BACKGROUND: Patients with atrial fibrillation and severe chronic kidney disease have higher risks of bleeding, thromboembolism, and mortality. However, optimal anticoagulant choice in these high-risk patients remains unclear.
RESULTS: Using deidentified electronic health records from the Optum Labs Data Warehouse, adults with atrial fibrillation and severe chronic kidney disease (estimated glomerular filtration rate <30 mL/min per 1.73 m2) initiating warfarin, apixaban, or rivaroxaban between 2011 and 2021 were included. Using inverse probability of treatment weighting, adjusted risks of major bleeding, stroke/systemic embolism, and death were compared among agents. A total of 6794 patients were included (mean age, 78.5 years; mean estimated glomerular filtration rate, 24.7 mL/min per 1.73 m2; 51% women). Apixaban versus warfarin was associated with a lower risk of major bleeding (incidence rate, 1.5 versus 2.9 per 100 person-years; subdistribution hazard ratio [sub-HR], 0.53 [95% CI, 0.39-0.70]), and similar risks for stroke/systemic embolism (incidence rate, 1.9 versus 2.4 per 100 person-years; sub-HR, 0.80 [95% CI, 0.59-1.09]) and death (incidence rate, 4.6 versus 4.5 per 100 person-years; HR, 1.03 [95% CI, 0.82-1.29]). Rivaroxaban versus warfarin was associated with a higher risk of major bleeding (incidence rate, 4.9 versus 2.9 per 100 person-years; sub-HR, 1.65 [95% CI, 1.10-2.48]), with no difference in risks for stroke/systemic embolism and death. Apixaban versus rivaroxaban was associated with a lower risk of major bleeding (sub-HR, 0.53 [95% CI, 0.36-0.78]).
CONCLUSIONS: These real-world findings are consistent with potential safety advantages of apixaban over warfarin and rivaroxaban for patients with atrial fibrillation and severe chronic kidney disease. Further randomized trials comparing individual oral anticoagulants are warranted.

OBJECTIVE: Although dual antiplatelet therapy (DAPT) with aspirin and a potent P2Y12 receptor inhibitor is currently recommended in patients with acute coronary syndrome (ACS), its use in elderly patients remain challenging. The aim of this trial is to evaluate the pharmacodynamic and pharmacokinetic profile of ticagrelor 60 vs. 90 mg twice daily among elderly patients (≥75 years) with ACS undergoing percutaneous coronary intervention (PCI).
RESULTS: PLINY The ELDER (NCT04739384) was a randomized, crossover trial testing the non-inferiority of a lower vs. standard dose of ticagrelor with respect to the primary endpoint of P2Y12 inhibition as determined by pre-dose P2Y12 reaction units (PRU) using the VerifyNow-P2Y12 (Accumetrics, San Diego, CA). Other pharmacodynamic tests included light transmittance aggregometry, multiple electrode aggregometry, and response to aspirin. Plasma levels of ticagrelor and its active metabolite AR-C124910XX were also evaluated. A total of 50 patients (mean age 79.6±4.0 years, females 44%) was included in the trial. Ticagrelor 60 mg was non-inferior to ticagrelor 90 mg according to VerifyNow-P2Y12 results (PRU 26.4±32.1 vs. 30.4±39.0; least squares mean difference: -4; 95% confidence interval: -16.27 to 8.06; p for non-inferiority=0.002). Other pharmacodynamic parameters were similar between the two ticagrelor doses and there were no differences in response to aspirin. Plasma levels of ticagrelor (398.29±312.36 ng/mL vs. 579.57±351.73 ng/mL, p=0.006) and its active metabolite were significantly lower during treatment with ticagrelor 60 mg.
CONCLUSIONS: Although plasma concentrations were lower, ticagrelor 60 mg twice daily provided a similar magnitude of platelet inhibition compared with ticagrelor 90 mg twice daily among elderly patients undergoing PCI. Clinical Trial registration: EudraCT 2019-002391-13. Clinicaltrials.gov NCT04739384.

OBJECTIVE: Although the amphiphilic nature of the widely used antithrombotic drug Ticagrelor is well known, it was never considered as a membranotropic agent capable of interacting with the lipid bilayer in a receptor-independent way. In this study, we investigated the influence of Ticagrelor on plasma membrane lipid order in platelets and if this modulates the potency of Ticagrelor at the P2Y12 receptor.
METHODS: We combined fluorescent in situ, in vitro and in silico approaches to probe the interactions between the plasma membrane of platelets and Ticagrelor. The influence of Ticagrelor on the lipid order of the platelet plasma membrane and large unilamellar vesicles was studied using the advanced fluorescent probe NR12S. Furthermore, the properties of model lipid bilayers in the presence of Ticagrelor were characterized by molecular dynamics simulations. Finally, the influence of an increased lipid order on the dose-response of platelets to Ticagrelor was studied.
RESULTS: Ticagrelor incorporates spontaneously into lipid bilayers and affects the lipid order of the membranes of model vesicles and isolated platelets, in a nontrivial composition and concentration-dependent manner. We showed that higher plasma membrane lipid order in platelets leads to a lower IC50 value for Ticagrelor. It is shown that membrane incorporation of Ticagrelor increases its potency at the P2Y12 receptor, by increasing the order of the platelet plasma membrane.
CONCLUSIONS: A novel dual mechanism of Ticagrelor action is suggested that combines direct binding to P2Y12 receptor with simultaneous modulation of receptor-lipid microenvironment.

