The extent of P2Y12 inhibition by clopidogrel in diabetes mellitus patients with acute coronary syndrome is not related to glycaemic control: Roles of white blood cell count and body weight

The Signaling Pathway of the ADP Receptor P2Y12 in the Immune System: Recent Discoveries and New Challenges

P2Y12 is a G-protein-coupled receptor that is activated upon ADP binding. Considering its well-established role in platelet activation, blocking P2Y12 has been used as a therapeutic strategy for antiplatelet aggregation in cardiovascular disease patients. However, receptor studies have shown that P2Y12 is functionally expressed not only in platelets and the microglia but also in other cells of the immune system, such as in monocytes, dendritic cells, and T lymphocytes. As a result, studies were carried out investigating whether therapies targeting P2Y12 could also ameliorate inflammatory conditions, such as sepsis, rheumatoid arthritis, neuroinflammation, cancer, COVID-19, atherosclerosis, and diabetes-associated inflammation in animal models and human subjects. This review reports what is known about the expression of P2Y12 in the cells of the immune system and the effect of P2Y12 activation and/or inhibition in inflammatory conditions. Lastly, we will discuss the major problems and challenges in studying this receptor and provide insights on how they can be overcome.

Impact of Pancreatic β-Cell Function on Clopidogrel Responsiveness and Outcomes in Chinese Nondiabetic Patients Undergoing Elective Percutaneous Coronary Intervention

PURPOSE

Insulin resistance and β-cell dysfunction are fundamental defects contributing to type 2 diabetes development. Prior studies indicated that insulin resistance may be correlated with low responsiveness to clopidogrel. This study aimed to investigate the effects of β-cell function on clopidogrel-induced platelet P2Y12 inhibition and the clinical outcomes of nondiabetic patients undergoing elective percutaneous coronary intervention (PCI).

METHODS

Patients scheduled to undergo elective PCI and receive clopidogrel in addition to aspirin were recruited for this study. Homeostatic model assessment 2 of β-cell function (HOMA2-β%) was used to classify participants into quartiles. Thromboelastography (TEG) was used to calculate the quantitative platelet inhibition rate to assess clopidogrel-induced antiplatelet reactivity. The clinical outcome was major adverse cardiovascular and cerebrovascular events (MACCEs).

RESULTS

Of the 784 participants evaluated, 21.3% of them (169 of 784) had low responsiveness to clopidogrel. According to multivariate linear regression analysis, the first quartile of HOMA2-β% (19.9-78.1), indicating greater β-cell dysfunction, was independently associated with low responsiveness to clopidogrel compared with the fourth quartile (126.8-326.2) after adjustment for potential covariates [odds ratio 2.140, 95% confidence interval (CI) (1.336 to 3.570), P = 0.038]. In addition, at one year, the first quartile of HOMA2-β% was associated with an increased risk of 1-year MACCE occurrence compared with the fourth quartile [adjusted hazard ratio 4.989, 95% CI (1.571 to 15.845), P = 0.006].

CONCLUSION

Increased β-cell dysfunction, indicated by a low HOMA2-β%, was associated with low responsiveness to clopidogrel and an increased risk of one-year MACCEs in nondiabetic patients undergoing elective PCI.

Similar Inflammatory Biomarkers Reflect Different Platelet Reactivity in Percutaneous Coronary Intervention Patients Treated With Clopidogrel: A Large-Sample Study From China

Background: Platelet reactivity is closely associated with adverse events in percutaneous coronary intervention (PCI) patients. Inflammation plays a crucial role in the development of coronary heart disease (CHD).

Aim: To investigate the association of inflammatory biomarkers such as leukocyte count and high-sensitivity C reactive proteins (hs-CRP) with platelet reactivity in PCI patients treated with clopidogrel.

Method: We examined 10,724 consecutive PCI patients in Fuwai hospital from January 2013 to December 2013. High on-treatment platelet reactivity (HTPR) was defined as adenosine diphosphate (ADP)-induced platelet maximum amplitude [MA(ADP)] of thromboelastogram (TEG) > 47 mm, and low on-treatment platelet reactivity (LTPR) MA(ADP) < 31 mm.

