Use of glycoprotein IIb/IIIa antagonists to prevent stent thrombosis in morphine-treated patients with ST-elevation myocardial infarction

Optimizing antithrombotic therapy in patients with coexisting cardiovascular and gastrointestinal disease

Balancing the safety and efficacy of antithrombotic agents in patients with gastrointestinal disorders is challenging because of the potential for interference with the absorption of antithrombotic drugs and for an increased risk of bleeding. In this Review, we address considerations for enteral antithrombotic therapy in patients with cardiovascular disease and gastrointestinal comorbidities. For those with gastrointestinal bleeding (GIB), we summarize a general scheme for risk stratification and clinical evidence on risk reduction approaches, such as limiting the use of concomitant medications that increase the risk of GIB and the potential utility of gastrointestinal protection strategies (such as proton pump inhibitors or histamine type 2 receptor antagonists). Furthermore, we summarize the best available evidence and potential gaps in our knowledge on tailoring antithrombotic therapy in patients with active or recent GIB and in those at high risk of GIB but without active or recent GIB. Finally, we review the recommendations provided by major medical societies, highlighting the crucial role of teamwork and multidisciplinary discussions to customize the antithrombotic regimen in patients with coexisting cardiovascular and gastrointestinal diseases.

Parenteral Antiplatelet Drugs in ST-Elevation Myocardial Infarction: Current Status and Future Directions

Oral inhibitors of the platelet P2Y₁₂ receptor are indispensable in the treatment of ST-elevation myocardial infarction (STEMI), improving outcomes and even reducing mortality in some studies. However, these drugs are limited by delayed absorption and suboptimal platelet inhibition at the time of primary percutaneous coronary intervention. Despite efforts to achieve faster and more sustained platelet inhibition, strategies such as prehospital administration, higher loading doses, and crushed formulations have not led to improved coronary reperfusion. Parenteral glycoprotein IIb/IIIa inhibitors act sooner and are more potent than oral P2Y₁₂ inhibitors, but their use has been limited by the increased risk of major bleeding and thrombocytopenia. Hence, there is a clinical need to refine drugs that deliver rapid, effective, yet safe platelet inhibition in the setting of STEMI. Novel parenteral antiplatelet drugs, such as cangrelor, selatogrel, and zalunfiban, have been recently developed to achieve rapid, potent antiplatelet effects while preserving hemostasis. We provide a description of currently available parenteral antiplatelet agents and of those in clinical development for prehospital administration in STEMI patients.

Current and Future Insights for Optimizing Antithrombotic Therapy to Reduce the Burden of Cardiovascular Ischemic Events in Patients with Acute Coronary Syndrome

The pharmacological treatment strategies for acute coronary syndrome (ACS) in recent years are constantly evolving to develop more potent antithrombotic agents, as reflected by the introduction of more novel P2Y₁₂ receptor inhibitors and anticoagulants to reduce the ischemic risk among ACS patients. Despite the substantial improvements in the current antithrombotic regimen, a noticeable number of ACS patients continue to experience ischemic events. Providing effective ischemic risk reduction while balancing bleeding risk remains a clinical challenge. This updated review discusses the currently approved and widely used antithrombotic agents and explores newer antithrombotic treatment strategies under development for the initial phase of ACS.

The role of platelet glycoprotein IIb / IIIa inhibitors in current treatment of acute coronary syndrome

Current management of patients with acute coronary syndrome (ACS) includes a dual antiplatelet therapy with acetylsalicylic acid and a platelet P2Y12 receptor inhibitor. For patients without a high risk of bleeding, prasugrel and ticagrelor are preferred, since their effect is more pronounced, less dependent on metabolism of a specific patient, and occurs faster that the effect of clopidogrel. The prescription rate of platelet glycoprotein IIb/IIIa (GP IIb / IIIa) receptor inhibitors has considerably decreased. However, these drugs remain relevant in percutaneous coronary interventions in patients with a high risk of coronary thrombosis or a massive coronary thrombus, in thrombotic complications of the procedure, and in the "no-reflow" phenomenon. The intravenous route of GP IIb / IIIa inhibitor administration provides their effectiveness in patients with difficulties of drug intake or with impaired absorption of oral medications. This review presents clinical and pharmacological characteristics of various GP IIb / IIIa inhibitors and data of randomized clinical studies and registries of recent years that evaluated results of their use in patients with ACS.

