P2Y(12) inhibitor monotherapy in patients undergoing percutaneous coronary intervention

Low-dose aspirin for the prevention of atherosclerotic cardiovascular disease

During the past 30 years, several developments have occurred in the antiplatelet field, including the role of aspirin in primary prevention of atherosclerotic cardiovascular disease. There have been several attempts to develop antiplatelet drugs more effective and safer than aspirin and a shift in emphasis from efficacy to safety, advocating aspirin-free antiplatelet regimens after percutaneous coronary intervention. Evidence supporting a chemopreventive effect of low-dose aspirin against colorectal (and other digestive tract) cancer has also strengthened. The aim of this article is to revisit the role of aspirin in the prevention of atherothrombosis across the cardiovascular risk continuum, in view of developments in the antiplatelet field. The review will offer a clinical perspective on aspirin's mechanism of action, pharmacokinetics, and pharmacodynamics. This will be followed by a detailed discussion of its clinical efficacy and safety.

Nanodrugs based on co-delivery strategies to combat cisplatin resistance

Cisplatin (CDDP), as a broad-spectrum anticancer drug, is able to bind to DNA and inhibit cell division. Despite the widespread use of cisplatin since its discovery, cisplatin resistance developed during prolonged chemotherapy, similar to other small molecule chemotherapeutic agents, severely limits its clinical application. Cisplatin resistance in cancer cells is mainly caused by three reasons: DNA repair, decreased cisplatin uptake/increased efflux, and cisplatin inactivation. In earlier combination therapies, the emergence of multidrug resistance (MDR) in cancer cells prevented the achievement of the desired therapeutic effect even with the accurate combination of two chemotherapeutic drugs. Therefore, combination therapy using nanocarriers for co-delivery of drugs is considered to be ideal for alleviating cisplatin resistance and reducing cisplatin-related toxicity in cancer cells. This article provides an overview of the design of cisplatin nano-drugs used to combat cancer cell resistance, elucidates the mechanisms of action of cisplatin and the pathways through which cancer cells develop resistance, and finally discusses the design of drugs and related carriers that can synergistically reduce cancer resistance when combined with cisplatin.

Extended Clopidogrel Monotherapy vs DAPT in Patients With Acute Coronary Syndromes at High Ischemic and Bleeding Risk: The OPT-BIRISK Randomized Clinical Trial

Importance

Purinergic receptor P2Y12 (P2Y12) inhibitor monotherapy after a certain period of dual antiplatelet therapy (DAPT) may be an attractive option of maintenance antiplatelet treatment for patients undergoing percutaneous coronary intervention (PCI) who are at both high bleeding and ischemic risk (birisk).

Objective

To determine if extended P2Y12 inhibitor monotherapy with clopidogrel is superior to ongoing DAPT with aspirin and clopidogrel after 9 to 12 months of DAPT after PCI in birisk patients with acute coronary syndromes (ACS).

Design, Setting, and Participants

This was a multicenter, double-blind, placebo-controlled, randomized clinical trial including birisk patients with ACS who had completed 9 to 12 months of DAPT after drug-eluting stent implantation and were free from adverse events for at least 6 months at 101 China centers between February 2018 and December 2020. Study data were analyzed from April 2023 to May 2023.

Interventions

Patients were randomized either to clopidogrel plus placebo or clopidogrel plus aspirin for an additional 9 months.

Main Outcomes and Measures

The primary end point was Bleeding Academic Research Consortium (BARC) types 2, 3, or 5 bleeding 9 months after randomization. The key secondary end point was major adverse cardiac and cerebral events (MACCE; the composite of all-cause death, myocardial infarction, stroke or clinically driven revascularization). The primary end point was tested for superiority, and the MACCE end point was tested for sequential noninferiority and superiority.

Results

A total of 7758 patients (mean [SD] age, 64.8 [9.0] years; 4575 male [59.0%]) were included in this study. The primary end point of BARC types 2, 3, or 5 bleeding occurred in 95 of 3873 patients (2.5%) assigned to clopidogrel plus placebo and 127 of 3885 patients (3.3%) assigned to clopidogrel plus aspirin (hazard ratio [HR], 0.75; 95% CI, 0.57-0.97; difference, -0.8%; 95% CI, -1.6% to -0.1%; P = .03). The incidence of MACCE was 2.6% (101 of 3873 patients) in the clopidogrel plus placebo group and 3.5% (136 of 3885 patients) in the clopidogrel plus aspirin group (HR, 0.74; 95% CI, 0.57-0.96; difference, -0.9%; 95% CI, -1.7% to -0.1%; P < .001 for noninferiority; P = .02 for superiority).

Conclusions and Relevance

Among birisk patients with ACS who completed 9 to 12 months of DAPT after drug-eluting stent implantation and were free from adverse events for at least 6 months before randomization, an extended 9-month clopidogrel monotherapy regimen was superior to continuing DAPT with clopidogrel in reducing clinically relevant bleeding without increasing ischemic events.

Trial Registration

ClinicalTrials.gov Identifier: NCT03431142.

Ticagrelor with or without aspirin following percutaneous coronary intervention in high-risk patients with concomitant peripheral artery disease: A subgroup analysis of the TWILIGHT randomized clinical trial

BACKGROUND

The optimal antiplatelet regimen after percutaneous coronary intervention (PCI) in patients with peripheral artery disease (PAD) is still debated. This analysis aimed to compare the effect of ticagrelor monotherapy versus ticagrelor plus aspirin in patients with PAD undergoing PCI.

