Platelet Function, Platelet Size and Content of Reticulated Platelets: Interactions in Patients Receiving Dual Antiplatelet Therapy.

Increased platelet activity is a risk factor of thrombotic events in cardiovascular patients. We studied the relationship between platelet function, platelet size, and the content of reticulated platelets (RP) in patients with coronary heart disease (CHD, n = 55) and acute coronary syndrome (ACS, n = 95) receiving acetylsalicylic acid + clopidogrel or ticagrelor, respectively. The control group consisted of patients with risk factors for CHD, but with no CHD/ACS and free of antiplatelet drugs (n = 66). Platelet function was evaluated by the exposure of activated glycoprotein (GP) IIb-IIIa and P-selectin. In the control group, platelets were activated by TRAP (Thrombin Receptor Activating Peptide) 10 µM, and ADP 20, 5, 2.5 µM, and in the CHD/ACS groups, by TRAP 10 µM, and ADP 20 5 µM (±epinephrine 20 µM). Platelet size was assessed by the mean volume, % large forms, and forward scattering. RP were stained by thiazole orange. In the control group, activated GP IIb-IIIa and P-selectin correlated with platelet size and RP content after platelet activation by all agonists. Despite the decrease in platelet activity by antiplatelet drugs, most correlations (primarily for activated GP IIb-IIIa) were preserved in the CHD/ACS patients. In conclusion, increased platelet size and RP content are associated with increased platelet activity and the reduced efficacy of antiplatelet therapy.

Harmony in Healing: Investigating Platelet-Rich Plasma Activation during Acetylsalicylic Acid Treatment.

Platelet-rich plasma (PRP) therapy holds promise for treating various clinical conditions. The activation process is crucial in releasing growth factors and cytokines from platelets, enhancing the therapeutic properties of PRP. Standard activation methods involve autologous thrombin or collagen, with variations in efficacy and growth factor release. This study explores the impact of acetylsalicylic acid (ASA), a commonly used antiplatelet drug, on PRP activation. The results indicate that non-activated PRP extracted from the whole blood of ASA-treated patients exhibits increased inflammatory cytokine concentrations, notably TNFa. After activation with autologous thrombin/CaCl2 or collagen IV, the measured fluorescence intensities suggest varying release patterns between treated and non-treated groups. Understanding the influence of ASA on platelet activation holds implications for personalized medicine and optimizing outcomes for individual patients undergoing PRP therapy. This research sheds light on the potential challenges associated with using antiplatelet drugs, emphasizing the need for careful consideration in tailoring PRP-based regenerative therapies.

Platelet integrin αIIbß3 plays a key role in a venous thrombogenesis mouse model.

Venous thrombosis (VT) is a common vascular disease associated with reduced survival and a high recurrence rate. VT is initiated by the accumulation of platelets and neutrophils at sites of endothelial cell activation. A role for platelet αIIbß3 in VT is not established, a task complicated by the increased bleeding risk caused by partial agonists such as tirofiban. Here, we show that m-tirofiban, a modified version of tirofiban, does not agonize αIIbß3 based on lack of neoepitope expression and the cryo-EM structure of m-tirofiban/full-length αIIbß3 complex. m-tirofiban abolishes agonist-induced platelet aggregation while preserving clot retraction ex vivo and, unlike tirofiban, it suppresses venous thrombogenesis in a mouse model without increasing bleeding. These findings establish a key role for αIIbß3 in VT initiation and suggest that m-tirofiban and compounds with a similar structurally-defined mechanism of action merit consideration as potential thromboprophylaxis agents in patients at high risk for VT and hemorrhage.

Base-Catalyzed Reaction of Isatins and (3-Hydroxyprop-1-yn-1-yl)phosphonates as a Tool for the Synthesis of Spiro-1,3-dioxolane Oxindoles with Anticancer and Anti-Platelet Properties.

An approach to the synthesis of phosphoryl substituted spiro-1,3-dioxolane oxindoles was developed from the base-catalyzed reaction of various isatins with (3-hydroxyprop-1-yn-1-yl)phosphonates. It was found that various aryl-substituted and N-functionalized isatins with the formation of appropriate products with high yields and stereoselectivity when using t-BuOLi are able to react. Cytotoxic activity evaluation suggests that the most significant results in relation to the HuTu 80 cell line were shown by N-benzylated spirodioxolanes. 5-Cloro-N-unsubstituted spirooxindoles exhibit antiaggregational activity exceeding the values of acetylsalicylic acid.

