Efficacy and Safety of Ticagrelor Monotherapy by Clinical Presentation: Pre-Specified Analysis of the GLOBAL LEADERS Trial

Short-Term Dual Antiplatelet Therapy After Drug-Eluting Stenting in Patients With Acute Coronary Syndromes: A Systematic Review and Network Meta-Analysis

Importance

The optimal duration of dual antiplatelet therapy (DAPT) in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) remains under debate.

Objectives

To analyze the efficacy and safety of DAPT strategies in patients with ACS using a bayesian network meta-analysis.

Data Sources

MEDLINE, Embase, Cochrane, and LILACS databases were searched from inception to April 8, 2024.

Study Selection

Randomized clinical trials (RCTs) comparing DAPT duration strategies in patients with ACS undergoing PCI were selected. Short-term strategies (1 month of DAPT followed by P2Y12 inhibitors, 3 months of DAPT followed by P2Y12 inhibitors, 3 months of DAPT followed by aspirin, and 6 months of DAPT followed by aspirin) were compared with conventional 12 months of DAPT.

Data Extraction and Synthesis

This systematic review and network meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The risk ratio (RR) with a 95% credible interval (CrI) was calculated within a bayesian random-effects network meta-analysis. Treatments were ranked using surface under the cumulative ranking (SUCRA).

Main Outcomes and Measures

The primary efficacy end point was major adverse cardiac and cerebrovascular events (MACCE); the primary safety end point was major bleeding.

Results

A total of 15 RCTs randomizing 35 326 patients (mean [SD] age, 63.1 [11.1] years; 26 954 male [76.3%]; 11 339 STEMI [32.1%]) with ACS were included. A total of 24 797 patients (70.2%) received potent P2Y12 inhibitors (ticagrelor or prasugrel). Compared with 12 months of DAPT, 1 month of DAPT followed by P2Y12 inhibitors reduced major bleeding (RR, 0.47; 95% CrI, 0.26-0.74) with no difference in MACCE (RR, 1.00; 95% CrI, 0.70-1.41). No significant differences were observed in MACCE incidence between strategies, although CrIs were wide. SUCRA ranked 1 month of DAPT followed by P2Y12 inhibitors as the best for reducing major bleeding and 3 months of DAPT followed by P2Y12 inhibitors as optimal for reducing MACCE (RR, 0.85; 95% CrI, 0.56-1.21).

Conclusion and Relevance

Results of this systematic review and network meta-analysis reveal that, in patients with ACS undergoing PCI with DES, 1 month of DAPT followed by potent P2Y12 inhibitor monotherapy was associated with a reduction in major bleeding without increasing MACCE when compared with 12 months of DAPT. However, an increased risk of MACCE cannot be excluded, and 3 months of DAPT followed by potent P2Y12 inhibitor monotherapy was ranked as the best option to reduce MACCE. Because most patients receiving P2Y12 inhibitor monotherapy were taking ticagrelor, the safety of stopping aspirin in those taking clopidogrel remains unclear.

Ticagrelor monotherapy after ≤ 1-month DAPT vs continued DAPT in patients with acute coronary syndrome treated with percutaneous coronary intervention: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Current guidelines recommend at least 12 months of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). However, DAPT prolonged use may increase the risk of bleeding complications. Therefore, we aimed to perform a meta-analysis to assess whether ticagrelor monotherapy after ≤1 month of DAPT improves clinical outcomes compared with continued DATP in acute coronary syndrome (ACS) patients post-PCI.

METHODS

We systematically searched PubMed, Embase and Cochrane databases for randomized controlled trials published up to August 2024. All-cause and cardiovascular death, overall and major bleeding events, myocardial infarction (MI), stroke, target vessel revascularization (TVR) and stent thrombosis within 1-2 years post-procedure were evaluated. Statistical analysis was performed using Review Manager 5.1.7.

RESULTS

Three studies and 13,737 patients were included, of whom 6861 (49.95 %) received ticagrelor alone. When compared with DAPT, ticagrelor monotherapy significantly reduced the risk of overall (2.0 % vs 4.5 %; RR 0.44; 95 % Cl 0.33-0,59; p < 0.00001) and major (1.4 % vs 2.5 %; RR 0.49; 95 % Cl 0.29-0.83; p = 0.04) bleeding events. Both antiplatelet regimens had similar rates of mortality, MI, stroke, TVR or stent thrombosis.