Pre-Hospital Antiplatelet Therapy for STEMI Patients Undergoing Primary Percutaneous Coronary Intervention: What We Know and What Lies Ahead

Early recanalization of the infarct-related artery to achieve myocardial reperfusion is the primary therapeutic goal in patients with ST-elevation myocardial infarction (STEMI). To decrease the duration of ischaemia, continuous efforts have been made to improve pre-hospital treatment and to target the early period after symptom onset. In this period the platelet content of the fresh coronary thrombus is maximal and the thrombi are dynamic, and thus more susceptible to powerful antiplatelet agents. There have been substantial advances in antiplatelet therapy in the last three decades with several classes of oral and intravenous antiplatelet agents with different therapeutic targets, pharmacokinetics, and pharmacodynamic properties. New parenteral drugs achieve immediate inhibition of platelet aggregation, and fast and easy methods of administration may create the opportunity to bridge the initial gap in platelet inhibition observed with oral P2Y12 inhibitors. Moreover, potential future management of STEMI could directly involve patients in the process of care with self-administered antiplatelet agents designed to achieve rapid reperfusion. However, the potential anti-ischaemic benefits of potent antiplatelet agents will need to be balanced against their risk of increased bleeding. This study presents a comprehensive and updated review of pre-hospital antiplatelet therapy among STEMI patients undergoing primary percutaneous intervention and explores new therapies under development.

Clinical efficacy and safety of tirofiban combined with conventional dual antiplatelet therapy in ACS patients undergoing PCI

Challenges remain for clinicians over balancing the efficacy of active antithrombotic therapy and simultaneous bleeding reduction in patients. The clinical data of 347 patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) were retrospectively analyzed. On the basis of the given tirofiban, the patients were assigned into three different dose groups: high dose group (group H), medium dose group (group M), and low dose group (group L). The tirofiban efficacy was evaluated in terms of major adverse cardiovascular event (MACE) parameters and lab endpoints, including platelet count and function. The tirofiban safety was assessed by the occurrence of bleeding events. The patients were followed up for 1 month after the PCI. No significant difference in MACE events was evident among these groups (p > 0.05). Groups H and M reported an obvious reduction in platelet count (p < 0.05 for both) and an increased platelet inhibition rate (p < 0.05 for both). Group H showed a higher rate of total bleeding events than the other groups (Group H vs. Group M: 34.4% vs. 16.5%; Group H vs. Group L: 34.4% vs. 10.3%; p < 0.05 for both). A proper administration of a low dose of tirofiban may be a superior alternative in treating ACS patients, which can produce a similar favorable clinical outcome and a decrease in bleeding complication.

Antithrombotic therapy in diabetes: which, when, and for how long?

Cardiovascular disease remains the main cause of mortality in individuals with diabetes mellitus (DM) and also results in significant morbidity. Premature and more aggressive atherosclerotic disease, coupled with an enhanced thrombotic environment, contributes to the high vascular risk in individuals with DM. This prothrombotic milieu is due to increased platelet activity together with impaired fibrinolysis secondary to quantitative and qualitative changes in coagulation factors. However, management strategies to reduce thrombosis risk remain largely similar in individuals with and without DM. The current review covers the latest in the field of antithrombotic management in DM. The role of primary vascular prevention is discussed together with options for secondary prevention following an ischaemic event in different clinical scenarios including coronary, cerebrovascular, and peripheral artery diseases. Antiplatelet therapy combinations as well as combination of antiplatelet and anticoagulant agents are examined in both the acute phase and long term, including management of individuals with sinus rhythm and those with atrial fibrillation. The difficulties in tailoring therapy according to the variable atherothrombotic risk in different individuals are emphasized, in addition to the varying risk within an individual secondary to DM duration, presence of complications and predisposition to bleeding events. This review provides the reader with an up-to-date guide for antithrombotic management of individuals with DM and highlights gaps in knowledge that represent areas for future research, aiming to improve clinical outcome in this high-risk population.

Tackling the gap in platelet inhibition with oral antiplatelet agents in high-risk patients undergoing percutaneous coronary intervention

Introduction: Oral P2Y₁₂ inhibitors represent the mainstay therapy for the prevention of thrombotic complications in patients presenting with an acute coronary syndrome and/or undergoing percutaneous coronary intervention (PCI). However, the onset of antiplatelet action of the oral P2Y₁₂ inhibitors is affected by their need to be absorbed in the gastrointestinal (GI) tract before becoming systemically available.Areas covered: Following oral intake of P2Y₁₂ inhibitors, the timeframe required for GI absorption leads to a window of inadequate antiplatelet protection during which patients are at increased thrombotic risk. The onset of action of the oral P2Y₁₂ inhibitors is even further delayed in high-risk patients, underscoring the need to define strategies to bridge the gap in platelet inhibitory effects following their intake.Expert opinion: Multiple mechanisms may impair GI absorption leading to a delay in the onset of action of oral P2Y₁₂ inhibitors. Several strategies have been tested to overcome the gap in platelet inhibition in high-risk patients undergoing PCI. These include administration of crushed or chewed tablets to improve the dissolution rate and use of opioid receptor antagonists or metoclopramide to counteract impairment of gastric motility induced by opioids. However, intravenous antiplatelet therapies represent the most effective strategy to bridge such gap in platelet inhibition.