Platelet Proteomics and Tissue Metabolomics Investigation for the Mechanism of Aspirin Eugenol Ester on Preventive Thrombosis Mechanism in a Rat Thrombosis Model.

Platelet activation is closely related to thrombosis. Aspirin eugenol ester (AEE) is a novel medicinal compound synthesized by esterifying aspirin with eugenol using the pro-drug principle. Pharmacological and pharmacodynamic experiments showed that AEE has excellent anti-inflammatory, antioxidant, and inhibitory platelet activation effects, preventing thrombosis. However, the regulatory network and action target of AEE in inhibiting platelet activation remain unknown. This study aimed to investigate the effects of AEE on platelets of thrombosed rats to reveal its regulatory mechanism via a multi-omics approach. The platelet proteomic results showed that 348 DEPs were identified in the AEE group compared with the model group, of which 87 were up- and 261 down-regulated. The pathways in this result were different from previous results, including mTOR signaling and ADP signaling at P2Y purinoceptor 12. The metabolomics of heart and abdominal aortic tissue results showed that the differential metabolites were mainly involved in steroid biosynthesis, the citric acid cycle, phenylalanine metabolism, phenylalanine, tyrosine, and tryptophan biosynthesis, and glutathione metabolism. Molecular docking results showed that AEE had a better binding force to both the COX-1 and P2Y12 protein. AEE could effectively inhibit platelet activation by inhibiting COX-1 protein and P2Y12 protein activity, thereby inhibiting platelet aggregation. Therefore, AEE can have a positive effect on inhibiting platelet activation.

Treatment with APAC, a dual antiplatelet anticoagulant heparin proteoglycan mimetic, limits early collar-induced carotid atherosclerotic plaque development in Apoe-/- mice.

BACKGROUND AND AIMS: Mast cell-derived heparin proteoglycans (HEP-PG) can be mimicked by bioconjugates carrying antithrombotic and anti-inflammatory properties. The dual antiplatelet and anticoagulant (APAC) construct administered, either locally or intravenously (i.v.), targets activated endothelium, its adhesion molecules, and subendothelial matrix proteins, all relevant to atherogenesis. We hypothesized that APAC influences cellular interactions in atherosclerotic lesion development and studied APAC treatment during the initiation and progression of experimental atherosclerosis. METHODS: Male western-type diet-fed Apoe-/- mice were equipped with perivascular carotid artery collars to induce local atherosclerosis. In this model, mRNA expression of adhesion molecules including ICAM-1, VCAM-1, P-Selectin, and Platelet Factor 4 (PF4) are upregulated upon lesion development. From day 1 (prevention) or from 2.5 weeks after lesion initiation (treatment), mice were administered 0.2 mg/kg APAC i.v. or control vehicle three times weekly for 2.5 weeks. At week 5 after collar placement, mice were sacrificed, and lesion morphology was microscopically assessed. RESULTS: APAC treatment did not affect body weight or plasma total cholesterol levels during the experiments. In the prevention setting, APAC reduced carotid artery plaque size and volume by over 50 %, aligning with decreased plaque macrophage area and collagen content. During the treatment setting, APAC reduced macrophage accumulation and necrotic core content, and improved markers of plaque stability. CONCLUSIONS: APAC effectively reduced early atherosclerotic lesion development and improved markers of plaque inflammation in advanced atherosclerosis. Thus, APAC may have potential to alleviate the progression of atherosclerosis.

NADPH oxidase 1/4 dual inhibitor setanaxib suppresses platelet activation and thrombus formation.