METHODS

In the TWILIGHT trial, patients at high ischemic or bleeding risk that underwent PCI were randomized after 3 months of dual antiplatelet therapy (DAPT) to aspirin or matching placebo in addition to open-label ticagrelor for 12 additional months. In this post-hoc analysis, patient cohorts were examined according to the presence or absence of PAD. The primary endpoint was Bleeding Academic Research Consortium (BARC) 2, 3, or 5 bleeding. The key secondary endpoint was a composite of all-cause death, myocardial infarction (MI), or stroke. Endpoints were assessed at 12 months after randomization.

RESULTS

Among 7,119 patients, 489 (7%) had PAD and were older, more likely to have comorbidities, and multivessel disease. PAD patients had more bleeding or ischemic complications than no-PAD patients. Ticagrelor monotherapy compared to ticagrelor plus aspirin was associated with less BARC 2, 3, or 5 bleeding in PAD (4.6% vs 8.7%; HR 0.52; 95%CI 0.25-1.07) and no-PAD patients (4.0% vs 7.0%; HR 0.56; 95%CI 0.45-0.69; interaction P-value .830) and a similar risk of death, MI, or stroke in these 2 groups (interaction P-value .446).

CONCLUSIONS

Despite their higher ischemic and bleeding risk, patients with PAD undergoing PCI derived a consistent benefit from ticagrelor monotherapy after 3 months of DAPT in terms of bleeding reduction without any relevant increase in ischemic events. CLINICAL TRIAL REGISTRY INFORMATION:: https://www.

CLINICALTRIALS

gov/study/NCT02270242.

One- versus three-month dual antiplatelet therapy in high bleeding risk patients undergoing percutaneous coronary intervention for non-ST-segment elevation acute coronary syndromes

BACKGROUND

A short dual antiplatelet therapy (DAPT) duration has been proposed for patients at high bleeding risk (HBR) undergoing drug-eluting coronary stent (DES) implantation. Whether this strategy is safe and effective after a non-ST-segment elevation acute coronary syndrome (NSTE-ACS) remains uncertain.

AIMS

We aimed to compare the impact of 1-month versus 3-month DAPT on clinical outcomes after DES implantation among HBR patients with or without NSTE-ACS.

METHODS

This is a prespecified analysis from the XIENCE Short DAPT programme involving three prospective, international, single-arm studies evaluating the safety and efficacy of 1-month (XIENCE 28 USA and Global) or 3-month (XIENCE 90) DAPT among HBR patients after implantation of a cobalt-chromium everolimus-eluting stent. Ischaemic and bleeding outcomes associated with 1- versus 3-month DAPT were assessed according to clinical presentation using propensity score stratification.

RESULTS

Of 3,364 HBR patients (1,392 on 1-month DAPT and 1,972 on 3-month DAPT), 1,164 (34.6%) underwent DES implantation for NSTE-ACS. At 12 months, the risk of the primary endpoint of death or myocardial infarction was similar between 1- and 3-month DAPT in patients with (hazard ratio [HR] 1.09, 95% confidence interval [CI]: 0.71-1.65) and without NSTE-ACS (HR 0.88, 95% CI: 0.63-1.23; p-interaction=0.34). The key secondary endpoint of Bleeding Academic Research Consortium (BARC) Type 2-5 bleeding was consistently reduced in both NSTE-ACS (HR 0.57, 95% CI: 0.37-0.88) and stable patients (HR 0.84, 95% CI: 0.61-1.15; p-interaction=0.15) with 1-month DAPT.

CONCLUSIONS

Among HBR patients undergoing implantation of an everolimus-eluting stent, 1-month, compared to 3-month DAPT, was associated with similar ischaemic risk and reduced bleeding at 1 year, irrespective of clinical presentation.

Inflammation and platelet reactivity during adjunctive colchicine versus aspirin in patients with acute coronary syndrome treated with potent P2Y12 inhibitor

Background

In patients undergoing percutaneous coronary intervention (PCI), the use of anti-inflammatory therapy with colchicine is associated with a reduction of recurrent ischemic events. The mechanisms of such findings are not fully elucidated.

Objectives

To investigate the effects of colchicine versus aspirin on inflammation and platelet reactivity in patients with acute coronary syndrome (ACS) undergoing PCI.

Methods

This observational study compared laboratory measurements in ACS patients receiving single antiplatelet therapy with ticagrelor or prasugrel plus colchicine (MACT) (n = 185) versus conventional dual-antiplatelet therapy (DAPT) with aspirin plus ticagrelor or prasugrel (n = 497). The primary outcome was the frequency of high residual inflammation, defined as high-sensitivity C-reactive protein (hs-CRP) ≥2 mg/L at 1 month post-PCI. Multiple sensitivity analyses were performed for the primary outcome, including multivariable adjustment, propensity-score matching, and inverse-probability weighted methods.

Results

One month after PCI, patients treated with MACT had significantly lower levels of hs-CRP compared to those treated with DAPT (0.6 [0.4-1.2] vs. 0.9 [0.6-2.3] mg/L, p < 0.001). The frequency of high residual inflammation was also lower in the MACT group (10.8% vs. 27.2%, p < 0.001) (odds ratio [95% confidence interval] = 0.33 [0.20-0.54], p < 0.001). This effect was consistent across sensitivity analyses. There was no difference in platelet reactivity between MACT and DAPT (49.6 ± 49.0 vs. 51.5 ± 66.4 P2Y12 reaction unit [PRU] measured by VerifyNow, p = 0.776).

