between the two groups.

Results

Both groups had a significantly reduced prevalence of HPR at 30 days versus baseline, but the TC group, compared with the placebo group, had greater reduction (15.8% vs. 24.8%, P = 0.013), especially among patients with one cytochrome P450 2C19 loss of function (LOF) allele (χ² = 2.931, P = 0.047). The TC group also had a lower prevalence of HPR (33.3% vs. 54.2%, t = 5.284, P = 0.022) and superior performance in light transmittance aggregometry and higher levels of high-sensitivity C-reactive protein (hsCRP), but the composite prevalence of ischemic events did not differ significantly (χ² = 1.587, P = 0.208).

Conclusions

In addition to standard DAPT with aspirin and clopidogrel, TCs further reduce PRU and hsCRP levels, especially in patients carrying only one LOF allele. The data suggest that TCs could be used in combination therapy for ACS patients with HPR undergoing PCI.

Impaired liver cytochrome P450 2C11 activity after dual antiplatelet therapy with aspirin and clopidogrel in rats

1. Aspirin (ASA) and clopidogrel (CLP) are used in combination as dual antiplatelet therapy (DAPT) for acute coronary syndrome based on their complementary mechanisms for platelet aggregation inhibition. However, the pharmacokinetics of such drug combination usage has not been thoroughly investigated. 2. In the current study, an LC-MS/MS method was developed to simultaneously determine the plasma concentrations of ASA and its metabolite salicylic acid (SA) with CLP and its metabolites, clopidogrel carboxylic acid (CLPM) and clopidogrel active metabolite derivative (CAMD). The pharmacokinetics of ASA, SA, CLP, CLPM and CAMD in rats receiving two-week DAPT with ASA and CLP were then determined. 3. After two-week DAPT with ASA and CLP in rats, the activities of aspirin esterase and rCyp2c11, enzymes mediating rat metabolism of ASA and CLP, respectively, in prepared rat liver microsomes were measured followed by further determination of rCyp2c11 mRNA expressions. The results demonstrated that DAPT led to minimal impact on aspirin esterase activity but significant decrease in rCyp2c11 activity and mRNA expression. 4. In conclusion, our findings on impairment in rCyp2C11 activity and mRNA expression by DAPT in rats could provide guidance on its safe clinical use with other CYP 2C19 substrates.

Cangrelor for the treatment of patients with Arterial Thrombosis

INTRODUCTION

All oral P2Y₁₂ receptor blockers are associated with some degree of delayed onset and offset of pharmacodynamic (PD) effects in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). Although intravenous glycoprotein IIb/IIIa inhibitors are associated with rapid onset of action, they are also associated with delayed offset and other limitations such as elevated bleeding risk and thrombocytopenia. Areas covered: In this review, the authors focus on cangrelor, an intravenous, reversible P2Y₁₂ receptor blocker with fast onset and offset of effects. The authors also describe the pharmacologic effects of cangrelor and its pharmacologic interaction with other P2Y₁₂ receptor inhibitors. Finally, the authors discuss the large-scale clinical trials that compared the efficacy and safety of cangrelor with clopidogrel. Expert opinion: In ACS patients undergoing PCI, cangrelor is most desirable to effectively prevent periprocedural ischemic events and to avoid excessive bleeding. Indeed, any high-risk patient with ST-segment elevation myocardial infraction or patient who is unable to take oral medications is a potential candidate for intravenous cangrelor therapy. Furthermore, stable patients with coronary artery disease, who are considered for ad hoc PCI following coronary angiography, may be considered for treatment with cangrelor to reduce post-PCI thrombotic events.

Consensus Document ANMCO/ANCE/ARCA/GICR-IACPR/GISE/SICOA: Long-term Antiplatelet Therapy in Patients with Coronary Artery Disease

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor is the cornerstone of pharmacologic management of patients with acute coronary syndrome (ACS) and/or those receiving coronary stents. Long-term (>1 year) DAPT may further reduce the risk of stent thrombosis after a percutaneous coronary intervention (PCI) and may decrease the occurrence of non-stent-related ischaemic events in patients with ACS. Nevertheless, compared with aspirin alone, extended use of aspirin plus a P2Y12 receptor inhibitor may increase the risk of bleeding events that have been strongly linked to adverse outcomes including recurrent ischaemia, repeat hospitalisation and death. In the past years, multiple randomised trials have been published comparing the duration of DAPT after PCI and in ACS patients, investigating either a shorter or prolonged DAPT regimen. Although the current European Society of Cardiology guidelines provide a backup to individualised treatment, it appears to be difficult to identify the ideal patient profile which could safely reduce or prolong the DAPT duration in daily clinical practice. The aim of this consensus document is to review contemporary literature on optimal DAPT duration, and to guide clinicians in tailoring antiplatelet strategies in patients undergoing PCI or presenting with ACS.

