Antibody-Based Ticagrelor Reversal Agent in Healthy Volunteers

Safety of Ticagrelor Use in Elective Endovascular Treatment of Unruptured Intracranial Aneurysms

BACKGROUND AND OBJECTIVES

Intracranial stent placement typically requires dual antiplatelet therapy (DAPT) to prevent thromboembolic complications. The standard combination of aspirin and clopidogrel has raised concerns because of the variability in clopidogrel's effectiveness, potentially leading to an increased risk of ischemic events. Ticagrelor presents a viable alternative; however, there are concerns about a higher risk of intracranial hemorrhage. The aim of this study was to evaluate the safety of combining ticagrelor with aspirin in patients undergoing aneurysm embolization with intracranial stenting.

METHODS

We conducted a retrospective study of patients with unruptured intracranial aneurysms treated with stents and DAPT, combining ticagrelor and aspirin, between 2013 and 2021. Clinical and radiological outcomes were collected to assess the safety and efficacy of ticagrelor. The primary outcome was composite and included intracranial hemorrhagic complication and death. Univariable and adjusted multivariable regression analyses were conducted to report factors associated with the primary outcome.

RESULTS

Data from 511 patients who underwent 540 stent-assisted embolization procedures were analyzed. Hemorrhagic neurological complications were observed in 13 patients (2.4%). Multivariate analysis revealed that a lower perioperative heparin dose (50 UI/Kg) was independently associated with fewer hemorrhagic complications compared with heparin dose of 70 UI/Kg (adjusted odds ratio [aOR] 0.28, 95% CI 0.09-0.83). In addition, older age (aOR 1.06, 95% CI 1.01-1.10) and use of multiple stents (aOR 4.21, 95% CI 1.42-12.49) were linked to higher rates of hemorrhagic events and death.

CONCLUSION

The use of DAPT with aspirin and ticagrelor seems to be a safe alternative to clopidogrel for unruptured aneurysm embolization using intracranial stent.

The latest therapeutic advances with spontaneous intracerebral hemorrhage

INTRODUCTION

Intracerebral hemorrhage (ICH) accounts for 10% of strokes; however, compared with ischemic stroke, progress leading to novel treatments and improved patient outcomes has been lacking. Recently, there have been several promising developments and renewed research interest within the field. Positive results from randomized controlled trials have now been reported in multiple domains of care for patients with ICH. Anticoagulation-associated ICH is increasingly frequent, and clinicians deciding on reversal and timing of re-initiation of oral anticoagulation now have more therapeutic agents available and evidence to guide them. Minimally invasive techniques are also added to the neurosurgical arsenal, leading to improvements in functional outcomes. Acute treatment at presentation is best served by bundled care approaches, which ensure goal-directed management of blood pressure, glucose and temperature.

AREAS COVERED

This narrative review summarizes the recent developments in this area, as well as the current recommendations of key international guidelines. Literature search was carried out using PubMed database with priority given to publications since 2020.

EXPERT OPINION

There is renewed optimism for innovation in ICH. The standard of care for this condition now leads to improvements in mortality and long-term functional ability. Efforts to improve the patient selection and surgical techniques for operative management are ongoing.

Mesoporous Silica Nanotraps for Mitigating Bleeding Risk From 'Irreversible' Antiplatelet Drugs

The severe bleeding complications of long-term antiplatelet therapy limit its broader application in the treatment or prevention of thrombosis-associated diseases. This risk is particularly serious when facing emergency surgeries where rapid restoration of normal platelet function is required. Timely reversal of the effects of antiplatelet agents becomes crucial in such scenarios. Despite the widespread use of clopidogrel and prasugrel for their potent antiplatelet activity, the absence of specific and effective reversal agents remains a notable challenge. The pharmacological activity of clopidogrel and prasugrel is mediated by sulfhydryl-containing active metabolites, which form disulfide bonds with P2Y12 receptors on the surface of platelets to inhibit their aggregation. Taking advantage of this action mechanism of these "irreversible" antiplatelet drugs, click chemistry-functionalized mesoporous silica (SiO2-Mal) nanotraps are fabricated to capture the antiplatelet drugs' active metabolites and restore hemostasis. Subsequently, a comprehensive assessment of the effectiveness and safety of the SiO2-Mal nanotraps is conducted using mouse, rabbit, and pig animal models, highlighting their potential application as a functional reversal agent for clinically relevant thienopyridine antiplatelet drugs, believed until now to be irreversible in their inhibition of platelet activity.

Escherichia coli in the production of biopharmaceuticals

Escherichia coli has shouldered a massive workload with the discovery of recombinant DNA technology. A new era began in the biopharmaceutical industry with the production of insulin, the first recombinant protein, in E. coli and its use in treating diabetes. After insulin, many biopharmaceuticals produced from E. coli have been approved by the US Food and Drug Administration and the European Medicines Agency to treat various human diseases. Although E. coli has some disadvantages, such as lack of post-translational modifications and toxicity, it is an important host with advantages such as being a well-known bacterium in recombinant protein production, cheap, simple production system, and high yield. This study examined biopharmaceuticals produced and approved in E. coli under the headings of peptides, hormones, enzymes, fusion proteins, antibody fragments, vaccines, and other pharmaceuticals. The topics on which these biopharmaceuticals were approved for treating human diseases, when and by which company they were produced, and their use and development in the field are included.

Early vs Delayed Bypass Surgery in Patients With Acute Coronary Syndrome Receiving Ticagrelor: The RAPID CABG Randomized Open-Label Noninferiority Trial

Importance

Perioperative bleeding is a major concern in patients receiving ticagrelor for acute coronary syndromes (ACS) when coronary artery bypass graft (CABG) surgery is required.

Objective

To evaluate whether early CABG surgery at 2 to 3 days after ticagrelor cessation is noninferior to waiting 5 to 7 days.

Design, Setting, and Participants

RAPID CABG was a noninferiority, open-label randomized trial with 6 months of follow-up. Participants were patients with ACS who had received ticagrelor and required CABG. Patients were enrolled in tertiary centers in Canada between January 2016 and March 2021. Data were analyzed from March 2021 to December 2023.

Intervention

Early or delayed CABG.

Main Outcomes and Measures

The primary outcome was based on noninferiority comparison of class 3 or 4 universal definition of perioperative bleeding (UDPB). Noninferiority was prespecified as 8% between groups. Twelve-hour chest tube drainage was reported as a noninferiority comparison. Other bleeding, ischemic, and length-of-stay outcomes were assessed for superiority.

Results

Among 143 randomized patients, the median (IQR) age was 65 (58-72) years; there were 117 male patients (82%) and 26 female (18%). Of these, 123 patients (86.0%) underwent surgery in the allocated time frame (per protocol). The median (IQR) time to surgery was 3 (2-3) days in the early group and 6 (5-7) days in the delayed group (P < .001). In a per-protocol analysis, severe or massive UDPB occurred in 3 of 65 early-group patients (4.6%) and 3 of 58 patients (5.2%) in the delayed group (between-group difference, -0.6%; 95% CI, -8.3% to 7.1%; P = .03 for noninferiority). Median (IQR) chest tube drainage was 470 (330-650) mL vs 495 (380-610) mL (between-group difference -25 mL; 95% CI, -111.25 to 35; P = .01 for noninferiority). Median (IQR) hospital stay was 9 (7-13) days and 12 (10-15) days for the early and delayed groups (P < .001).