CONCLUSION

This meta-analysis suggests that ticagrelor alone after ≤1 month of DAPT post-PCI in ACS patients reduces bleeding complications without increasing major adverse events compared with traditional DAPT for 12 months.

Abbreviated ticagrelor based dual antiplatelet therapy in acute coronary syndrome: A systematic review and meta-analysis

BACKGROUND

Few randomized clinical trials have evaluated the safety and efficacy of abbreviated ticagrelor based dual antiplatelet therapy (DAPT) in acute coronary syndrome (ACS); however, these trials were underpowered to detect differences in hard clinical outcomes.

METHODS

A systematic search of MEDLINE, Cochrane, and Scopus databases was performed through June 2024, for trials that compared abbreviated (≤3-months) versus standard 12-months ticagrelor based DAPT in ACS. The primary endpoint was all-cause mortality. Secondary endpoints included cardiovascular death, myocardial infarction, stent thrombosis, ischemic stroke, and major bleeding. Endpoints were measured at 12-months after DAPT initiation. Data were pooled using random-effects model. Effect measure utilized was risk ratio (RR). Heterogeneity was assessed via Chi-squared and Higgin's I2 test. RevMan 5.0 (Cochrane Collaboration, Oxford, United Kingdom) was utilized to perform statistical analysis.

RESULTS

Five trials were included in this analysis with 21,407 patients assessed. ULTIMATE-DAPT, T-PASS, and GLOBAL LEADERS-ACS assessed 1-month DAPT duration while TICO and TWILIGHT-ACS assessed 3-months DAPT duration. The average age was 62.7 years and 22.7 % were women. ACS presentations included non-ST elevation myocardial infarction (40.1 %), unstable angina (35.2 %), and ST-segment elevation myocardial infarction (31.5 %). Abbreviated ticagrelor based DAPT was associated with lower risk of all-cause mortality (RR 0.78; 95 % Confidence Interval (CI) 0.62-0.98, I2 = 0 %) compared with standard duration DAPT. There was no difference between groups in cardiovascular death (RR 0.65; 95 % CI 0.41-1.03, I2 = 0 %), myocardial infarction (RR 1.04; 95 % CI 0.85-1.27, I2 = 0 %), stent thrombosis (RR 0.97; 95 % CI 0.64-1.45, I2 = 0 %), or ischemic stroke (RR 0.90; 95 % CI 0.62-1.30, I2 = 0 %). Abbreviated DAPT was associated with lower risk of major bleeding (RR 0.50; 95 % CI 0.38-0.66, I2 = 46 %).

CONCLUSION

Our analysis includes the totality of randomized data evaluating the merits of abbreviated ticagrelor based DAPT after ACS. The salient study finding was the observed reduced risk of all-cause mortality and major bleeding with abbreviated DAPT approach.

Ticagrelor monotherapy for acute coronary syndrome: an individual patient data meta-analysis of TICO and T-PASS trials

BACKGROUND AND AIMS

In patients with acute coronary syndrome (ACS), dual antiplatelet therapy (DAPT) with aspirin and a potent P2Y12 inhibitor is recommended for 12 months after drug-eluting stent (DES) implantation. Monotherapy with a potent P2Y12 inhibitor after short-term DAPT is an attractive option to better balance the risks of ischaemia and bleeding. Therefore, this study evaluated the efficacy and safety of ticagrelor monotherapy after short-term DAPT, especially in patients with ACS.

METHODS

Electronic databases were searched from inception to 11 November 2023, and for the primary analysis, individual patient data were pooled from the relevant randomized clinical trials comparing ticagrelor monotherapy after short-term (≤3 months) DAPT with ticagrelor-based 12-month DAPT, exclusively in ACS patients undergoing DES implantation. The co-primary endpoints were ischaemic endpoint (composite of all-cause death, myocardial infarction, or stroke) and bleeding endpoint [Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding] at 1 year.

