Ticagrelor versus clopidogrel in patients with acute coronary syndromes intended for non-invasive management: substudy from prospective randomised PLATelet inhibition and patient Outcomes (PLATO) trial

Prolonged Dual Antiplatelet Therapy in Acute Myocardial Infarction Patients Without Revascularization: China Acute Myocardial Infarction Registry Study

At least 12 months of dual antiplatelet therapy (DAPT) is 1 of the standards of care following percutaneous coronary intervention in patients with acute coronary syndrome. However, study on prolonged DAPT for patients with acute myocardial infarction (AMI) without revascularization is limited. We studied 1,744 patients with AMI without revascularization from the China Acute Myocardial Infarction registry between January 2013 and September 2014. These patients were on DAPT and did not experience AMI, stroke, or bleeding events at the 12-month follow-up. We divided them into 2 groups: 12-month DAPT group (DAPT for at least 12 months but <18 months) and 18-month DAPT group (DAPT for at least 18 months). The primary outcome was 24-month all-cause death. Overall, 1,221 patients (70.0%) took DAPT for ≥12 months but <18 months, whereas 523 patients (30.0%) took DAPT for ≥18 months. The proportion of patients at high ischemic risk and the proportion of patients at high bleeding risk were similar in the 2 groups. At 24 months, the all-cause mortality rate of the 18-month DAPT group was significantly lower than that for the 12-month DAPT group (3.7% vs 5.9%, p = 0.0471). The adjusted hazard ratio for all-cause death also showed statistical significance (0.59, 95% confidence interval 0.35 to 0.99, p = 0.0444). In conclusion, DAPT for at least 18 months appears to be associated with lower 24-month mortality for non-revascularization AMI patients without events within 12 months after onset.

Antithrombotic therapy in patients with acute coronary syndrome: similarities and differences between a European expert consensus document and the 2023 European Society of Cardiology guidelines

Antithrombotic therapy represents the cornerstone of the pharmacological treatment in patients with acute coronary syndrome (ACS). The optimal combination and duration of antithrombotic therapy is still matter of debate requiring a critical assessment of patient comorbidities, clinical presentation, revascularization modality, and/or optimization of medical treatment. The 2023 European Society of Cardiology (ESC) guidelines for the management of patients with ACS encompassing both patients with and without ST segment elevation ACS have been recently published. Shortly before, a European expert consensus task force produced guidance for clinicians on the management of antithrombotic therapy in patients with ACS as well as chronic coronary syndrome. The scope of this manuscript is to provide a critical appraisal of differences and similarities between the European consensus paper and the latest ESC recommendations on oral antithrombotic regimens in ACS patients.

Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology 2023 Focused Update of the Guidelines for the Use of Antiplatelet Therapy

Antiplatelet therapy (APT) is the foundation of treatment and prevention of atherothrombotic events in patients with atherosclerotic cardiovascular disease. Selecting the optimal APT strategies to reduce major adverse cardiovascular events, while balancing bleeding risk, requires ongoing review of clinical trials. Appended, the focused update of the Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology guidelines for the use of APT provides recommendations on the following topics: (1) use of acetylsalicylic acid in primary prevention of atherosclerotic cardiovascular disease; (2) dual APT (DAPT) duration after percutaneous coronary intervention (PCI) in patients at high bleeding risk; (3) potent DAPT (P2Y12 inhibitor) choice in patients who present with an acute coronary syndrome (ACS) and possible DAPT de-escalation strategies after PCI; (4) choice and duration of DAPT in ACS patients who are medically treated without revascularization; (5) pretreatment with DAPT (P2Y12 inhibitor) before elective or nonelective coronary angiography; (6) perioperative and longer-term APT management in patients who require coronary artery bypass grafting surgery; and (7) use of APT in patients with atrial fibrillation who require oral anticoagulation after PCI or medically managed ACS. These recommendations are all on the basis of systematic reviews and meta-analyses conducted as part of the development of these guidelines, provided in the Supplementary Material.

Comparison between ticagrelor and clopidogrel in myocardial infarction patients with high bleeding risk

AIMS

Ticagrelor is associated with a lower risk of ischemic events than clopidogrel. However, it is uncertain whether the benefits of more intensive anti-ischemic therapy outweigh the risks of major bleeding in patients who have a high bleeding risk (HBR). Therefore, this study compared ticagrelor and clopidogrel in myocardial infarction (MI) patients with HBR.

METHODS AND RESULTS

This study included all patients enrolled in the SWEDEHEART registry who were discharged with dual antiplatelet therapy using ticagrelor or clopidogrel following MI between 2010 and 2017. High bleeding risk was defined as a PRECISE-DAPT score ≥25. Information on ischemic events, major bleeding, and mortality was obtained from national registries, with 365 days of follow-up. Additional outcomes include major adverse cardiovascular events (MACE), a composite of MI, stroke and all-cause mortality, and net adverse clinical events (NACE), a composite of MACE and bleeding. This study included 25 042 HBR patients, of whom 11 848 were treated with ticagrelor. Ticagrelor was associated with a lower risk of MI, stroke, and MACE, but a higher risk of bleeding compared to clopidogrel. There were no significant differences in mortality and NACE. Additionally, when examining the relationship between antiplatelet therapy and bleeding risk in 69 040 MI patients, we found no statistically significant interactions between the PRECISE-DAPT score and treatment effect.

CONCLUSIONS

We observed no difference in NACE when comparing ticagrelor and clopidogrel in HBR patients. Moreover, we found no statistically significant interactions between bleeding risk and the comparative effectiveness of clopidogrel and ticagrelor in a larger population of MI patients.

Efficacy and Safety Profile of Ticagrelor Versus Clopidogrel in Percutaneous Coronary Intervention (PCI) for Acute Coronary Syndrome (ACS): A Systematic Review and Meta-Analysis

The utilization of individualized anti-platelet therapy is of paramount significance in this era of cardiovascular advancement. This meta-analysis is also aiming to get more information relating to the effectiveness of ticagrelor versus clopidogrel among patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). A comprehensive literature search was done through various databases like PubMed, Google Scholar, EMBASE, Web of Science, and the Cochrane Database Library from January 15, 2023, to February 23, 2023. After careful screening, eight articles with highly significant variables were involved in the synthesis of this meta-analysis. Data analysis was done through Review Manager (RevMan, Version 5.4; The Cochrane Collaboration, Copenhagen, Denmark). In our study, ticagrelor and clopidogrel were evaluated in 10614 and 14662 patients, respectively. Ticagrelor was significantly superior to Clopidogrel in terms of all-cause mortality (RR 0.79, 95% CI 0.69-0.91, p = 0.001), risk of MI (RR 0.74, 95% CI 0.61-0.89, p = 0.001), and stroke (RR 0.64, 95% CI 0.42-0.98, p = 0.04), but a higher risk of bleeding events was observed with Ticagrelor (RR 1.36, 95% CI 1.04-1.79, p = 0.03). The two regimens were comparable in terms of stent thrombosis. Ticagrelor was found to be best in terms of reducing post-PCI myocardial infarction, stroke, stent thrombosis, and all other mortality events in comparison to Clopidogrel. However, the bleeding events were of significant concern for the utilization of ticagrelor and required further investigations.

Sex-Related Bleeding Risk in Acute Coronary Syndrome Patients Receiving Dual Antiplatelet Therapy with Aspirin and a P2Y12 Inhibitor

OBJECTIVE

The aim of this work was to study sex differences in major bleeding risk in relation to dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS).

