The intriguing role of platelets as custodians of brain-derived neurotrophic factor.

A State of the Art lecture titled "Platelets and neurotrophins" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. Neurotrophins, a family of neuronal growth factors known to support cognitive function, are increasingly recognized as important players in vascular health. Indeed, along with their canonical receptors, neurotrophins are expressed in peripheral tissues, particularly in the vasculature. The better-characterized neurotrophin in vascular biology is the brain-derived neurotrophic factor (BDNF). Its largest extracerebral pool resides within platelets, partly inherited from megakaryocytes and also likely internalized from circulation. Activation of platelets releases vast amounts of BDNF into their milieu and interestingly leads to platelet aggregation through binding of its receptor, the tropomyosin-related kinase B, on the platelet surface. As BDNF is readily available in plasma, a mechanism to preclude excessive platelet activation and aggregation appears critical. As such, binding of BDNF to α2-macroglobulin hinders its ability to bind its receptor and limits its platelet-activating effects to the site of vascular injury. Altogether, addition of BDNF to a forming clot facilitates not only paracrine platelet activation but also binding to fibrinogen, rendering the resulting clot more porous and plasma-permeable. Importantly, release of BDNF into circulation also appears to be protective against adverse cardiovascular and cerebrovascular outcomes, which has been reported in both animal models and epidemiologic studies. This opens an avenue for platelet-based strategies to deliver BDNF to vascular lesions and facilitate wound healing through its regenerative properties. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress.

Standardization of definition and management for bleeding disorder of unknown cause: communication from the SSC of the ISTH.

In many patients referred with significant bleeding phenotype, laboratory testing fails to define any hemostatic abnormalities. Clinical practice with respect to diagnosis and management of this patient cohort poses significant clinical challenges. We recommend that bleeding history in these patients should be objectively assessed using the International Society on Thrombosis and Haemostasis (ISTH) bleeding assessment tool. Patients with increased bleeding assessment tool scores should progress to hemostasis laboratory testing. To diagnose bleeding disorder of unknown cause (BDUC), normal complete blood count, prothrombin time, activated partial thromboplastin time, thrombin time, von Willebrand factor antigen, von Willebrand factor function, coagulation factors VIII, IX, and XI, and platelet light transmission aggregometry should be the minimum laboratory assessment. In some laboratories, additional specialized hemostasis testing may be performed to identify other rare causes of bleeding. We recommend that patients with a significant bleeding phenotype but normal laboratory investigations should be registered with a diagnosis of BDUC in preference to other terminology. Global hemostatic tests and markers of fibrinolysis demonstrate variable abnormalities, and their clinical significance remains uncertain. Targeted genomic sequencing examining candidate hemostatic genes has a low diagnostic yield. Underlying BDUC should be considered in patients with heavy menstrual bleeding since delays in diagnosis often extend to many years and negatively impact quality of life. Treatment options for BDUC patients include tranexamic acid, desmopressin, and platelet transfusions.

Association of laboratory test results with the bleeding history in patients with inherited platelet function disorders (the Bleeding Assesment Tool - LABoratory tests substudy): communication from the Platelet Physiology ISTH-SSC.