AIMS: The production of reactive oxygen species (ROS) by NADPH oxidase (NOX) is able to induce platelet activation, making NOX a promising target for antiplatelet therapy. In this study, we examined the effects of setanaxib, a dual NOX1/4 inhibitor, on human platelet function and ROS-related signaling pathways. MATERIALS AND METHODS: In collagen-stimulated human platelets, aggregometry, assessment of ROS and Ca2+, immunoblotting, ELISA, flow cytometry, platelet adhesion assay, and assessment of mouse arterial thrombosis were performed in this study. KEY FINDINGS: Setanaxib inhibited both intracellular and extracellular ROS production in collagen-activated platelets. Additionally, setanaxib significantly inhibited collagen-induced platelet aggregation, P-selectin exposure from α-granule release, and ATP release from dense granules. Setanaxib blocked the specific tyrosine phosphorylation-mediated activation of Syk, LAT, Vav1, and Btk within collagen receptor signaling pathways, leading to reduced activation of PLCγ2, PKC, and Ca2+ mobilization. Setanaxib also inhibited collagen-induced activation of integrin αIIbß3, which is linked to increased cGMP levels and VASP phosphorylation. Furthermore, setanaxib suppressed collagen-induced p38 MAPK activation, resulting in decreased phosphorylation of cytosolic PLA2 and reduced TXA2 generation. Setanaxib also inhibited ERK5 activation, affecting the exposure of procoagulant phosphatidylserine. Setanaxib reduced thrombus formation under shear conditions by preventing platelet adhesion to collagen. Finally, in vivo administration of setanaxib in animal models led to the inhibition of arterial thrombosis. SIGNIFICANCE: This study is the first to show that setanaxib suppresses ROS generation, platelet activation, and collagen-induced thrombus formation, suggesting its potential use in treating thrombotic or cardiovascular diseases.

Integrated microfluidic multiple electrode aggregometry for point-of-care platelet function analysis.

Point-of-care (POC) platelet function analysis can enable timely and precise management of bleeding and clotting in emergency rooms, operation rooms and intensive care units. However, POC platelet testing is currently not commonly performed, due to the complexity of sample preparation and limitations of existing technologies. Here, we report the development of an integrated microfluidic multiple electrode aggregometry (µMEA) sensor which uses multi-frequency impedance measurement of an embedded microelectrode array to perform platelet aggregometry directly from whole blood, sensing and measuring platelet activation in a label-free manner and without requiring any additional sample preparation. Additionally, the sensor incorporates blood flow during the assay to account for physiological flow and shear conditions. We show that the impedance signal from the sensor can be used to accurately detect and quantify platelet aggregation in a label-free manner, which was further validated by simultaneous fluorometric measurement and visualization of platelet aggregation. Further, we optimized the sensitivity and repeatability of the sensor using its frequency response and demonstrated that the sensor could be used to characterize drug dose-response in antiplatelet therapy with a frequency-tunable dynamic range. We also demonstrate that the sensor provides high sensitivity to perform platelet aggregometry under thrombocytopenic or low platelet count conditions. The µMEA sensor could thus enable POC platelet function analysis across several clinical applications.

Impact of CYP2C19 Genotype Status on Clinical Outcomes in Patients with Symptomatic Coronary Artery Disease, Stroke, and Peripheral Arterial Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Clopidogrel is widely used for the secondary prevention of atherothrombotic events in patients with coronary artery disease (CAD), ischemic stroke, and peripheral arterial disease (PAD). CYP2C19 plays a pivotal role in the conversion of clopidogrel to its active metabolite. Clopidogrel-treated carriers of a CYP2C19 loss-of-function allele (LOF) may have a higher risk of new atherothrombotic events. Previous studies on genotype-guided treatment were mainly performed in CAD and showed mixed results. PURPOSE: To simultaneously investigate the impact of CYP2C19 genotype status on the rate of atherothrombotic events in the most common types of atherosclerotic disease (CAD, stroke, PAD). METHODS: A comprehensive search in Pubmed, EMBASE, and MEDLINE from their inception to July 23rd 2023 was performed. Randomized controlled trials (RCTs) comparing genotype-guided and standard antithrombotic treatment, and cohort studies and post hoc analyses of RCTs concerning the association between CYP2C19 genotype status and clinical outcomes in clopidogrel-treated patients were included. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the safety end point major bleeding. Secondary endpoints were myocardial infarction, stent thrombosis, and ischemic stroke. RESULTS: Forty-four studies were identified: 11 studies on CAD, 29 studies on stroke, and 4 studies on PAD. In CAD, genotype-guided therapy significantly reduced the risk of MACE [risk ratio (RR) 0.60, 95% confidence interval (CI) 0.43-0.83], myocardial infarction (RR 0.53, 95% CI 0.42-0.68), and stent thrombosis (RR 0.64, 95% CI 0.43-0.94), compared with standard antithrombotic treatment. The rate of major bleeding did not differ significantly (RR 0.93, 95% CI 0.70-1.23). Most RCTs were performed in patients after percutaneous coronary intervention (9/11). In stroke, LOF carriers had a significantly higher risk of MACE (RR 1.61, 95% CI 1.25-2.08) and recurrent ischemic stroke (RR 1.89, 95% CI 1.48-2.40) compared with non-carriers. No significant differences were found in major bleeding (RR 0.90, 95% CI 0.43-1.89). In the 6955 patients with symptomatic PAD treated with clopidogrel in the EUCLID trial, no differences in MACE or major bleeding were found between LOF carriers and non-carriers. In three smaller studies on patients with PAD treated with clopidogrel after endovascular therapy, CYP2C19 genotype status was significantly associated with atherothrombotic events. CONCLUSIONS: Genotype-guided treatment significantly decreased the rate of atherothrombotic events in patients with CAD, especially after PCI. In patients with history of stroke, LOF carriers treated with clopidogrel had a higher risk of MACE and recurrent stroke. The available evidence in PAD with regard to major adverse limb events is too limited to draw meaningful conclusions. REGISTRATION: PROSPERO identifier no. CRD42020220284.