Antithrombotic treatment in primary percutaneous coronary intervention

INTRODUCTION

Despite a timely mechanical reperfusion with primary percutaneous coronary intervention (pPCI) patients presenting with ST-elevation myocardial infarction (STEMI) display an increased risk of adverse cardiovascular events. Several studies have demonstrated that guideline-directed antithrombotic therapy is effective to reduce this risk. However, there is still much to be accomplished to improve antithrombotic therapies in this clinical setting.

AREAS COVERED

This paper reviews current data on antithrombotic therapy in STEMI patients undergoing pPCI.

EXPERT OPINION

Antithrombotic therapy for STEMI patients undergoing pPCI should take into account the variability of thrombotic and bleeding risk in the short and long term. Patients with STEMI profit from the administration of early onset antiplatelet agents and anticoagulation to achieve sufficient and predictable antithrombotic effect at the time of pPCI. Thereafter, antithrombotic therapies should be tailored to individual risk of recurrence over the long term, to avoid excess bleeding, while ensuring adequate secondary ischemic prevention.

New Antithrombotic Drugs in Acute Coronary Syndrome

In recent years, much progress has been made in the field of antithrombotic drugs in acute coronary syndrome (ACS) treatment, as reflected by the introduction of the more potent P2Y12-inhibitors prasugrel and ticagrelor, and novel forms of concomitant anticoagulation, such as fondaparinux and bivalirudin. However, despite substantial improvements in contemporary ACS treatment, there remains residual ischemic risk in this group and hence the need for even more effective antithrombotic drugs, while balancing antithrombotic efficacy against bleeding risk. This review discusses recently introduced and currently developed antiplatelet and anticoagulant drugs in ACS treatment.

Cangrelor, Tirofiban, and Chewed or Standard Prasugrel Regimens in Patients With ST-Segment-Elevation Myocardial Infarction: Primary Results of the FABOLUS-FASTER Trial

Supplemental Digital Content is available in the text.

Background:

Standard administration of newer oral P2Y₁₂ inhibitors, including prasugrel or ticagrelor, provides suboptimal early inhibition of platelet aggregation (IPA) in patients with ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention. We aimed to investigate the effects of cangrelor, tirofiban, and prasugrel, administered as chewed or integral loading dose, on IPA in patients undergoing primary percutaneous coronary intervention.

Methods:

The FABOLUS-FASTER trial (Facilitation Through Aggrastat or Cangrelor Bolus and Infusion Over Prasugrel: A Multicenter Randomized Open-Label Trial in Patients with ST-Elevation Myocardial Infarction Referred for Primary Percutaneous Intervention) is an investigator-initiated, multicenter, open-label, randomized study. A total of 122 P2Y₁₂-naive patients with ST-segment–elevation myocardial infarction were randomly allocated (1:1:1) to cangrelor (n=40), tirofiban (n=40) (both administered as bolus and 2-hour infusion followed by 60 mg of prasugrel), or 60-mg loading dose of prasugrel (n=42). The latter group underwent an immediate 1:1 subrandomization to chewed (n=21) or integral (n=21) tablets administration. The trial was powered to test 3 hypotheses (noninferiority of cangrelor compared with tirofiban using a noninferiority margin of 9%, superiority of both tirofiban and cangrelor compared with chewed prasugrel, and superiority of chewed prasugrel as compared with integral prasugrel, each with α=0.016 for the primary end point, which was 30-minute IPA at light transmittance aggregometry in response to 20 μmol/L adenosine diphosphate.

Results:

At 30 minutes, cangrelor did not satisfy noninferiority compared with tirofiban, which yielded superior IPA over cangrelor (95.0±8.9 versus 34.1±22.5; P<0.001). Cangrelor or tirofiban were both superior to chewed prasugrel (IPA, 10.5±11.0; P<0.001 for both comparisons), which did not provide higher IPA over integral prasugrel (6.3±11.4; P=0.47), despite yielding higher prasugrel active metabolite concentration (ng/mL; 62.3±82.6 versus 17.1±43.5; P=0.016).