Background: In hemophilia and von Willebrand disease, the degree of alteration of laboratory assays correlates with bleeding manifestations. Few studies have assessed the predictive value for bleeding of laboratory assays in patients with inherited platelet function disorders (IPFDs). Objectives: To assess whether there is an association between platelet function assay results and bleeding history, as evaluated by the International Society on Thrombosis and Haemostasis (ISTH) bleeding assessment tool (BAT). Methods: Centers participating in the international ISTH-BAT validation study were asked to provide results of the diagnostic assays employed for the patients they enrolled, and the association with the individual patients' bleeding score (BS) was assessed. Results: Sixty-eight patients with 14 different IPFDs were included. Maximal amplitude of platelet aggregation was significantly lower in patients with a pathologic BS and correlated inversely with the BS, a finding largely driven by the subgroup of patients with Glanzmann thrombasthenia and CalDAG-GEFI deficiency; after their exclusion, TRAP-induced aggregation remained significantly lower in patients with a pathologic BS. Bleeding time was significantly more prolonged in patients with a high BS than in those with a normal BS (27.1 ± 6.2 minutes vs 15.1 ± 10.6 minutes; P < .01). Reduced α-granule content was significantly more common among patients with a pathologic BS than among those with a normal BS (80% vs 20%; P < .05). Receiver operating characteristic curve analysis revealed a significant discriminative ability of all the aforementioned tests for pathologic BS (P < .001), also after exclusion of patients with Glanzmann thrombasthenia and CalDAG-GEFI deficiency. Conclusion: This study shows that altered platelet laboratory assay results are associated with an abnormal ISTH-BAT BS in IPFD.

Megakaryocytes possess a STING pathway that is transferred to platelets to potentiate activation.

Platelets display unexpected roles in immune and coagulation responses. Emerging evidence suggests that STING is implicated in hypercoagulation. STING is an adaptor protein downstream of the DNA sensor cyclic GMP-AMP synthase (cGAS) that is activated by cytosolic microbial and self-DNA during infections, and in the context of loss of cellular integrity, to instigate the production of type-I IFN and pro-inflammatory cytokines. To date, whether the cGAS-STING pathway is present in platelets and contributes to platelet functions is not defined. Using a combination of pharmacological and genetic approaches, we demonstrate here that megakaryocytes and platelets possess a functional cGAS-STING pathway. Our results suggest that in megakaryocytes, STING stimulation activates a type-I IFN response, and during thrombopoiesis, cGAS and STING are transferred to proplatelets. Finally, we show that both murine and human platelets contain cGAS and STING proteins, and the cGAS-STING pathway contributes to potentiation of platelet activation and aggregation. Taken together, these observations establish for the first time a novel role of the cGAS-STING DNA sensing axis in the megakaryocyte and platelet lineage.

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

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

Illustrated State-of-the-Art Capsules of the ISTH 2023 Congress.

This year's Congress of the International Society of Thrombosis and Haemostasis (ISTH) took place in person in Montréal, Canada, from June 24-28, 2023. The conference, held annually, highlighted cutting-edge advances in basic, translational, population and clinical sciences relevant to the Society. As for all ISTH congresses, we offered a special, congress-specific scientific theme; this year, the special theme was immunothrombosis. Certainly, over the last few years, COVID-19 infection and its related thrombotic and other complications have renewed interest in the concepts of thromboinflammation and immunothrombosis; namely, the relationship between inflammation, infection and clotting. Other main scientific themes of the Congress included Arterial Thromboembolism, Coagulation and Natural Anticoagulants, Diagnostics and Omics, Fibrinolysis and Proteolysis, Hemophilia and Rare Bleeding Disorders, Hemostatic System in Cancer, Inflammation and Immunity, Pediatrics, Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies, Platelets and Megakaryocytes, Vascular Biology, Venous Thromboembolism and Women's Health. Among other sessions, the program included 28 State-of-the-Art (SOA) sessions with a total of 84 talks given by internationally recognized leaders in the field. SOA speakers were invited to prepare brief illustrated reviews of their talks that were peer reviewed and are included in this article. These illustrated capsules highlight the major scientific advances with potential to impact clinical practice. Readers are invited to take advantage of the excellent educational resource provided by these illustrated capsules. They are also encouraged to use the image in social media to draw attention to the high quality and impact of the science presented at the Congress.

Alpha-2-macroglobulin prevents platelet aggregation induced by brain-derived neurotrophic factor.