Regulation of Platelet Activation and Coagulation: Current Concepts, Novel Targets, and Therapies.

Antiplatelet and anticoagulant therapies are cornerstones of secondary prevention in high-risk cardiovascular patients. Whereas in former days the focus was set on effective antithrombotic effects, more recent trials and guidelines placed emphasis on a more balanced approach, thus including the bleeding risk for an individualized therapy. Type, strength, combination, and duration are important components to modify the individual bleeding risk. Novel antiplatelet and anticoagulant agents have shown promising results that might offer safer options in the future for high-risk cardiovascular patients. This review aims to give an overview about established drug target and pharmacologic approaches that are currently in the pipeline.

Differential Effect of Omega-3 Fatty Acids on Platelet Inhibition by Antiplatelet Drugs In Vitro.

The omega-3 polyunsaturated fatty acids (PUFAs) Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) exert multiple cardioprotective effects, influencing inflammation, platelet activation, endothelial function and lipid metabolism, besides their well-established triglyceride lowering properties. It is not uncommon for omega-3 PUFAs to be prescribed for hypertriglyceridemia, alongside antiplatelet therapy in cardiovascular disease (CVD) patients. In this regard, we studied the effect of EPA and DHA, in combination with antiplatelet drugs, in platelet aggregation and P-selectin and αIIbß3 membrane expression. The antiplatelet drugs aspirin and triflusal, inhibitors of cyclooxygenase-1 (COX-1); ticagrelor, an inhibitor of the receptor P2Y12; vorapaxar, an inhibitor of the PAR-1 receptor, were combined with DHA or EPA and evaluated against in vitro platelet aggregation induced by agonists arachidonic acid (AA), adenosine diphosphate (ADP) and TRAP-6. We further investigated procaspase-activating compound 1 (PAC-1) binding and P-selectin membrane expression in platelets stimulated with ADP and TRAP-6. Both DHA and EPA displayed a dose-dependent inhibitory effect on platelet aggregation induced by AA, ADP and TRAP-6. In platelet aggregation induced by AA, DHA significantly improved acetylsalicylic acid (ASA) and triflusal's inhibitory activity, while EPA enhanced the inhibitory effect of ASA. In combination with EPA, ASA and ticagrelor expressed an increased inhibitory effect towards ADP-induced platelet activation. Both fatty acids could not improve the inhibitory effect of vorapaxar on AA- and ADP-induced platelet aggregation. In the presence of EPA, all antiplatelet drugs displayed a stronger inhibitory effect towards TRAP-6-induced platelet activation. Both omega-3 PUFAs inhibited the membrane expression of αIIbß3, though they had no effect on P-selectin expression induced by ADP or TRAP-6. The antiplatelet drugs exhibited heterogeneity regarding their effect on P-selectin and αIIbß3 membrane expression, while both omega-3 PUFAs inhibited the membrane expression of αIIbß3, though had no effect on P-selectin expression induced by ADP or TRAP-6. The combinatory effect of DHA and EPA with the antiplatelet drugs did not result in enhanced inhibitory activity compared to the sum of the individual effects of each component.