Conclusion

In ACS patients undergoing PCI, MACT was associated with a lower rate of high residual inflammation without increasing platelet reactivity compared to conventional DAPT.

Clinical trial registration

NCT04949516 for MACT pilot trial and NCT04650529 for Gyeongsang National University Hospital registry.

Antiplatelet De-Escalation Strategies in Patients Undergoing Percutaneous Coronary Intervention

Dual antiplatelet therapy-the combination of aspirin and a P2Y12 inhibitor-remains the standard antiplatelet regimen recommended to prevent ischemic complications immediately after percutaneous coronary intervention. Nonetheless, recent advances in stent technologies, percutaneous coronary intervention techniques, adjunctive pharmacotherapy for secondary prevention, and the rising awareness of the prognostic impact of bleeding, which are inevitably associated with dual antiplatelet therapy, led to the investigation of alternative antiplatelet regimens related to fewer bleeding and a preserved ischemic protection. Thrombotic complications occur mostly in the first months after percutaneous coronary intervention, while the risk of bleeding remains stable over time; this observation laid the foundation of the concept of antiplatelet de-escalation, consisting of a more intense antiplatelet regimen early after percutaneous coronary intervention, followed by a less potent antiplatelet therapy thereafter. According to new definitions proposed by the Academic Research Consortium, de-escalation can be achieved by discontinuation of 1 antiplatelet agent, switching from a potent P2Y12 inhibitor to clopidogrel, or by reducing the dose of antiplatelet agents. This review discusses the rationale and the evidence supporting antiplatelet de-escalation, provides practical guidance to use these new regimens, and gives insights into future developments in the field.

Comprehensive insights into potential roles of purinergic P2 receptors on diseases: Signaling pathways involved and potential therapeutics

BACKGROUND

Purinergic P2 receptors, which can be divided into ionotropic P2X receptors and metabotropic P2Y receptors, mediate cellular signal transduction of purine or pyrimidine nucleoside triphosphates and diphosphate. Based on the wide expression of purinergic P2 receptors in tissues and organs, their significance in homeostatic maintenance, metabolism, nociceptive transmission, and other physiological processes is becoming increasingly evident, suggesting that targeting purinergic P2 receptors to regulate biological functions and signal transmission holds significant promise for disease treatment.

AIM OF REVIEW

This review highlights the detailed mechanisms by which purinergic P2 receptors engage in physiological and pathological progress, as well as providing prospective strategies for discovering clinical drug candidates.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The purinergic P2 receptors regulate complex signaling and molecular mechanisms in nervous system, digestive system, immune system and as a result, controlling physical health states and disease progression. There has been a significant rise in research and development focused on purinergic P2 receptors, contributing to an increased number of drug candidates in clinical trials. A few influential pioneers have laid the foundation for advancements in the evaluation, development, and of novel purinergic P2 receptors modulators, including agonists, antagonists, pharmaceutical compositions and combination strategies, despite the different scaffolds of these drug candidates. These advancements hold great potential for improving therapeutic outcomes by specifically targeting purinergic P2 receptors.

P2Y12 Inhibitor Monotherapy vs Dual Antiplatelet Therapy After Deployment of a Drug-Eluting Stent: The SHARE Randomized Clinical Trial

Importance

P2Y12 inhibitor monotherapy after dual antiplatelet therapy (DAPT; a P2Y12 inhibitor plus aspirin) for a brief duration has recently emerged as an attractive alternative for patients undergoing percutaneous coronary intervention (PCI) with a drug-eluting stent.

Objective

To investigate whether P2Y12 inhibitor monotherapy after 3 months of DAPT was noninferior to 12 months of DAPT following PCI with a drug-eluting stent.

Design, Setting, and Participants

The Short-Term Dual Antiplatelet Therapy After Deployment of Bioabsorbable Polymer Everolimus-Eluting Stent (SHARE) open-label, noninferiority randomized clinical trial was conducted from December 15, 2017, through December 14, 2020. Final 1-year clinical follow-up was completed in January 2022. This study was a multicenter trial that was conducted at 20 hospitals in South Korea. Patients who underwent successful PCI with bioabsorbable polymer everolimus-eluting stents were enrolled.

Interventions

Patients were randomly assigned to receive P2Y12 inhibitor monotherapy after 3 months of DAPT (n = 694) or 12 months of DAPT (n = 693).

Main Outcomes and Measures

The primary outcome was a net adverse clinical event, a composite of major bleeding (based on Bleeding Academic Research Consortium type 3 or type 5 bleeding) and major adverse cardiac and cerebrovascular events (cardiac death, myocardial infarction, stent thrombosis, stroke, or ischemia-driven target lesion revascularization) between 3 and 12 months after the index PCI. The major secondary outcomes were major adverse cardiac and cerebrovascular events and major bleeding. The noninferiority margin was 3.0%.