Results: Finally, 6,772 PCI patients treated with clopidogrel who had the results of postoperative TEG were enrolled. Among them, 2,070 (30.57%) presented HTPR and 2,568 (37.92%) presented LTPR. As for LTPR, multivariate logistic regression showed that leukocyte count (OR: 1.153, 95% CI 1.117–1.191) and hs-CRP (OR: 0.920, 95% CI 0.905–0.936) were independent predictors, along with diabetes mellites, hemoglobin, platelet count and glucose. As for HTPR, multivariate logistic regression showed that leukocyte count (OR: 0.885, 95% CI 0.854–0.917) and hs-CRP (OR: 1.094, 95% CI 1.077–1.112) were independent predictors, along with sex, hemoglobin, platelet count and glucose.

Conclusions: This was the first large real-world study reporting that both leukocyte count and hs-CRP were the independent factors for platelet reactivity in PCI populations treated with clopidogrel, among which higher leukocyte count was associated with more LTPR while higher hs-CRP was associated with more HTPR, providing new insights on individualized antiplatelet therapy.

Effects of Hyperglycemia and Diabetes Mellitus on Coagulation and Hemostasis

In patients with diabetes, metabolic disorders disturb the physiological balance of coagulation and fibrinolysis, leading to a prothrombotic state characterized by platelet hypersensitivity, coagulation disorders and hypofibrinolysis. Hyperglycemia and insulin resistance cause changes in platelet number and activation, as well as qualitative and/or quantitative modifications of coagulatory and fibrinolytic factors, resulting in the formation of fibrinolysis-resistant clots in patients with diabetes. Other coexisting factors like hypoglycemia, obesity and dyslipidemia also contribute to coagulation disorders in patients with diabetes. Management of the prothrombotic state includes antiplatelet and anticoagulation therapies for diabetes patients with either a history of cardiovascular disease or prone to a higher risk of thrombus generation, but current guidelines lack recommendations on the optimal antithrombotic treatment for these patients. Metabolic optimizations like glucose control, lipid-lowering, and weight loss also improve coagulation disorders of diabetes patients. Intriguing, glucose-lowering drugs, especially cardiovascular beneficial agents, such as glucagon-like peptide-1 receptor agonists and sodium glucose co-transporter inhibitors, have been shown to exert direct anticoagulation effects in patients with diabetes. This review focuses on the most recent progress in the development and management of diabetes related prothrombotic state.

Elevated Glycated Albumin in Serum Is Associated with Adverse Cardiac Outcomes in Patients with Acute Coronary Syndrome Who Underwent Revascularization Therapy

Aims: The associations between increased glycated albumin (GA) in the serum and diabetic complications and mortality have been revealed in the general population. However, less is known regarding the prognostic value of GA in patients diagnosed with acute coronary syndrome (ACS).

Methods: In this study, all patients admitted for ACS who underwent a successful percutaneous coronary intervention (PCI) at our center from January 2018 to February 2019 were retrospectively examined. Clinical characteristics, laboratory results (e.g., serum GA levels), and procedural details were collected. The primary outcome included a composite of major adverse cardio-cerebral events (MACCE), such as death, myocardial infarction, stroke, and unplanned revascularization. The association between serum GA levels and clinical outcomes was tested in three multivariable models using Cox proportional hazard analysis. Subgroup analysis was performed in patients who were diagnosed with diabetes versus patients without diabetes.

Results: A total of 1,806 ACS patients (mean age of 59.4 years; 77.8% were men; 44.9% were diagnosed with diabetes) were enrolled in this study, where the majority exhibited unstable angina (81.6%) and showed preserved left ventricular systolic function. Patients in the high GA level group were commonly female and were more likely to have metabolic disorders and to exhibit severe CAD (all p ＜0.05). MACCE occurred in 126 patients (7.0%) during a mean follow-up time of 17.2 months. The cumulative risk of MACCE at the 18-month follow-up visit significantly increased in a stepwise fashion along with increased GA levels (log-rank p =0.018) in the serum. The association between serum GA levels and MACCE was further determined after adjusting traditional risk factors and hemoglobin A1c (HbA1c) (GA, per 1% increase: hazard ratio [HR] 1.09, 95% confidence interval [CI] 1.06–1.13; GA, higher vs. lower tertial: HR 1.92, 95% CI 1.01–3.67). In a subgroup analysis, the prognostic role of serum GA only existed in diabetic patients, even when adjusting for traditional risk factors and HbA1c levels.