Selection of P2Y12 Inhibitor in Percutaneous Coronary Intervention and/or Acute Coronary Syndrome

The P2Y₁₂ receptor plays a critical role in the amplification of platelet aggregation in response to various agonists and stable thrombus generation at the site of vascular injury leading to deleterious ischemic complications. Therefore, treatment with a P2Y₁₂ receptor blocker is a major effective strategy to prevent ischemic complications in high-risk patients with acute coronary syndrome (ACS) and patients undergoing percutaneous coronary intervention (PCI). The determination of optimal platelet inhibition is based on maximizing antithrombotic properties while minimizing bleeding risk and is critically dependent on individual patient's propensity for thrombotic and bleeding risks. Immediately after ACS and during PCI, where highly elevated thrombotic activity is present, a loading dose administration with a potent P2Y₁₂ receptor blocker such as ticagrelor or prasugrel is preferred. In stable coronary artery disease patients undergoing PCI, clopidogrel is widely used. In addition, in patients with ST-segment elevation myocardial infraction who cannot take oral medications, a fast acting intravenous glycoprotein IIb/IIIa inhibitor or P2Y₁₂ receptor blocker, cangrelor, may add clinical benefits. During long term therapy, a strategy that prevents ischemic risk while avoiding excessive bleeding risk is similarly desired. Although up to one year dual antiplatelet therapy (DAPT) is recommended in patients undergoing elective stenting, the available data support the anti-ischemic benefit of prolonged DAPT (more than1 year) in patients with prior MI. In addition to the DAPT risk calculator tool, future risk assessment methods that analyze intrinsic thrombogenicity and atherosclerotic coronary burden may further identify the optimal candidate for prolonged DAPT to improve net clinical outcomes.

Vorapaxar expands antiplatelet options

Vorapaxar is the first substance of a new class of antiplatelet drugs that has been tested in large clinical trials. The protease-activated receptor 1 (PAR-1) antagonist inhibits thrombin-induced platelet activation to prevent atherothrombosis. In the phase 3 trials TRACER (acute coronary syndrome) and TRA 2P-TIMI 50 (stable atherosclerosis) reducing ischemic events with vorapaxar came at the cost of bleeding.

TRACER compared vorapaxar to placebo in 12 944 patients who had non-ST-segment elevation acute coronary syndromes on top of contemporary treatment including dual antiplatelet therapy (aspirin and clopidogrel). Vorapaxar reduced ischemic events non-significantly, but increased bleeding significantly, therefore not justifying triple antiplatelet therapy in this setting. Follow-up was stopped early because of bleeding. TRA 2P-TIMI 50 examined 26 449 patients who had a history of myocardial infarction, ischemic stroke, or peripheral arterial disease. Vorapaxar reduced ischemic events and increased bleeding both significantly. Recruitment of patients with prior stroke was stopped early. Net clinical outcome and subgroup analyses suggested that vorapaxar could be beneficial for patients with prior myocardial infarction – but no history of stroke.