Effects of different doses of tirofiban combined with dual antiplatelet drugs on platelet indices, vascular endothelial function, and major adverse cardiovascular events in patients with acute ST-segment elevated myocardial infarction undergoing percutaneous coronary intervention.

This trial targeted to analyze the effects of different doses of tirofiban combined with dual antiplatelet drugs on platelet indices, vascular endothelial function, and major adverse cardiovascular events (MACE) in patients with acute ST-segment elevated myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). A total of 180 patients with STEMI who underwent PCI were divided into Group A, Group B, and Group C (60 cases per group). Group A was given conventional medication, and Groups B and C were given a standard dose (10 µg/kg) and a high dose (20 µg/kg) of tirofiban on the basis of Group A, respectively. Thrombolysis in myocardial infarction (TIMI) myocardial perfusion grade and TIMI blood flow grade were compared. Myocardial enzymes, platelet indices, vascular endothelial function, inflammatory factors, and cardiac function indices were detected. In-hospital bleeding events and follow-up MACE were recorded. After PCI, Group C had a higher number of TIMI myocardial perfusion grade III and TIMI blood flow grade III versus Group A. Group C achieved the greatest changes in myocardial enzymes, platelet indices, vascular endothelial function-related factors, inflammatory factors, and cardiac function indices, followed by Group B and Group A. The incidence of bleeding events was higher in Group C than in Group A, and that of MACE in Group C was lower than in Group A. The addition of high-dose tirofiban to PCI and dual antiplatelet drugs for STEMI patients can improve myocardial blood perfusion, cardiac function, and vascular endothelial function, inhibit platelet activation and aggregation, and reduce the occurrence of MACE.

What is the context?Acute myocardial infarction is a branch of acute coronary syndromes, which can be categorized into ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction. Percutaneous coronary intervention is a non-surgical, invasive treatment used to improve blood flow to ischemic tissues and relieve coronary artery stenosis or occlusion. Despite the fact that percutaneous coronary intervention allows for timely mechanical reperfusion, patients with myocardial infarction have to face an increased risk of adverse cardiovascular events.What is the new?The addition of high-dose tirofiban to percutaneous coronary intervention and dual antiplatelet drugs for ST-segment elevation myocardial infarction patients can improve myocardial blood perfusion, cardiac function, and vascular endothelial function, inhibit platelet activation and aggregation, and reduce the occurrence of major adverse cardiovascular events.What is the impact?These findings favor the future application of tirofiban combination therapies and can improve patients' conditions alone.

Elevated High-Sensitivity C-Reactive Protein Level Enhances the Impact of Lipoprotein(a) on Platelet Reactivity in PCI Patients Treated with Clopidogrel.

BACKGROUND: Recently, the effect of Lipoprotein(a) [Lp(a)] on thrombogenesis has aroused great interest, while inflammation has been reported to modify the Lp(a)-associated risks through an unidentified mechanism. PURPOSE: This study aimed to evaluate the association between platelet reactivity with Lp(a) and high-sensitivity C-reactive protein (hs-CRP) levels in percutaneous intervention (PCI) patients treated with clopidogrel. METHODS: Data were collected from 10,724 consecutive PCI patients throughout the year 2013 in Fuwai Hospital. High on-treatment platelet reactivity (HTPR) and low on-treatment platelet reactivity (LTPR) were defined as thrombelastography (TEG) maximum amplitude of adenosine diphosphate-induced platelet (MAADP) > 47 mm and < 31 mm, respectively. RESULTS: 6615 patients with TEG results were finally enrolled. The mean age was 58.24 ± 10.28 years and 5131 (77.6%) were male. Multivariable logistic regression showed that taking Lp(a) < 30 mg/dL and hs-CRP < 2 mg/L as the reference, isolated Lp(a) elevation [Lp(a) ≥ 30 mg/dL and hs-CRP < 2 mg/L] was not significantly associated with HTPR (P = 0.153) or LTPR (P = 0.312). However, the joint elevation of Lp(a) and hs-CRP [Lp(a) ≥ 30 mg/dL and hs-CRP ≥ 2 mg/L] exhibited enhanced association with both HTPR (OR:1.976, 95% CI 1.677-2.329) and LTPR (OR:0.533, 95% CI 0.454-0.627). CONCLUSIONS: The isolated elevation of Lp(a) level was not an independent indicator for platelet reactivity, yet the concomitant elevation of Lp(a) and hs-CRP levels was significantly associated with increased platelet reactivity. Whether intensified antiplatelet therapy or anti-inflammatory strategies could mitigate the risks in patients presenting combined Lp(a) and hs-CRP elevation requires future investigation.