Conclusions:

Cangrelor provided inferior IPA compared with tirofiban; both treatments yielded greater IPA compared with chewed prasugrel, which led to higher active metabolite concentration but not greater IPA compared with integral prasugrel.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02978040; URL: https://www.clinicaltrialsregister.eu; EudraCT 2017-001065-24.

Prolonged enoxaparin therapy compared with standard-of-care antithrombotic therapy in opiate-treated patients undergoing primary percutaneous coronary intervention

A novel enoxaparin regimen consisting of intra-arterial bolus (0.75 mg/kg) followed by intravenous infusion (0.75 mg/kg/6 hours) has been developed as a possible solution to the delayed absorption of oral P2Y₁₂ inhibitors in opiate-treated ST-elevation myocardial infarction (STEMI) patients undergoing primary angioplasty. We aimed to study the feasibility of this regimen as an alternative to standard-of-care treatment (SOC) with unfractionated heparin ± glycoprotein IIb/IIIa antagonist (GPI). One hundred opiate-treated patients presenting with STEMI and accepted for primary angioplasty were randomized (1:1) to either enoxaparin or SOC. Fifty patients were allocated enoxaparin (median age 61, 40% females) and 49 allocated SOC (median age 62, 22% females). One developed stroke before angiography and was withdrawn. One SOC patient had a gastrointestinal bleed resulting in 1 g drop in hemoglobin and early cessation of GPI infusion. Two enoxaparin patients had transient minor bleeding: one transient gingival bleed and one episode of coffee ground vomit with no hemoglobin drop or hemodynamic instability. Two SOC and no enoxaparin group patients had acute stent thrombosis. These preliminary data support further study of this novel 6-hour enoxaparin regimen in opiate-treated PPCI patients.

Antithrombotic therapy in patients with acute coronary syndrome complicated by cardiogenic shock or out-of-hospital cardiac arrest: a joint position paper from the European Society of Cardiology (ESC) Working Group on Thrombosis, in association with the Acute Cardiovascular Care Association (ACCA) and European Association of Percutaneous Cardiovascular Interventions (EAPCI)

Timely and effective antithrombotic therapy is critical to improving outcome, including survival, in patients with acute coronary syndrome (ACS). Achieving effective platelet inhibition and anticoagulation, with minimal risk, is particularly important in high-risk ACS patients, especially those with cardiogenic shock (CS) or those successfully resuscitated following out-of-hospital cardiac arrest (OHCA), who have a 30-50% risk of death or a recurrent ischaemic event over the subsequent 30 days. There are unique challenges to achieving effective and safe antithrombotic treatment in this cohort of patients that are not encountered in most other ACS patients. This position paper focuses on patients presenting with CS or immediately post-OHCA, of presumed ischaemic aetiology, and examines issues related to thrombosis and bleeding risk. Both the physical and pharmacological impacts of CS, namely impaired drug absorption, metabolism, altered distribution and/or excretion, associated multiorgan failure, co-morbidities and co-administered treatments such as opiates, targeted temperature management, renal replacement therapy and circulatory or left ventricular assist devices, can have major impact on the effectiveness and safety of antithrombotic drugs. Careful attention to the choice of antithrombotic agent(s), route of administration, drug-drug interactions, therapeutic drug monitoring and factors that affect drug efficacy and safety, may reduce the risk of sub- or supra-therapeutic dosing and associated adverse events. This paper provides expert opinion, based on best available evidence, and consensus statements on optimising antithrombotic therapy in these very high-risk patients, in whom minimising the risk of thrombosis and bleeding is critical to improving outcome.

Novel approaches to P2Y12 inhibition and aspirin dosing

Aspirin and P2Y₁₂ inhibitors remain commonly prescribed antiplatelet drugs in the treatment of atherothrombotic conditions. Despite established benefits of dual antiplatelet therapy (DAPT) in the setting of acute coronary syndromes, there remains residual ischemic risk in this group and the problem of bleeding complications is an ongoing issue. DAPT with aspirin and ticagrelor has now been studied in other patient groups such as those with concurrent diabetes and stable coronary artery disease, and those undergoing elective percutaneous coronary intervention (PCI). Recent trials of ticagrelor monotherapy have suggested this may have benefits over standard-of-care in some settings, such as PCI, but not in others such as peripheral arterial disease or stroke. A novel subcutaneously administered P2Y₁₂ inhibitor, selatogrel, has shown powerful, rapid and consistent effect in a phase 2 study. Aspirin dosing remains an area of investigation, particularly in the setting of DAPT. A novel regimen of very-low-dose twice-daily aspirin has hypothetical advantages in pharmacodynamic and pharmacokinetic effects, maintaining antiplatelet effect whilst reducing potentially harmful peak-trough variation.