The study focused on grape seed-derived polyphenols for their antiplatelet, anti-inflammatory, and fibrinolytic properties through molecular docking and dynamics simulations. Compounds were evaluated for their effects on P2Y12, PTP1B, thromboxane A2, and other targets. Compounds 1 and 6 showed strong inhibitory potential on P2Y12. Compounds 2 and 7, plus epigallocatechin gallate, demonstrated effective inhibition on NF-KB and COX1. The compounds exhibited drug-like properties and potential for new thrombotic disease therapies. The research sheds light on the interactions between polyphenols and target proteins, paving the way for novel antiplatelet strategies.

BACKGROUND: Debates persist regarding the optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) in coronary artery disease (CAD). Recent trials have introduced a novel approach involving P2Y12 inhibitor monotherapy with ticagrelor or clopidogrel, after a short DAPT. However, the effectiveness and safety of this strategy remains to be established. We aimed to perform a meta-analysis comparing monotherapy with P2Y12 inhibitors versus standard DAPT in patients undergoing PCI at 12 months.
METHODS: Multiple databases were searched. Six RCTs with a total of 24877 patients were included. The primary endpoint was all-cause mortality at 12 months of follow-up. The secondary endpoints were cardiovascular mortality, myocardial infarction, probable or definite stent thrombosis, stroke events, and major bleeding. The study is registered with PROSPERO (CRD42024499529).
RESULTS: Monotherapy with P2Y12 inhibitor ticagrelor significantly reduced both allcause mortality (HR 0.71, 95 CI [0.55-0.91], P = 0.007) and cardiovascular mortality (HR 0.66, 95% CI [0.49-0.89], P = 0.006) compared to standard DAPT. In contrast, clopidogrel monotherapy did not demonstrate a similar reduction. The decrease in mortality associated with ticagrelor was primarily due to a lower risk of major bleeding (HR 0.56, 95% CI [0.43-0.72], P < 0.001), while the risk of myocardial infarction (MI) remained unchanged (HR 0.90, 95% CI [0.73-1.11], P = 0.32). The risk of stroke was found to be similar across treatments.
CONCLUSIONS: In comparison to standard DAPT, P2Y12 inhibitor monotherapy with ticagrelor may lead to a reduced mortality. The clinical benefits are driven by a reduction of bleeding risk without ischemic risk trade-off.

UNASSIGNED: This study investigated the role of the P2Y12 receptor in autogenous arteriovenous fistula (AVF) failure resulting from stenosis.
UNASSIGNED: Stenotic venous tissues and blood samples were obtained from patients with end-stage renal disease (ESRD) together with AVF stenosis, while venous tissues and blood samples were collected from patients with ESRD undergoing initial AVF surgery as controls. Immunohistochemistry and/or immunofluorescence techniques were utilized to assess the expression of P2Y12, transforming growth factor-β1 (TGF-β1), monocyte chemotactic protein 1 (MCP-1), and CD68 in the venous tissues. The expression levels of P2Y12, TGFβ1, and MCP-1 were quantified using quantitative reverse transcription-polymerase chain reaction and western blot analyses. Double and triple immunofluorescence staining was performed to precisely localize the cellular localization of P2Y12 expression.
UNASSIGNED: Expression levels of P2Y12, TGFβ1, MCP-1, and CD68 were significantly higher in stenotic AVF venous tissues than in the control group tissues. Double and triple immunofluorescence staining of stenotic AVF venous tissues indicated that P2Y12 was predominantly expressed in α-SMA-positive vascular smooth muscle cells (VSMCs) and, to a lesser extent, in CD68-positive macrophages, with limited expression in CD31-positive endothelial cells. Moreover, a subset of macrophage-like VSMCs expressing P2Y12 were observed in both stenotic AVF venous tissues and control venous tissues. Additionally, a higher number of P2Y12+/TGF-β1+ double-positive cells were identified in stenotic AVF venous tissues than in the control group tissues.
UNASSIGNED: Increased expression of P2Y12 in stenotic AVF venous tissues of patients with ESRD suggests its potential involvement in the pathogenesis of venous stenosis within AVFs.