METHODS AND RESULTS

The Rijnmond Collective Cardiology Research registry was designed to evaluate the application and outcomes of DAPT after ACS/PCI in the Rijnmond region in the Netherlands. Overall, 1,172 women (median age 67.5 years) and 3,087 men (median age 62.2 years) with ACS/PCI were enrolled between August 2011 and June 2013. Based on a tailored regional DAPT guideline aiming at bleeding risk minimization, 52.6% women and 66.9% men received prasugrel as first-choice P2Y12 inhibitor, in addition to aspirin. Women more frequently had contraindications for the use of prasugrel (and therefore received clopidogrel) than men (47.9 vs. 26.9%, p < 0.001). Femoral access was more common in women than in men (47.6 vs. 38.1%, p < 0.001). Women had higher incidence of major bleeding at 1 year than men (2.6 vs. 1.6%, p = 0.018). After adjustment for established bleeding risk factors, female sex was associated with over two-fold higher risk of major bleeding (adjusted hazard ratio 2.33; 95% confidence interval 1.26-4.32). This difference was apparent at discharge and appeared to be caused by access site bleedings (0.9 vs. 0.1%, p < 0.001). No sex differences were found in non-access site-related major bleeding up to 1 year.

CONCLUSION

Women with ACS/PCI receiving DAPT had higher major bleeding risk caused by an excess in access site bleeds, mainly in relation to the femoral approach.

Cytochrome P450 2C19 Polymorphisms and Its Association With Major Adverse Cardiac Events in Post-coronary Intervention Patients on Clopidogrel in the Tertiary Care Center

Background Clopidogrel has become essential in managing coronary artery disease and other atherothrombotic diseases. It is an inactive prodrug that needs biotransformation in the liver by various cytochrome P (CYP) 450 isoenzymes for its active metabolite formation. However, 4-30% of patients on clopidogrel have shown no or decreased antiplatelet response. This condition is called 'clopidogrel non-responsiveness' or 'clopidogrel resistance.' This is attributed to genetic heterogeneity causing interindividual variation and increased risk of major adverse cardiac events (MACEs). This study aimed to assess MACEs and their association with CYP450 2C19 polymorphisms in post-coronary intervention patients on clopidogrel. Methods This prospective observational study was conducted on acute coronary syndrome patients, started on clopidogrel following coronary intervention. After considering inclusion and exclusion criteria, 72 patients were enrolled, and a genetic analysis was done. Based on genetic analysis, patients were divided into two groups, normal (CYP2C19*1) and abnormal phenotypes (CYP2C19*2 & *3). These patients were followed for two years, and the MACE during the first year and second year was compared between these two groups. Results Of 72 patients, 39 (54.1%) were normal, and 33 (45.8%) were abnormal genotypes. The mean age of patients is 67.71 ± 9.968. A total of 19 and 27 MACEs were seen during first- and second-year follow-ups. During the first-year follow-up, three (9.1%) patients with abnormal phenotypes developed ST-elevation myocardial infarction (STEMI), and none of the phenotypically normal patients developed STEMI (p-value = 0.183). Non-ST elevation myocardial infarction (NSTEMI) was seen in three (7.7%) normal and seven (21.2%) abnormal phenotype patients (p-value=0.19). Other events, such as thrombotic stroke, stent thrombosis, and cardiac death, were seen in two (6.1%) abnormal phenotypic patients (p-value=0.401). During the second-year follow-up, STEMI was seen in one (2.6%) normal and three (9.7%) abnormal phenotypic patients (p-value=0.183). NSTEMI was seen in four (10.3%) normal and nine (29%) abnormal phenotype patients (p=0.045). Comparison of total MACEs between normal and abnormal phenotypic groups at the end of the first year (p-value=0.011) and second year (p-value=<0.01) has statistical significance. Conclusion We can infer that the risk of developing a recurrent MACE in post-coronary intervention patients on clopidogrel is significantly high in the abnormal phenotypic group (CYP2C19*2 & *3) than in normal phenotypic patients.

The Implementation of Pharmacogenetics in the United Kingdom

There is considerable inter-individual variability in the effectiveness and safety of pharmaceutical interventions. This phenomenon can be attributed to a multitude of factors; however, it is widely acknowledged that common genetic variation affecting drug absorption or metabolism play a substantial contributory role. This is a concept known as pharmacogenetics. Understanding how common genetic variants influence responses to medications, and using this knowledge to inform prescribing practice, could yield significant advantages for both patients and healthcare systems. Some health services around the world have introduced pharmacogenetics into routine practice, whereas others are less advanced along the implementation pathway. This chapter introduces the field of pharmacogenetics, the existing body of evidence, and discusses barriers to implementation. The chapter will specifically focus on efforts to introduce pharmacogenetics in the NHS, highlighting key challenges related to scale, informatics, and education.

Effects of CYP3A4*22 and CYP3A5 on clinical outcome in patients treated with ticagrelor for ST-segment elevation myocardial infarction: POPular Genetics sub-study

Aims: To determine the clinical efficacy, adverse events and side-effect dyspnea of CYP3A4*22 and CYP3A5 expressor status in ticagrelor treated patients. Methods and results: Ticagrelor treated patients from the POPular Genetics randomized controlled trial were genotyped for CYP3A4*22 and CYP3A5*3 alleles. Patients were divided based on their genotype. In total 1,281 patients with ST-segment elevation myocardial infarction (STEMI) were included. CYP3A4*22 carriers (n = 152) versus CYP3A4*22 non-carrier status (n = 1,129) were not found to have a significant correlation with the primary thrombotic endpoint: cardiovascular death, myocardial infarction, definite stent thrombosis and stroke [1.3% vs. 2.5%, adjusted hazard ratio 1.81 (0.43-7.62) p = 0.42], or the primary bleeding endpoint: PLATO major and minor bleeding [13.2% vs. 11.3%, adjusted hazard ratio 0.93 (0.58-1.50) p = 0.77]. Among the CYP3A4*1/*1 patients, CYP3A5 expressors (n = 196) versus non-expressors (n = 926) did not show a significant difference for the primary thrombotic [2.6% vs. 2.5%, adjusted hazard ratio 1.03 (0.39-2.71) p = 0.95], or the primary bleeding endpoint [12.8% vs. 10.9%, adjusted hazard ratio 1.13 (0.73-1.76) p = 0.58]. With respect to dyspnea, no significant difference was observed between CYP3A4*22 carriers versus CYP3A4*22 non-carriers [44.0% vs. 45.0%, odds ratio 1.04 (0.45-2.42) p = 0.93], or in the CYP3A4*1/*1 group, CYP3A5 expressors versus CYP3A5 non-expressors [35.3% vs. 47.8%, odds ratio 0.60 (0.27-1.30) p = 0.20]. Conclusion: In STEMI patients treated with ticagrelor, neither the CYP3A4*22 carriers, nor the CYP3A5 expressor status had a statistical significant effect on thrombotic and bleeding event rates nor on dyspnea. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT01761786.

The role of CYP2C19 genotyping to guide antiplatelet therapy following ischemic stroke or transient ischemic attack

Introduction

Clopidogrel is an antiplatelet agent recommended for secondary prevention of ischemic stroke (IS) and transient ischemic attack (TIA). Conversion of clopidogrel to its active metabolite by hepatic cytochrome P450-2C19 (CYP2C19) is essential for the inhibition of the P2Y12 receptor and subsequent platelet aggregation to prevent thrombotic events. CYP2C19 is highly polymorphic, with over 30 loss of function (LoF) alleles. This review considers whether there is sufficient data to support genotype guided antiplatelet therapy after stroke.