RESULTS

Individual patient data from two randomized clinical trials including 5906 ACS patients were analysed. At 1 year, the primary ischaemic endpoint did not differ between the ticagrelor monotherapy and ticagrelor-based DAPT groups [1.9% vs. 2.5%; adjusted hazard ratio (HR) 0.79; 95% confidence interval (CI) 0.56-1.13; P = .194]. The incidence of the primary bleeding endpoint was lower in the ticagrelor monotherapy group (2.4% vs. 4.5%; adjusted HR 0.54; 95% CI 0.40-0.72; P < .001). The results were consistent in a secondary aggregate data meta-analysis including the ACS subgroup of additional randomized clinical trials which enrolled patients with ACS as well as chronic coronary syndrome.

CONCLUSIONS

In ACS patients undergoing DES implantation, ticagrelor monotherapy after short-term DAPT was associated with less major bleeding without a concomitant increase in ischaemic events compared with ticagrelor-based 12-month DAPT.

STUDY REGISTRATION

PROSPERO (ID: CRD42023476470).

De-escalation of antithrombotic treatment after acute coronary syndrome, a new paradigm

After an acute coronary syndrome (ACS) it is imperative to balance the bleeding vs. the ischemic risk given the similar prognostic impact of the two events. Since the post-discharge bleeding risk is substantially stable over time whereas the ischemic risk accumulates in the first weeks to months, a strategy of de-escalation of antithrombotic treatment, consisting in the reduction of either the duration (i.e., early interruption of one antiplatelet agent) or the intensity (i.e., switching from the more potent P2Y12-inhibitors prasugrel or ticagrelor to clopidogrel) of dual antiplatelet therapy (DAPT), has been proposed. Reducing the intensity of DAPT can be carried out as a default strategy (unguided approach) or based on the results of either platelet function tests or genetic tests (guided approach). Overall, all de-escalation strategies have shown to consistently decrease bleeding events with no apparent increase in ischemic events as compared to 12-month standard-of-care DAPT. Owing however to several limitations and weaknesses of the available evidence, de-escalation strategies are currently not recommended as a routine, but should rather be considered for selected ACS patients, such as those at increased risk of bleeding.

P2Y12 Receptor Inhibitor for Antiaggregant Therapies: From Molecular Pathway to Clinical Application

Platelets play a significant role in hemostasis, forming plugs at sites of vascular injury to limit blood loss. However, if platelet activation is not controlled, it can lead to thrombotic events, such as myocardial infarction and stroke. To prevent this, antiplatelet agents are used in clinical settings to limit platelet activation in patients at risk of arterial thrombotic events. However, their use can be associated with a significant risk of bleeding. An enhanced comprehension of platelet signaling mechanisms should facilitate the identification of safer targets for antiplatelet therapy. Over the past decade, our comprehension of the breadth and intricacy of signaling pathways that orchestrate platelet activation has expanded exponentially. Several recent studies have provided further insight into the regulation of platelet signaling events and identified novel targets against which to develop novel antiplatelet agents. Antiplatelet drugs are essential in managing atherothrombotic vascular disease. The current antiplatelet therapy in clinical practice is limited in terms of safety and efficacy. Novel compounds have been developed in response to patient variability and resistance to aspirin and/or clopidogrel. Recent studies based on randomized controlled trials and systematic reviews have definitively demonstrated the role of antiplatelet therapy in reducing the risk of cardiovascular events. Antiplatelet therapy is the recommended course of action for patients with established atherosclerosis. These studies compared monotherapy with a P2Y12 inhibitor versus aspirin for secondary prevention. However, in patients undergoing percutaneous coronary intervention, it is still unclear whether the efficacy of P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy depends on the type of P2Y12 inhibitor. This paper focuses on the advanced-stage evaluation of several promising antiplatelet drugs.

Preferred monotherapy after short-term dual antiplatelet therapy: Systematic review and network meta-analysis of randomized trials

BACKGROUND

Randomized controlled trials (RCTs) have demonstrated the efficacy and safety of P2Y12 inhibitor monotherapy following short-term dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI). However, no studies have compared P2Y12 inhibitor and aspirin monotherapy following short-term DAPT. We aimed to compare available strategies for DAPT duration and post-DAPT antiplatelet monotherapy following PCI.

METHODS

Seven DAPT strategies [ticagrelor or clopidogrel following 1-month DAPT, ticagrelor following 3-month DAPT, aspirin following 3-6 months of DAPT (reference strategy), aspirin or P2Y12 inhibitor following 6-18-months of DAPT, and DAPT for ≥18 months] were compared using a network meta-analysis. The primary efficacy outcome was defined as a composite of all-cause death, myocardial infarction, and stroke. The primary bleeding outcome was trial-defined major or minor bleeding.