BACKGROUND: P2X7 receptor has emerged as a potentially superior PET imaging marker to TSPO, the gold standard for imaging glial reactivity. [11C]SMW139 is the most recently developed radiotracer to image P2X7 receptor. The aim of this study was to image reactive glia in the APP/PS1-21 transgenic (TG) mouse model of Aβ deposition longitudinally using [11C]SMW139 targeting P2X7 receptor and to compare tracer uptake to that of [18F]F-DPA targeting TSPO at the final imaging time point. TG and wild type (WT) mice underwent longitudinal in vivo PET imaging using [11C]SMW139 at 5, 8, 11, and 14 months, followed by [18F]F-DPA PET scan only at 14 months. In vivo imaging results were verified by ex vivo brain autoradiography, immunohistochemical staining, and analysis of [11C]SMW139 unmetabolized fraction in TG and WT mice.
RESULTS: Longitudinal change in [11C]SMW139 standardized uptake values (SUVs) showed no statistically significant increase in the neocortex and hippocampus of TG or WT mice, which was consistent with findings from ex vivo brain autoradiography. Significantly higher [18F]F-DPA SUVs were observed in brain regions of TG compared to WT mice. Quantified P2X7-positive staining in the cortex and thalamus of TG mice showed a minor increase in receptor expression with ageing, while TSPO-positive staining in the same regions showed a more robust increase in expression in TG mice as they aged. [11C]SMW139 was rapidly metabolized in mice, with 33% of unmetabolized fraction in plasma and 29% in brain homogenates 30 min after injection.
CONCLUSIONS: [11C]SMW139, which has a lower affinity for the rodent P2X7 receptor than the human version of the receptor, was unable to image the low expression of P2X7 receptor in the APP/PS1-21 mouse model. Additionally, the rapid metabolism of [11C]SMW139 in mice and the presence of several brain-penetrating radiometabolites significantly impacted the analysis of in vivo PET signal of the tracer. Finally, [18F]F-DPA targeting TSPO was more suitable for imaging reactive glia and neuroinflammatory processes in the APP/PS1-21 mouse model, based on the findings presented in this study and previous studies with this mouse model.

Microglia regulate anesthesia by altering the activity of neurons in specific regions of the brain via a purinergic receptor.

Cardiovascular disease (CVD) is a major cause of death worldwide. Although there are many variables that contribute to the development of this disease, it is predominantly the activity of platelets that provides the mechanisms by which this disease prevails. While there are numerous platelet receptors expressed on the surface of platelets, it is largely the consensus that there are 10 main platelet receptors that contribute to a majority of platelet function. Understanding these key platelet receptors is vitally important for patients suffering from myocardial infarction, CVD, and many other diseases that arise due to overactivation or mutations of these receptors. The goal of this manuscript is to review the main platelet receptors that contribute most to platelet activity.

BACKGROUND: Dual antiplatelet therapy is used to reduce the risk of thromboembolic complications in neuroendovascular surgery. However, the predictive utility of preoperative platelet-sensitivity testing for decreasing bleed risk in patients undergoing endovascular neurointervention remains unclear.
OBJECTIVE: We conducted a systematic review and meta-analysis to illustrate the association between platelet response and risk of hemorrhagic complications from neuroendovascular surgery, examine the efficacy of the VerifyNow platelet reactivity unit (PRU) assay in predicting hemorrhagic outcomes, and assess whether a clinically useful threshold for platelet response can be defined to standardize guidelines.
METHODS: PubMed, Embase, and Scopus were searched. Articles were screened for relevance by title and abstract, followed by full text.
RESULTS: Of 735 resultant articles, 17 studies of 2084 patients undergoing neuroendovascular intervention were included. Diagnoses included both intracranial and extracranial pathologies, of which 37.8% were treated with flow diversion, 22.4% with stent-assisted coil embolization, 14.3% with intracranial stenting, 12.8% with simple coil embolization, 5.8% with balloon-assisted coil embolization, 2.0% with extracranial stenting, and 4.8% with an alternate method. Precisely, 52.9% (9 out of 17) of studies determined platelet hyperresponse to be an independent predictor of postoperative hemorrhagic complications, with 11.8% (2 out of 17) of studies reporting a similar but non-statistically significant trend. 35.3% (6 out of 17) of studies found no relationship between platelet response and postoperative hemorrhagic complications. The estimated clinical threshold for PRU to prevent hemorrhagic complications varied considerably across studies (range: <46-118 PRU). Meta-analysis found platelet hyperresponse to have more than a 3-fold increased risk of hemorrhagic complications compared to normoresponders (relative risk = 3.2, p = 0.001).
CONCLUSIONS: Although this meta-analysis shows the predictive utility of the P2Y12 assay for postoperative hemorrhagic complications in neuroendovascular surgery, the optimal therapeutic threshold for minimizing bleeding risk is still uncertain. To better understand the utility of the P2Y12 assay in the perioperative period, further prospective research is needed.