Safety and efficacy of P2Y12 inhibitor monotherapy in patients undergoing percutaneous coronary interventions

De-escalation of antiplatelet therapy in patients with coronary artery disease: Time to change our strategy?

Dual antiplatelet therapy (DAPT) is the gold standard after acute coronary syndromes (ACS) or chronic coronary syndromes (CCS) undergoing percutaneous coronary intervention (PCI). Because local and systemic ischemic complications can occur particularly in the early phase (i.e. 1-3 months) after ACS or PCI, the synergistic platelet inhibition of aspirin and a P2Y₁₂ inhibitor is of the utmost importance in this early phase. Moreover, the use of the more potent P2Y₁₂ inhibitors prasugrel and ticagrelor have shown to further reduce the incidence of ischemic events compared to clopidogrel after an ACS. On the other hand, prolonged and potent antiplatelet therapy are inevitably associated with increased bleeding, which unlike thrombotic risk, tends to be stable over time and may outweigh the benefit of reducing ischemic events in these patients. The duration and composition of antiplatelet therapy remains a topic of debate in cardiology due to competing ischemic and bleeding risks, with guidelines and recommendations considerably evolving in the past years. An emerging strategy, called "de-escalation", consisting in the administration of a less intense antithrombotic therapy after a short course of standard DAPT, has shown to reduce bleeding without any trade-off in ischemic events. De-escalation may be achieved with different antithrombotic strategies and can be either unguided or guided by platelet function or genetic testing. The aim of this review is to summarize the evidence and provide practical recommendations on the use of different de-escalation strategies in patients with ACS and CCS.

Impact of coronary stenting on top of medical therapy and of inclusion of periprocedural infarctions on hard composite endpoints in patients with chronic coronary syndromes: a meta-analysis of randomized controlled trials

INTRODUCTION

Composite endpoints are pivotal when assessing rare outcomes over relatively short follow-ups. Most randomized controlled trials (RCTs) comparing percutaneous coronary intervention (PCI) with stent implantation to optimal medical therapy (OMT) in chronic coronary syndromes (CCS) patients included both hard and soft outcomes in their primary endpoint, with periprocedural myocardial infarctions (MIs) systematically allocated to the PCI arm. We meta-analyzed the above RCTs for composite hard endpoints, with and without periprocedural MIs.

EVIDENCE ACQUISITION

This study is registered in PROSPERO CRD42020166754 and follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane Collaboration reporting. Patients had inducible ischemia, no left main disease nor severe left ventricular dysfunction.

EVIDENCE SYNTHESIS

Six RCTs involving 10,751 patients followed for a mean of 4.4 years were included. PCI+OMT versus OMT alone was associated with no difference in the two co-primary composite endpoints of all-cause death/MI/stroke and cardiovascular death/MI including all-MIs (IRR 0.99; 95% CI 0.90-1.08 and IRR 0.95; 95% CI 0.83-1.08 respectively). After inclusion of spontaneous rather than all-MIs (i.e., excluding periprocedural MIs), the odds showed benefit of PCI+OMT for both co-primary endpoints (IRR 0.88; 95% CI 0.80-0.97, P<0.01 and IRR 0.81; 95% CI 0.69-0.95, P=0.01 respectively) with numbers needed to treat of 42 in both cases.

CONCLUSIONS

Among CCS patients with inducible myocardial ischemia without severely reduced ejection fraction or left main disease, adding PCI to OMT reduces hard composite outcomes only after exclusion of periprocedural MIs. Continued efforts to define periprocedural MIs reproducibly, to assess their prognostic relevance and to prevent them are warranted.

Antithrombotic Treatment in Coronary Artery Disease

Coronary artery disease exhibits growing mortality and morbidity worldwide despite the advances in pharmacotherapy and coronary intervention. Coronary artery disease is classified in the acute coronary syndromes and chronic coronary syndromes according to the most recent guidelines of the European Society of Cardiology. Antithrombotic treatment is the cornerstone of therapy in coronary artery disease due to the involvement of atherothrombosis in the pathophysiology of the disease. Administration of antiplatelet agents, anticoagulants and fibrinolytics reduce ischemic risk, which is amplified early post-acute coronary syndromes or post percutaneous coronary intervention; though, antithrombotic treatment increases the risk for bleeding. The balance between ischemic and bleeding risk is difficult to achieve and is affected by patient characteristics, procedural parameters, concomitant medications and pharmacologic characteristics of the antithrombotic agents. Several pharmacological strategies have been evaluated in patients with coronary artery disease, such as the effectiveness and safety of antithrombotic agents, optimal dual antiplatelet treatment schemes and duration, aspirin de-escalation strategies of dual antiplatelet regimens, dual inhibition pathway strategies as well as triple antithrombotic therapy. Future studies are needed in order to investigate the gaps in our knowledge, including special populations.