Conclusion and Relevance

This study found that an early surgical strategy, 2 to 3 days after ticagrelor cessation, was noninferior in incurring perioperative bleeding. The data support a reduction in the delay between ticagrelor cessation and CABG surgery and may decrease hospital length of stay.

Trial Registration

ClinicalTrials.gov Identifier: NCT02668562.

Clickable liposomes for on-demand reversal of antiplatelet drugs: Towards a safe management of bleeding risks associated with antithrombotic therapy

Antithrombotic drugs are widely used to prevent thrombotic events in patients with cardiovascular diseases. However, they all carry varying degrees of bleeding risk. Currently, there are no approved reversal agents for antiplatelet medications, which limits their further clinical application and poses challenges in managing bleeding complications. In this proof-of-concept study, we explore the feasibility of a reversal agent system using ticagrelor and a corresponding liposome-based antidote. Specifically, we developed an azide-functionalized ticagrelor derivative (Tic-N3) and a clickable DBCO-modified liposome (Lipo-DBCO) to enable controlled reversal of antiplatelet activity. Our findings demonstrate that the azide modification does not compromise the antiplatelet efficacy and biocompatibility of ticagrelor. The antiplatelet effects of Tic-N3 were successfully reversed by Lipo-DBCO, as validated through platelet aggregation assays and in vivo mouse models of tail bleeding and liver injury. Additionally, we investigated the thiol-maleimide pairing as an alternative system, enhancing the versatility of our approach. This strategy reveals the possibility and clinical application prospects of antiplatelet drug reversal agents, offering a promising solution for the safe management of bleeding risks associated with antiplatelet therapy.

Half-dose ticagrelor versus standard-dose clopidogrel in a dual antiplatelet regimen for stent-assisted coiling or flow diversion of unruptured intracranial aneurysms: a cohort study

BACKGROUND

Intracranial hemorrhage is the major safety concern of standard-dose ticagrelor (90 mg twice daily) based dual antiplatelet therapy (DAPT). The bleeding avoidance strategy through dose de-escalation has been investigated in interventional cardiology. However, the preserved antithrombotic efficacy and better safety of half-dose (45 mg twice daily) ticagrelor remains unverified in patients undergoing stent-assist coiling (SAC) or flow diversion (FD) treating unruptured intracranial aneurysms (UIA).

METHODS

A single-center, prospective, cohort study was conducted to compare DAPT with aspirin 100 mg daily plus half-dose ticagrelor vs standard-dose clopidogrel (75 mg daily) in UIA patients. The adenosine diphosphate inhibition (ADPi) rate was utilized to quantify the antagonization of adenosine diphosphate (ADP)-induced platelet aggregation. The patients were followed-up at 6 month after discharge. The primary efficacy outcome was the major adverse cardiovascular and cerebrovascular events (MACCE), and the primary safety outcome was major bleeding. The secondary outcome was minor hemorrhage.

RESULTS

Our study included 322 UIA patients, of which 254 patients were eventually enrolled after propensity score matching. The ADPi of half-dose ticagrelor (51.56%±31.46%) was comparable (P=0.089) to that of clopidogrel (57.44%±22.76%). The outcomes were also comparable. Five (3.94%) patients in the ticagrelor group and eight (6.30%) patients in the clopidogrel group reported MACCE (P=0.393). One patient in the ticagrelor group was diagnosed with asymptomatic intracranial hemorrhage 1 month after stenting. There were 36 (28.35%) minor hemorrhagic events in the ticagrelor group and 35 (27.56%) in the clopidogrel group, (P=0.889).

CONCLUSION

Half-dose ticagrelor was effective and safe as a potential alternative to clopidogrel in the DAPT regimen for patients undergoing SAC/FD for UIA.

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Engineered P2Y12-Overexpressing Cell-Membrane-Wrapped Nanoparticles for the Functional Reversal of Ticagrelor and Clopidogrel

Antiplatelet agents, particularly P2Y12 receptor inhibitors, are critical medicines in the prevention and treatment of thrombotic diseases in the clinic. However, their long-term use introduces a significant risk of bleeding in patients with cardiovascular diseases. Whether the bleeding is caused by the drug itself or due to surgical procedures or trauma, the need to rapidly reverse the effects of antiplatelet agents in the circulation is essential; however, no such agents are currently available. To address this need, here we describe a strategy that uses cell-membrane-wrapped nanoparticles (CM-NPs) for the rapid reversal of P2Y12 inhibitors. CM-NPs are fabricated with membranes derived from 293T cells genetically engineered to overexpress the P2Y12 receptor. Our findings support the potential of CM-NPs as a strategy for managing bleeding complications associated with P2Y12 receptor inhibitors, offering an approach to improve the safety in the use of these drugs in clinical settings.

Combined effect of cortical superficial siderosis and cerebral microbleed on short-term and long-term outcomes after intracerebral haemorrhage

BACKGROUND AND PURPOSE

Cortical superficial siderosis (cSS) and cerebral microbleed (CMB) have distinct effects on intracerebral haemorrhage (ICH). We aim to investigate the combined effect of cSS and CMB on outcomes after ICH.

METHODS

Based on a single-centre stroke registry database, patients with spontaneous ICH who had CT scan within 48 hours after ictus and MRI subsequently were identified. Eligible patients were divided into four groups (cSS-CMB-, cSS-CMB+, cSS+CMB-, cSS+CMB+) according to cSS and CMB on susceptibility-weighted image of MRI. Primary outcomes were haematoma volume on admission and unfavourable outcome defined as modified Rankin Scale scores ≥3 at 3 months. Secondary outcomes were all-cause death, recurrence of stroke and ICH during follow-up (median follow-up 2.0 years, IQR 1.0-3.0 years).

RESULTS

A total of 673 patients were identified from 1044 patients with spontaneous ICH. 131 (19.5%) had cSS and 468 (69.5%) had CMB. Patients with cSS+CMB+ had the highest rate of poor outcome at 3 months, as well as all-cause death, recurrent stroke and ICH during follow-up. In cSS- patients, CMB was associated with smaller haematoma (β -0.13; 95% CI -0.22 to -0.03; p=0.009), but it still increased risks of recurrent ICH (OR 4.6; 95% CI 1.3 to 15.6; p=0.015) and stroke (OR 2.0; 95% CI 1.0 to 4.0; p=0.049). These effects of CMB became unremarkable in the context of cSS+.

CONCLUSIONS

Patients with different combinations of cSS and CMB have distinct patterns of short-term and long-term outcomes. Although CMB is related to restrained haematoma, it does not improve long-term outcomes.

TRIAL REGISTRATION NUMBER

NCT04803292.

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.