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.

Studies on in vivo antithrombotic activity of quercetin, a natural flavonoid isolated from a traditional medicinal plant, African eggplant (Solanum indicum).

ETHNOPHARMACOLOGICAL RELEVANCE: Every year, cardiovascular diseases (CVDs) account for about 17.9 million deaths, making them the primary cause of both morbidity and mortality. Conventional drugs, which are often prescribed to treat cardiovascular diseases, are costly and have adverse effects. Consequently, dietary modifications and other medications are needed. Traditional use of Solanum indicum as cardiotonic to treat hypertension and anticoagulant potency has been reported but poorly evaluated scientifically. AIM OF THE STUDY: This study investigated the in vivo anticoagulant activity and mechanism of anticoagulation of quercetin (QC), a bioactive compound isolated from S. indicum (SI) hydroethanolic fruit extract. MATERIALS AND METHODS: Bioassay-guided fractionation (anticoagulant activity) extracted QC from hydroethanolic SI extract. QC was extensively characterized biochemically and pharmacologically. The interaction between QC and thrombin was investigated using spectrofluorometric and isothermal calorimetric methods. Cytotoxicity, antiplatelet, and thrombolytic studies were carried out in vitro. The Swiss albino mice were used to assess the in vivo, anticoagulant, and antithrombotic activities of QC. RESULTS: QC exhibits anticoagulant activity via (i) uncompetitive inhibition of thrombin but not FXa with a Ki value of 33.11 ± 4.2 µM and (ii) a partial inhibition of thrombin-catalyzed platelet aggregation with an IC50 value of 13.2 ± 1.2 µM. The experimental validation of the in silico study's prediction of QC's binding to thrombin was confirmed by spectrofluorometric and isothermal calorimetric analyses. QC was nontoxic to mammalian, non-hemolytic cells and demonstrated thrombolytic activity by activating plasminogen. QC demonstrated in vivo anticoagulant efficacy, preventing k-carrageen-induced thrombus formation in mice's tails. In the acute circulatory stasis paradigm in mice, QC reduces thromboxane B2 (TXB2) and endothelin-1 (ET-1) while increasing nitric oxide synthase (eNOS) and 6-keto prostaglandin F1α (6-keto-PGF1 α). CONCLUSION: Effective in vivo anticoagulant and antithrombotic properties of S. indicum's bioactive component QC point to the plant's potential use as a herbal anticoagulant medication for preventing and treating cardiovascular diseases linked to thrombosis.

The safety and efficacy of indobufen or aspirin combined with clopidogrel in patients with acute myocardial infarction after percutaneous coronary intervention.