Areas covered

A systematic literature review retrieved articles, which describe the interaction between CYP2C19 genotype and clinical outcomes following IS or TIA when treated with clopidogrel. The review documents efforts to identify optimal antiplatelet regimens and explores the value genotype guided antiplatelet therapy. The work outlines the contemporary understanding of clopidogrel metabolism and appraises evidence linking CYP2C19 LoF variants with attenuated platelet inhibition and poorer outcomes.

Expert opinion

There is good evidence that CYP2C19 LoF allele carriers of Han-Chinese ancestry have increased risk for further vascular events following TIA or IS when treated with clopidogrel. The evidence base is less certain in other populations. The expansion of pharmacogenetics into routine clinical practice will facilitate further research and help tailor other aspects of secondary prevention.

Balancing the Risks of Recurrent Ischaemic and Bleeding Events in a Stable Post ACS Population

OBJECTIVE

To better guide decisions regarding antithrombotic treatment in individual patients surviving 6 months following an acute coronary syndrome (ACS) by balancing between subsequent recurrent ischaemic and bleeding risk.

METHODS

Patients surviving 6 months following an ACS were followed in an Australian registry. Ischaemic (composite of cardiovascular death, myocardial infarction or stroke) and bleeding (≥BARC 2) events were collected. A dual binary outcome modelling strategy was used arriving at a common set of variables from which bleeding and ischaemic risk could be independently determined in individual patients. Patients in whom bleeding rates exceeded composite ischaemic event rates during the follow-up period were identified.

RESULTS

The cohort comprised 5,905 patients in whom 215 experienced an ischaemic event and 49 a bleeding event. The single set of variables included in both ischaemic and bleeding models (C-statistics 0.71 and 0.72 respectively) included modified TIGRIS¹ ischaemic score, mode of revascularisation, history of heart failure, anaemia, multivessel disease, readmission within 6 months of index ACS and age >75. In the majority, ischaemic events were more frequent than bleeding events. In higher risk patients post coronary artery bypass grafting (CABG), bleeding events were more frequent than recurrent ischaemic events.

CONCLUSION

The risk of recurrent ischaemic events exceeds bleeding in most patients followed 6 to 24 months following an ACS. Post CABG patients with comorbidities have a higher risk of bleeding over this period during which time attention should be directed towards modifiable bleeding risk factors including requirement for dual antiplatelet therapy.

Effectiveness and Safety of Ticagrelor Implementation in Patients with Acute Coronary Syndrome undergoing Percutaneous Coronary Intervention: A Cohort Study in Western Denmark

Background

Methods

Findings

Interpretation

Current Perspectives on Antithrombotic Therapy for the Treatment of Acute Coronary Syndrome

Acute coronary syndrome (ACS) is one of the leading causes of death worldwide. Percutaneous coronary intervention (PCI) is the treatment of choice for ACS as this procedure reduces the morbidity and mortality rates of patients in clinical trials and daily practice. However, patients with a history of prior ACS who undergo PCI are still at high risk for recurrent major adverse cardiac events (MACE). Because the antithrombotic drugs reduce the rate of MACE and minimize stent-related complications such as target vessel failure or stent thrombosis, the utilization of these agents is the cornerstone treatment for secondary prevention of ACS patients after PCI. Unfortunately, using the antithrombotic agents may be associated with bleeding complications, including major or fatal bleeding. Therefore, premature discontinuation of antithrombotic regimens regarding the hemorrhagic events is sometimes inevitable and possibly leads to fatal complications such as stent thrombosis. To minimize the bleeding issues, shorten antithrombotic regimens have been proposed, which theoretically offers improved safety. Nevertheless, inappropriate withdrawal of antithrombotic drugs may increase the rate of ischemic events. On the other hand, an unnecessary prolonged antithrombotic regimen may cause avoidable bleeding. Balancing the risk of bleeding against the benefits of using antithrombotic drugs is therefore challenging especially for the patients who contain both bleeding and ischemic risks such as ACS patients who are concomitant using the anticoagulants. Currently, the treatment paradigms are shifting from the “one size fits all approach” toward the “tailored approach”. This means that the antithrombotic regimens can be adjustable individually. As a result, various clinical risk scoring systems have been established to help physicians with their decision-making. However, besides the development of these dedicated scoring tools, clinical judgment for balancing the safety versus the efficacy before deciding on the antithrombotic plan is still imperative.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

Addressing Posttreatment Selection Bias in Comparative Effectiveness Research, Using Real-World Data and Simulation

To examine methodologies that address imbalanced treatment switching and censoring, 6 different analytical approaches were evaluated under a comparative effectiveness framework: intention-to-treat, as-treated, intention-to-treat with censor-weighting, as-treated with censor-weighting, time-varying exposure, and time-varying exposure with censor-weighting. Marginal structural models were employed to address time-varying exposure, confounding, and possibly informative censoring in an administrative data set of adult patients who were hospitalized with acute coronary syndrome and treated with either clopidogrel or ticagrelor. The effectiveness endpoint included first occurrence of death, myocardial infarction, or stroke. These methodologies were then applied across simulated data sets with varying frequencies of treatment switching and censoring to compare the effect estimate of each analysis. The findings suggest that implementing different analytical approaches has an impact on the point estimate and interpretation of analyses, especially when censoring is highly unbalanced.

P2Y12 inhibition in acute coronary syndromes treated with percutaneous intervention - Understanding the debate on Prasugrel or Ticagrelor

After more than 10 years of routine clinical use, a debate about the preference of prasugrel over ticagrelor has been unveiled following publication of the ISAR-REACT 5 trial, an investigator-initiated trial directly comparing both substances as part of dual anti-platelet therapy following interventional treatment in patients with acute coronary syndromes (ACS). Both substances had been tested in trials, approved by authorities and subsequently recommended by guidelines according to the strategy applied in the respective approval trial. This resulted in prasugrel tested in TRITON only be given after diagnostic coronary angiography in the absence of ST-segment elevations (NSTE-ACS) and ticagrelor tested in PLATO being administered even before diagnostic coronary angiography in all forms of acute coronary syndromes. Whichever way was safest and most efficient, had never been clarified before. ISAR-REACT 5 showed superior efficacy of prasugrel over ticagrelor in general, and of deferred administration of prasugrel over pre-treatment with ticagrelor in NSTE-ACS patients undergoing percutaneous coronary interventions. Subsequently, in 2020 the European guidelines for NSTE-ACS adopted both positions in recommending the respective preference. Afterwards, a confrontational debate erupted between those favouring the ISAR-REACT 5 results and their implementation in guidelines and others still preferring the generalized interpretation of the overall study results from PLATO. In this review, we reflect the history leading to trial design of TRITON and PLATO and the way this subsequently impacted on clinical practice and guideline recommendations.

Safety of Oral P2Y12 Inhibitors in Interventional Neuroradiology: Current Status and Perspectives

In the field of interventional neuroradiology, antiplatelet agents are commonly used to prepare patients before the implantation of permanent endovascular materials. Among the available drugs, clopidogrel is the most frequently used one, but resistance phenomena are considered to be relatively common. Prasugrel and ticagrelor were recently added to the pharmacologic arsenal, but the safety of these agents in patients undergoing neurointerventional procedures is still a subject of discussion. The cumulative experience with both drugs is less extensive than that with clopidogrel, and the experience with patients in the neurology field is less extensive than in the cardiology domain. In the present article, we provide a narrative review of studies that investigated safety issues of oral P2Y12 inhibitors in interventional neuroradiology and discuss potential routes for future research.