Conclusions: Elevated GA levels in the serum were associated with poor intermediate-term outcomes in low-risk ACS patients who underwent PCI, especially in patients with preexisting diabetes.

High glycated albumin is an independent predictor of low response to clopidogrel in ACS patients: a cross-sectional study

BACKGROUND

Glycated albumin (GA) is a marker of short-term glycemic control and is strongly associated with the occurrence of diabetes. Previous studies have shown an association between GA and the effect of clopidogrel therapy on ischemic stroke. However, limited information is available regarding this relationship in acute coronary syndrome (ACS) patients. In this study, we evaluated the effect of GA on platelet P2Y12 inhibition by clopidogrel in patients with ACS.

METHODS

Consecutive Chinese patients with ACS who received loading or maintenance doses of clopidogrel in addition to aspirin were recruited. At least 12 h after the patient had taken the clopidogrel dose, thromboelastography (TEG) and light transmittance aggregometry (LTA) were used to calculate the quantitative platelet inhibition rate to determine clopidogrel-induced antiplatelet reactivity. A prespecified cutoff of the maximum amplitude of adenosine diphosphate (ADP)-induced platelet-fibrin clot strength > 47 mm plus an ADP-induced platelet inhibition rate < 50% assessed by TEG or ADP-induced platelet aggregation > 40% assessed by LTA to indicate low responsiveness to clopidogrel were applied for evaluation. Patients were categorized into two groups based on a GA level of 15.5%, the cutoff point indicating the development of early-phase diabetes. Multivariate linear regression analysis was used to assess the interaction of GA with clopidogrel antiplatelet therapy.

RESULTS

A total of 1021 participants were evaluated, and 28.3% of patients (289 of 1021) had low responsiveness to clopidogrel assessed by TEG. In patients with elevated GA levels, low responsiveness to clopidogrel assessed by TEG was observed in 33.7% (139 of 412) of patients, which was a significantly higher rate than that in the lower-GA-level group (24.6%, P = 0.002). According to multivariate linear regression analysis, a GA level > 15.5% was independently associated with low responsiveness to clopidogrel after adjustment for age, sex and other conventional confounding factors. This interaction was not mediated by a history of diabetes mellitus. A GA level ≤ 15.5% was associated with a high positive value [75.4%, 95% CI 73.0-77.6%] for predicting a normal responsiveness to clopidogrel.

CONCLUSIONS

GA could be a potential biomarker to predict the effects of clopidogrel antiplatelet therapy in ACS patients and might be a clinical biomarker to guide DAPT de-escalation.

SWEDEHEART-1-year data show no benefit of newer generation drug-eluting stents over bare-metal stents in patients with severe kidney dysfunction following percutaneous coronary intervention

BACKGROUND

We hypothesized that the transition from bare-metal stents (BMS) to newer generation drug-eluting stents (n-DES) in clinical practice may have reduced the risk also in patients with kidney dysfunction.

METHODS

Observational study in the national SWEDEHEART registry, that compared the 1-year risk of in-stent restenosis (RS) and stent thrombosis (ST) in all percutaneous coronary intervention treated patients(n = 92 994) during 2007-2013.

RESULTS

N-DES patients were younger than BMS, but had more often diabetes, previous myocardial infarction, previous revascularization and were more often treated with potent platelet inhibition. N-DES versus BMS, was associated with lower 1-year risk of RS in patients with estimated glomerular filtration rate (eGFR) >60 with a cumulative probability of 2.1% versus 5.3%, adjusted hazard ratio 0.30, 95% CI (0.27-0.34) and with eGFR 30-60: 3.0% versus 4.9%; hazard ratio 0.46 (0.36-0.60) but not in patients with eGFR <30: 8.1% versus 6.0%; hazard ratio 1.32 (0.71-2.45) (pinteraction = 0.009) as well as lower risk of ST for eGFR >60 and eGFR 30-60: 0.5% versus 0.9%; hazard ratio 0.52 (0.40-0.68) and 0.6% versus 1.3%; hazard ratio 0.54 (0.54-0.72) but not for eGFR <30; 2.1% versus 1.1%; hazard ratio 1.49 (0.56-3.98) (pinteraction = 0.027).

CONCLUSION

N-DES is associated with lower 1-year risk of in-stent restenosis and stent thrombosis in patients with normal or moderately reduced kidney function but not in patients with severe kidney dysfunction, where stenting is associated with worse outcomes regardless of stent type.