Results

Of the total 1452 eligible patients, 65 patients were excluded before the 3-month follow-up, and 1387 patients (mean [SD] age, 63.0 [10.7] years; 1055 men [76.1%]) were assigned to P2Y12 inhibitor monotherapy (n = 694) or DAPT (n = 693). Between 3 and 12 months of follow-up, the primary outcome (using Kaplan-Meier estimates) occurred in 9 patients (1.7%) in the P2Y12 inhibitor monotherapy group and in 16 patients (2.6%) in the DAPT group (absolute difference, -0.93 [1-sided 95% CI, -2.64 to 0.77] percentage points; P < .001 for noninferiority). For the major secondary outcomes (using Kaplan-Meier estimates), major adverse cardiac and cerebrovascular events occurred in 8 patients (1.5%) in the P2Y12 inhibitor monotherapy group and in 12 patients (2.0%) in the DAPT group (absolute difference, -0.49 [95% CI, -2.07 to 1.09] percentage points; P = .54). Major bleeding occurred in 1 patient (0.2%) in the P2Y12 inhibitor monotherapy group and in 5 patients (0.8%) in the DAPT group (absolute difference, -0.60 [95% CI, -1.33 to 0.12] percentage points; P = .10).

Conclusions and Relevance

In patients with coronary artery disease undergoing PCI with the latest generation of drug-eluting stents, P2Y12 inhibitor monotherapy after 3-month DAPT was not inferior to 12-month DAPT for net adverse clinical events. Considering the study population and lower-than-expected event rates, further research is required in other populations.

Trial Registration

ClinicalTrials.gov Identifier: NCT03447379.

Optimal anti-platelet therapy for older patients with acute coronary syndrome: a network meta-analysis of randomized trials comprising 59,284 older patients

The aim of this study was to identify the optimal anti-platelet therapy in older acute coronary syndrome (ACS) patients with a mean age ≥ 60 years by comparing the efficacy and safety of different anti-platelet therapies. The selection of antiplatelet therapy in older patients with ACS is a clinical challenge. Numerous evidences indicate that the de-escalation of dual anti-platelet therapy (DAPT) or P2Y12 inhibitor monotherapy may reduce bleeding risk without increasing thrombotic events. However, there is a lack of systematic reviews and optimal strategy analysis regarding older ACS patients. Randomized controlled trials (RCTs) of anti-platelet therapy in older ACS patients were identified. Major adverse cardiovascular events (MACE) were the primary outcome. Secondary outcomes included all death, cardiovascular death, myocardial infarction, stroke, stent thrombosis, and trial-defined major bleeding. Frequentist and Bayesian network meta-analyses were conducted. Treatments were ranked on posterior probability. Summary odds ratios (ORs) were estimated using Bayesian network meta-analysis. A total of 12 RCTs including 59,284 older ACS patients treated with five anti-platelet strategies were included. Ticagrelor monotherapy after 3 months DAPT was comparable to the other strategies (OR 0.73; 95% CI 0.32-1.6) in terms of MACE risk. Additionally, P score analysis and SUCRA Bayesian analysis showed that it was the most beneficial treatment for all deaths, cardiovascular death and revascularization. For safety, although there was no significant difference in direct comparisons, both SUCRA Bayesian (0.806) and P score (0.519) analysis suggested that ticagrelor monotherapy was the safest strategy. The current evidence demonstrated that ticagrelor monotherapy after 3 months DAPT may be a promising approach for achieving a more favorable balance between risk and benefit for older ACS patients, with a relatively low bleeding risk and without an increased risk of MACE events. Moreover, it remains the preferred option for clinical outcomes such as all death, CV death and revascularization. Further high-quality and long-term studies are required to validate anti-platelet therapies among older ACS patients.

Antithrombotic Therapy Optimization in Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention

The antithrombotic management of patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) poses numerous challenges. Triple antithrombotic therapy (TAT), which combines dual antiplatelet therapy (DAPT) with oral anticoagulation (OAC), provides anti-ischemic protection but increases the risk of bleeding. Therefore, TAT is generally limited to a short phase (1 week) after PCI, followed by aspirin withdrawal and continuation of 6-12 months of dual antithrombotic therapy (DAT), comprising OAC plus clopidogrel, followed by OAC alone. This pharmacological approach has been shown to mitigate bleeding risk while preserving adequate anti-ischemic efficacy. However, the decision-making process remains complex in elderly patients and those with co-morbidities, significantly influencing ischemic and bleeding risk. In this review, we discuss the available evidence in this area from randomized clinical trials and meta-analyses for post-procedural antithrombotic therapies in patients with non-valvular AF undergoing PCI.

Balancing Benefits and Risks of Oral Antiplatelet Strategies in patients With Coronary Artery Diseases: An Evolving Issue

Identifying the most appropriate antiplatelet therapy for each patient to prevent ischemic events while minimizing the risk of bleeding is an integral part of the short- and long-term management of patients with coronary artery disease (CAD). This review aims to summarize the available evidence on the contemporary use of P2Y12 inhibitors in CAD patients, focusing on strategies aimed at providing adequate ischemic protection while preventing bleeding risk through dual antiplatelet therapy (DAPT) modulation. Randomized trials and observational studies have been reviewed to determine the most appropriate antiplatelet treatment for CAD patients with different risk profiles. Both ischemic and bleeding events have a significant prognostic impact and should be carefully considered in clinical decision-making. Current guidelines recommend the use of third-generation PY2Y12 inhibitors (prasugrel or ticagrelor) over clopidogrel, as a part of DAPT, in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention. Newer P2Y12 inhibitors have a more rapid onset of action and less interindividual variability in platelet inhibition than clopidogrel but are associated with an increased risk of bleeding that may limit their benefit. Importantly, the anti-ischemic benefit of ticagrelor and prasugrel is mainly observed in the first weeks after ACS, whereas clopidogrel seems to provide the best balance between ischemic protection and bleeding as long-term maintenance therapy. These concepts support DAPT modulation after the acute phase, by de-escalating from full-dose to low-dose newer P2Y12 inhibitors, by switching to clopidogrel, or by early withdrawing aspirin to maximize both the efficacy and safety of antiplatelet therapy in patients with CAD.