Currently, the standard treatment for patients who have undergone percutaneous coronary intervention (PCI) following acute myocardial infarction (MI) involves dual antiplatelet therapy (DAPT) with a combination of aspirin and a potent P2Y12 receptor inhibitor. However, the potential benefits of aspirin were partially constrained by the intolerance of some patients. The safety and efficacy of indobufen, an alternative antiplatelet agents to aspirin, in patients with AMI after PCI are yet to be thoroughly investigated.This retrospective study was conducted at a single center and utilized propensity score matching. The enrollment spanned from January 2019 to June 2022, incorporating patients with AMI after PCI. The participants were categorized into two groups based on discharged prescriptions: the aspirin DAPT group and the indobufen DAPT group. The primary endpoint focused on net adverse clinical event (NACE), defined as a composite outcome, including cardiac death, recurrence of MI, definite or probable stent thrombosis (ST), target lesion revascularization (TLR), ischemic stroke and Bleeding Academic Research Consortium (BARC) criteria type 2, 3, or 5. All the patients underwent a one-year follow-up period.A total of 1451 patients were enrolled in this study, with 258 assigned to the indobufen DAPT group and 1193 to the aspirin DAPT group. Following 1:1 propensity score matching, 224 patients were retained in each group. In the indobufen DAPT group, 58 individuals (25.9%) experienced the primary endpoint within one year, compared to 52 individuals (23.2%) in the aspirin DAPT group (HR 1.128, 95% CI 0.776-1.639, p = .527). Specifically, no significant differences were observed in either the efficacy endpoint (MACCE, 20.1% vs. 14.7%, HR 1.392, 95% CI 0.893-2.170, p = .146) or the safety endpoint (BARC 2,3 or 5, 8.04% vs. 10.30%, HR 0.779, p = .427). These findings remained consistent at 1, 3, or 6 months. Additionally, the incidence of gastrointestinal symptoms were significantly lower in indobufen DAPT group compared to the aspirin DAPT group (7.1% vs. 14.3%, p = .022).Our research reveals that the efficacy and safety of indobufen are comparable to aspirin in Chinese patients with AMI following PCI. Given the potential advantages of indobufen in alleviating gastrointestinal symptoms, we propose it as a viable alternative for individuals intolerant to aspirin.

What is the context? Currently, the standard treatment for patients who have undergone percutaneous coronary intervention following acute myocardial infarction involves dual antiplatelet therapy with a combination of aspirin and a potent P2Y12 receptor inhibitor.However, the potential benefits of aspirin were partially constrained by the intolerance of some patients.The safety and efficacy of indobufen, an alternative antiplatelet agents to aspirin, in patients with AMI after PCI are yet to be thoroughly investigated.What is new? While both American and European clinical guidelines recommend the use of indobufen as an alternative treatment for patients who cannot tolerate aspirin, there exists a limited body of research on this subject.Our research is the first to address this gap by comparing the efficacy and safety of indobufen and aspirin in patients with AMI.Our research reveals that the efficacy and safety of indobufen are comparable to aspirin in Chinese patients with AMI following PCI. Given the potential advantages of indobufen in alleviating gastrointestinal symptoms, we propose it as a viable alternative for individuals intolerant to aspirin.What is the impact? These findings might pave the way for further exploration of alternatives to aspirin in patients with AMI.

Platelet aggregation response to cyclooxygenase inhibition and thromboxane receptor antagonism using impedance aggregometry: A pilot study.

Impedance aggregometry is an alternative to light transmission aggregometry that allows analysis of platelet function in whole blood samples. We hypothesized (1) impedance aggregometry would produce repeatable results, (2) inhibition of cyclooxygenase with aspirin would attenuate aggregation responses to collagen and abolish the aggregation response to arachidonic acid (AA), and (3) thromboxane receptor antagonism (terutroban) would attenuate the aggregation response to AA. Venous blood was obtained from 11 participants three times separated by at least 2 weeks. One sample followed 7-day-aspirin intervention (81 mg once daily; ASA), the others no intervention (control). Aggregation was induced using 1 µg/mL collagen ([col 1]), 5 µg/mL collagen ([col 5]), and 50 mM AA via impedance aggregometry to determine total aggregation (AUC) analyzed for intra-test repeatability, inter-test repeatability, intervention (ASA or control), and incubation (saline or terutroban). [col 1] showed high intra-test (p ≤ 0.03 visit 1 and 2) and inter-test repeatability (p < 0.01). [col 5] and AA showed intra- ([col 5] p < 0.01 visit 1 and 2; AA p < 0.001 visit 1 and 2) but not inter-test repeatability ([col 5] p = 0.48; AA p = 0.06). ASA attenuated AUC responses to [col 1] (p < 0.01), [col 5] (p = 0.03), and AA (p < 0.01). Terutroban attenuated AUC in response to AA (p < 0.01). [col 1] shows sufficient repeatability for longitudinal investigations of platelet function. [col 5] and AA may be used to investigate mechanisms of platelet function and metabolism at a single time point.

Novel Small-Molecule Atypical Chemokine Receptor 3 Agonists: Design, Synthesis, and Pharmacological Evaluation for Antiplatelet Therapy.