Central aortic pulse pressure, thrombogenicity and cardiovascular risk

High central aortic pulse pressure (CPP) and thrombin-induced platelet-fibrin clot strength (TIP-FCS) have been associated with ischemic outcomes in patients with coronary artery disease in separate studies. But, the ischemic risk associated with these factors has never been analyzed in a single study and their interrelation is unknown. The primary aim of the study was to establish cut points for CPP and TIP-FCS measured at the time of catheterization associated with long term major adverse cardiovascular events. We enrolled 334 consecutive patients undergoing cardiac catheterization and assessed thrombogenicity by thrombelastography. Patients were followed up to 3 years. The primary endpoint was a composite of cardiovascular death, myocardial infarction, and ischemic stroke and the secondary endpoint was occurrence of the primary endpoint or recurrent ischemic events requiring hospitalization. Patients with primary and secondary endpoint occurrence had higher CPP (83 ± 20 vs. 60 ± 18 mmHg, p < 0.0001; 70 ± 21 vs. 59 ± 18 mmHg, p < 0.0001, respectively) and TIP-FCS (68.5 ± 5.8 vs. 65.5 ± 5.0 mm, p = 0.008; 67.4 ± 5.9 vs. 65.2 ± 4.8 mm, p = 0.001, respectively). CPP >60 mmHg and TIP-FCS >69 mm were both independent predictors of primary endpoint occurrence (p = 0.0001 and p = 0.02, respectively). ROC analysis for CPP and TIP-FCS showed a C-statistic of 0.81 (p < 0.0001) and 0.68 (p = 0.007) for the primary endpoint, respectively. Patients with CPP >60 mmHg had higher TIP-FCS (66.8 ± 5.1 vs. 64.8 ± 5.0 mm, p < 0.001) and primary and secondary endpoint occurrence (13 vs. 1.1%, p < 0.0001 and 31.8 vs. 14.4%, p = 0.0002, respectively). CPP >60 mmHg + TIP-FCS > 69 mm was associated with a markedly increased risk of primary endpoint occurrence [HR (95% CI) 5.4(2.3-12.5), p = 0.0001]. High CPP and thrombogenicity are interrelated; each are independently associated with increased cardiovascular risk; and simultaneous presence markedly enhances risk. The mechanistic link between CPP and thrombogenicity deserves further study.

Current controversies in the use of aspirin and ticagrelor for the treatment of thrombotic events

INTRODUCTION

A P2Y₁₂ inhibitor plus aspirin is the most widely used antiplatelet strategy to prevent adverse outcomes in the setting of atherothrombotic vascular disease. Areas covered: A paucity of robust evidence for an optimal dose, gastrointestinal toxicity, ineffectiveness in high-risk patients and interactions with other antiplatelet agents, are major controversies associated with aspirin therapy. Ticagrelor is a reversibly binding oral P2Y₁₂ receptor blocker that mediates potent inhibition of adenosine diphosphate-induced platelet function. It is more effective than clopidogrel in preventing thrombotic events in acute coronary syndrome patients. The absence of a beneficial effect for ticagrelor versus clopidogrel in ACS observed in the North American subgroup of the PLATelet inhibition and patient Outcomes (PLATO) trial has been attributed to a higher concomitant aspirin dose. Expert commentary: Ongoing studies are now investigating the plausibility of removing aspirin therapy in the setting of potent P2Y₁₂ receptor blockade via ticagrelor monotherapy or replacing aspirin with an oral anticoagulant.

Increased Benefit With Vorapaxar Use in Patients With a History of Myocardial Infarction and Diabetes Mellitus: What the Data Show Us

Type 2 diabetes mellitus (T2DM) is a progressive and multifactorial metabolic disease mainly characterized by hyperglycemia and insulin resistance. Abnormal platelet reactivity associated with an increased risk of cardiovascular disease (CVD) is also a feature characteristic of patients with T2DM. Dual antiplatelet therapy consisting of aspirin and an adenosine diphosphate platelet P2Y₁₂ receptor antagonist, such as clopidogrel, represents the standard antithrombotic regimen for the secondary prevention of CVD risk in T2DM. However, a high proportion of patients with T2DM exhibit high on-treatment platelet reactivity to aspirin and/or clopidogrel, associated with a greater risk of adverse cardiovascular events compared with nondiabetic patients. Consequently, novel antiplatelet therapeutic approaches may be required in order to avoid such events. Vorapaxar is a novel antiplatelet agent that targets the platelet protease-activated receptor 1 and inhibits thrombin-induced platelet activation. Vorapaxar has been studied in 2 phase III clinical trials and has been approved for use in the secondary prevention of atherothrombotic events in patients with a previous myocardial infarction (MI) or peripheral arterial disease. New data from the Thrombin-Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events (TRA 2°P)-TIMI 50 trial MI cohort demonstrate that the subgroup of patients with T2DM exhibits increased benefit from vorapaxar use compared with non-T2DM patients. The aim of the present work is to critically review the current knowledge concerning vorapaxar use in patients with T2DM as well as to discuss the possible mechanism(s) underlying vorapaxar's beneficial effect in T2DM.