Platelet inhibitor withdrawal and outcomes after coronary artery surgery: an individual patient data meta-analysis

OBJECTIVES

To evaluate the association between guideline-conforming as compared to shorter than recommended withdrawal period of P2Y12 receptor inhibitors prior to isolated on-pump coronary artery bypass grafting (CABG) and the incidence of severe bleeding and ischaemic events. Randomized controlled trials are lacking in this field.

METHODS

We searched PUBMED, Embase and other suitable databases for studies including patients on P2Y12 receptor inhibitors undergoing isolated CABG and reporting bleeding and postoperative ischaemic events from 2013 to March 2024. The primary outcome was incidence of Bleeding Academic Research Consortium type 4 (BARC-4) bleeding defined as any of the following: perioperative intracranial bleeding, reoperation for bleeding, transfusion of ≥5 units of red blood cells, chest tube output of ≥2 l. The secondary outcome was postoperative ischaemic events according to the Academic Research Consortium 2 Consensus Document. Patient-level data provided by each observational trial were synthesized into a single dataset and analysed using a 2-stage IPD-MA.

RESULTS

Individual data of 4837 patients from 7 observational studies were synthesized. BARC-4 bleeding, 30-day mortality and postoperative ischaemic events occurred in 20%, 2.6% and 5.2% of patients. After adjusting for EuroSCORE II and cardiopulmonary bypass time, guideline-conforming withdrawal was associated with decreased BARC-4 bleeding risk in patients on clopidogrel [adjusted odds ratio (OR) 0.48; 95% confidence intervals (CI) 0.28-0.81; P = 0.006] and a trend towards decreased risk in patients on ticagrelor (adjusted OR 0.48; 95% CI 0.22-1.05; P = 0.067). Guideline-conforming withdrawal was not significantly associated with 30-day mortality risk (clopidogrel: adjusted OR 0.70; 95% CI 0.30-1.61; ticagrelor: adjusted OR 0.89; 95% CI 0.37-2.18) but with decreased risk of postoperative ischaemic events in patients on clopidogrel (clopidogrel: adjusted OR 0.50; 95% CI 0.30-0.82; ticagrelor: adjusted OR 0.78; 95% CI 0.45-1.37). BARC-4 bleeding was associated with 30-day mortality risk (adjusted OR 4.76; 95% CI 2.67-8.47; P < 0.001).

CONCLUSIONS

Guideline-conforming preoperative withdrawal of ticagrelor and clopidogrel was associated with a 50% reduced BARC-4 bleeding risk when corrected for EuroSCORE II and cardiopulmonary bypass time but was not associated with increased risk of 30-day mortality or postoperative ischaemic events.

ANMCO/SIMEU consensus document on the use of reversal agents for antithrombotic therapies in patients with ongoing bleeding or at high risk of haemorrhagic events

In recent decades, an incredible evolution in antithrombotic therapies used for treating patients with atherosclerosis, atrial fibrillation, and venous thromboembolism has been observed, leading to the availability of increasingly safe drugs. Nonetheless, bleeding complications remain a significant concern, with considerable health, social, and economic implications. To improve the acute management of patients experiencing or at risk for major bleeding events, specific reversal agents for antithrombotic drugs have been recently developed. While these agents demonstrate effectiveness in small-scale pharmacodynamic studies and clinical trials, it is imperative to balance the benefits of reversing antiplatelet or anticoagulant therapy against the risk of prothrombotic effects. These risks include the potential loss of antithrombotic protection and the prothrombotic tendencies associated with bleeding, major surgery, or trauma. This joint document of the Italian Association of Hospital Cardiologists (Associazione Nazionale Medici Cardiologi Ospedalieri) and the Italian Society of Emergency Medicine (Società Italiana di Medicina d'Emergenza-Urgenza) delineates the key features and efficacy of available reversal agents. It also provides practical flowcharts to guide their use in patients with active bleeding or those at elevated risk of major bleeding events.

Ticagrelor Versus Clopidogrel in Endovascular Therapy for Cerebral Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Antiplatelet therapy is pivotal in endovascular treatment for intracranial aneurysms. However, there is a lack of studies comparing ticagrelor to clopidogrel in patients with aneurysms undergoing endovascular therapy. Additionally, the existing literature lacks adequate sample size, significant subgrouping, and follow-up, making our study important to cover these gaps.

METHODS

We searched 5 databases to collect all relevant studies. Categorical outcomes were pooled as relative risk (R.R.) with a 95% confidence interval (CI). In the single-arm meta-analysis, outcomes were pooled as proportions and their corresponding 95% CI.

RESULTS

This comprehensive analysis of 18 studies involving 2,427 patients. For thromboembolic events, the pooled (R.R.) did not show significant differences, whether considering overall events. A similar pattern was observed for thromboembolic events stratified by aneurysmal rupture status, with no significant differences in overall events. Hemorrhagic events did not also exhibit significant differences in previously mentioned stratifications. Furthermore, there were no substantial differences in death and mRS (0-2) on discharge between Ticagrelor and Clopidogrel. Single-arm meta-analyses for Ticagrelor demonstrated low rates of thromboembolic events, hemorrhage, death, and favorable mRS scores, with associated confidence intervals (CIs). Main line of endovascular treatment did not significantly affect either thromboembolic or hemorrhagic outcomes with Ticagrelor and Clopidogrel.

CONCLUSIONS

We found no significant differences in key outcomes like thromboembolic events, hemorrhagic events, mortality rates, and favorable mRS (0-2) upon discharge in the studied patients between Ticagrelor and Clopidogrel. Moreover, the single-arm meta-analysis for Ticagrelor revealed low rates of thromboembolic events, hemorrhage, mortality, and high rates of favorable mRS scores.

The role of platelet P2Y12 receptors in inflammation

Inflammation is a complex pathophysiological process underlying many clinical conditions. Platelets contribute to the thrombo-inflammatory response. Platelet P2Y12 receptors amplify platelet activation, potentiating platelet aggregation, degranulation and shape change. The contents of platelet alpha granules, in particular, act directly on leucocytes, including mediating platelet-leucocyte aggregation and activation via platelet P-selectin. Much evidence for the role of platelet P2Y12 receptors in inflammation comes from studies using antagonists of these receptors, such as the thienopyridines clopidogrel and prasugrel, and the cyclopentyltriazolopyrimidine ticagrelor, in animal and human experimental models. These suggest that antagonism of P2Y12 receptors decreases markers of inflammation with some evidence that this reduces incidence of adverse clinical sequelae during inflammatory conditions. Interpretation is complicated by pleiotropic effects such as those of the thienopyridines on circulating leucocyte numbers and of ticagrelor on adenosine reuptake. The available evidence suggests that P2Y12 receptors are prominent mediators of inflammation and P2Y12 receptor antagonism as a potentially powerful strategy in a broad range of inflammatory conditions. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

Progress in the clinical effects and adverse reactions of ticagrelor

BACKGROUND

Ticagrelor is a novel receptor antagonist that selectively binds to the P2Y12 receptor, thereby inhibiting adenosine diphosphate (ADP)-mediated platelet aggregation. Compared to clopidogrel, ticagrelor has the advantages of a fast onset, potent effects, and a reversible platelet inhibition function, which make this drug clinically suitable for treating acute coronary syndrome (ACS), especially acute ST-segment elevation myocardial infarction (STEMI).