RESULTS

Our analysis identified 25 eligible RCTs, including 89,371 patients who underwent PCI. Overall, none of the strategies negatively affected the primary efficacy outcomes. For primary bleeding outcomes, ticagrelor following 3-month DAPT was associated with a reduced risk of primary bleeding outcomes (HR 0.73; 95 % CI 0.57-0.95). Clopidogrel following 1-month DAPT was also associated with a reduced risk of primary bleeding outcomes (HR 0.54; 95 % CI 0.34-0.85), however, the strategy was associated with an increased risk of myocardial infarction or stent thrombosis. Similar trends were observed among patients with acute coronary syndrome and high bleeding risk.

CONCLUSIONS

Compared with aspirin monotherapy following short-term DAPT, ticagrelor following 3-month DAPT was associated with a reduced risk of primary bleeding outcomes without increasing any ischemic outcomes.

Aspirin-free antiplatelet strategies after percutaneous coronary interventions

Dual antiplatelet therapy (DAPT) with aspirin and a platelet P2Y12 receptor inhibitor is the standard antithrombotic treatment after percutaneous coronary interventions (PCI). Several trials have challenged guideline-recommended DAPT after PCI by testing the relative clinical effect of an aspirin-free antiplatelet approach-consisting of P2Y12 inhibitor monotherapy after a short course (mostly 1-3 months) of DAPT-among patients undergoing PCI without a concomitant indication for oral anticoagulation (OAC). Overall, these studies have shown P2Y12 inhibitor monotherapy after short DAPT to be associated with a significant reduction in the risk of bleeding without an increase in thrombotic or ischaemic events compared with continued DAPT. Moreover, the effects of the P2Y12 inhibitor monotherapy without prior DAPT or following a very short course of DAPT after PCI are being investigated in emerging studies, of which one has recently reported unfavourable efficacy results associated with the aspirin-free approach compared with conventional DAPT. Finally, P2Y12 inhibitor alone has been compared with aspirin alone as chronic therapy after DAPT discontinuation, thus challenging the historical role of aspirin as a standard of care for secondary prevention following PCI. A thorough understanding of study designs, populations, treatments, results, and limitations of trials testing P2Y12 inhibitor monotherapy vs. DAPT or vs. aspirin is required to consider adopting this treatment in clinical practice. This review addresses the use of aspirin-free antiplatelet strategies among patients undergoing PCI without a concomitant indication for OAC, providing an overview of clinical evidence, guideline indications, practical implications, ongoing issues, and future perspectives.

One-Month Dual Antiplatelet Therapy in Patients With Chronic and Acute Coronary Syndromes Treated With Bioresorbable Polymer Everolimus-Eluting Stents

There is a paucity of data regarding the safety of a 1-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) in patients at high bleeding risk (HBR) presenting with acute coronary syndromes (ACS). We aimed to compare the clinical outcomes of patients at HBR with chronic coronary syndrome (CCS) or ACS treated with PCI using bioresorbable polymer everolimus-eluting stent (BP-EES) followed by 1-month DAPT. Patients at HBR who underwent PCI with BP-EES were prospectively enrolled in 10 Italian centers. All patients were treated with 1-month DAPT. In case of need for anticoagulation, patients received an oral anticoagulant in addition to a P2Y12 inhibitor for 1 month, followed by oral anticoagulation only after that. The primary end point was a composite of cardiac death, myocardial infarction, or definite/probable stent thrombosis at 12 months. Overall, 263 patients (59.4%) with CCS and 180 patients (40.6%) with ACS were enrolled. No significant difference was evident between patients with CCS and ACS for the primary end point (4.3% vs 5.6%, respectively, p = 0.497) and for each isolated component. The risk for Bleeding Academic Research Consortium (BARC) type 1 to 5 or type 3 to 5 bleedings was also similar between patients with CCS and ACS (4.3% vs 5.2%, p = 0.677, and 1.6% vs 2.9%, p = 0.351, respectively). In conclusion, among HBR patients with ACS who underwent PCI with BP-EES, a 1-month DAPT strategy is associated with a similar risk of ischemic and bleeding events compared with those with CCS.