Evaluation of the antithrombotic abilities of non-vitamin K antagonist oral anticoagulants using the Total Thrombus-formation Analysis System®

The Total Thrombus-formation Analysis System (T-TAS^®) is a novel automated microchip flow-chamber system for the quantitative evaluation of thrombus formation under blood flow conditions. T-TAS^® uses two types of microchip to evaluate thrombus formation: the AR-chip quantifies white thrombus formation and the PL-chip quantifies platelet thrombus formation. We assessed the antithrombotic abilities of various non-vitamin K antagonist oral anticoagulants (NOACs) using T-TAS^®. One hundred and three consecutive patients who were hospitalized with cardiovascular diseases were enrolled. We divided the patients into 2 groups; a control group that did not receive an anticoagulant (non-AC group) and an anticoagulant group (AC group). The AC group was further divided into warfarin, dabigatran, rivaroxaban and apixaban groups. We performed common coagulation tests and evaluated the area under the flow pressure curve (AR-AUC and PL-AUC) to quantify antithrombotic ability using T-TAS^® at the trough. There were no significant differences in patient characteristics between the non-AC and AC groups. Only 55.1 % of patients in the AC group achieved the target blood pressure (BP) of less than 130/80 mmHg. Compared with the non-AC group, AR-AUC was significantly decreased in the AC, warfarin, dabigatran and apixaban groups. Only the rivaroxaban group did not show a significant decrease in AR-AUC. NOACs showed a significant decrease in PL-AUC compared with the non-AC group. In conclusion, T-TAS^® was a useful tool for evaluating anticoagulation activity. NOACs was significantly effective as an antiplatelet agent. BP control should be a higher priority than the selection of an anticoagulant drug, especially NOACs.

Impaired platelet activation and cAMP homeostasis in MRP4-deficient mice

Molecules that reduce the level of cyclic adenosine 5'-monophosphate (cAMP) in the platelet cytosol, such as adenosine 5'-diphosphate (ADP) secreted from dense granules, trigger platelet activation. Therefore, any change in the distribution and/or availability of cyclic nucleotides or ADP may interfere with platelet reactivity. In this study, we evaluated the role of multidrug resistance protein 4 (MRP4, or ABCC4), a nucleotide transporter, in platelet functions in vivo and in vitro by investigating MRP4-deficient mice. MRP4 deletion resulted in a slight increase in platelet count but had no impact on platelet ultrastructure. In MRP4-deficient mice, the arterial occlusion was delayed and the tail bleeding time was prolonged. In a model of platelet depletion and transfusion mimicking a platelet-specific knockout, mice injected with MRP4(-/-) platelets also showed a significant increase in blood loss compared with mice injected with wild-type platelets. Defective thrombus formation and platelet activation were confirmed in vitro by studying platelet adhesion to collagen in flow conditions, integrin αIIbβ3 activation, washed platelet secretion, and aggregation induced by low concentrations of proteinase-activated receptor 4-activating peptide, U46619, or ADP. We found no role of MRP4 in ADP dense-granule storage, but MRP4 redistributed cAMP from the cytosol to dense granules, as confirmed by increased vasodilator-stimulated phosphoprotein phosphorylation in MRP4-deficient platelets. These data suggest that MRP4 promotes platelet aggregation by modulating the cAMP-protein kinase A signaling pathway, suggesting that MRP4 might serve as a target for novel antiplatelet agents.

Current antiplatelet treatment strategy in patients with diabetes mellitus

Patients with diabetes mellitus (DM) have accelerated atherosclerosis with an increased risk for atherothrombotic cardiovascular complications. A state of high platelet reactivity and activation, hypercoagulability (prothrombotic state) and a subdued response to standard antiplatelet agents may explain high rate of adverse cardiovascular events in patients with DM. Several antithrombotic treatment strategies have been developed to control the prothrombotic state in patients with DM: dose modification of commonly used agents; use of potent agents; and addition of a third antithrombotic drug (triple therapy) to commonly prescribed dual antiplatelet therapy of aspirin and a P2Y12 inhibitor. The present review aims to provide an overview of the current knowledge on platelet abnormalities in patients with DM, focusing on the challenges and perspectives of antiplatelet treatment strategies in this population.