The brain-derived neurotrophic factor (BDNF) has been recently shown to have activating effects in isolated platelets. However, BDNF circulates in plasma and a mechanism to preclude constant activation of platelets appears necessary. Hence, we investigated the mechanism regulating BDNF bioavailability in blood. Protein-protein interactions were predicted by molecular docking and validated through immunoprecipitation. Platelet aggregation was assessed using light transmission aggregometry with washed platelets in response to classical agonists or BDNF, in the absence or presence of alpha-2-macroglobulin (α2M), and in platelet-rich plasma. BDNF signaling was assessed with phospho-blots. As little as 25% autologous plasma was sufficient to completely abolish platelet aggregation in response to BDNF. Docking predicted two forms of BDNF binding to native or activated α2M, in parallel and perpendicular arrangements, and the model suggested that the BDNF-α2M complex cannot bind to the high-affinity BDNF receptor, tropomyosin receptor kinase B (TrkB). Experimentally, native and activated α2M formed stable complexes with BDNF preventing BDNF-induced TrkB activation and signal transduction. Both native and activated α2M inhibited BDNF induced-platelet aggregation in a concentration-dependent manner with comparable half-maximal inhibitory concentrations (IC50≈ 125-150 nM). Our study implicates α2M as a physiological regulator of BDNF bioavailability, and as an inhibitor of BDNF-induced platelet activation in blood.

Consensus report on flow cytometry for platelet function testing in thrombocytopenic patients: communication from the SSC of the ISTH.

BACKGROUND: Platelet count alone does not reliably predict bleeding risk, suggesting platelet function is important to monitor in patients with thrombocytopenia. There is still an unmet need for improved platelet function diagnostics in patients with low platelet count in many clinical situations. Flow cytometry is a promising tool allowing reliable platelet function study in this setting. OBJECTIVES: The goal of this joint project between the International Society on Thrombosis and Haemostasis (ISTH) Scientific Standardization Committee (SSC) Subcommittees on Platelet Physiology and Platelet Immunology is to provide expert consensus guidance on the use of flow cytometry for the evaluation of platelet function, particularly activation, in patients with low platelet counts. METHODS: A literature review was performed to identify relevant questions and areas of interest. An electronic expression of interest form was thereafter announced on the ISTH webpage, followed by a survey encompassing 37 issues regarding preanalytical, analytical, postanalytical, and performance aspects. Areas of disagreement or uncertainty were identified and formed the basis for 2 focus group discussions. RESULTS: Consensus recommendations relative to patient sample collection, preanalytical variables, sample type, platelet-count cutoff, any potential specific modification of the standard flow cytometry protocol, and results expression and reporting are proposed based on the current practices of experts in the field as well as on literature review. CONCLUSION: The proposed consensus recommendations would allow standardization of protocols in upcoming clinical studies. The clinical utility of platelet function testing using flow cytometry to predict bleeding risk still needs rigorous multicenter outcome studies in patients with thrombocytopenia.

Multicenter evaluation of light transmission platelet aggregation reagents: communication from the ISTH SSC Subcommittee on Platelet Physiology.

BACKGROUND: Light transmission aggregation (LTA) is used widely by the clinical and research communities. Although it is a gold standard, there is a lack of interlaboratory harmonization. OBJECTIVES: The primary objective was to assess whether sources of activators (mainly adenosine diphosphate [ADP], collagen, arachidonic acid, epinephrine, and thrombin receptor activating peptide6) and ristocetin contribute to poor LTA reproducibility. The secondary objective was to evaluate interindividual variability of results to appreciate the distribution of normal values and consequently better interpret pathologic results. METHODS: An international multicenter study involving 28 laboratories in which we compared LTA results obtained with center-specific activators and a comparator that we supplied. RESULTS: We report variability in the potency (P) of activators in comparison with the comparator. Thrombin receptor activating peptide 6 (P, 1.32-2.68), arachidonic acid (P, 0.87-1.43), and epinephrine (P, 0.97-1.34) showed the greatest variability. ADP (P, 1.04-1.20) and ristocetin (P, 0.98-1.07) were the most consistent. The data highlighted clear interindividual variability, notably for ADP and epinephrine. Four profiles of responses were observed with ADP from high-responders, intermediate-responders, and low-responders. A fifth profile corresponding to nonresponders (5% of the individuals) was observed with epinephrine. CONCLUSION: Based on these data, the establishment and adoption of simple standardization principles should mitigate variability due to activator sources. The observation of huge interindividual variability for certain concentrations of activators should lead to a cautious interpretation before reporting a result as abnormal. Confidence can be taken from the fact that difference between sources is not exacerbated in patients treated with antiplatelet agents.