Synthesis and biological evaluation of N 6 derivatives of 8-azapurine as novel antiplatelet agents

Two series of novel N 6 derivatives of 8-azapurine I and II were designed as antiplatelet agents. Series I and II were N 6 amino derivatives and N 6 hydrazone derivatives of 8-azapurine, respectively. The compounds were synthesized in acceptable yields via conventional procedures, including nucleophilic substitution, diazotization, and amination or hydrazonation with amino alcohol and 4,6-dichloropyrimidine as starting materials. To assess the ability of the synthesized compounds as antiplatelet agents, the ADP-induced platelet aggregation assay of Born was performed both in vitro and in vivo using ticagrelor as a reference control substance. The analysis of the structure-activity relationship and molecular docking were also discussed in detail. The results demonstrated that series I and II compounds exhibited antiplatelet activity in vitro and IIh was the most active compound (IC50 = 0.20 μM) among the target compounds, being almost 4-fold better than ticagrelor (IC50 = 0.74 μM). For a preliminary assessment of the safety profile, a bleeding test (mouse tail) and a single-dose toxicity test were conducted. The use of compound IIh resulted in a shorter bleeding time, less blood loss and lower acute toxicity compared to ticagrelor. In addition, a molecular docking study was performed to investigate the binding capacity and binding mode between IIh and P2Y12.

2020 ESC Guidelines on acute coronary syndrome without ST-segment elevation : Recommendations and critical appraisal from the Dutch ACS and Interventional Cardiology working groups

Recently, the European Society of Cardiology (ESC) has updated its guidelines for the management of patients with acute coronary syndrome (ACS) without ST-segment elevation. The current consensus document of the Dutch ACS working group and the Working Group of Interventional Cardiology of the Netherlands Society of Cardiology aims to put the 2020 ESC Guidelines into the Dutch perspective and to provide practical recommendations for Dutch cardiologists, focusing on antiplatelet therapy, risk assessment and criteria for invasive strategy.

Cost-Effectiveness of Ticagrelor Compared with Clopidogrel in Patients with Acute Coronary Syndrome from Vietnamese Healthcare Payers' Perspective

INTRODUCTION

The PLATelet inhibition and patient Outcomes (PLATO) trial (NCT00391872) demonstrated that ticagrelor compared to clopidogrel significantly reduced the rate of death from cardiovascular causes, myocardial infarction or stroke in patients with acute coronary syndrome (ACS). The aim of this study is to analyze the long-term cost-effectiveness of ticagrelor compared to clopidogrel in ACS patients from a Vietnamese healthcare payers' perspective.

METHODS

A two-part cost-effectiveness model was developed to estimate long-term costs and quality-adjusted life-years (QALY). Cardiovascular event rates, hospital bed days, interventions, investigations, study drug utilization and EuroQol 5 Dimension (EQ-5D) data were derived from the PLATO trial. Unit costs of medical services were derived from the Vietnamese governmental price list, and drug costs were based on the weighted average price from the Vietnamese social security report (in VND; 10.000 VND = 0.405 USD). An annual discount rate of 3% was used. Probabilistic and deterministic sensitivity analyses were conducted to evaluate uncertainty of the results.

RESULTS

Ticagrelor was associated with an incremental cost of VND 5.34 million (USD 216.49) and a QALY gain of 0.11. This resulted in a cost per QALY gained of VND 49.58 million (USD 2009.96) from the Vietnamese healthcare payers' perspective. Probabilistic sensitivity analysis indicates that ticagrelor has 59% probability of being cost-effective compared with clopidogrel when using a willingness-to-pay threshold of one gross domestic products (GDP) per capita. Deterministic sensitivity analysis using clinical outcomes from the Asian sub-population of PLATO resulted in a cost per QALY of VND 42.25 million (USD 1712.80).

CONCLUSION

Ticagrelor can be considered a cost-effective treatment for ACS compared with clopidogrel from a Vietnamese healthcare payers' perspective.

Ticagrelor Utilization in Patients With Non-ST Elevation Acute Coronary Syndromes in Romania

BACKGROUND

Dual antiplatelet therapy (DAPT) represents a major tool of non-ST elevation acute coronary syndrome (NSTE-ACS) management. The real-world usage of potent P2Y12 inhibitors within DAPT in middle-income countries is poorly described.

STUDY QUESTION

To assess the factors that influence P2Y12 inhibitor choice at discharge in invasively managed NSTE-ACS patients, without an indication for oral anticoagulation, treated across Romania.

STUDY DESIGN

The Romanian National NSTE-ACS Registry allows the consecutive enrollment of NSTE-ACS patients admitted in 11 (of 24) interventional centers reimbursed from public funds.

MEASURES AND OUTCOMES

NSTE-ACS patients that received DAPT at discharge were identified. Deceased patients, those with an indication for oral anticoagulation or not receiving DAPT at discharge, were excluded. P2Y12 inhibitor choice was analyzed based on demographic, clinical, and invasive management characteristics.

RESULTS

One thousand fifty (63 ± 10 years, 73% male) of 1418 patients enrolled between 2016 and 2019 were analyzed. The P2Y12 inhibitor pretreatment rate was 90%. Obstructive coronary artery disease was found in 95.3% of patients. 84.6% underwent percutaneous coronary interventions (PCIs). Single vessel PCI was reported in 84% of PCI patients. The clopidogrel usage rate was 49.6%, ticagrelor 50.0%, and prasugrel 0.4%. Overall, higher ticagrelor usage was associated with: non-ST elevation myocardial infarction (P 0.035), age below 65 (P < 0.001), prior treatment with ticagrelor (P < 0.001), PCI during admission (P < 0.001), and its full 12-month reimbursement (since November 2017). Reimbursement increased the use of ticagrelor from 23.7% in 2016-2017 to 56.9% in 2018-2019 (P < 0.001). In PCI patients, ticagrelor use was associated with PCI with stenting (P 0.016) and multivessel PCI (0.013).

CONCLUSIONS

DAPT, P2Y12 inhibitor pretreatment, and single vessel PCI are the standards of care in invasively managed NSTE-ACS patients in Romania. Besides the clinical and invasive characteristics that favor its use, the full reimbursement of ticagrelor introduced in November 2017 doubled its yearly usage.

Toward Brief Dual Antiplatelet Therapy and P2Y12 Inhibitors for Monotherapy After PCI

The optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention remains a controversial topic. The European Society of Cardiology and the American College of Cardiology/American Heart Association recommend at least 6 and 12 months of DAPT after PCI in patients with stable coronary artery disease or acute coronary syndrome, respectively. Although prolonging DAPT duration reduces ischemic events, it is associated with higher rates of bleeding and possible fatal outcomes. The DAPT score can be an important tool to identify patients who may still benefit from prolonged therapy. Nevertheless, several recent randomized controlled trials showed that shortening DAPT duration from 12 to 1-3 months reduces bleeding rates without significantly increasing ischemic event rates. These trials also suggested replacing acetylsalicylic acid (aspirin) with P2Y12 inhibitors after short-term DAPT. We review and compare past and present studies regarding DAPT and analyze the evidence favoring a short DAPT duration and the long-term single antiplatelet agent of choice.

Association of Sex With Outcomes in Patients Undergoing Percutaneous Coronary Intervention: A Subgroup Analysis of the GLOBAL LEADERS Randomized Clinical Trial

Importance

Women experience worse ischemic and bleeding outcomes after percutaneous coronary intervention (PCI).