Comparison of Antiplatelet Monotherapies After Percutaneous Coronary Intervention According to Clinical, Ischemic, and Bleeding Risks

BACKGROUND

Clopidogrel was superior to aspirin monotherapy in secondary prevention after percutaneous coronary intervention (PCI).

OBJECTIVES

The purpose of this study was to evaluate the benefits of clopidogrel across high-risk subgroups METHODS: This was a post hoc analysis of the HOST-EXAM (Harmonizing Optimal Strategy for Treatment of coronary artery diseases-EXtended Antiplatelet Monotherapy) trial that randomly assigned patients who were event free for 6 to 18 months post-PCI on dual antiplatelet therapy (DAPT) to clopidogrel or aspirin monotherapy. Two clinical risk scores were used for risk stratification: the DAPT score and the Thrombolysis In Myocardial Infarction Risk Score for Secondary Prevention (TRS 2°P) (the sum of age ≥75 years, diabetes, hypertension, current smoking, peripheral artery disease, stroke, coronary artery bypass grafting, heart failure, and renal dysfunction). The primary composite endpoint was a composite of all-cause death, nonfatal myocardial infarction, stroke, readmission because of acute coronary syndrome, and major bleeding (Bleeding Academic Research Consortium type ≥3) at 2 years after randomization.

RESULTS

Among 5,403 patients, clopidogrel monotherapy showed a lower rate of the primary composite endpoint than aspirin monotherapy (HR: 0.73; 95% CI: 0.59-0.90). The benefit of clopidogrel over aspirin was consistent regardless of TRS 2°P (high TRS 2°P [≥3] group: HR: 0.65 [95% CI: 0.44-0.96]; and low TRS 2°P [<3] group: HR: 0.77 [95% CI: 0.60-0.99]) (P for interaction = 0.454) and regardless of DAPT score (high DAPT score [≥2] group: HR: 0.68 [95% CI: 0.46-1.00]; and low DAPT score [<2] group: HR: 0.75 [95% CI: 0.59-0.96]) (P for interaction = 0.662). The association was similar for the individual outcomes.

CONCLUSIONS

The beneficial effect of clopidogrel over aspirin monotherapy was consistent regardless of clinical risk or relative ischemic and bleeding risks compared with aspirin monotherapy. (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis- EXtended Antiplatelet Monotherapy [HOST-EXAM]; NCT02044250).

Personalised antiplatelet therapies for coronary artery disease: what the future holds

Coronary artery disease (CAD) is one of the leading causes of death globally, and antiplatelet therapy is crucial for both its prevention and treatment. Antiplatelet drugs such as aspirin and P2Y12 inhibitors are commonly used to reduce the risk of thrombotic events, including myocardial infarction, stroke, and stent thrombosis. However, the benefits associated with the use of antiplatelet drugs also come with a risk of bleeding complications. The ever-growing understanding of the poor prognostic implications associated with bleeding has set the foundations for defining strategies that can mitigate such safety concern without any trade-off in antithrombotic protection. To this extent, personalised antiplatelet therapy has emerged as a paradigm that optimizes the balance between safety and efficacy by customizing treatment to the individual patient's needs and risk profile. Accurate risk stratification for both bleeding and thrombosis can aid in selecting the optimal antiplatelet therapy and prevent serious and life-threatening outcomes. Risk stratification has traditionally included clinical and demographic characteristics and has expanded to incorporate angiographic features and laboratory findings. The availability of bedside platelet function testing as well as rapid genotyping assays has also allowed for a more individualized selection of antiplatelet therapy. This review provides a comprehensive overview of the current state of the art and future trends in personalised antiplatelet therapy for patients with CAD, with emphasis on those presenting with an acute coronary syndrome and undergoing percutaneous coronary revascularization. The aim is to provide clinicians with a comprehensive understanding of personalised antiplatelet therapy and facilitate informed clinical decision-making.

Bleeding and Ischemic Risks of Ticagrelor Monotherapy After Coronary Interventions

BACKGROUND

In TWILIGHT (Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention), among high-risk patients undergoing percutaneous coronary intervention (PCI), ticagrelor monotherapy vs continuation of dual antiplatelet therapy (DAPT) with aspirin and ticagrelor after completing a 3-month course of DAPT was associated with reduced bleeding, without an increase in ischemic events.

OBJECTIVES

This investigation sought to study the clinical benefit of ticagrelor monotherapy vs DAPT by simultaneously modeling its associated potential bleeding benefits and ischemic harms on an individual patient basis.

METHODS

Multivariable Cox regression models for: 1) Bleeding Academic Research Consortium type 2, 3, or 5 (BARC-2/3/5); and 2) cardiovascular death, nonfatal myocardial infarction, and nonfatal ischemic stroke (major adverse cardiac and cerebrovascular event [MACCE]) were developed using stepwise forward variable selection. The coefficients in the BARC-2/3/5 and MACCE models were used to calculate bleeding and ischemic risk scores, respectively, for each patient (excluding the coefficient for randomized treatment).