Consensus report on markers to distinguish procoagulant platelets from apoptotic platelets: communication from the Scientific and Standardization Committee of the ISTH.

BACKGROUND: Procoagulant platelets are a subpopulation of highly activated platelets that promote coagulation through surface-exposed, negatively charged phospholipids, especially phosphatidylserine. Procoagulant platelets are important for clot stabilization during hemostasis, and an increased number of these platelets is associated with thrombotic risk. There is a need for harmonization in this area since many of the markers and methods used to assess procoagulant platelets are not specific when used in isolation but are also associated with platelet apoptosis. OBJECTIVES: We initiated this project to identify a minimum set of markers and/or methods that can detect and distinguish procoagulant platelets from apoptotic platelets. METHODS: The study design involved a primary panel with 27 international experts who participated in an online survey and moderated virtual focus group meetings. Primary and secondary panel members were then invited to provide input on themes and statements generated from the focus groups. RESULTS: This led to a recommendation to use flow cytometry and a combination of the following 3 surface markers to differentiate procoagulant platelets from apoptotic platelets: P-selectin (CD62P), phosphatidylserine (recognized by annexin V), and the platelet-specific receptor GPIX (CD42a) or αIIb integrin (CD41, GPIIb). CONCLUSION: Procoagulant platelets are expected to be positive for all 3 markers, while apoptotic platelets are positive for annexin V and the platelet-specific surface receptor(s) but negative for P-selectin.

Assessment of Platelet Function by High-Throughput Screening Light Transmission Aggregometry: Optimul Assay.

Platelet function testing is critical in the diagnosis of bleeding disorders and allows monitoring of antiplatelet therapy. The gold standard assay, light transmission aggregometry (LTA), was developed 60 years ago and remains widely used worldwide. It requires, however, access to expensive equipment and is time-consuming, and the interpretation of results requires evaluation by an experienced investigator. It also suffers from a lack of standardization, resulting in widely variable results between laboratories. 96-well plate-based Optimul aggregometry utilizes the same principles of LTA and aims to standardize agonist concentrations with the development of 96-well plates which are precoated with 7 concentrations of each lyophilized agonist (arachidonic acid, adenosine diphosphate, collagen, epinephrine, TRAP-6 amide, and U46619) and stored at ambient room temperature (20-25 °C) for up to 12 weeks. For platelet function testing, 40 µL of platelet-rich plasma is added to each well, and the plate is placed onto a plate shaker, after which platelet aggregation is determined by changes in light absorbance. This method reduces the blood volume required and allows for in-depth platelet function analysis without specialist training, or the need to purchase expensive, dedicated equipment.

Aspirin for the Primary Prevention of Vascular Ischemic Events: An Updated Systematic Review and Meta-analysis to Support Shared Decision-Making.