Antiplatelet Therapy in ACS Patients: Comparing Appropriate P2Y12 Inhibition by Clopidogrel to the Use of New P2Y12 Inhibitors

AIM

In percutaneous coronary intervention (PCI)-treated acute coronary syndrome (ACS) patients on clopidogrel therapy, high on-treatment platelet adenosine diphosphate (ADP) reactivity was observed in numerous studies, with significant increases in non-fatal myocardial infarction, definite/probable stent thrombosis, or cardiovascular mortality. Compared to clopidogrel, prasugrel and ticagrelor provide more potent platelet inhibition. Whether new P2Y12 inhibitors reduce thrombotic events in a similar manner compared to the rate observed with appropriate P2Y12 inhibition by clopidogrel must still be determined. This study sought to compare long-term outcomes between clopidogrel responders (platelet reactivity index [PRI] vasodilator-stimulated phosphoprotein [VASP] ＜61%) and patients under prasugrel or ticagrelor therapy following PCI-treated ACS.

METHODS

730 ACS patients undergoing urgent PCI were prospectively enrolled into two groups: clopidogrel responders (n=448) and those under ticagrelor or prasugrel therapy (n=282). The primary endpoint was a composite of cardiovascular death, myocardial infarction, stent thrombosis, and stroke; the secondary endpoint comprised major hemorrhagic events.

RESULTS

The median follow-up was 260±186 days. Clopidogrel patients were older and more likely to present non-ST segment elevation myocardial infarction, cardiovascular risk factors, atrial fibrillation, or prior vascular disease. After propensity score matching, the primary endpoint was met in 7.1% of the clopidogrel group and 4.1% of the prasugrel/ticagrelor group (p=0.43). Minor bleeding events were significantly reduced in the clopidogrel group (1.1% vs. 3%; p=0.03). In a multivariate analysis, the antiplatelet treatment strategy was not an independent primary endpoint predictor.

CONCLUSION

In PCI-treated ACS patients, clopidogrel therapy and PRI VASP ＜61% were not associated with increased risks of thrombotic events compared to prasugrel or ticagrelor therapy.

Impaired P2Y12 inhibition by clopidogrel in kidney transplant recipients: results from a cohort study

Background

Cardiovascular complications represent a major cause of morbidity and mortality for patients who received kidney transplantation (KT). However, the impact of KT and chronic immunosuppression on platelet response to clopidogrel in patients undergoing coronary or peripheral revascularization procedures remains unclear. This cohort study compares platelet responsiveness to clopidogrel as assessed byvasodilator-stimulated phosphoprotein (VASP) phosphorylation.

Methods

The study population was divided between chronic kidney disease (CKD) patients who underwent KT (n = 36) and non-transplanted CKD patients (control group, n = 126). Patients were on maintenance antiplatelet therapy with clopidogrel 75 mg daily for at least 8 days. The mean platelet reactivity index (PRI) VASP values and the prevalence of high on-treatment platelet reactivity (HPR, defined as PRI VASP ≥61 %) were compared.

Results

The mean PRI VASP value was significantly higher in the transplant group (60.1 ± 3 vs 51.2 ± 1.6 %; p=0.014). HPR was significantly more common in the transplant group on clopidogrel maintenance therapy (58 vs. 31 %; p = 0.011). KT was the only independent predictor of HPR (odds ratio: 2.6; 95 % confidence interval: 1.03–6.27, p = 0.03). The effect of treatment with calcineurin inhibitors on clopidogrel response could not be analyzed separately from the kidney transplant status.

Conclusions

KT is associated with an increased prevalence of HPR. Our results suggest that plateletfunction tests may be clinically useful for the management of this specific population.