Gender-differences in antithrombotic therapy across the spectrum of ischemic heart disease: Time to tackle the Yentl syndrome?

The incidence and clinical presentation of ischemic heart disease (IHD), as well as thrombotic and bleeding risks, appear to differ between genders. Compared with men, women feature an increased thrombotic risk, probably related to an increased platelet reactivity, higher level of coagulation factors, and sex-associated unique cardiovascular risk factors, such as pregnancy-related (i.e., pre-eclampsia and gestational diabetes), gynecological disorders (i.e., polycystic ovary syndrome, early menopause) and autoimmune or systemic inflammatory diseases. At the same time, women are also at increased risk of bleeding, due to inappropriate dosing of antithrombotic agents, smaller blood vessels, lower body weight and comorbidities, such as diabetes and chronic kidney disease. Pharmacological strategies focused on the personalization of antithrombotic treatment may, therefore, be particularly appealing in women in light of their higher bleeding and ischemic risks. Paradoxically, although women represent a large proportion of cardiovascular patients in our practice, adequate high-quality clinical trial data on women remain scarce and inadequate to guide decision-making processes. As a result, IHD in women tends to be understudied, underdiagnosed and undertreated, a phenomenon known as a "Yentl syndrome." It is, therefore, compelling for the scientific community to embark on dedicated clinical trials to address underrepresentation of women and to acquire evidence-based knowledge in the personalization of antithrombotic therapy in women.

P2Y12 Inhibitor Monotherapy after Percutaneous Coronary Intervention

In patients with acute and chronic coronary artery disease undergoing percutaneous coronary intervention (PCI), dual antiplatelet therapy (DAPT) has been the cornerstone of pharmacotherapy for the past two decades. Although its antithrombotic benefit is well established, DAPT is associated with an increased risk of bleeding, which is independently associated with poor prognosis. The improvement of the safety profiles of drug-eluting stents has been critical in investigating and implementing shorter DAPT regimens. The introduction into clinical practice of newer generation oral P2Y₁₂ inhibitors such as prasugrel and ticagrelor, which provide more potent and predictable platelet inhibition, has questioned the paradigm of standard DAPT durations after coronary stenting. Over the last five years, several trials have assessed the safety and efficacy of P2Y₁₂ inhibitor monotherapy after a short course of DAPT in patients treated with PCI. Moreover, ongoing studies are testing the role of P2Y₁₂ inhibitor monotherapy immediately after PCI in selected patients. In this review, we provide up-to-date evidence on the efficacy and safety of P2Y₁₂ inhibitor monotherapy after a short period of DAPT compared to DAPT in patients undergoing PCI as well as outcomes associated with P2Y₁₂ inhibitor monotherapy compared to aspirin for long-term prevention.

De-escalation of antiplatelet therapy in acute coronary syndromes: Why, how and when?

The synergistic blockade of the key platelet signaling pathways of cyclooxygenase-1 blockade and P2Y12 signaling by combining aspirin plus a potent P2Y12 inhibitor (prasugrel or ticagrelor), the so called dual antiplatelet treatment (DAPT), has represented the antithrombotic regimen of choice in patients with acute coronary syndrome (ACS) for nearly a decade. Nevertheless, the use of such antiplatelet treatment regimen, while reduced the risk of thrombotic complications, it is inevitably associated with increased bleeding and this risk may outweigh the benefit of a reduction of ischemic events in specific subgroup of patients. In light of the adverse prognostic implications of a bleeding complication, there has been a great interest in the development of antiplatelet regimens aimed at reducing bleeding without any trade-off in ischemic events. The fact that the ischemic risk is highest in the early phase after an ACS while the risk of bleeding remains relatively stable over time has represented the rationale for the implementation of a more intense antithrombotic regimen early after an ACS, followed by a less intense antithrombotic regimen thereafter. This practice, known as a "de-escalation" strategy, represents one of the more promising approaches for personalization of antithrombotic therapy in ACS. In this review we discuss the rationale, appraise the evidence and provide practical recommendations on the use of a de-escalation strategy of antiplatelet therapy in patients with an ACS.