Making Sense of Composite Endpoints in Clinical Research

Multiple drugs currently used in clinical practice have been approved by regulatory agencies based on studies that utilize composite endpoints. Composite endpoints are appealing because they reduce sample size requirements, follow-up periods, and costs. However, interpreting composite endpoints can be challenging, and their misuse is not uncommon. Incorrect interpretation of composite outcomes can lead to misleading conclusions that impact patient care. To correctly interpret composite outcomes, several important questions should be considered. Are the individual components of the composite outcome equally important to patients? Did the more and less important endpoints occur with similar frequency? Do the component endpoints exhibit similar relative risk reductions? If these questions receive affirmative answers, the use and interpretation of the composite endpoint would be appropriate. However, if any component of the composite endpoint fails to satisfy the aforementioned criteria, interpretation can become difficult, necessitating additional steps. Regulatory agencies acknowledge these challenges and have specific considerations when approving drugs based on studies employing composite endpoints. In conclusion, composite endpoints are valuable tools for evaluating the efficacy and net clinical benefit of interventions; however, cautious interpretation is advised.

Comparison of De-escalation of DAPT Intensity or Duration in East Asian and Western Patients with ACS Undergoing PCI: A Systematic Review and Meta-analysis

BACKGROUND

 Guideline-recommended dual antiplatelet therapy (DAPT; aspirin plus prasugrel/ticagrelor) for 12 months in acute coronary syndrome (ACS) patients increases bleeding, with East Asians (EAs) exhibiting higher bleeding and lower ischemic risk, compared with non-East Asians (nEAs). We sought to compare DAPT "de-escalation" strategies in EA and nEA populations.

METHODS

 A systematic review and meta-analysis of randomized controlled trials assessing reduction of DAPT intensity or duration in ACS patients undergoing percutaneous coronary intervention, in EA and nEA, was performed using a random-effects model.

RESULTS

 Twenty-three trials assessed reduction of DAPT intensity (n = 12) or duration (n = 11). Overall, reduced DAPT intensity attenuated major bleeding (odds ratio [OR]: 0.78, 95% confidence interval [CI]: 0.65-0.94, p = 0.009), without impacting net adverse cardiovascular events (NACE) or major adverse cardiovascular events (MACE). In nEA, this increased MACE (OR: 1.20, 95% CI: 1.09-1.31, p < 0.0001) without impacting NACE or bleeding; while in EA, it reduced major bleeding (OR: 0.71, 95% CI: 0.53-0.95, p = 0.02) without affecting NACE or MACE. Overall, abbreviation of DAPT duration reduced NACE (OR: 0.90, 95% CI: 0.82-0.99, p = 0.03) due to major bleeding (OR: 0.69, 95% CI: 0.53-0.99, p = 0.006), without impacting MACE. In nEA, this strategy did not impact NACE, MACE, or major bleeding; while in EA, it reduced major bleeding (OR: 0.60, 95% CI: 0.4-0.91, p = 0.02) without impacting NACE or MACE.

CONCLUSION

 In EA, reduction of DAPT intensity or duration can minimize bleeding, without safety concerns. In nEA, reduction of DAPT intensity may incur an ischemic penalty, while DAPT abbreviation has no overall benefit.

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.

PRECISE-DAPT and ARC-HBR Predict in-Hospital Outcomes in Patients Who Underwent Percutaneous Coronary Intervention

Bleeding events result in morbidity and mortality in patients who underwent percutaneous coronary intervention (PCI). There are limited data on the predicting bleeding complications in patients who underwent stent implantation and subsequent dual antiplatelet therapy (PRECISE-DAPT) and Academic Research Consortium for High Bleeding Risk (ARC-HBR) scores' ability to predict in-hospital outcomes in patients who underwent PCI. Consecutive patients who underwent PCI at tertiary centers from January 2016 to March 2018 were identified and the bleeding risk scores were calculated. The primary end point was the National Cardiovascular Data Registry-defined in-hospital bleeding stratified by low versus high predicted bleeding risk. The major and net adverse cardiovascular events were also examined. The discriminatory ability of the risk models was determined using receiver operating characteristic curves. Among 3,659 patients studied, the in-hospital major bleeding was 3.3% (n = 121). The patients characterized as high bleeding risk by either criterion had significantly higher bleeding rates than those meeting the low-risk criteria (ARC-HBR 5.4% vs 3.3%, p <0.001; PRECISE-DAPT 5.8% vs 2.4%, p <0.001), and higher major adverse cardiovascular events and net adverse clinical events. These risk estimates showed moderate and similar predictive ability (ARC-HBR high-risk area under the receiver operating characteristic curve [AUC] 0.62, PRECISE-DAPT ≥25 AUC 0.61, p = 0.49), with no incremental benefit to adding the estimates (AUC 0.60). The subgroup analysis revealed that women had higher bleeding rates than men (5.53% vs 2.39%, p <0.001); however, the predictive ability of the criteria were similar in women and men. The patients identified as having a high bleeding risk by the PRECISE-DAPT and the ARC-HBR criteria before PCI are at high risk for in-hospital bleeding and adverse outcomes independent of gender. The 2 scores have moderate predictive ability for bleeds. Further study is needed to determine strategies to reduce risk in this population.