OBJECTIVE

This review was performed to determine the basic characteristics, clinical effects, and adverse reactions of ticagrelor.

METHODS

Relevant trials and reports were obtained from the MEDLINE, Embase, and Cochrane Library databases.

RESULTS

Ticagrelor is rapidly absorbed by the body after oral administration, exhibits inherent activity without requiring metabolic activation, and binds reversibly to the P2Y12 receptor. Ticagrelor has been recommended in ACS treatment guidelines worldwide due to its advantageous pharmacological properties and significant clinical benefits. Ticagrelor inhibits platelet aggregation, inhibits inflammatory response, enhances adenosine function, and has cardioprotective effects. However, ticagrelor also causes adverse reactions such as bleeding tendency, dyspnea, ventricular pause, gout, kidney damage, and thrombotic thrombocytopenic purpura in clinical treatment. Therefore, it is necessary to pay attention to risk assessments when using ticagrelor.

CONCLUSION

Ticagrelor is a promising drug for the effective treatment of ACS. When using ticagrelor, individualized treatment should be provided based on the specific conditions of the patients to avoid serious adverse events.

Ticagrelor inverse agonist activity at the P2Y12 receptor is non-reversible versus its endogenous agonist adenosine 5´-diphosphate

BACKGROUND AND PURPOSE

Ticagrelor is labelled as a reversible, direct-acting platelet P2Y12 receptor (P2Y12 R) antagonist that is indicated clinically for the prevention of thrombotic events in patients with acute coronary syndrome (ACS). As with many antiplatelet drugs, ticagrelor therapy increases bleeding risk in patients, which may require platelet transfusion in emergency situations. The aim of this study was to further examine the reversibility of ticagrelor at the P2Y12 R.

EXPERIMENTAL APPROACH

Studies were performed in human platelets, with P2Y12 R-stimulated GTPase activity and platelet aggregation assessed. Cell-based bioluminescence resonance energy transfer (BRET) assays were undertaken to assess G protein-subunit activation downstream of P2Y12 R activation.

KEY RESULTS

Initial studies revealed that a range of P2Y12 R ligands, including ticagrelor, displayed inverse agonist activity at P2Y12 R. Only ticagrelor was resistant to washout and, in human platelet and cell-based assays, washing failed to reverse ticagrelor-dependent inhibition of ADP-stimulated P2Y12 R function. The P2Y12 R agonist 2MeSADP, which was also resistant to washout, was able to effectively compete with ticagrelor. In silico docking revealed that ticagrelor and 2MeSADP penetrated more deeply into the orthosteric binding pocket of the P2Y12 R than other P2Y12 R ligands.

CONCLUSION AND IMPLICATIONS

Ticagrelor binding to P2Y12 R is prolonged and more akin to that of an irreversible antagonist, especially versus the endogenous P2Y12 R agonist ADP. This study highlights the potential clinical need for novel ticagrelor reversal strategies in patients with spontaneous major bleeding, and for bleeding associated with urgent invasive procedures.

Acute Spontaneous Subdural Hematoma in a Patient With an End-Stage Renal Disease After Starting Dual Antiplatelet Therapy Post Drug-Eluting Stent Insertion: A Case Report

Dual antiplatelet therapy (DAPT) has been widely utilized for secondary prevention in patients with cardiovascular diseases, such as post-drug eluting stent insertion, stroke, and peripheral vascular disease. The occurrence of bleeding complications, including intracranial hemorrhage, has been extensively studied in relation to DAPT. However, the occurrence of acute spontaneous subdural hematomas in this context is relatively rare. These hematomas can manifest through various symptoms, including altered mental status (AMS) and confusion. The risk of intracranial hemorrhage is particularly higher in patients receiving aspirin with ticagrelor, especially in those with reduced estimated glomerular filtration rate (eGFR) and liver disease. In this case report, we present the case of a patient with end-stage renal disease undergoing peritoneal hemodialysis and a remote history of liver transplant. The patient presented to the hospital with chest pain, subsequently underwent drug-eluting stent placement, and was initiated on DAPT. Following the initiation of DAPT, the patient developed confusion and was diagnosed with an acute spontaneous subdural hematoma. The patient underwent middle meningeal artery embolization to manage the hematoma.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Clinical and Pre-Clinical Pharmacokinetics and Pharmacodynamics of Bentracimab

Antiplatelet agents are among the most frequently used medications in cardiovascular medicine. Although in patients with atherosclerotic disease manifestations, in particular those treated by percutaneous coronary intervention, antiplatelet agents are beneficial for the prevention of ischemic events, they inevitably increase the risk of bleeding. Furthermore, 5-15% of patients treated by percutaneous coronary intervention may need a surgical procedure within 2 years, creating challenges to safe and effective antiplatelet drug management. Importantly, major spontaneous or procedural-related bleedings are associated with increased hospital admission, length, costs, and poor prognosis. Although the effects of other antithrombotic therapies, such as direct oral anticoagulants, can be reversed by approved specific agents, there are no approved reversal agents for any antiplatelet drugs. The fact that many antiplatelet agents, such as aspirin and thienopyridines (i.e., clopidogrel and prasugrel), bind irreversibly to their targets represents a challenge for the development of a drug-specific reversal agent. In contrast, ticagrelor is a non-thienopyridine with a plasma half-life of 7-9 h that reversely binds the P2Y₁₂ receptor producing potent signaling blockage. In 2015, bentracimab (also known as PB2452 or MEDI2452), a neutralizing monoclonal antibody fragment that binds free plasma ticagrelor and its major active metabolite, was identified. This systematic overview provides a comprehensive summary of the drug development program of bentracimab, focusing on its pharmacodynamic, pharmacokinetic, and safety profiles.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Novel Antithrombotic Agents in Pregnancy Anticoagulants and Antiplatelet Agents

Increasing rates of thromboembolic complications have required increasing use of anticoagulant and antiplatelet agents during and after pregnancy. Furthermore, thromboembolism is both a cause and a complication of severe maternal morbidity requiring intensive care. As a consequence, almost all patients admitted to intensive care units receive an anticoagulant or an antiplatelet agent (or both) for either treatment or prevention of thromboembolism. In this review, we summarize commonly used anticoagulants and antiplatelet agents and outline the potential role of newly developed (novel) antithrombotic agents for pregnant and postpartum patients.

Platelet-Mimicking Nanosponges for Functional Reversal of Antiplatelet Agents

BACKGROUND

During long-term antiplatelet agents (APAs) administration, patients with thrombotic diseases take a fairly high risk of life-threatening bleeding, especially when in need of urgent surgery. Rapid functional reversal of APAs remains an issue yet to be efficiently resolved by far due to the lack of any specific reversal agent in the clinic, which greatly restricts the use of APAs.