Precision medicine in interventional cardiology: implications for antiplatelet therapy in patients undergoing percutaneous coronary intervention

Precision medicine is a medical model that proposes the customization of medical treatments to the individual patient, as opposed to a one-drug-fits-all model. Such a "personalized medicine" approach has been widely adopted in several medical fields, such as cancer medicine, but the implementation of precision medicine in cardiovascular medicine has not been similarly straightforward. Because pharmacogenomics plays an important role in the safety and efficacy of cardiovascular drug therapy, there has been a great interest in the use of tools aiming at personalizing antiplatelet therapy. Moreover, antiplatelet therapy is essential for the treatment of cardiovascular patients to reduce the risk of thrombotic complications, particularly those undergoing percutaneous coronary intervention, but it is inevitably associated with increased bleeding risk. In this review, the authors discuss the rationale, summarize the evidence and discuss the current and future directions for the personalization of antiplatelet treatment regimens in patients undergoing percutaneous coronary intervention.

Antiplatelet therapy after percutaneous coronary intervention

Antiplatelet therapy is key to reducing local thrombotic complications and systemic ischaemic events among patients undergoing percutaneous coronary interventions (PCI), but it is inevitably associated with increased bleeding. The continuous refinement in stent technologies, together with the high incidence of ischaemic recurrences after PCI and the understanding of prognostic implications associated with bleeding, have led to a substantial evolution in antiplatelet treatment regimens over the past decades. Numerous investigations have been conducted to better stratify patients undergoing PCI according to their ischaemic and bleeding risks and to implement antithrombotic regimens accordingly. Evidence from these investigations have resulted in a number of antithrombotic treatment options as recommended by recent guidelines. In this State-of-the-Art review we provide the rationale, summarise the evidence, and discuss current and future directions of antiplatelet treatment regimens after PCI.

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

AIM

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

METHODS AND RESULTS

This investigation was a sub-study analysis conducted in selected cohorts of patients with stable atherosclerotic disease enrolled from a larger prospective, open-label, parallel-group pharmacodynamics (PD) study. We analyzed data from 40 patients treated with either clopidogrel or ticagrelor-based DAPT first, and clopidogrel or ticagrelor-based DPI thereafter. PD measures explored key pathways involved in thrombus formation and included markers of: 1) P2Y12 reactivity, 2) platelet-mediated global thrombogenicity, 3) cyclooxygenase-1 activity, 3) TRAP-induced platelet aggregation; 4) tissue factor (TF)-induced platelet aggregation, and 5) thrombin generation. As compared to DAPT, on a background of the same P2Y12 inhibitor (clopidogrel or ticagrelor), DPI was associated with reduced thrombin generation, increased markers of cyclooxygenase-1 activity and TRAP-induced platelet aggregation and no differences in markers of P2Y12 signaling, platelet-mediated global thrombogenicity and TF-induced platelet aggregation. In an analysis according to P2Y12 inhibitor type, ticagrelor reduced markers of platelet-mediated global thrombogenicity, P2Y12 signaling and rates of high platelet reactivity compared to clopidogrel.

CONCLUSIONS

Compared to DAPT with aspirin and a P2Y12 inhibitor, the use of a P2Y12 inhibitor in adjunct to a vascular dose of rivaroxaban as part of a DPI strategy is associated with similar effects on platelet-mediated global thrombogenicity but reduced thrombin generation. A DPI strategy with ticagrelor is associated with enhanced antithrombotic efficacy, the clinical implications of which warrant larger scale investigations.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03718429.

Pharmacodynamic profiles of dual-pathway inhibition with or without clopidogrel vs dual antiplatelet therapy in patients with atherosclerotic disease

AIM

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

METHODS AND RESULTS

This investigation was conducted in selected cohorts of patients (n=40) with stable atherosclerotic disease enrolled within a larger prospective PD study who were treated with either aspirin plus clopidogrel (DAPT), aspirin plus rivaroxaban 2.5 mg/bid (DPI) or DAPT plus rivaroxaban 2.5 mg/bid. Multiple PD assays assessing of markers of thrombosis were used. PD endpoints included platelet-mediated global thrombogenicity measured by light transmittance aggregometry (LTA) following stimuli with CATF [collagen-related peptide +adenosine diphosphate (ADP) +tissue factor (TF)], markers of P2Y12 reactivity, markers of platelet aggregation using LTA following several stimuli (arachidonic acid, ADP, collagen, TF, and TRAP), thrombin generation and thrombus formation. There was no difference in platelet-mediated global thrombogenicity between groups. Rivaroxaban significantly reduced thrombin generation and was associated with a trend towards reduced TF-induced platelet aggregation. Clopidogrel-based treatments reduced markers of P2Y12 signaling and TRAP-induced platelet aggregation. There were no differences between groups on markers of cyclooxygenase-1 mediated activity.