The role of P2Y₁₂ receptor and activated platelets during inflammation

Platelets play an important role not only during thrombosis, but also in modulating immune responses through their interaction with immune cells and by releasing inflammatory mediators upon activation. The P2Y12 receptor is a Gi-coupled receptor that not only regulates ADP-induced aggregation but can also dramatically potentiate secretion, when platelets are activated by other stimuli. Considering the importance of P2Y12 receptor in platelet function, a class of antiplatelet drugs, thienopyridines, have been designed and successfully used to prevent thrombosis. This review will focus on the role of activated platelets in inflammation and the effects that P2Y12 antagonism exerts on the inflammatory process. A change in platelet functions was noted in patients treated with thienopyridines during inflammatory conditions, suggesting that platelets may modulate the inflammatory response. Further experiments in a variety of animal models of diseases, such as sepsis, rheumatoid arthritis, myocardial infarction, pancreatitis and pulmonary inflammation have also demonstrated that activated platelets influence the inflammatory state. Platelets can secrete inflammatory modulators in a P2Y12-dependent manner, and, as a result, directly alter the inflammatory response. P2Y12 receptor may also be expressed in other cells of the immune system, indicating that thienopyridines could directly influence the immune system rather than only through platelets. Overall the results obtained to date strongly support the notion that activated platelets significantly contribute to the inflammatory process and that antagonizing P2Y12 receptor can influence the immune response.

Effect of diabetes mellitus on periprocedural myocardial infarction in patients undergoing coronary stent implantation

BACKGROUND

Diabetic patients undergoing percutaneous coronary interventions are still regarded as a very high risk category because of an increased platelet reactivity and risk of complications, especially in patients with inadequate glycaemic control. However, although its prognostic effect on long-term outcome is well-defined, still unclear is the effect of diabetes on the risk of periprocedural myocardial infarction in patients undergoing percutaneous coronary interventions, which was therefore the aim of our study.

METHODS

Myonecrosis biomarkers were dosed at intervals from 6 to 48 h after nonemergent percutaneous coronary interventions. Periprocedural myocardial infarction was defined as creatine kinase-MB increase by three times the upper limit normal or by 50% of an elevated baseline value, whereas periprocedural myonecrosis as troponin I increase by three times the upper limit normal or 50% of baseline.

RESULTS

Of 1311 patients, diabetes mellitus was found in 458 patients (34.9%) and associated with age (p = 0.03), hypertension (p < 0.001), renal failure (p = 0.01), previous MI (p = 0.03), previous coronary revascularization (p < 0.001), higher fasting glycaemia and lower haemoglobin (p < 0.001), more severe coronary disease (p < 0.001), multivessel percutaneous coronary interventions (p = 0.03), coronary calcification (p = 0.003) and in-stent restenosis (p < 0.001) but lower presence of thrombus (p = 0.03). Diabetic patients were receiving significantly more frequent specific pharmacological treatment at admission. Diabetic status did not influence the risk of periprocedural myocardial infarction or periprocedural myonecrosis [adjusted OR(95%CI) = 0.90(0.64-1.27), p = 0.57 and adjusted OR(95%CI) = 0.92(0.70-1.21), p = 0.55]. Amongst diabetic patients, we did not observe any effect of chronic glycaemic control on periprocedural myocardial infarction.

CONCLUSIONS

Diabetic status, independent of chronic glycaemic control, is not associated with increased risk of periprocedural myocardial infarction and myonecrosis in patients undergoing percutaneous coronary interventions.

Time-related changes in determinants of antiplatelet effect of clopidogrel in patients after myocardial infarction

Substantial variability of antiplatelet action is an important limitation of clopidogrel. The aim of this study was to evaluate time-related changes in determinants of clopidogrel responsiveness in patients after myocardial infarction. The study population comprised 191 consecutive patients treated with primary percutaneous coronary intervention for acute myocardial infarction. Follow-up visits were scheduled at 3, 6 and 9 months after discharge. ADP-induced platelet aggregation was tested with Multiplate Analyzer. Patients with ADP-PA>46.8U were defined as clopidogrel non-responders. The prevalence of clopidogrel non-responsiveness was highest during hospitalization and at 9 month follow-up visit, while it was lowest at 3 and 6 months after myocardial infarction (P=0.004). According to multivariate analysis, platelet count, mean platelet volume, concentration of hsCRP and leukocyte count influenced ADP-induced platelet aggregation in multiple assessment points. BMI, concentrations of hemoglobin, glycated hemoglobin, and BNP, hematocrit, adherence to medication, and patient׳s age were found to be independent predictors of high on-treatment ADP-induced platelet aggregation only at a single follow-up visit. Determinants of clopidogrel responsiveness in patients after myocardial infarction change within the long-term therapy. During hospitalization and early after discharge only biological factors affect ADP-induced platelet aggregation, while non-adherence to antiplatelet therapy may be a significant factor in determining clopidogrel non-responsiveness during late follow-up visits.