METHODS

Flow cytometry analysis was first applied to assess the dose-dependent reversal activity of platelet-mimicking perfluorocarbon-based nanosponges (PLT-PFCs) toward ticagrelor. The tail bleeding time of mice treated with APAs followed by PLT-PFCs was recorded at different time points, along with corresponding pharmacokinetic analysis of ticagrelor and tirofiban. A hemorrhagic transformation model was established in experimental stroke mice with thrombolytic/antiplatelet therapy. Magnetic resonance imaging was subsequently applied to observe hemorrhage and thrombosis in vivo. Further evaluation of the spontaneous clot formation activity of PLT-PFCs was achieved by clot retraction assay in vitro.

RESULTS

PLT-PFCs potently reversed the antiplatelet effect of APAs by competitively binding with APAs. PLT-PFCs showed high binding affinity comparable to fresh platelets in vitro with first-line APAs, ticagrelor and tirofiban, and efficiently reversed their function in both tail bleeding and postischemic-reperfusion models. Moreover, the deficiency of platelet intrinsic thrombotic activity diminished the risk of thrombogenesis.

CONCLUSIONS

This study demonstrated the safety and effectiveness of platelet-mimicking nanosponges in ameliorating the bleeding risk of different APAs, which offers a promising strategy for the management of bleeding complications induced by antiplatelet therapy.

Ticagrelor versus clopidogrel dual antiplatelet therapy for unruptured intracranial aneurysms treated with flowdiverter

BACKGROUND AND PURPOSE

Antiplatelet therapy (APT) is a key element limiting the risk of thromboembolic events (TEE) in neuroendovascular procedures, including aneurysm treatment with flowdiverter. Clopidogrel combined with aspirin is the mostly reported dual APT (DAPT). However, resistance phenomenon and intraindividual efficacy fluctuation are identified limitations. In recent years, ticagrelor has been increasingly used in this indication. We compared these two DAPT regimens for intracranial aneurysm treated with flowdiverter.

METHODS

We conducted a multicentric retrospective study from prospectively maintained databases in two high volume centers extracting consecutive patients presenting unruptured intracranial aneurysm treated with flowdiverter and receiving DAPT (May 2015 to December 2019).  Two groups were compared according to their DAPT regimen: "ticagrelor+aspirin" and "clopidogrel+aspirin". Clopidogrel group was systematically checked with platelet test inhibition before endovascular procedure. The primary endpoint was composite, defined as any thrombo-embolic event (TEE) or major hemorrhagic event occurring the first 6 months during and after embolization RESULTS: 260 patients met our inclusion criteria. Baseline patients and aneurysms characteristics were comparable between groups, except for aneurysm location, median size and pre-treatment modified Rankin scale. No significant difference was observed regarding the primary composite outcome: 11.5% (12/104) in the ticagrelor group versus 10.9% (17/156) in the clopidogrel group (p = 1.000). There was also no significant difference in secondary outcomes including TEE (10.5 vs 9.0%; p = 0.673), major hemorrhage (0.9 vs 1.2%; p = 0.651) and clinical outcome (at least 1-point mRS worsening during follow up: 6.7% vs 8.3%; p = 0.813).

CONCLUSION

First-line DAPT with ticagrelor+aspirin seems as safe and effective as clopidogrel+aspirin regimen.

Impact of Ticagrelor Versus Clopidogrel on Bleeding Outcomes of Isolated Coronary Artery Bypass Grafting

BACKGROUND

Increased bleeding risks have been documented in patients exposed to P2Y₁₂ inhibitors within 5 days of coronary artery bypass surgery (CABG). This study aimed to determine the relative CABG bleeding risks of clopidogrel versus ticagrelor exposure and the proper time course of ticagrelor discontinuation prior to surgery.

METHODS

Clinical outcomes were assessed in 2075 isolated CABG patients, including 375 who had received P2Y₁₂ inhibitors within 5 days of surgery (155 clopidogrel, 213 ticagrelor, 7 prasugrel). BARC-4 CABG bleeding complications and perioperative blood product usage were assessed in propensity-matched P2Y₁₂-inhibited and non-P2Y₁₂-inhibited cohorts.

RESULTS

P2Y₁₂-inhibited patients (n = 375) in comparison to matched non-P2Y₁₂-inhibited patients (n = 1138) had higher rates of re-operation for bleeding (3.8 % vs 1.3 %, p = 0.003), postoperative red blood cell transfusion ≥5 units (5.7 % vs 2.7 %, p = 0.007), and intraoperative and postoperative blood product utilization (42.3 % vs 27.1 %, p < 0.001; 41.8 % vs 32.2 %, p < 0.001, respectively). Univariate predictors of BARC-4 bleeding included clopidogrel (OR: 2.145, 95 % CI: 1.131-4.067, p = 0.019) and ticagrelor discontinued within 3 days of surgery (OR: 2.153, 95 % CI: 1.003-4.169, p = 0.049). Multivariate logistic regression demonstrated that only clopidogrel exposure was an independent BARC-4 bleeding predictor (OR: 1.850, 95 % CI: 1.007-3.398, p = 0.048). Unadjusted ticagrelor patients with drug discontinuation 4-5 days prior to CABG only demonstrated higher rates of perioperative platelet transfusion, without additional signs of excessive bleeding.

CONCLUSIONS

Clopidogrel exposure within 5 days of CABG is an independent predictor of BARC-4 bleeding, whereas major ticagrelor bleeding effects are confined to drug exposure within 3 days of surgery.

Coagulopathy management of multiple injured patients - a comprehensive literature review of the European guideline 2019

The European guideline on the management of trauma-induced major bleeding and coagulopathy summarises the most relevant recommendations for trauma coagulopathy management. The management of trauma-induced major bleeding should interdisciplinary follow algorithms which distinguish between life-threatening and non-life-threatening bleeding. Point-of-care viscoelastic methods (VEM) assist target-controlled haemostatic treatment. Neither conventional coagulation assays nor VEM should delay treatment in life-threatening trauma-induced bleeding. Adjustments may be rational due to local circumstances, including the availability of blood products, pharmaceuticals, and employees.

Case-fatality rate of major bleeding events in patients on dual antiplatelet therapy after percutaneous coronary intervention: A systematic review and meta-analysis

Background

Assessment of the case-fatality rate (CFR) of major bleeding on dual antiplatelet therapy (DAPT) may improve balancing risks and benefits of different durations of DAPT following percutaneous coronary intervention (PCI).

Objectives

To determine the CFR of major bleeding in patients on DAPT after PCI and to compare rates among different durations of DAPT.

Methods

Medline, Embase, and CENTRAL were searched from inception to August 2021 for randomized trials that reported fatal bleeding among patients who were randomized to ≥1 month of DAPT following PCI. Summary estimates for CFRs of major bleeding were calculated using the random-effects inverse-variance method. Statistical heterogeneity was evaluated using the I 2 statistic.