Objectives

To assess the association of sex with patient outcomes at 2 years after contemporary PCI and with the efficacy and safety of 2 antiplatelet strategies.

Design, Setting, and Participants

This study is a prespecified subgroup analysis of the investigator-initiated, prospective, randomized GLOBAL LEADERS study evaluating 2 strategies of antiplatelet therapy after PCI in an unselected population including 130 secondary/tertiary care hospitals in different countries. The main study enrolled 15 991 unselected patients undergoing PCI between July 2013 and November 2015. Patients had an outpatient clinic visit at 30 days and 3, 6, 12, 18, and 24 months after the index procedure. Data were analyzed between January 1, 2019, and March 31, 2019.

Interventions

Eligible patients were randomized to either the experimental or reference antiplatelet strategy. Experimental strategy consisted of 1 month of dual antiplatelet therapy (DAPT) followed by 23 months of ticagrelor monotherapy, while the reference strategy comprised of 12 months of DAPT followed by 12 months of aspirin monotherapy.

Main Outcomes and Measures

The primary efficacy end point was the composite of all-cause mortality and new Q-wave myocardial infarction at 2 years. The secondary safety end point was Bleeding Academic Research Consortium type 3 or 5 bleeding.

Results

Of the 15 968 patients included in this study, 3714 (23.3%) were women. The risk of the primary end point at 2 years was similar between women and men (adjusted hazard ratio [HR], 1.00; 95% CI, 0.83-1.20). Compared with men, women had higher risk of Bleeding Academic Research Consortium type 3 or 5 bleeding (adjusted HR, 1.32; 95% CI, 1.04-1.67) and hemorrhagic stroke at 2 years (adjusted HR, 4.76; 95% CI, 1.92-11.81). At 2 years, there was no between-sex difference in the efficacy and safety of the 2 antiplatelet strategies. At 1 year, compared with DAPT, ticagrelor monotherapy was associated with a lower risk of bleeding in men (HR, 0.72; 95% CI, 0.53-0.98) but not in women (HR, 1.23; 95% CI, 0.80-1.89; P for interaction = .045).

Conclusions and Relevance

Compared with men, women experienced a higher risk of bleeding and hemorrhagic stroke after PCI. The effect of 2 antiplatelet strategies on death and Q-wave myocardial infarction following PCI did not differ between the sexes at 2 years.

Trial Registration

ClinicalTrials.gov identifier: NCT01813435.

Actual Issues of Ischemic and Hemorrhagic Events Risk Management During Antithrombotic Therapy in Patients with Acute Coronary Syndrome

Today, optimal duration of double antiplatelet (DAPT) and triple antithrombotic therapy (TATT) in patients with acute coronary syndrome (ACS) remains the subject of scientific and practical discussion on possibilities of ischemic and hemorrhagic risks assessment. Good clinical risk metrics is based on validated risk scales. However, actual clinical guidelines do not provide a universal and generally accepted scale for assessing the balance of risks of ischemic events and bleeding. Is very necessary to determine the optimal content and DAPT or TATT duration is the existence of validated risk assessment scales would allow to optimize the accuracy of risk assessment of ischemic and hemorrhagic events in patients after ACS. One of the probable reasons is absence of validation of existing scales for each specific population of patients with ACS. In this regard, the use of «new» risk assessment systems: PRECISE DAPT and DAPT, in addition to the routine risk assessment scales (GRACE, CRUSADE), could become optimal in all ACS patient categories. In order to identify the initial risk of community-acquired hemorrhagic events during the first 12 months all patients with ACS at the inpatient stage of treatment is used the PRECISE DAPT score. In order to determine the need for prolongation of the standard DAPT. It should be used after 12 months of receiving DAPT in survivors of ACS patients without ischemic events, must be used the DAPT score.

Downstream or upstream administration of P2Y12 receptor blockers in non-ST elevated acute coronary syndromes: study protocol for a randomized controlled trial

Background

The optimal timing to administer a P2Y12 inhibitor in patients presenting with a non-ST elevation acute coronary syndrome remains a topic of debate. Pretreatment with ticagrelor before coronary anatomy is known as a widely adopted strategy. However, there is poor evidence on how this compares with administration of a P2Y12 inhibitor after defining coronary anatomy (i.e., downstream administration). Moreover, there are limited head-to-head comparisons of the two P2Y12 inhibitors—ticagrelor and prasugrel—currently recommended by the guidelines.

Study design

DUBIUS is a phase 4, multicenter, parallel-group, double randomized study conducted in NSTE-ACS patients designed to compare a pretreatment strategy (including only ticagrelor) versus a downstream strategy (including prasugrel or ticagrelor) and to compare downstream prasugrel with downstream ticagrelor. A total of 2520 patients will be randomly assigned to pretreatment with ticagrelor or to no pretreatment. The PCI group of the downstream arm will be further randomized to receive prasugrel or ticagrelor. The two primary hypotheses are that the downstream strategy is superior to the upstream strategy and that downstream ticagrelor is non-inferior to downstream prasugrel, both measured by the incidence of a composite efficacy and safety endpoint of death from vascular causes, non-fatal MI, or non-fatal stroke, and Bleeding Academic Research Consortium (BARC) type 3, 4, and 5 bleedings.

Conclusions

The DUBIUS study will provide important evidence related to the benefits and risks of pretreatment with ticagrelor compared with a strategy of no pretreatment. Moreover, the clinical impact of using downstream ticagrelor compared with downstream prasugrel will be assessed.

Trial registration

ClinicalTrials.gov NCT02618837. Registered on 1 December 2015.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13063-020-04859-1.

Long-term antiplatelet therapy in medically managed non-ST-segment elevation acute coronary syndromes: The EPICOR Asia study

OBJECTIVES

To describe long-term antithrombotic management patterns (AMPs) in medically managed Asian patients with non-ST-segment myocardial infarction (NSTEMI) or unstable angina (UA).

BACKGROUND

Current guidelines support an early invasive strategy in NSTEMI and UA patients, but many are medically managed, and data are limited on long-term AMPs in Asia.

METHODS

Data were analyzed from medically managed NSTEMI and UA patients included in the prospective, observational EPICOR Asia study (NCT01361386). Survivors to hospital discharge were enrolled (June 2011 to May 2012) from 8 countries/regions across Asia. Baseline characteristics and AMP use up to 2 years post-discharge were collected. Outcomes were major adverse cardiovascular events (MACE: myocardial infarction, ischemic stroke, and death) and bleeding.

RESULTS

Among 2289 medically managed patients, dual antiplatelet therapy (DAPT) use at discharge was greater in NSTEMI than in UA patients (81.8% vs 65.3%), and was significantly associated with male sex, positive cardiac markers, and prior cardiovascular medications (p < 0.0001). By 2 years, 57.9% and 42.6% of NSTEMI and UA patients, respectively, were on DAPT. On multivariable Cox regression analysis, risk of MACE at 2 years was most significantly associated with older age (HR [95% CI] 1.85 [1.36, 2.50]), diagnosis of NSTEMI vs UA (1.96 [1.47, 2.61]), and chronic renal failure (2.14 [1.34, 3.41]), all p ≤ 0.001. Risk of bleeding was most significantly associated with region (East Asia vs Southeast/South Asia) and diabetes.

CONCLUSIONS

Approximately half of all patients were on DAPT at 2 years. MACE were more frequent in NSTEMI than UA patients during follow-up.