CONCLUSIONS

Compared with DAPT, DPI does not result in any differences in platelet-mediated global thrombogenicity, but reduces thrombin generation. These PD observations support that modulating thrombin generation by means of factor Xa inhibition in adjunct to antiplatelet therapy provides effective antithrombotic effects, supporting the efficacy and safety findings of DPI observed in clinical.

Role of platelet function and genetic testing in patients undergoing percutaneous coronary intervention

Dual antiplatelet therapy (DAPT) represents the standard of care for patients undergoing percutaneous coronary intervention (PCI). Increasing evidence indicates that a "one-size-fits-all" approach with the use of a standard DAPT regimen for all patients undergoing PCI could lead to either suboptimal efficacy or prohibitively high bleeding in specific cohorts of patients. Moreover, the broad interindividual variability in response to P2Y₁₂ inhibitors can impact outcomes and resource utilization. Among the strategies proposed to provide a more balanced trade-off between bleeding and ischemic events at a single patient level, a guided selection of P2Y₁₂ inhibitors, by using platelet function or genetic testing, has shown promising results. In this review, we provide a focused summary of the rationale and evidence on the use of platelet function and genetic testing-guided antiplatelet therapy, and we explore the implications for their use in the modern setting of patients undergoing PCI.

Comparative effects of guided vs. potent P2Y12 inhibitor therapy in acute coronary syndrome: a network meta-analysis of 61 898 patients from 15 randomized trials

AIMS

Guidelines recommend the use of potent P2Y12 inhibitors over clopidogrel for the reduction of ischaemic events in patients with acute coronary syndrome (ACS). However, this comes at the expense of increased bleeding. A guided selection of P2Y12 inhibiting therapy has the potential to overcome this limitation. We aimed at evaluating the comparative safety and efficacy of guided vs. routine selection of potent P2Y12 inhibiting therapy in patients with ACS.

METHODS AND RESULTS

We performed a network meta-analysis of randomized controlled trials (RCTs) comparing different oral P2Y12 inhibitors currently recommended for the treatment of patients with ACS (clopidogrel, prasugrel, and ticagrelor). RCTs including a guided approach (i.e. platelet function or genetic testing) vs. standard selection of P2Y12 inhibitors among patients with ACS were also included. Incidence rate ratios (IRR) and associated 95% confidence intervals (CIs) were estimated. P-scores were used to estimate hierarchies of efficacy and safety. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the primary safety endpoint was all bleeding. A total of 61 898 patients from 15 RCTs were included. Clopidogrel was used as reference treatment. A guided approach was the only strategy associated with reduced MACE (IRR: 0.80, 95% CI: 0.65-0.98) without any significant trade-off in all bleeding (IRR: 1.22, 95% CI: 0.96-1.55). A guided approach and prasugrel were associated with reduced myocardial infarction. A guided approach, prasugrel, and ticagrelor were associated with reduced stent thrombosis. Ticagrelor was also associated with reduced total and cardiovascular mortality. Prasugrel was associated with increased major bleeding. Prasugrel and ticagrelor were associated with increased minor bleeding. The incidence of stroke did not differ between treatments.

CONCLUSION

In patients with an ACS, compared with routine selection of potent P2Y12 inhibiting therapy (prasugrel or ticagrelor), a guided selection of P2Y12 inhibiting therapy is associated with the most favourable balance between safety and efficacy. These findings support a broader adoption of guided approach for the selection of P2Y12 inhibiting therapy in patients with ACS.

STUDY REGISTRATION NUMBER

This study is registered in PROSPERO (CRD42021258603).

KEY QUESTION

A guided selection of P2Y12 inhibiting therapy using platelet function or genetic testing improves outcomes among patients undergoing percutaneous coronary intervention. Nevertheless, the comparative safety and efficacy of a guided versus routine selection of potent P2Y12-inhibiting therapy in acute coronary syndrome has not been explored.