Results

Of 2777 citations obtained by the search, 15 (48%) of 31 potentially eligible studies were excluded because fatal bleeding was not reported, leaving 16 studies that were included in the analysis. Overall, there were 823 major bleeding events including 91 fatal events in 48,884 patients who were assigned to receive DAPT during study follow-up. The CFR of major bleeding was 10.8% (95% confidence interval [CI], 7.1-16.2; I 2 = 50%) in the entire study population, and 13.8% (95% CI, 6.5-27.1; I 2 = 28%), 11.2% (95% CI, 6.7-18.0; I 2 = 0%), and 5.8% (95% CI, 3.0-11.1; I 2 = 0%) in those on short-term (≤6 months; n = 16,553), standard-term (12 months; n = 19,453), and long-term DAPT (>12 months; n = 10,238), respectively.

Conclusion

Fatal bleeding is not reported in many studies evaluating DAPT after PCI. The CFR of major bleeding on DAPT is substantial and may be higher in the first 12 months of DAPT than during long-term DAPT.

Clinical pharmacology of antiplatelet drugs

INTRODUCTION

Platelets play a key role in arterial thrombosis and antiplatelet therapy is pivotal in the treatment of cardiovascular disease. Current antiplatelet drugs target different pathways of platelet activation and show specific pharmacodynamic and pharmacokinetic characteristics, implicating clinically relevant drug-drug interactions.

AREAS COVERED

This article reviews the role of platelets in hemostasis and cardiovascular thrombosis, and discusses the key pharmacodynamics, drug-drug interactions and reversal strategies of clinically used antiplatelet drugs.

EXPERT OPINION

Antiplatelet therapies target distinct pathways of platelet activation: thromboxane A₂ synthesis, adenosine diphosphate-mediated signaling, integrin α_IIbβ₃ (GPIIb/IIIa), thrombin-mediated platelet activation via the PAR1 receptor and phosphodiesterases. Key clinical drug-drug interactions of antiplatelet agents involve acetylsalicylic acid - ibuprofen, clopidogrel - omeprazole, and morphine - oral P2Y₁₂ inhibitors, all of which lead to an attenuated antiplatelet effect. Platelet function and genetic testing and the use of scores (ARC-HBR, PRECISE-DAPT, ESC ischemic risk definition) may contribute to a more tailored antiplatelet therapy. High on-treatment platelet reactivity presents a key problem in the acute management of ST-elevation myocardial infarction (STEMI). A treatment strategy involving early initiation of an intravenous antiplatelet agent may be able to bridge the gap of insufficient platelet inhibition in high ischemic risk patients with STEMI.

Emergent Reversal of Antithrombotics and Treatment of Life-Threatening Bleeding from Coagulopathies: A Clinical Review

BACKGROUND

Reversal of antithrombotic agents and treatment of life-threatening bleeding episodes from coagulopathies can be a stressful scenario for clinicians, especially when the selection of treatment options should occur quickly. Understanding the options available for these agents requires emergency physicians to be familiar with the current data surrounding new therapies and dosing strategies for the treatment of bleeding from reversible and nonreversible antithrombotics and coagulopathic conditions.

OBJECTIVE

To provide quick resource guides for the reversal of major or life-threatening bleeding caused by antithrombotic agents or in the setting of coagulopathies.

METHODS

A literature search for articles published through September 2021 related to antithrombotic reversal and treatment of acute bleeding from coagulopathies was conducted using the PubMed clinical database. Selected articles were used to generate 5 guidance tables in this clinical review.

DISCUSSION

Four guidance tables for how to treat major or life-threatening bleeding from antithrombotic agents and 1 table for how to manage life-threatening bleeding for coagulopathies are presented as a quick reference tool for the emergency physician. Additional information on upcoming reversal agents and possible treatment options are provided herein.

CONCLUSIONS

In this clinical review, a series of 5 tables were created to provide quick and comprehensive guidance for the emergency physician when treating major or life-threatening bleeding caused by antithrombotic agents or coagulopathies. © 2022 Elsevier Inc.

P2Y12 Antagonists in Cardiovascular Disease—Finding the Best Balance Between Preventing Ischemic Events and Causing Bleeding

Dual antiplatelet therapy comprising of aspirin and oral P2Y₁₂ receptor antagonists are an established cornerstone of therapy in acute coronary syndromes and percutaneous coronary intervention. As a result, the platelet P2Y₁₂ receptor remains a key therapeutic target in cardiovascular medicine since pharmacological antagonists were first developed in the 1990’s. With a greater understanding of platelet biology and the role played by the P2Y₁₂ receptor in the amplification of platelet activation and thrombus formation, there has been progressive refinement in the development of P2Y₁₂ receptor antagonists with greater potency and consistency of antiplatelet effect. However, challenges remain in the utilization of these agents particularly in balancing the need for greater protection from ischemic events whilst minimizing the bleeding risk and present a real opportunity for the institution of individualized medicine. Future drug developments will provide clinicians with greater avenues to achieve this.

Advanced pharmacodynamics of cangrelor in healthy volunteers: a dose-finding, open-label, pilot trial

BACKGROUND

High on-treatment platelet reactivity (HTPR) remains a major problem in the acute management of ST-elevation myocardial infarction (STEMI), leading to higher rates of stent thrombosis and mortality. We aimed to investigate a novel, prehospital treatment strategy using cangrelor and tested its pharmacodynamic effects in a model using healthy volunteers.

METHODS

We conducted a dose-finding, open-label, pilot trial including 12 healthy volunteers and tested three ascending bolus infusions of cangrelor (5 mg, 10 mg and 20 mg) and a bolus infusion followed by a continuous infusion via an intravenous (IV) flow regulator. Platelet function was assessed using multiple electrode aggregometry (MEA), vasodilator-stimulated phosphoprotein phosphorylation assay (VASP-P) and the platelet function analyzer. In an ex vivo experiment, epinephrine was used to counteract the antiplatelet effect of cangrelor.

RESULTS

All cangrelor bolus infusions resulted in immediate and pronounced platelet inhibition. Bolus infusions of cangrelor 20 mg resulted in sufficient platelet inhibition assessed by MEA for 20 min in 90% of subjects. Infusion of cangrelor via the IV flow regulator resulted in sufficient platelet inhibition throughout the course of administration. Ex vivo epinephrine, in concentrations of 200 and 500 ng/mL was able to partially reverse the antiplatelet effect of cangrelor in a dose-dependent manner.

CONCLUSIONS

Weight-adapted bolus infusions followed by a continuous infusion of cangrelor via IV flow regulator result in immediate and pronounced platelet inhibition in healthy subjects. Cangrelor given as weight-adapted bolus infusion followed by a continuous infusion using an IV flow regulator may be a viable treatment approach for effective and well controllable prehospital platelet inhibition.

TRIAL REGISTRATION

EC (Medical University of Vienna) 1835/2019 and EudraCT 2019-002792-34 .