Oral Antiplatelet Therapy Administered Upstream to Patients With NSTEMI

To describe from a noninterventional registry (Utilization of Ticagrelor in the Upstream Setting for Non-ST-Segment Elevation Acute Coronary Syndrome), the short-term ischemic and hemorrhagic outcomes in patients with non-ST elevation myocardial infarction (MI) are managed with a loading dose (LD) of a P2Y₁₂ inhibitor (P2Y₁₂i) given at least 4 hours before diagnostic angiography and delineation of coronary anatomy. Prior data on the effects of such “upstream loading” have been inconsistent.

CYP2C19 genotype-guided antiplatelet therapy: promises and pitfalls

Pharmacogenetic variants can alter the mechanism of action (pharmacodynamic gene variants) or kinetic processes such as absorption, distribution, metabolism and elimination (pharmacokinetic gene variants). Many initial successes in precision medicine occurred in the context of genes encoding the cytochromes P450 (CYP enzymes). CYP2C19 activates the antiplatelet drug clopidogrel, and polymorphisms in the CYP2C19 gene are known to alter the outcome for patients taking clopidogrel in the context of cardiovascular disease. CYP2C19 loss-of-function alleles are specifically associated with increased risk for coronary stent thrombosis and major adverse cardiovascular events in patients taking clopidogrel following percutaneous coronary intervention. We explore successes and challenges encountered as the clinical and scientific communities advance CYP2C19 genotyping in the context of routine patient care.

Efficacy and safety of different ticagrelor regimens versus clopidogrel in patients with coronary artery disease: a retrospective multicenter study (SUPERIOR)

Current guidelines favor dual anti-platelet therapy with ticagrelor 90 mg BID (T90BID) over clopidogrel 75 mg QD (C75QD) in addition to aspirin for acute coronary syndrome. However, an increased risk of ticagrelor-related adverse events prompted the evaluation of low-dose regimens. This study (NCT03381742) retrospectively analyzed the data from 11 hospitals on 3,043 patients with coronary artery disease, who received C75QD, T90BID, ticagrelor 45 mg BID (T45BID), or ticagrelor 90 mg QD (T90QD). Compared with C75QD, both T45BID and T90QD showed significantly higher inhibition of platelet aggregation (P < .0001) and lower platelet-fibrin clot strength (P < .0001) induced by adenosine diphosphate. Furthermore, compared with T90BID, two low-dose regimens had a much lower minor bleeding rate and a significantly higher proportion of patients within the therapeutic window for P2Y₁₂ receptor reactivity. There were no significant differences between T45BID and T90QD in the trough plasma concentrations of ticagrelor and its active metabolite. Similar efficacy and safety outcomes were observed in the propensity score-matched analysis. In conclusion, the low-dose ticagrelor regimen, either T45BID or T90QD, may provide a more attractive benefit-risk profile than C75QD or T90BID.

Necessity of Antiaggregation and Anticoagulation and Its Prognostic Impact: A Cardiologist’s View

<b><i>Background:</i></b> In modern cardiology, anticoagulation and antiaggregation are key components of current treatment strategies. However, in patients treated with anticoagulation and antiplatelet substances, bleeding is a major risk. <b><i>Findings:</i></b> In all major cardiovascular diseases, a multitude of studies have shown a positive impact of antithrombotic treatment on cardiovascular death. In patients with higher bleeding risks, recent studies showed the safety of reducing the period of dual antiplatelet therapy (DAPT), i.e., after percutaneous coronary intervention. In patients with coronary artery disease and atrial fibrillation (AF), triple therapy including DAPT and anticoagulation is associated with very high bleeding risks. However, recently published data showed the safety of direct oral anticoagulants (DOACs) and P2Y12 inhibitors only compared to vitamin K antagonist (VKA) and DAPT. Anticoagulation in nonvalvular AF reduces major cerebrovascular ischemic events. However, the inherent cerebrovascular bleeding risk is an important concern of this treatment. With the advent of DOACs, this risk could be reduced compared to VKA. Furthermore, anticoagulation and antiaggregation are crucial after treatment of valve disease, both after surgical and interventional procedures. Even in heart failure, new data show benefits using antithrombotic substances. <b><i>Conclusions:</i></b> Anticoagulation and antiaggregation are of major prognostic relevance in cardiovascular diseases. However, the inherent bleeding risk has to be considered.

Long-term ticagrelor for secondary prevention in patients with prior myocardial infarction and no history of coronary stenting: insights from PEGASUS-TIMI 54

Aims

PEGASUS-TIMI 54 demonstrated that long-term dual antiplatelet therapy (DAPT) with aspirin and ticagrelor reduced the risk of major adverse cardiovascular events (MACE), with an acceptable increase in bleeding, in patients with prior myocardial infarction (MI). While much of the discussion around prolonged DAPT has been focused on stented patients, patients with prior MI without prior coronary stenting comprise a clinically important subgroup.

Methods and results

This was a pre-specified analysis from PEGASUS-TIMI 54, which randomized 21 162 patients with prior MI (1–3 years) and additional high-risk features to ticagrelor 60 mg, 90 mg, or placebo twice daily in addition to aspirin. A total of 4199 patients had no history of coronary stenting at baseline. The primary efficacy outcome (MACE) was the composite of cardiovascular death, MI, or stroke. Patients without history of coronary stenting had higher baseline risk of MACE [13.2% vs. 8.0%, adjusted hazard ratio (HR) 1.41, 95% confidence interval (CI) 1.15–1.73, in the placebo arm]. The relative risk reduction in MACE with ticagrelor (pooled doses) was similar in patients without (HR 0.82, 95% CI 0.68–0.99) and with prior stenting (HR 0.85, 95% CI 0.75–0.96; P for interaction = 0.76).

Conclusion

Long-term ticagrelor reduces thrombotic events in patients with prior MI regardless of whether they had prior coronary stenting. These data highlight the benefits of DAPT in prevention of spontaneous atherothrombotic events and indicate that long-term ticagrelor may be considered in high-risk patients with prior MI even if they have not been treated with stenting.

ClinicalTrials.gov Identifier

NCT01225562.

Ticagrelor or Prasugrel in Patients with Acute Coronary Syndromes

BACKGROUND

The relative merits of ticagrelor as compared with prasugrel in patients with acute coronary syndromes for whom invasive evaluation is planned are uncertain.

METHODS

In this multicenter, randomized, open-label trial, we randomly assigned patients who presented with acute coronary syndromes and for whom invasive evaluation was planned to receive either ticagrelor or prasugrel. The primary end point was the composite of death, myocardial infarction, or stroke at 1 year. A major secondary end point (the safety end point) was bleeding.

RESULTS

A total of 4018 patients underwent randomization. A primary end-point event occurred in 184 of 2012 patients (9.3%) in the ticagrelor group and in 137 of 2006 patients (6.9%) in the prasugrel group (hazard ratio, 1.36; 95% confidence interval [CI], 1.09 to 1.70; P = 0.006). The respective incidences of the individual components of the primary end point in the ticagrelor group and the prasugrel group were as follows: death, 4.5% and 3.7%; myocardial infarction, 4.8% and 3.0%; and stroke, 1.1% and 1.0%. Definite or probable stent thrombosis occurred in 1.3% of patients assigned to ticagrelor and 1.0% of patients assigned to prasugrel, and definite stent thrombosis occurred in 1.1% and 0.6%, respectively. Major bleeding (as defined by the Bleeding Academic Research Consortium scale) was observed in 5.4% of patients in the ticagrelor group and in 4.8% of patients in the prasugrel group (hazard ratio, 1.12; 95% CI, 0.83 to 1.51; P = 0.46).