Reduced-dose prasugrel monotherapy without aspirin after PCI with the SYNERGY stent in East Asian patients presenting with chronic coronary syndromes or non-ST-elevation acute coronary syndromes: rationale and design of the ASET Japan pilot study

The Acetyl Salicylic Elimination Trial (ASET) Japan pilot study is a multicentre, single-arm, open-label, proof-of-concept study with a stopping rule based on the occurrence of definite stent thrombosis. This study aims to demonstrate the feasibility and safety of low-dose prasugrel monotherapy following percutaneous coronary intervention (PCI) in Japanese patients presenting with chronic coronary syndromes (CCS) or non-ST-elevation acute coronary syndromes (NSTE-ACS). Four hundred patients with a SYNTAX score <23 requiring PCI due to CCS or NSTE-ACS will be screened and considered eligible for the study. The enrolment is planned in two phases: 1) 200 patients presenting with CCS, followed by 2) 200 patients presenting with NSTE-ACS. After optimal PCI with implantation of a SYNERGY (Boston Scientific) stent, patients will be enrolled and loaded with prasugrel 20 mg, followed by a maintenance dose of prasugrel 3.75 mg once daily without aspirin continued for 3 months in Phase 1 (CCS patients), and for 12 months in Phase 2 (NSTE-ACS patients). After these follow-up periods, prasugrel will be replaced by standard antiplatelet therapy according to local practice. The primary endpoint is a composite of cardiac death, target vessel myocardial infarction, or definite stent thrombosis after the index procedure. The primary bleeding endpoint is any Bleeding Academic Research Consortium type 3 or 5 bleeding occurring within 3 months of the index PCI for CCS patients, or 12 months for NSTE-ACS patients. The ASET Japan study is designed to demonstrate the feasibility and safety of reduced-dose prasugrel monotherapy after PCI in East Asian patients with acute and chronic coronary syndromes.

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 versus Conventional Dual Antiplatelet Therapy in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention: A Meta-Analysis

P2Y12 inhibitor monotherapy is a feasible alternative treatment for patients after percutaneous coronary intervention (PCI) in the modern era. Clinical trials have shown that it could lower the risk of bleeding complications without increased ischemic events as compared to standard dual antiplatelet therapy (DAPT). However, the efficacy and safety of this novel approach among patients with acute coronary syndrome (ACS) are controversial because they have a much higher risk for recurrent ischemic events. The purpose of this study is to evaluate the efficacy and safety of this novel approach among patients with ACS. We conducted a meta-analysis of randomized controlled trials that compared P2Y12 inhibitor monotherapy with 12-month DAPT in ACS patients who underwent PCI with stent implantation. PubMed, Embase, the Cochrane library database, ClinicalTrials.gov, and other three websites were searched for data from the earliest report to July 2022. The primary efficacy outcome was major adverse cardiovascular and cerebrovascular events (MACCE), a composite of all-cause mortality, myocardial infarction, stent thrombosis, or stroke. The primary safety outcome was major or minor bleeding events. The secondary endpoint was net adverse clinical events (NACE), defined as a composite of major bleeding and adverse cardiac and cerebrovascular events. Five randomized controlled trials with a total of 21,034 patients were included in our meta-analysis. The quantitative analysis showed a significant reduction in major or minor bleeding events in patients treated with P2Y12 inhibitor monotherapy as compared with standard DAPT(OR: 0.59, 95% CI: 0.46-0.75, p < 0.0001) without increasing the risk of MACCE (OR: 0.98, 95% CI: 0.86-1.13, p = 0.82). The NACE was favorable in the patients treated with P2Y12 inhibitor monotherapy (OR: 0.82, 95% CI: 0.73-0.93, p = 0.002). Of note, the overall clinical benefit of P2Y12 inhibitor monotherapy was quite different between ticagrelor and clopidogrel. The incidence of NACE was significantly lower in ticagrelor monotherapy as compared with DAPT (OR: 0.79, 95% CI: 0.68-0.91), but not in clopidogrel monotherapy (OR: 1.14, 95% CI: 0.79-1.63). Both clopidogrel and ticagrelor monotherapy showed a similar reduction in bleeding complications (OR: 0.46, 95% CI: 0.22-0.94; OR: 0.60, 95% CI: 0.44-0.83, respectively). Although statistically insignificant, the incidence of MACCE was numerically higher in clopidogrel monotherapy as compared with standard DAPT (OR: 1.50, 95% CI: 0.99-2.28, p = 0.06). Based on these findings, P2Y12 inhibitor monotherapy with ticagrelor would be a better choice of medical treatment for ACS patients after PCI with stent implantation in the current era.