RESULTS

In the total study group (N = 7,119), BARC-2/3/5 occurred in 391 (5.5%) patients, and MACCE occurred in 258 (3.6%). There was a consistent reduction in bleeding events associated with ticagrelor monotherapy compared with DAPT across both bleeding and ischemic risk strata (P interaction = 0.54 and 0.11, respectively). Importantly, this benefit associated with ticagrelor monotherapy was not offset by an increase in MACCE at any level of bleeding or ischemic risk.

CONCLUSIONS

Three months after PCI, discontinuing aspirin and maintaining ticagrelor monotherapy reduces bleeding in both higher-bleeding risk and lower-bleeding risk patients compared with continued DAPT. This benefit does not appear to be offset by greater ischemic risk. (Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention [TWILIGHT]; NCT02270242).

Management of patients on antithrombotic therapy with severe infections: a joint clinical consensus statement of the ESC Working Group on Thrombosis, the ESC Working Group on Atherosclerosis and Vascular Biology, and the International Society on Thrombosis and Haemostasis

Patients with severe infections and a pre-existing indication for antithrombotic therapy, i.e. antiplatelet agents, anticoagulant drugs, or their combinations, require integrated clinical counselling among coagulation, infectious disease, and cardiology specialists, due to sepsis-induced coagulopathy that frequently occurs. Bacterial and viral pathogens constitute an increasing threat to global public health, especially for patients with ongoing antithrombotic treatment who have a high risk of thrombotic recurrences and high susceptibility to severe infections with increased morbidity and mortality. Similarly, sepsis survivors are at increased risk for major vascular events. Coagulopathy, which often complicates severe infections, is associated with a high mortality and obligates clinicians to adjust antithrombotic drug type and dosing to avoid bleeding while preventing thrombotic complications. This clinical consensus statement reviews the best available evidence to provide expert opinion and statements on the management of patients hospitalized for severe bacterial or viral infections with a pre-existing indication for antithrombotic therapy (single or combined), in whom sepsis-induced coagulopathy is often observed. Balancing the risk of thrombosis and bleeding in these patients and preventing infections with vaccines, if available, are crucial to prevent events or improve outcomes and prognosis.

P2Y12 Inhibitor or Aspirin Monotherapy for Secondary Prevention of Coronary Events

BACKGROUND

Aspirin is the only antiplatelet agent with a Class I recommendation for long-term prevention of cardiovascular events in patients with coronary artery disease (CAD). There is inconsistent evidence on how it compares with alternative antiplatelet agents.

OBJECTIVES

This study compared P2Y12 inhibitor monotherapy vs aspirin in patients with CAD.

METHODS

We conducted a patient-level meta-analysis of randomized trials comparing P2Y12 inhibitor monotherapy vs aspirin monotherapy for the prevention of cardiovascular events in patients with established CAD. The primary outcome was the composite of cardiovascular death, myocardial infarction, and stroke. Prespecified key secondary outcomes were major bleeding and net adverse clinical events (the composite of the primary outcome and major bleeding). Data were pooled in a 1-step meta-analysis.

RESULTS

Patient-level data were obtained from 7 trials. Overall, 24,325 participants were available for analysis, including 12,178 patients assigned to receive P2Y12 inhibitor monotherapy (clopidogrel in 7,545 [62.0%], ticagrelor in 4,633 [38.0%]) and 12,147 assigned to receive aspirin. Risk of the primary outcome was lower with P2Y12 inhibitor monotherapy compared with aspirin over 2 years (HR: 0.88; 95% CI: 0.79-0.97; P = 0.012), mainly owing to less myocardial infarction (HR: 0.77; 95% CI: 0.66-0.90; P < 0.001). Major bleeding was similar (HR: 0.87; 95% CI: 0.70-1.09; P = 0.23) and net adverse clinical events were lower (HR: 0.89; 95% CI: 0.81-0.98; P = 0.020) with P2Y12 inhibitors. The treatment effect was consistent across prespecified subgroups and types of P2Y12 inhibitors.

CONCLUSIONS

Given its superior efficacy and similar overall safety, P2Y12 inhibitor monotherapy might be preferred over aspirin monotherapy for long-term secondary prevention in patients with established CAD. (P2Y12 Inhibitor or Aspirin Monotherapy as Secondary Prevention in Patients With Coronary Artery Disease: An Individual Patient Data Meta-Analysis of Randomized Trials [PANTHER collaborative initiative]; CRD42021290774).

Bleeding in acute coronary syndrome: from definitions, incidence, and prognosis to prevention and management

INTRODUCTION

In patients with acute coronary syndrome (ACS), the ischemic benefit of antithrombotic treatment is counterbalanced by the risk of bleeding. The recognition that bleeding events have prognostic implications (i.e. mortality) similar to recurrent ischemic events led to the development of treatment regimens aimed at balancing both ischemic and bleeding risks.

AREAS COVERED

This review aims at describing definitions, incidence, and prognosis related to bleeding events in ACS patients as well as bleeding-avoidance strategies for their prevention and management of bleeding complications.

EXPERT OPINION

Management of ACS patients has witnessed remarkable progress after the shift in focusing on the trade-off between ischemia and bleeding. Efforts in standardizing bleeding definitions will allow for better defining the prognostic impact of different types of bleeding events and enable to identify the high-bleeding risk patient. Such efforts will allow to balance the trade-off between the thrombotic and bleeding risk of the individual patient translating into better downward diagnostic and therapeutic decision-making. Novel strategies aiming at maximizing the safety and efficacy of antithrombotic regimens as well as the development of novel antithrombotic drugs and reversal agents and technological advances will allow for optimization of bleeding-avoidance strategies and management of bleeding complications.