CONCLUSIONS

Among patients who presented with acute coronary syndromes with or without ST-segment elevation, the incidence of death, myocardial infarction, or stroke was significantly lower among those who received prasugrel than among those who received ticagrelor, and the incidence of major bleeding was not significantly different between the two groups. (Funded by the German Center for Cardiovascular Research and Deutsches Herzzentrum München; ISAR-REACT 5 ClinicalTrials.gov number, NCT01944800.).

Medical Therapy for Long-Term Prevention of Atherothrombosis Following an Acute Coronary Syndrome: JACC State-of-the-Art Review

Following an acute coronary syndrome (ACS), heightened predisposition to atherothrombotic events may persist for years. Advances in understanding the pathobiology that underlies this elevated risk furnish a mechanistic basis for devising long-term secondary prevention strategies. Recent progress in ACS pathophysiology has challenged the focus on single "vulnerable plaques" and shifted toward a more holistic consideration of the "vulnerable patient," thus highlighting the primacy of medical therapy in secondary prevention. Despite current guideline-directed medical therapy, a consistent proportion of post-ACS patients experience recurrent atherothrombosis due to unaddressed "residual risk": contemporary clinical trials underline the pivotal role of platelets, coagulation, cholesterol, and systemic inflammation and provide a perspective on a personalized, targeted approach. Emerging data sheds new light on heretofore unrecognized residual risk factors. This review aims to summarize evolving evidence relative to secondary prevention of atherothrombosis, with a focus on recent advances that promise to transform the management of the post-ACS patient.

Real-world use of ticagrelor versus clopidogrel in percutaneous coronary intervention-treated ST-elevation myocardial infarction patients: A single-center registry study

Objectives

The primary aim was to investigate the efficacy and safety of dual antiplatelet therapy (DAPT) using ticagrelor (T-DAPT) versus clopidogrel (C-DAPT) in a real-world ST-elevation myocardial infarction (STEMI) population.

Methods

We retrospectively analyzed 655 consecutive patients having primary percutaneous coronary intervention (PCI) for STEMI at Liverpool Hospital, Sydney, Australia (from January 2013 to April 2016). Medical and procedural therapies were at clinician discretion. Patient data were retrieved from hospital records and primary clinicians.

Results

T-DAPT (65%) was used more frequently, and in patients with lower mean CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association Guidelines) score, than C-DAPT (24.6 vs. 32.2; p < 0.0001, respectively). All-cause mortality was 9.0% at 2.7 years follow-up, with fewer deaths for T-DAPT (4.5% vs. 17.2%; p < 0.0001). T-DAPT incurred less BARC (Bleeding Academic Research Consortium) 3-5 major bleeding (5.0% vs. 12.4%; p < 0.0001). Multivariate regression showed that C-DAPT, GRACE (Global Registry of Acute Cardiac Events) score, and renal insufficiency were independently associated with mortality. Intra-aortic balloon pump (IABP) and GRACE score independently predicted BARC 3-5 bleeding. Early DAPT discontinuation (1.7%) and ticagrelor intolerance (7.6%) was rare. Switching DAPT regimen was infrequent (21.7%) and mostly attributed to clinician preference (73.2%). Independent determinants of C-DAPT selection were older age, diabetes, prior PCI, IABP, and higher CRUSADE score.

Conclusion

Ticagrelor was preferred in low bleeding risk patients, which may have contributed to less BARC 3-5 bleeding and lower mortality for T-DAPT. Thus, bleeding mitigation is a clinical priority when selecting DAPT for PCI-treated STEMI patients. Continuation of initial DAPT regimen was typical, but early switching from clopidogrel to ticagrelor shows willingness to optimize DAPT. Patients with very low CRUSADE scores (<21.5) may be appropriate for switching to a potent P2Y12 inhibitor.

Role of Platelet Activation and Oxidative Stress in the Evolution of Myocardial Infarction

Myocardial infarction, commonly known as heart attack, evolves from the rupture of unstable atherosclerotic plaques to coronary thrombosis and myocardial ischemia–reperfusion injury. A body of evidence supports a close relationship between the alterations following an ischemia–reperfusion injury-induced oxidative stress and platelet activity. Through their critical role in thrombogenesis and inflammatory responses, platelets are fully (totally) implicated from atherothrombotic plaque formation to myocardial infarction onset and expansion. However, mere platelet aggregation prevention does not offer full protection, suggesting that other antiplatelet therapy mechanisms may also be involved. Thus, the present review discusses the integrative role of platelets, oxidative stress, and antiplatelet therapy in triggering myocardial infarction pathophysiology.

The impact of CYP2C19 and CYP4F2 variants and clinical factors on treatment outcomes during antiplatelet therapy

Aim: The aim of this study was to determine the impact of genetic and nongenetic factors on treatment outcomes in patients receiving dual antiplatelet therapy after percutaneous coronary intervention and stent implantation. Materials & methods: Patients (n = 628) used clopidogrel or ticagrelor for at least 1 week before platelet aggregation test. Results: Multivariate binary regression analysis demonstrated that aspirin use and CYP4F2 T allele significantly increased odds for bleeding in clopidogrel users (OR: 2.488, 95% CI: 1.452-4.265; p = 0.001 and OR: 1.573, 95% CI: 1.066-2.320; respectively; p = 0.022). CYP4F2 T allele significantly increased odds for bleeding in ticagrelor users (OR: 8.270, 95% CI: 3.917-17.462; p < 0.001). Conclusion: Aspirin use and CYP4F2 T allele were significantly associated with bleeding during dual antiplatelet therapy.

Antibody-Based Ticagrelor Reversal Agent in Healthy Volunteers

BACKGROUND

Ticagrelor is an oral P2Y₁₂ inhibitor that is used with aspirin to reduce the risk of ischemic events among patients with acute coronary syndromes or previous myocardial infarction. Spontaneous major bleeding and bleeding associated with urgent invasive procedures are concerns with ticagrelor, as with other antiplatelet drugs. The antiplatelet effects of ticagrelor cannot be reversed with platelet transfusion. A rapid-acting reversal agent would be useful.

METHODS

In this randomized, double-blind, placebo-controlled, phase 1 trial, we evaluated intravenous PB2452, a monoclonal antibody fragment that binds ticagrelor with high affinity, as a ticagrelor reversal agent. We assessed platelet function in healthy volunteers before and after 48 hours of ticagrelor pretreatment and again after the administration of PB2452 or placebo. Platelet function was assessed with the use of light transmission aggregometry, a point-of-care P2Y₁₂ platelet-reactivity test, and a vasodilator-stimulated phosphoprotein assay.

RESULTS

Of the 64 volunteers who underwent randomization, 48 were assigned to receive PB2452 and 16 to receive placebo. After 48 hours of ticagrelor pretreatment, platelet aggregation was suppressed by approximately 80%. PB2452 administered as an initial intravenous bolus followed by a prolonged infusion (8, 12, or 16 hours) was associated with a significantly greater increase in platelet function than placebo, as measured by multiple assays. Ticagrelor reversal occurred within 5 minutes after the initiation of PB2452 and was sustained for more than 20 hours (P<0.001 after Bonferroni adjustment across all time points for all assays). There was no evidence of a rebound in platelet activity after drug cessation. Adverse events related to the trial drug were limited mainly to issues involving the infusion site.

CONCLUSIONS

In healthy volunteers, the administration of PB2452, a specific reversal agent for ticagrelor, provided immediate and sustained reversal of the antiplatelet effects of ticagrelor, as measured by multiple assays. (Funded by PhaseBio Pharmaceuticals; ClinicalTrials.gov number, NCT03492385.).