ACKR3, an atypical chemokine receptor, has been associated with prothrombotic events and the development of cardiovascular events. We designed, synthesized, and evaluated a series of novel small molecule ACKR3 agonists. Extensive structure-activity relationship studies resulted in several promising agonists with potencies ranging from the low micromolar to nanomolar range, for example, 23 (EC50 = 111 nM, Emax = 95%) and 27 (EC50 = 69 nM, Emax = 82%) in the ß-arrestin-recruitment assay. These compounds are selective for ACKR3 versus ACKR2, CXCR3, and CXCR4. Several agonists were subjected to investigations of their P-selectin expression reduction in the flow cytometry experiments. In particular, compounds 23 and 27 showed the highest potency for platelet aggregation inhibition, up to 80% and 97%, respectively. The most promising compounds, especially 27, exhibited good solubility, metabolic stability, and no cytotoxicity, suggesting a potential tool compound for the treatment of platelet-mediated thrombosis.

Milvexian, a novel factor XIa inhibitor for stroke prevention: pharmacokinetic and pharmacodynamic evaluation.

INTRODUCTION: Antiplatelets and oral anticoagulants are commonly used to treat patients with various cardiovascular and cerebrovascular diseases. However, the primary concern for clinicians remains the risk of bleeding, thus necessitating the development of new therapies. Milvexian is a new anticoagulant that inhibits factor XIa, preventing the pathological formation of thrombi without increasing bleeding risk. AREAS COVERED: This drug evaluation examines the pharmacokinetic properties of milvexian and provides information on its pharmacodynamics and clinical efficacy in treating some cerebrovascular conditions. EXPERT OPINION: Milvexian shows a good pharmacokinetic profile with low renal elimination rates, justifying its use in patients with a high degree of renal impairment, and without relevant drug-drug interactions. In patients affected by acute non-cardioembolic ischemic stroke or high-risk transient ischemic stroke, milvexian, in addition to dual antiplatelet therapy, seems to have a positive efficacy profile without any safety concerns, especially in terms of intracranial hemorrhage. Two phase 3 trials are ongoing to investigate the efficacy and safety of milvexian for preventing cardioembolic and non-cardioembolic ischemic stroke.

Establishment of an antiplatelet aggregation efficacy-oriented effect-constituent index for quality evaluation of Curcumae Rhizoma from different species (Curcuma phaeocaulis Val, Curcuma kwangsiensis S. G. Lee et C. F. Liang and Curcuma wenyujin Y. H. Chen et C. Ling).

Curcumae rhizoma (CR) is the dried rhizoma of Curcuma phaeocaulis Val (CP), Curcuma kwangsiensis S. G. Lee et C. F. Liang (CK) and Curcuma wenyujin Y. H. Chen et C. Ling (CW), used widely to treat blood stagnation in China. Currently, quality control indicators for CR are limited to chemical composition analysis. It is unclear whether the current quality standard of the multicomponent content of CR can reflect clinical effects, due to the lack of the evaluation of biological effects. A method of evaluating quality was developed called the effect-constituent index (ECI). By meticulously measuring and calibrating the key active components, the ECI offers a comprehensive assessment of the CR's biological effects, establishing a crucial link to clinical efficacy and safety. An analytical protocol employing high-performance liquid chromatography (HPLC) was devised to ascertain the presence and measure ten principal constituents within CR sourced from various species and the content of total volatile oil was also measured. An In vitro antiplatelet aggregation assay was developed to measure the antiplatelet aggregation biopotencies of thirty batches of CR and ten main components. Then, the calibration weights for each constituent in the ECI were determined based on the antiplatelet aggregation biopotency values of eight components with notable efficacy. The ECI calculation involved summing the products obtained by multiplying the content (Ci) of each component by its corresponding biopotency weight (Wi). Correlation analysis unveiled a the most robust correlation (R = 0.8579, p < 0.001) between ECI and antiplatelet aggregation biopotency of CR, when compared to individual components or volatile oil content. The devised ECI, synthesizing chemical and biological data pertinent to clinical effectiveness, facilitates a nuanced assessment of CR quality across various species in its efficacy in treating blood stagnation. This method addresses the challenge of guaranteeing effectiveness through chemical analysis alone. This study offers substantiation for the applicability of the ECI as a tool for assessing the quality of traditional Chinese medicine (TCM).