Antioxidant Properties of Oral Antithrombotic Therapies in Atherosclerotic Disease and Atrial Fibrillation

The thrombosis-related diseases are one of the leading causes of illness and death in the general population, and despite significant improvements in long-term survival due to remarkable advances in pharmacologic therapy, they continue to pose a tremendous burden on healthcare systems. The oxidative stress plays a role of pivotal importance in thrombosis pathophysiology. The anticoagulant and antiplatelet drugs commonly used in the management of thrombosis-related diseases show several pleiotropic effects, beyond the antithrombotic effects. The present review aims to describe the current evidence about the antioxidant effects of the oral antithrombotic therapies in patients with atherosclerotic disease and atrial fibrillation.

Individualized or Uniform De-Escalation Strategies for Antiplatelet Therapy in Acute Coronary Syndrome: A Review of Clinical Trials with Platelet Function Testing and Genetic Testing-Based Protocols

This comprehensive literature review assessed the effectiveness of precision medicine approaches in individualizing P2Y12 de-escalation strategies, such as platelet function testing guidance, genetic testing guidance, and uniform de-escalation, for acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). Analyzing six trials with a total of 13,729 patients, the cumulative analyses demonstrated a significant reduction in major adverse cardiac events (MACE), net adverse clinical events (NACE), and major and minor bleeding events with P2Y12 de-escalation. Specifically, the analysis found a 24% reduction of MACE and a 22% reduction of adverse event risk (relative risk (RR) 0.76, 95% confidence interval (CI): 0.71-0.82, and RR: 0.78, 95% CI 0.67-0.92, respectively). Reductions in bleeding events were highest with uniform unguided de-escalation, followed by guided de-escalations, while ischemic event rates were similarly lower across all three strategies. Although the review highlights the potential of individualized P2Y12 de-escalation strategies to offer a safer alternative to the long-term potent P2Y12 inhibitor-based dual antiplatelet therapy, it also indicates that laboratory-guided precision medicine approaches may not yet offer the expected benefits, necessitating further research to optimize individualized strategies and evaluate the potential of precision medicine approaches in this context.

Advances in the available pharmacotherapy for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation

INTRODUCTION

Non-ST-segment elevation acute coronary syndromes (NSTE-ACS), including non-ST-segment-elevation myocardial infarction (NSTEMI) and unstable angina, represent a leading cause of mortality worldwide, with important socio-economic consequences. NSTEMI accounts for the majority of acute coronary syndromes and usually develops on the background of a nonocclusive thrombus. We searched for relevant literature in the field in PubMed and clinicaltrials.gov as of July 2022.

AREAS COVERED

A number of pharmacotherapies are currently available for treatment and secondary prevention, mainly including antithrombotic, lipid-lowering and anti-inflammatory drugs. Pretreatment with aspirin, anticoagulant and statin therapy is of key importance in the preprocedural phase, while pretreating with an oral P2Y12 inhibitor is not routinely indicated in patients undergoing early invasive management. For patients undergoing percutaneous coronary revascularization, pharmacotherapy essentially consists of antithrombotic drugs, which should be carefully selected. Finally, antithrombotic, lipid-lowering and anti-inflammatory drugs are important components of long-term secondary prevention after a NSTE-ACS.

EXPERT OPINION

This article reviews the evidence supporting recommendation on pharmacotherapy in patients presenting with a NSTE-ACS. Several randomized clinical trials are still ongoing and are expected to further inform scientific knowledge and clinical practice, with the final aim to improve the treatment of NSTE-ACS patients.

P2Y12 Inhibitor Monotherapy or Dual Antiplatelet Therapy After Complex Percutaneous Coronary Interventions

BACKGROUND

It remains unclear whether P2Y₁₂ inhibitor monotherapy preserves ischemic protection while limiting bleeding risk compared with dual antiplatelet therapy (DAPT) after complex percutaneous coronary intervention (PCI).

OBJECTIVES

We sought to assess the effects of P2Y₁₂ inhibitor monotherapy after 1-month to 3-month DAPT vs standard DAPT in relation to PCI complexity.

METHODS

We pooled patient-level data from randomized controlled trials comparing P2Y₁₂ inhibitor monotherapy and standard DAPT on centrally adjudicated outcomes after coronary revascularization. Complex PCI was defined as any of 6 criteria: 3 vessels treated, ≥3 stents implanted, ≥3 lesions treated, bifurcation with 2 stents implanted, total stent length >60 mm, or chronic total occlusion. The primary efficacy endpoint was all-cause mortality, myocardial infarction, and stroke. The key safety endpoint was Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding.

RESULTS

Of 22,941 patients undergoing PCI from 5 trials, 4,685 (20.4%) with complex PCI had higher rates of ischemic events. The primary efficacy endpoint was similar between P2Y₁₂ inhibitor monotherapy and DAPT among patients with complex PCI (HR: 0.87; 95% CI: 0.64-1.19) and noncomplex PCI (HR: 0.91; 95% CI: 0.76-1.09; P_interaction = 0.770). The treatment effect was consistent across all the components of the complex PCI definition. Compared with DAPT, P2Y₁₂ inhibitor monotherapy consistently reduced BARC 3 or 5 bleeding in complex PCI (HR: 0.51; 95% CI: 0.31-0.84) and noncomplex PCI patients (HR: 0.49; 95% CI: 0.37-0.64; P_interaction = 0.920).