KEY FINDING

In a comprehensive network meta-analysis including the totality of available evidence and using clopidogrel as treatment reference, a guided approach was the only strategy associated with reduced major adverse cardiovascular events without any significant trade-off in bleeding. Prasugrel and ticagrelor increased bleeding and only ticagrelor reduced mortality.

TAKE HOME MESSAGE

A guided selection of P2Y12-inhibiting therapy represents the strategy associated with the most favourable balance between safety and efficacy. These findings support a broader adoption of guided P2Y12 inhibiting therapy in patients with acute coronary syndrome.

Antiplatelet therapy in percutaneous coronary intervention: latest evidence from randomized controlled trials

PURPOSE OF REVIEW

Antiplatelet therapy is key to reduce systemic and local thrombotic events among patients undergoing percutaneous coronary interventions (PCI). Antiplatelet treatment regimens have been subject to continuous changes over the years, with a dual antiplatelet therapy (DAPT), consisting of aspirin and a P2Y12 inhibitor representing the cornerstone of treatment in these patients.

RECENT FINDINGS

The need for less aggressive antithrombotic drugs to prevent local ischemic events with newer generation drug-eluting stent together with the increased understanding of the prognostic relevance of bleeding events in PCI patients, have prompted investigations aimed at identifying antiplatelet treatment regimens associated with a more favorable balance between ischemic and bleeding risks. Several key randomized controlled trials (RCTs) on antiplatelet regimens in patients undergoing PCI have been recently reported resulting in updates in practice guidelines.

SUMMARY

This manuscript provides an overview of the advancements in the field deriving from key RCTs on antiplatelet regimens in patients undergoing PCI.

Efficacy and safety of dual pathway inhibition in patients with cardiovascular disease: a systematic review and Meta-analysis

BACKGROUND

Low-dose direct oral anticoagulants (DOACs) in adjunct to antiplatelet therapy, known as dual pathway inhibition (DPI), have been tested to prevent ischaemic events in patients with cardiovascular disease (CVD). We conducted a systematic review and meta-analysis to determine the overall safety and efficacy of low-dose DOACs vs. placebo on a background of antiplatelet therapy.

METHODS

All randomized controlled trials (RCTs) comparing low-dose DOAC (defined as a dosage below the lowest approved for stroke prevention) vs. placebo among patients with CVD receiving single or dual antiplatelet therapy in at least 50% of the population and followed for at least 6 months, were included. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were used to overcome different follow-up durations across trials. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the primary safety endpoint major bleeding. A pre-specified subgroup analysis was performed for different DOAC-dose regimens.

RESULTS

A total of 55,782 patients from 7 RCTs were included. Low-dose DOACs vs placebo were associated with significant reductions in MACE (IRR 0.85, 95% CI 0.78-0.91) and myocardial infarction (IRR 0.86, 95% CI 0.78-0.95) and significant increases of major (IRR 2.05, 95% CI 1.50-2.80) or all bleeding (IRR 1.82, 95% CI 1.49-2.22). CV death (IRR 0.90, 95% CI 0.79-1.03), intracranial (IRR 1.18, 95% CI 0.71-1.96) and fatal bleeding (IRR 1.13, 95% CI 0.76-1.69) did not differ significantly between strategies. Non-significant reductions of all-cause death (IRR 0.90, 95% CI 0.80-1.01) and stroke (IRR 0.73, 95% CI 0.53-1.01) favoured low-dose DOACs. Meta-regression analyses showed a significant interaction between percentage of DAPT use and increased risk of major bleeding (p = 0.04), intracranial Haemorrhage (p = 0.035) and stroke (p = 0.0003). Subgroup analysis of very low-dose DOAC, defined as ≤ 1/3 of the lowest approved dose for stroke prevention (i.e., rivaroxaban 2.5 mg twice daily) seems to mitigate the risk of bleeding without any trade-off in efficacy compared to other low-dose DOAC regimens.

CONCLUSIONS

In patients with CVD, a low-dose DOAC regimen vs. placebo, on a background of antiplatelet therapy, is effective in reducing ischaemic events at the expense of increased major and all bleeding, but without significantly increasing intracranial or fatal bleeds, while the reduction of cardiovascular and total mortality is not statistically significant. A DPI with very low-dose DOAC (i.e. rivaroxaban 2.5 mg twice daily) appears particularly advantageous, especially when combined with a single antiplatelet agent and used among patients at high ischaemic and low bleeding risk.

STUDY REGISTRATION

This study is registered in PROSPERO (CRD42021232744).