Background: Since the publication of the 2010 Canadian antiplatelet guidelines, several large randomized controlled trials (RCTs) have evaluated the role of aspirin (ASA) use in primary prevention. We evaluated the effect of ASA use, compared with no ASA, on ischemic and bleeding events in patients without known atherosclerotic cardiovascular diseases. Methods: We updated a published systematic review and meta-analysis by searching MEDLINE, Embase, and CENTRAL for the period up to March 2023. We included RCTs that enrolled patients for primary prevention of atherosclerotic cardiovascular diseases, and compared use of ASA to no ASA. We assessed risk of bias (RoB) using the Cochrane RoB tool, and certainty of evidence using the grading recommendations, assessment, development, and evaluation (GRADE) criteria. The primary efficacy outcome was major adverse cardiovascular events (MACE) (death, myocardial infarction, or stroke). The primary safety outcomes were intracranial hemorrhage and extracranial major bleeding events. We used a random-effects model to generate pooled risk ratios (RRs) and 95% confidence intervals (CIs). Results: We included 14 RCTs (n = 167,587) at overall low RoB, with a median follow-up of 5 years. Compared to no ASA, ASA use reduced the incidence of MACE (RR 0.90, 95% CI 0.86-0.94), with a higher risk of intracranial hemorrhage (RR 1.33, 95% CI 1.13-1.56) and extracranial major bleeding (RR 1.67, 95% CI 1.36-2.06). In prespecified subgroups of age, sex, and diabetes, effect estimates were consistent. Conclusions: ASA use in primary prevention is associated with a consistent reduction in MACE, but at the expense of major bleeding events. Patient values and preferences should be taken into account when considering ASA use for primary prevention.

Contexte: Depuis la publication, en 2010, des lignes directrices canadiennes sur les agents antiplaquettaires, plusieurs importants essais contrôlés randomisés (ECR) ont été menés pour évaluer le rôle de l'aspirine (AAS) en prévention primaire. Nous avons comparé l'effet de l'AAS à la non-utilisation de l'AAS sur les événements ischémiques et hémorragiques chez des patients présentant une maladie cardiovasculaire athéroscléreuse (MCVAS) connue. Méthodologie: Nous avons mis à jour une revue systématique et une méta-analyse déjà publiées en effectuant une recherche dans les bases de données MEDLINE, Embase et CENTRAL jusqu'en mars 2023. Nous avons inclus les ECR ayant porté sur la prévention primaire de la MCVAS chez les patients et comparé l'AAS et la non-utilisation de l'AAS. Nous avons évalué le risque de biais à l'aide de l'outil RoB de Cochrane, et le degré de certitude des données probantes au moyen des critères GRADE. Le principal critère d'évaluation de l'efficacité était les événements cardiovasculaires indésirables majeurs (ECIM; décès, infarctus du myocarde ou accident vasculaire cérébral). Les principaux critères d'évaluation de l'innocuité étaient les hémorragies intracrâniennes (HIC) et les saignements extracrâniens majeurs (SECM). Nous avons utilisé un modèle à effets aléatoires afin de générer les rapports de risque (RR) et les intervalles de confiance (IC) à 95 % regroupés. Résultats: Nous avons inclus 14 ECR (n = 167 587) associés à un faible risque de biais et dont le suivi médian était de 5 ans. Comparativement à la non-utilisation d'AAS, l'AAS a réduit les ECIM (RR : 0,90; IC à 95 % : 0,86-0,94), mais était associé à un risque plus élevé d'HIC (RR : 1,33; IC à 95 % : 1,13-1,56) et de SECM (RR : 1,67; IC à 95 % : 1,36-2,06). Les estimations de l'effet étaient constantes dans les sous-groupes définis au préalable selon l'âge, le sexe et le diabète. Conclusion: En prévention primaire, l'AAS est associé à une réduction systématique des ECIM, mais au détriment de manifestations hémorragiques majeures. Les valeurs et les préférences du patient doivent être prises en compte lorsqu'on envisage l'AAS en prévention primaire.

Plasminogen Activator Inhibitor-1-Positive Platelet-Derived Extracellular Vesicles Predicts MACE and the Proinflammatory SMC Phenotype.

Patients with established coronary artery disease remain at elevated risk of major adverse cardiac events. The goal of this study was to evaluate the utility of plasminogen activator inhibitor-1-positive platelet-derived extracellular vesicles as a biomarker for major adverse cardiac events and to explore potential underlying mechanisms. Our study suggests these extracellular vesicles as a potential biomarker to identify and a therapeutic target to ameliorate neointimal formation of high-risk patients.

Expert opinion on the use of platelet secretion assay for the diagnosis of inherited platelet function disorders: Communication from the ISTH SSC Subcommittee on Platelet Physiology.