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.

Antiplatelet Therapy Aims and Strategies in Asian Patients with Acute Coronary Syndrome or Stable Coronary Artery Disease

Dual antiplatelet therapy (DAPT) has been the mainstay treatment to reduce ischemic events, such as myocardial infarction or stroke, in patients with coronary artery disease (CAD). The development of potent P2Y12 inhibitors (ticagrelor and prasugrel) has helped to further reduce ischemic events, particularly among high-risk patients. Meanwhile, the evolution of newer generations of drug-eluting stents are also improving outcomes of percutaneous coronary intervention. Research studies on antiplatelet therapy in recent years have focused on balancing ischemic and bleeding risks through different strategies, which include P2Y12 inhibitor monotherapy, escalation and de-escalation, and extended DAPT. Because results from the large number of clinical studies may sometimes appear conflicting, this review aims to summarize recent advances, and demonstrate that they are aligned by a general principle, namely, strategies may be adopted based on treatment aims for specific patients at several time points. Another aim of this review is to outline the important considerations for using antiplatelet therapy in Asian patients, in whom there is a greater prevalence of CYP2C19 loss-of-function mutations, and a common increased risk of bleeding, despite high platelet reactivity (the so-called "East Asian Paradox").

P2Y12 inhibitor monotherapy in patients undergoing percutaneous coronary intervention

For 20 years, dual antiplatelet therapy (DAPT), consisting of the combination of aspirin and a platelet P2Y₁₂ receptor inhibitor, has been the gold standard of antithrombotic pharmacology after percutaneous coronary intervention (PCI). In the past 5 years, several investigations have challenged this paradigm by testing the efficacy and safety of P2Y₁₂ inhibitor monotherapy (that is, without aspirin) following a short course of DAPT. Collectively, these studies suggested a reduction in the risk of major bleeding and no significant increase in thrombotic or ischaemic events compared with guideline-recommended DAPT. Current recommendations are evolving to inform clinical practice on the ideal candidates for P2Y₁₂ inhibitor monotherapy after PCI. Generalizing the results of studies of P2Y₁₂ inhibitor monotherapy requires a thorough understanding of their design, populations, interventions, comparators and results. In this Review, we provide an up-to-date overview on the use of P2Y₁₂ inhibitor monotherapy after PCI, including supporting pharmacodynamic and clinical evidence, practical recommendations and future directions.

Reduction or de-escalation of dual antiplatelet therapy intensity or duration in patients with acute coronary syndromes undergoing percutaneous coronary intervention: A mini-review

Current guidelines for patients with acute coronary syndrome (ACS) recommend dual antiplatelet therapy (DAPT) for 12 months. Since bleeding is the main Achilles' heel of DAPT, in recent years several randomized controlled trials have evaluated the safety and efficacy of de-escalation of DAPT with respect to ischaemic and bleeding endpoints. These trials can be broadly divided into studies evaluating a shorter duration of DAPT, and those studies in which DAPT that includes a potent P2Y₁₂ inhibitor, such as prasugrel or ticagrelor, is compared to less intense DAPT, mainly clopidogrel or reduced-dose prasugrel. We sought to evaluate the studies assessing de-escalation of DAPT in patients with ACS undergoing PCI. We review the studies evaluating the strategies of de-escalation of DAPT intensity and those evaluating a strategy of de-escalation of DAPT duration in ACS patients undergoing PCI. We summarize the limitations of studies to date, gaps in evidence and make recommendations for future studies.