Association of P2Y12 gene promoter DNA methylation with the risk of clopidogrel resistance in coronary artery disease patients

Background. Clopidogrel inhibits the ADP receptor P2Y12 to keep down the platelet aggregation. The goal of our study is to investigate the contribution of P2Y12 promoter DNA methylation to the risk of clopidogrel resistance (CR). Methods. The platelet functions were measured by the VerifyNow P2Y12 assay. Applying the bisulfite pyrosequencing technology, DNA methylation levels of two CpG dinucleotides on P2Y12 promoter were tested among 49 CR cases and 57 non-CR controls. We also investigated the association among P2Y12 DNA methylation, various biochemical characteristics, and CR. Result. Lower methylation of two CpGs indicated the poorer clopidogrel response (CpG1, P = 0.009; CpG2, P = 0.022) in alcohol abusing status. Meanwhile CpG1 methylation was inversely correlated with CR in smoking patients (P = 0.026) and in subgroup of Albumin < 35 (P = 0.002). We observed that the level of DNA methylation might be affected by some clinical markers, such as TBIL, LEVF, Albumin, AST. The results also showed that the quantity of stent, fasting blood-glucose, and lower HbAC1 were the predictors of CR. Conclusions. The evidence from our study indicates that P2Y12 methylation may bring new hints to elaborate the pathogenesis of CR.

LPS-induced systemic inflammation is more severe in P2Y12 null mice

Thienopyridines are a class of antiplatelet drugs that are metabolized in the liver to several metabolites, of which only one active metabolite can irreversibly antagonize the platelet P2Y12 receptor. Possible effects of these drugs and the role of activated platelets in inflammatory responses have also been investigated in a variety of animal models, demonstrating that thienopyridines could alter inflammation. However, it is not clear whether it is caused only by the P2Y12 antagonism or whether off-target effects of other metabolites also intervene. To address this question, we investigated P2Y12 KO mice during a LPS-induced model of systemic inflammation, and we treated these KO mice with a thienopyridine drug (clopidogrel). Contrary to the reported effects of clopidogrel, numbers of circulating WBCs and plasma levels of cytokines were increased in LPS-exposed KO mice compared with WT in this inflammation model. Moreover, both spleen and bone marrow show an increase in cell content, suggesting a role for P2Y12 in regulation of bone marrow and spleen cellular composition. Finally, the injury was more severe in the lungs of KO mice compared with WT. Interestingly, clopidogrel treatments also exerted protective effects in KO mice, suggesting off-target effects for this drug. In conclusion, the P2Y12 receptor plays an important role during LPS-induced inflammation, and this signaling pathway may be involved in regulating cell content in spleen and bone marrow during LPS systemic inflammation. Furthermore, clopidogrel may have effects that are independent of P2Y12 receptor blockade.

Prasugrel metabolites inhibit neutrophil functions

Clopidogrel and prasugrel belong to a thienopyridine class of oral antiplatelet drugs that, after having been metabolized in the liver, can inhibit platelet function by irreversibly antagonizing the P2Y(12) receptor. Furthermore, thienopyridines influence numerous inflammatory conditions, but their effects on neutrophils have not been evaluated, despite the important role of these cells in inflammation. Therefore, we investigated the effect of prasugrel metabolites on neutrophils to further clarify the role of thienopyridines in inflammation. Interestingly, a prasugrel metabolite mixture, produced in vitro using rat liver microsomes, significantly inhibited N-formyl-methionyl-leucyl-phenylalanine (fMLP)- and platelet-activating factor (PAF)-induced neutrophil activation. More specifically, prasugrel metabolites inhibited neutrophil transmigration, CD16 surface expression, and neutrophil-platelet aggregation. Moreover, prasugrel metabolite pretreatment also significantly decreased fMLP- or PAF-induced extracellular-signal-regulated kinase phosphorylation as well as calcium mobilization. To determine the target of prasugrel in neutrophils, the role of both P2Y(12) and P2Y(13) receptors was studied using specific reversible antagonists, AR-C69931MX and MRS2211, respectively. Neither antagonist had any direct effect on the agonist-induced neutrophil functional responses. Our findings indicate that prasugrel metabolites may directly target neutrophils and inhibit their activation, suggesting a possible explanation for their anti-inflammatory effects previously observed. However, these metabolites do not act through either the P2Y(12) or P2Y(13) receptor in neutrophils.