CONCLUSIONS

P2Y₁₂ inhibitor monotherapy after 1-month to 3-month DAPT was associated with similar rates of fatal and ischemic events and lower risk of major bleeding compared with standard DAPT, irrespective of PCI complexity. (PROSPERO [P2Y12 Inhibitor Monotherapy Versus Standard Dual Antiplatelet Therapy After Coronary Revascularization: Individual Patient Data Meta-Analysis of Randomized Trials]; CRD42020176853).

Tailoring oral antiplatelet therapy in acute coronary syndromes: from guidelines to clinical practice

The assessment of bleeding and ischemic risk is a crucial step in establishing appropriate composition and duration of dual antiplatelet therapy (DAPT) in patients with acute coronary syndrome (ACS) treated with percutaneous coronary angioplasty. Evidence from recent randomized clinical trials led to some paradigm shifts in current guidelines recommendations. Options alternative to the standard 12-month DAPT duration include shorter periods of DAPT followed by single antiplatelet treatment with either aspirin or P2Y12 monotherapy, guided or unguided de-escalation DAPT, prolonged DAPT beyond the 12-month treatment period. Although DAPT composition and duration should be selected for each ACS patient on an individual basis weighing clinical and procedural variables, data from latest trials and meta-analyses may permit suggesting the most appropriate DAPT strategy according to the ischemic and bleeding risk assessed using validated tools and scores.

Timing, Selection, Modulation, and Duration of P2Y12 Inhibitors for Patients With Acute Coronary Syndromes Undergoing PCI

Dual antiplatelet therapy with aspirin and the oral P2Y₁₂ inhibitor clopidogrel as the cornerstone of treatment for patients with an acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) was firstly established in 2001. Soon thereafter, the newer-generation P2Y₁₂ inhibitors prasugrel and ticagrelor became commercially available. The clinical management of ACS patients undergoing PCI has evolved significantly in the last 2 decades, with a shift toward more rapid invasive management, broader use of drug-eluting stents, and the increasing recognition that major bleeding due to antiplatelet therapy is detrimental. In this ever-changing scenario, numerous studies have addressed 4 main questions regarding P2Y₁₂ inhibition in ACS patients undergoing PCI: timing, selection, modulation, and duration. This paper reviews the latest evidence surrounding these topical questions, with a focus on efficacy and safety data, practice guidelines, and residual areas of uncertainty.

Clopidogrel Monotherapy After 1-Month Dual Antiplatelet Therapy in Patients With Diabetes Undergoing Percutaneous Coronary Intervention

BACKGROUND

Diabetes was reported to be associated with an impaired response to clopidogrel.

OBJECTIVES

The aim of this study was to evaluate the safety and efficacy of clopidogrel monotherapy after very short dual antiplatelet therapy (DAPT) in patients with diabetes undergoing percutaneous coronary intervention (PCI).

METHODS

A subgroup analysis was conducted on the basis of diabetes in the STOPDAPT-2 (Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2) Total Cohort (N = 5,997) (STOPDAPT-2, n = 3,009; STOPDAPT-2 ACS [Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 for the Patients With ACS], n = 2,988), which randomly compared 1-month DAPT followed by clopidogrel monotherapy with 12-month DAPT with aspirin and clopidogrel after cobalt-chromium everolimus-eluting stent implantation. The primary endpoint was a composite of cardiovascular (cardiovascular death, myocardial infarction, definite stent thrombosis, or stroke) or bleeding (TIMI [Thrombolysis In Myocardial Infarction] major or minor) endpoints at 1 year.

RESULTS

There were 2,030 patients with diabetes (33.8%) and 3967 patients without diabetes (66.2%). Regardless of diabetes, the risk of 1-month DAPT relative to 12-month DAPT was not significant for the primary endpoint (diabetes, 3.58% vs 4.12% [HR: 0.87; 95% CI: 0.56-1.37; P = 0.55]; nondiabetes, 2.46% vs 2.49% [HR: 0.99; 95% CI: 0.67-1.48; P = 0.97]; P_interaction = 0.67) and for the cardiovascular endpoint (diabetes, 3.28% vs 3.05% [HR: 1.10; 95% CI: 0.67-1.81; P = 0.70]; nondiabetes, 1.95% vs 1.43% [HR: 1.38; 95% CI: 0.85-2.25; P = 0.20]; P_interaction = 0.52), while it was lower for the bleeding endpoint (diabetes, 0.30% vs 1.50% [HR: 0.20; 95% CI: 0.06-0.68; P = 0.01]; nondiabetes, 0.61% vs 1.21% [HR: 0.51; 95% CI: 0.25-1.01; P = 0.054]; P_interaction = 0.19).

CONCLUSIONS

Clopidogrel monotherapy after 1-month DAPT compared with 12-month DAPT reduced major bleeding events without an increase in cardiovascular events regardless of diabetes, although the findings should be considered as hypothesis generating, especially in patients with acute coronary syndrome, because of the inconclusive result in the STOPDAPT-2 ACS trial. (Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 [STOPDAPT-2], NCT02619760; Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 for the Patients With ACS [STOPDAPT-2 ACS], NCT03462498).

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.