Review of Target-Specific Anticoagulation Reversal Agents

Bleeding related to direct oral anticoagulants accounts for nearly half of emergency department visits annually and until recently there were no reversal antidotes available. As there continues to be a shift in prescribing practices away from warfarin, it is essential to have these reversal agents readily available for the treatment of life-threatening bleeds associated with these anticoagulants. In addition, for agents that continue to lack a targeted reversal agent (eg, low-molecular-weight heparin, antiplatelets, and new antithrombotics), it is imperative that research continues to evaluate improved reversal strategies. This review focuses on target-specific anticoagulation reversal agents currently available in the United States (protamine, idarucizumab, and andexanet alfa) and summarizes agents that are in the pipeline for these anticoagulants and antiplatelets.

Spontaneous Coronary Artery Dissection: Rediscovering an Old Cause of Myocardial Infarction

Spontaneous coronary artery dissection is an uncommon, but not insignificant cause of acute coronary syndrome that overwhelmingly affects middle-aged women. The pathophysiology of coronary dissection appears to be an outside-in mechanism, where the initiating event is not an intimal tear but rather the formation of an intramural hematoma, which compromises blood flow by reducing the arterial lumen. Considering this mechanism, it is clear to see how intracoronary imaging techniques, such as optical coherence tomography and intravascular ultrasound, are most accurate in the diagnosis. However, they carry a high rate of complications and are therefore generally avoided when the clinical scenario and angiographic appearance both support the diagnosis of spontaneous coronary artery dissection. The natural history of the disease is toward healing of the vessel wall and restoration of blood flow. Therefore, conservative medical management is the preferred approach unless there are high-risk factors such as hemodynamic instability, signs of ischemia and severe proximal or multivessel lesions, in which percutaneous or surgical revascularization should be considered. Perioperative evaluation of these patients must take into account several aspects of this disease. Most of these patients will be receiving single or dual antiplatelet therapy, so one must consider the timing of the event and the surgical hemorrhagic risk when deciding to stop these therapies. Extracoronary vascular disease also must be assessed because it can have an effect on patient monitoring and risk of postoperative complications.

Bentracimab for Ticagrelor Reversal in Patients Undergoing Urgent Surgery

BACKGROUND: Ticagrelor is a reversible oral P2Y12 platelet inhibitor used to treat patients with acute coronary syndromes, prior myocardial infarction, high-risk coronary artery disease, transient ischemic attack, or ischemic stroke. A healthy volunteer study showed that the intravenous monoclonal antibody bentracimab rapidly reverses ticagrelor, but the effect in patients was unknown. METHODS: In a prespecified interim analysis of a single-arm, prospective study, bentracimab was evaluated in ticagrelor-treated patients who required urgent surgery or had major hemorrhage. The extent of reversal was determined using the VerifyNow P2Y12 assay. Clinical hemostasis was assessed by central adjudication using validated criteria. Treatment-emergent safety events were evaluated. The trial is ongoing and will enroll approximately 200 patients with evaluable data. RESULTS: Of 150 enrolled patients, 142 required urgent surgery and 8 had major hemorrhage. For the end-point analysis, 129 patients had analyzable platelet data; 122 had data on adjudicated hemostasis. Bentracimab provided a rapid reversal of ticagrelor’s antiplatelet effects within 5 to 10 minutes. The reversal was sustained for more than 24 hours, as measured with the VerifyNow P2Y12 and vasodilator-stimulated phosphoprotein phosphorylation assays (P<0.001, with both assays and in all subgroups). Adjudicated hemostasis was achieved for more than 90% of patients (P<0.001); approximately 5% of patients had thrombotic events. No allergic or infusion-related reactions were reported. CONCLUSIONS: Bentracimab provided immediate and sustained reversal of the antiplatelet effects of ticagrelor in patients undergoing surgical procedures. (Funded by PhaseBio Pharmaceuticals, Inc.; ClinicalTrials.gov number, NCT04286438.)

Hemadsorption for removal of ticagrelor and direct oral anticoagulants in cardiac surgery

INTRODUCTION

Cardiac patients on antiplatelets or oral anticoagulation undergoing emergent cardiac surgery without appropriate washout periods are at increased risk for developing perioperative bleeding. CytoSorb is a commercially available hemadsorption filter that can simultaneously remove a wide range of substances including ticagrelor, and direct oral anticoagulants (DOACs). Areas covered: Although CytoSorb has been used to remove various protein-bound substances, this review will specifically evaluate and review current evidence for applying CytoSorb in removing ticagrelor and DOACs using 4 in vivo studies, 3 case reports, one retrospective clinical study and 2 cost analysis studies. Based on limited evidence, CytoSorb may be effective in reducing perioperative bleeding as demonstrated by reducing chest tube output, blood product transfusions, and re-thoracotomy rates. CytoSorb can also reduce length of intensive care unit (ICU) and hospital stay. Although, CytoSorb has an initial upfront cost, it was proven to be cost effective due to potential health resource savings on both short- and long-term projections.Expert Commentary: CytoSorb provides a novel strategy to remove ticagrelor and DOACs in patients requiring emergency cardiac surgery. Although promising results, more solid evidence is required to establish its clinical effectiveness in reducing perioperative bleeding, bleeding-related complications, mortality, and finally, its overall safety.

Regional anaesthesia in patients on antithrombotic drugs: Joint ESAIC/ESRA guidelines

BACKGROUND

Bleeding is a potential complication after neuraxial and peripheral nerve blocks. The risk is increased in patients on antiplatelet and anticoagulant drugs. This joint guideline from the European Society of Anaesthesiology and Intensive Care and the European Society of Regional Anaesthesia aims to provide an evidence-based set of recommendations and suggestions on how to reduce the risk of antithrombotic drug-induced haematoma formation related to the practice of regional anaesthesia and analgesia.

DESIGN

A systematic literature search was performed, examining seven drug comparators and 10 types of clinical intervention with the outcome being peripheral and neuraxial haematoma. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for assessing the methodological quality of the included studies and for formulating recommendations. A Delphi process was used to prepare a clinical practice guideline.

RESULTS

Clinical studies were limited in number and quality and the certainty of evidence was assessed to be GRADE C throughout. Forty clinical practice statements were formulated. Using the Delphi-process, strong consensus (>90% agreement) was achieved in 57.5% of recommendations and consensus (75 to 90% agreement) in 42.5%.

DISCUSSION

Specific time intervals should be observed concerning the adminstration of antithrombotic drugs both prior to, and after, neuraxial procedures or those peripheral nerve blocks with higher bleeding risk (deep, noncompressible). These time intervals vary according to the type and dose of anticoagulant drugs, renal function and whether a traumatic puncture has occured. Drug measurements may be used to guide certain time intervals, whilst specific reversal for vitamin K antagonists and dabigatran may also influence these. Ultrasound guidance, drug combinations and bleeding risk scores do not modify the time intervals. In peripheral nerve blocks with low bleeding risk (superficial, compressible), these time intervals do not apply.

CONCLUSION

In patients taking antiplatelet or anticoagulant medications, practitioners must consider the bleeding risk both before and after nerve blockade and during insertion or removal of a catheter. Healthcare teams managing such patients must be aware of the risk and be competent in detecting and managing any possible haematomas.