Assessment of platelet secretion is crucial for diagnosing suspected inherited platelet function disorders (IPFD). A previous survey of the SSC on Platelet Physiology of the ISTH and a comprehensive review highlighted that most of the platelet secretion assays (PSAs) lack standardization and validation. The aim of this study was to provide expert consensus guidance on the use of PSAs for IPFD diagnosis. We surveyed 26 experts from 10 different countries using the RAND/UCLA methodology, to attain a consensus on sensitivity, specificity, feasibility, time to readout, and cost of most PSAs. Answers were then graded in three categories: appropriate, uncertain, and inappropriate. Equivocal or misinterpretable statements required a second and third round survey involving 14 of the original 26 experts. We report here the consolidated results of the entire procedure. There was uniform agreement on several general statements, including that PSAs should be performed in hemostasis laboratories as first line diagnostic tests even in patients with normal platelet aggregation, and should include a δ-granule secretion marker. Among the specific assays examined, lumiaggregometry, other luciferin/luciferase-based assays, high-performance liquid chromatography methods, radiolabeled-serotonin based assays, and whole-mount transmission electron microscopy were rated as appropriate for the measurement of δ-granule release, and platelet P-selectin expression by flow cytometry and released proteins by ELISA for α-granule release. For most of the other PSAs, the expert opinions were widely dispersed. Lack of expert consensus on many PSAs clearly indicates an unmet need for rigorous standardization, multicenter comparison of results, and validation of PSAs for clinical laboratory practice.

Antiplatelet Therapy in Atherothrombotic Diseases: Similarities and Differences Across Guidelines.

Antiplatelet therapy, mainly consisting of aspirin and P2Y12 receptor antagonists, is the cornerstone of the pharmacological treatment and prevention of atherothrombotic diseases. Its use, especially in secondary cardiovascular prevention, has significantly improved patient clinical outcomes in the last decades. Primary safety endpoint (i.e., bleeding complications) remain a major drawback of antiplatelet drugs. National and international societies have published and regularly updated guidelines for antiplatelet therapy aiming to provide clinicians with practical recommendations for a better handling of these drugs in various clinical settings. Many recommendations find common ground between international guidelines, but certain strategies vary across the countries, particularly with regard to the choice of molecules, dosage, and treatment duration. In this review, we detail and discuss the main antiplatelet therapy indications in the light of the different published guidelines and the significant number of recently published clinical trials and meta-analyses and highlight the areas that deserve further investigation in order to improve antiplatelet therapy in patients with atherothrombotic diseases.

Assessing cardiometabolic parameter monitoring in inpatients taking a second-generation antipsychotic: The CAMI-SGA study - a cross-sectional study.

OBJECTIVES: This study aims to determine the proportion of initial cardiometabolic assessment and its predicting factors in adults with schizophrenia, bipolar disorder or other related diagnoses for whom a second-generation antipsychotic was prescribed in the hospital setting. DESIGN: Cross-sectional study. SETTING: The psychiatry unit of a Canadian tertiary care teaching hospital in Montreal, Canada. PARTICIPANTS: 402 patients with aforementioned disorders who initiated, restarted or switched to one of the following antipsychotics: clozapine, olanzapine, risperidone, paliperidone or quetiapine, between 2013 and 2016. PRIMARY OUTCOME MEASURES: We assessed the proportion of cardiometabolic parameters monitored. SECONDARY OUTCOME MEASURES: We identified predictors that influence the monitoring of cardiometabolic parameters and we assessed the proportion of adequate interventions following the screening of uncontrolled blood pressure and fasting glucose or glycated haemoglobin (HbA1c) results. RESULTS: Only 37.3% of patients received monitoring for at least three cardiometabolic parameters. Blood pressure was assessed in 99.8% of patients; lipid profile in 24.4%; fasting glucose or HbA1c in 33.3% and weight or body mass index in 97.8% of patients while waist circumference was assessed in 4.5% of patients. For patients with abnormal blood pressure and glycaemic values, 42.3% and 41.2% subsequent interventions were done, respectively. The study highlighted the psychiatric diagnosis (substance induced disorder OR 0.06 95% CI 0.00 to 0.44), the presence of a court-ordered treatment (OR 0.79 95% CI 0.35 to 1.79) and the treating psychiatrist (up to OR 34.0 95% CI 16.2 to 140.7) as predictors of cardiometabolic monitoring. CONCLUSIONS: This study reports suboptimal baseline cardiometabolic monitoring of patients taking an antipsychotic in a Canadian hospital. Optimising collaboration within a multidisciplinary team may increase cardiometabolic monitoring.