P2Y12 Inhibitor Monotherapy: Considerations for Acute and Long-Term Secondary Prevention Post-PCI

Following percutaneous coronary intervention (PCI), an initial course of dual antiplatelet therapy (DAPT) with aspirin and a P2Y 12 inhibitor ( P2Y 12 -i) is recommended to minimize the risk of thrombotic complications. After the initial period of DAPT, antiplatelet monotherapy, usually consisting of aspirin, is administered for long-term secondary prevention. However, over the last few years there has been accruing evidence on P2Y 12 -i monotherapy, both in the acute (i.e., post-PCI; after a brief period of DAPT, transitioning to monotherapy before six or 12 months in patients with chronic or acute coronary syndrome, respectively) and chronic (i.e., long-term secondary prevention; after completion of six or 12 months of DAPT, in patients with chronic or acute coronary syndrome, respectively) settings. In aggregate, most studies of short DAPT with transition to P2Y 12 -i monotherapy showed a reduced risk of bleeding complications, without any significant increase in ischemic events as compared to standard DAPT. On the other hand, the evidence on long-term P2Y 12 -i monotherapy is scarce, but results from a randomized trial showed that clopidogrel monotherapy outperformed aspirin monotherapy in terms of net benefit, ischemic events and bleeding. Antiplatelet therapy is also recommended for patients undergoing PCI and with an established indication for long-term oral anticoagulation (OAC). In this scenario, a brief period of triple therapy (i.e., aspirin, P2Y 12 -i and OAC) is followed by a course of dual antithrombotic therapy (usually with P2Y 12 -i and OAC) and ultimately by lifelong OAC alone. European and American guidelines have been recently updated to provide new recommendations on antithrombotic therapy, including the endorsement of P2Y 12 -i monotherapy in different settings. However, some areas of uncertainty still remain and further randomized investigations are ongoing to fulfil current gaps in knowledge. In this review, we assess the current knowledge and evidence on P2Y 12 -i monotherapy for the early and long-term secondary prevention in patients undergoing PCI, and explore upcoming research and future directions in the field.

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.

Ticagrelor vs. Clopidogrel After Complex Percutaneous Coronary Intervention in Patients With Stable Coronary Artery Disease

Background: Patients undergoing complex percutaneous coronary intervention (PCI) have an increased risk of cardiovascular events. Whether potent antiplatelet therapy after complex PCI improves outcomes in patients with stable coronary artery disease (SCAD) remains unclear. Objectives: To assess the efficacy and safety of ticagrelor vs. clopidogrel in patients with SCAD undergoing complex PCI. Methods: Patients with a diagnosis of SCAD and undergoing PCI during January 2016 to December 2018 were selected from an institutional registry. The primary efficacy endpoint was major adverse cardiac events (MACE) within 12 months after PCI. The primary safety endpoint was major bleeding. Results: Among 15,459 patients with SCAD included in this analysis, complex PCI was performed in 6,335 (41.0%) patients. Of patients undergoing complex PCI, 1,123 patients (17.7%) were treated with ticagrelor. The primary efficacy outcome after complex PCI occurred in 8.6% of patients in the ticagrelor group and 11.2% in the clopidogrel group. Compared with clopidogrel, ticagrelor decreased the risk of MACE in patients undergoing complex PCI [adjusted hazard ratio (HR): 0.764; 95% confidence interval (CI): 0.615 to 0.949; p = 0.015], but not in non-complex PCI (p for interaction = 0.001). There was no significant difference in incidence of major bleeding between patients treated with ticagrelor and clopidogrel (p = 0.221), while ticagrelor was associated with an increased risk of minor bleeding (adjusted HR: 3.099; 95% CI: 2.049 to 4.687; p < 0.001). Conclusion: In patients with SCAD and undergoing complex PCI, ticagrelor could substantially reduce the risk of adverse cardiovascular outcomes without increasing the risk of major bleeding compared with clopidogrel.