Bleeding avoidance strategies in percutaneous coronary intervention

For many years, bleeding has been perceived as an unavoidable consequence of strategies aimed at reducing thrombotic complications in patients undergoing percutaneous coronary intervention (PCI). However, the paradigm has now shifted towards bleeding being recognized as a prognostically unfavourable event to the same extent as having a new or recurrent ischaemic or thrombotic complication. As such, in parallel with progress in device and drug development for PCI, there is clinical interest in developing strategies that maximize not only the efficacy but also the safety (for example, by minimizing bleeding) of any antithrombotic treatment or procedural aspect before, during or after PCI. In this Review, we discuss contemporary data and aspects of bleeding avoidance strategies in PCI, including risk stratification, timing of revascularization, pretreatment with antiplatelet agents, selection of vascular access, choice of coronary stents and antithrombotic treatment regimens.

Antiplatelet Therapy for Atherothrombotic Disease in 2022—From Population to Patient-Centered Approaches

Antiplatelet agents, with aspirin and P2Y₁₂ receptor antagonists as major key molecules, are currently the cornerstone of pharmacological treatment of atherothrombotic events including a variety of cardio- and cerebro-vascular as well as peripheral artery diseases. Over the last decades, significant changes have been made to antiplatelet therapeutic and prophylactic strategies. The shift from a population-based approach to patient-centered precision medicine requires greater awareness of individual risks and benefits associated with the different antiplatelet strategies, so that the right patient gets the right therapy at the right time. In this review, we present the currently available antiplatelet agents, outline different management strategies, particularly in case of bleeding or in perioperative setting, and develop the concept of high on-treatment platelet reactivity and the steps toward person-centered precision medicine aiming to optimize patient care.

Perioperative Guidelines on Antiplatelet and Anticoagulant Agents: 2022 Update

Purpose of Review

Multiple guidelines and recommendations have been written to address the perioperative management of antiplatelet and anticoagulant drugs. In this review, we evaluated the recent guidelines in non-cardiac, cardiac, and regional anesthesia. Furthermore, we focused on unresolved problems and novel approaches for optimized perioperative management.

Recent Findings

Vitamin K antagonists should be stopped 3 to 5 days before surgery. Preoperative laboratory testing is recommended. Bridging therapy does not decrease the perioperative thromboembolic risk and might increase perioperative bleeding risk. In patients on direct-acting oral anticoagulants (DOAC), a discontinuation interval of 24 and 48 h in those scheduled for surgery with low and high bleeding risk, respectively, has been shown to be saved. Several guidelines for regional anesthesia recommend a conservative interruption interval of 72 h for DOACs before neuraxial anesthesia. Finally, aspirin is commonly continued in the perioperative period, whereas potent P2Y12 receptor inhibitors should be stopped, drug-specifically, 3 to 7 days before surgery.

Summary

Many guidelines have been published from various societies. Their applicability is limited in emergent or urgent surgery, where novel approaches might be helpful. However, their evidence is commonly based on small series, case reports, or expert opinions.

Population pharmacokinetic-pharmacodynamic modeling of PB2452, a monoclonal antibody fragment being developed as a ticagrelor reversal agent, in healthy volunteers

PB2452, a neutralizing monoclonal antibody fragment that binds the antiplatelet drug ticagrelor with high affinity, is being developed as a ticagrelor reversal agent. To identify a clinically useful intravenous (i.v.) reversal regimen, a semimechanistic exposure-response model was developed during the PB2452 first-in-human phase I study. From a randomized, double-blind, placebo-controlled, single-dose trial to evaluate the safety, efficacy, and pharmacokinetics (PKs) of PB2452 in 61 healthy volunteers pretreated with ticagrelor, sequential dose cohort data were used to build and refine an exposure-response model that combined population PK models for ticagrelor (TICA), ticagrelor active metabolite (TAM), and PB2452, and related their binding relationships to the PK of uncomplexed TICA and TAM which is predictive of platelet inhibition. Platelet function was assessed by multiple assays. The model was developed using Bayesian methods in NONMEM. Human PK and pharmacodynamic data from sequential dose cohorts were used to initially define and then refine model parameters. Model simulations indicated that an initial i.v. bolus of PB2452, followed by a high-rate infusion, and then a slower-rate infusion would provide immediate and sustained reversal of the antiplatelet effects of ticagrelor. Based on model predictions, a 6 g i.v. bolus followed by 6 g infused over 4 h and then 6 g over 12 h was identified and tested in study subjects and shown to provide complete reversal within 5 min of infusion onset that was sustained for 20-24 h. The model is predictive of the reversal profile of PB2452 and will inform future trials of PB2452.

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.

Management of stroke in patients on antithrombotic therapy: Practical issues in the era of direct oral anticoagulants

Antithrombotic drugs (ADs) are the mainstay of secondary prevention of thrombotic vascular diseases. Management of patients under long-term treatment with ADs admitted for acute cerebrovascular disease, either ischemic stroke (IS) or intracerebral hemorrhage (ICH), has become a frequent situation that might influence decision-making processes from diagnosis to therapeutic strategies. The aim of this review is to summarize current data from the literature to help clinicians in their decisions for stroke care in patients taking ADs. While a large body of data have made it possible to codify the management of patients presenting IS or ICH under antiplatelet drugs and vitamin K antagonists, the increasing use of direct oral anticoagulants (DOAs) and future development of new antiplatelet drugs raise new problems. Development of rapid assessment tools measuring specific biological activity and reversion agents dedicated to each class of DOAs should make it possible to optimize individual therapeutic strategies. This review highlights the main steps of IS and ICH management from early identification of ADs, and use of dedicated biological assays, to the stepwise strategy to apply revascularization or reversal therapies and finally the resumption of ADs with a focus on individual clinical and radiological characteristics for more personalized care.

[Perioperative management of platelet function and anticoagulation in geriatric patients]

Geriatric patients often have cardiovascular diseases that require differentiated perioperative management of hemostasis. The operation-related bleeding risk and the individual thromboembolism risk mutually influence each other, so that a differentiated preoperative assessment of the further prescription of coagulation-modulating medication is required. In many cases the active coagulation medication can be interrupted without replacement or continued unchanged. In cardiovascular diseases with antiplatelet medication, the preoperative risk-benefit assessment for most operations leads to the continuation of previous platelet aggregation inhibitor monotherapy; however, if there is a high risk of cardiovascular thromboembolism with dual platelet inhibition, the individual perioperative medication should be closely coordinated with a geriatrician or cardiologist.In most cases, the intake of vitamin K antagonists (VKA) can be preoperatively interrupted. In cases of high risk of thromboembolism, a temporary bridging with heparin must be carried out. The introduction of the four new direct oral antagonists (DOAC) has made the perioperative management of anticoagulation much easier. Bridging with heparin is not necessary. Perioperatively, only the dosage and timing of interruption of the DOACs have to be determined individually depending on the operative bleeding risk as well as the age, body weight and kidney function of the patient. If bleeding complications arise under the influence of the DOACs, antidotes are available for three of the four DOACs, which in acute cases can be used in addition to prothrombin complex concentrates and fresh frozen plasma to normalize coagulation.