Effects of Ticagrelor versus Clopidogrel in Patients with Coronary Bifurcation Lesions Undergoing Percutaneous Coronary Intervention

Background

Percutaneous treatment of coronary bifurcation lesions can potentially lead to higher risk of ischemic events than the nonbifurcation ones, thus calling for further optimization of dual antiplatelet therapy (DAPT). This study aimed to compare the clinical outcomes from ticagrelor and clopidogrel in bifurcation lesions patients undergoing percutaneous coronary intervention (PCI).

Methods

We performed a retrospective cohort study in patients with coronary bifurcation lesions. A total of 553 patients discharged on ticagrelor or clopidogrel combined with aspirin were recruited for 1-year follow-up. The incidences of primary endpoint (major adverse cardiovascular event [MACE]: a composite of cardiac death, myocardial infarction [MI] or stroke), secondary endpoints (the individual component of the primary endpoint or definite/probable stent thrombosis), and major bleeding (Bleeding Academic Research Consortium [BARC]≥3 bleeding events) were evaluated. To minimize the selection bias, a propensity score-matched population analysis was also conducted.

Results

The risks of both primary endpoint (8.15% and 12.01% for the ticagrelor and clopidogrel groups, respectively; adjusted hazards ratio [HR]: 0.488, 95% confidence interval [CI]: 0.277-0.861, P=0.013) and MI (4.44% and 8.48% for the ticagrelor and clopidogrel groups, respectively; adjusted HR: 0.341, 95% CI: 0.162-0.719, P=0.005) were significantly reduced in the ticagrelor group as compared with those of the clopidogrel counterpart, whereas the risk of major bleeding was comparable (2.96% and 2.47% for the ticagrelor and clopidogrel groups, respectively; adjusted HR: 0.972, 95% CI: 0.321-2.941, P=0.960). Propensity score-matched analysis confirmed such findings.

Conclusions

For patients with bifurcation lesions after PCI, ticagrelor treatment shows lower MACE and MI rates than the clopidogrel one, along with comparable major bleeding.

Long-term dual antiplatelet therapy: pharmacological and clinical implications

: Patients experiencing an acute coronary syndrome are exposed to an increased residual risk of recurrent coronary events. Dual antiplatelet therapy (DAPT) is highly effective in preventing atherothrombotic complications in patients with previous myocardial infarction and current guidelines recommend the prescription of DAPT for at least 12 months in all patients experiencing an acute event. However, recent findings demonstrated that long-term DAPT (over 12 months) is related to a better outcome in patients at high risk, suggesting the use of a long-term DAPT to achieve a better clinical outcome. The choice of DAPT duration is still a difficult issue and a personalized approach to the patients is mandatory to manage both the residual ischemic risk and the risk of bleeding events.The aim of this review is to analyze the pharmacological characteristics of available antiplatelet agents and to revise the use of DAPT in clinical practice, focusing on the benefits of a long-term approach.

Ticagrelor and Statin Interaction Induces Rhabdomyolysis and Acute Renal Failure: Case reports and Scoping Review

Ever since evidence about the increased risk of stent thrombosis with drug eluting stents (DES) surfaced in 2005, the Food and Drug Administration (FDA) has recommended the use of dual antiplatelet therapy (aspirin with P2Y12 inhibitor) following DES placement. The PLATO trial demonstrated lower mortality rates with the use of Ticagrelor when compared to clopidogrel (9.8% vs. 11.7%, p<0.001) when treating patients with acute coronary syndrome. Given their pleiotropic benefits, statins are today the second most prescribed drug in the United States and often co-prescribed with Ticagrelor. FDA's post market surveillance of Ticagrelor use along with statins in post-myocardial infarction care is now revealing novel and serious adverse events. We present two cases of rhabdomyolysis and acute renal failure (ARF) which develop while the patients were on statins and Ticagrelor. Case 1: A 66-year-old female presented with bilateral thigh pain for 3 days. One month prior to presentation, she was managed for non-ST segment elevation myocardial infarction (NSTEMI) and had been started on aspirin, ticagrelor and simvastatin. Laboratory values revealed creatinine kinase (CK) level at 40,000 U/L and creatinine 3.2 mg/dL suggesting rhabdomyolysis and ARF. Case 2: A 63-year-old male presented with generalized body aches and fatigue for 4 days. He had sustained STEMI two months before and received two drug eluting stents (DES) and aspirin, ticagrelor and rosuvastatin had been initiated. CK was 380,000 U/L and creatinine 7.94 mg/dL suggesting rhabdomyolysis and ARF. Both patients presented with rhabdomyolysis and acute renal failure within weeks after ticagrelor and statin were commenced. A review of the literature indicated that 11 similar cases of ticagrelor-induced ARF and rhabdomyolysis had been reported. Ticagrelor competes with statins when metabolized by cytochrome P450 (CYP) 3A4 leading to statin retention, leading to major adverse effects like rhabdomyolysis and acute renal failure. Our review is intended to alert clinicians about this important drug interaction.

Increased Use of Ticagrelor After Myocardial Infarction Is Not Associated With Intracranial Hemorrhage

Background and Purpose- Guidelines recommend dual antiplatelet treatment with ticagrelor instead of clopidogrel after acute myocardial infarction. Ticagrelor increases major and minor noncoronary artery bypass graft bleeding compared with clopidogrel, but whether the risk of intracranial hemorrhage (ICH) increases is unknown. We aimed to examine any association between ticagrelor and ICH and to identify predictors of ICH among unselected patients after acute myocardial infarction. Methods- Patients with acute myocardial infarction were identified using the Register of Information and Knowledge About Swedish Heart Intensive Care Admissions, and the data were combined with the Swedish National Patient Registry to identify ICH occurrence. To avoid obvious selection bias related to the choice of dual antiplatelet treatment, we divided the study cohorts into 2 time periods of similar length using the first prescription of ticagrelor as a cutoff point (December 20, 2011). The risk of ICH during the first period (100% clopidogrel treatment) versus the second period (52.1% ticagrelor and 47.8% clopidogrel treatment) was assessed using Kaplan-Meier analysis. Cox proportional-hazards regression analyses, with assessment of interactions between all significant variables, were used to identify predictors of ICH. Results- The analysis included 47 674 patients with acute myocardial infarction. The cumulative incidence of ICH during the first period was 0.59% (91 cases [95% CI, 0.49-0.69]) versus 0.52% (97 cases [95% CI, 0.43-0.61]) during the second period ( P=0.83). In multivariable Cox analysis, study period (second versus first period) was not predictive of ICH. Interaction analyses showed that age and prior cardiovascular morbidities were of importance in predicting the risk of ICH. Conclusions- The increased use of ticagrelor was not associated with ICH, whereas age and prior cardiovascular morbidities were related to the risk of ICH and interacted significantly.

Oral Antiplatelet Therapy for Secondary Prevention of Acute Coronary Syndrome

Patients surviving an acute coronary syndrome (ACS) remain at increased risk of ischemic events long term. This paper reviews current evidence and guidelines for oral antiplatelet therapy for secondary prevention following ACS, with respect to decreased risk of ischemic events versus bleeding risk according to individual patient characteristics and risk factors. Specifically, data are reviewed from clinical studies of clopidogrel, prasugrel, ticagrelor and vorapaxar, as well as the results of systematic reviews and meta-analyses looking at the benefits and risks of oral antiplatelet therapy, and the relative merits of shorter versus longer duration of dual antiplatelet therapy, in different patient groups.