Aspirin for Primary Cardiovascular Prevention in Patients with Diabetes: Uncertainties and Opportunities.

The use of the antiplatelet agent aspirin (acetylsalicylic acid) was previously routinely recommended for the primary prevention of cardiovascular (CV) events in patients with diabetes, but recent large-scale randomized trials have failed to demonstrate a sizeable net clinical benefit with a once-daily, low-dose (81-100 mg) regimen in this population. Previous pharmacokinetic and pharmacodynamic studies have suggested that the aspirin formulation (enteric-coated) and dosing schedule (once daily) studied in randomized trials for primary prevention of CV events defining contemporary clinical practice may not leverage the full potential of the drug, particularly in patients with diabetes. Indeed, the diabetic platelets bear characteristics that increase their thrombotic potential and alter their pharmacologic response to the drug. Consequently, the appropriateness of studying a uniform aspirin regimen in landmark primary prevention trials needs to be revisited. In this review, we present the evidence showing that diabetes not only increases baseline platelet reactivity, but also alters platelet response to aspirin through different mechanisms including a faster platelet turnover rate. Obesity, which is frequently associated with diabetes, also impacts its pharmacokinetics via an increase in distribution volume. Small-scale pharmacokinetic and pharmacodynamic studies have suggested that the relative aspirin resistance phenotype observed in patients with diabetes may be reversed with a twice-daily dosing schedule, and with nonenteric-coated aspirin formulations. Properly powered randomized controlled trials investigating the efficacy and safety of aspirin dosing schedules and formulations tailored to the population of patients with diabetes are urgently required to optimize patient care.

Clinical Correlates Identify ProBDNF and Thrombo-Inflammatory Markers as Key Predictors of Circulating p75NTR Extracellular Domain Levels in Older Adults.

The p75NTR receptor binds all neurotrophins and is mostly known for its role in neuronal survival and apoptosis. Recently, the extracellular domain (ECD) of p75NTR has been reported in plasma, its levels being dysregulated in numerous neurological diseases. However, the factors associated with p75NTR ECD levels remain unknown. We investigated clinical correlates of plasma p75NTR ECD levels in older adults without clinically manifested neurological disorders. Circulating p75NTR levels were measured by enzyme-linked immunosorbent assay in plasma obtained from participants in the BEL-AGE cohort (n = 1,280). Determinants of plasma p75NTR ECD levels were explored using linear and non-linear statistical models. Plasma p75NTR ECD levels were higher in male participants; were positively correlated with circulating concentrations of pro-brain-derived neurotrophic factor, and inflammatory markers interleukin-6 and CD40 Ligand; and were negatively correlated with the platelet activation marker P-selectin. While most individuals had p75NTR levels ranging from 43 to 358 pg/ml, high p75NTR levels reaching up to 9,000 pg/ml were detectable in a subgroup representing 15% of the individuals studied. In this cohort of older adults without clinically manifested neurological disorders, there was no association between plasma p75NTR ECD levels and cognitive performance, as assessed by the Montreal Cognitive Assessment score. The physiological relevance of high p75NTR ECD levels in plasma warrants further investigation. Further research assessing the source of circulating p75NTR is needed for a deeper understanding of the direction of effect, and to investigate whether high p75NTR ECD levels are predictive biomarkers or consequences of neuropathology.

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.