Spectral classification by generative adversarial linear discriminant analysis.

Generative adversarial linear discriminant analysis (GALDA) is formulated as a broadly applicable tool for increasing classification accuracy and reducing overfitting in spectrochemical analysis. Although inspired by the successes of generative adversarial neural networks (GANs) for minimizing overfitting artifacts in artificial neural networks, GALDA was built around an independent linear algebra framework distinct from those in GANs. In contrast to feature extraction and data reduction approaches for minimizing overfitting, GALDA performs data augmentation by identifying and adversarially excluding the regions in spectral space in which genuine data do not reside. Relative to non-adversarial analogs, loading plots for dimension reduction showed significant smoothing and more prominent features aligned with spectral peaks following generative adversarial optimization. Classification accuracy was evaluated for GALDA together with other commonly available supervised and unsupervised methods for dimension reduction in simulated spectra generated using an open-source Raman database (Romanian Database of Raman Spectroscopy, RDRS). Spectral analysis was then performed for microscopy measurements of microsphereroids of the blood thinner clopidogrel bisulfate and in THz Raman imaging of common constituents in aspirin tablets. From these collective results, the potential scope of use for GALDA is critically evaluated relative to alternative established spectral dimension reduction and classification methods.

Occurrence of intraocular hemorrhages under monotherapy or combination therapy of antiplatelets and anticoagulants using the Japanese Adverse Drug Event Report database.

Purpose: An intraocular hemorrhage is an adverse event that can lead to visual acuity impairment. Antithrombotic therapy with antiplatelet agents and anticoagulants may increase intraocular hemorrhage. However, since their frequency is low, studies on the risk of intraocular hemorrhage with these drugs, especially under combination therapy, are limited. This study aimed to investigate the occurrence of intraocular hemorrhages under monotherapy and combination therapy with antiplatelets and anticoagulants by analyzing a large pharmacovigilance database. Methods: Intraocular hemorrhage signals with oral antiplatelets and anticoagulants were evaluated by calculating reporting odds ratios and information components using the Japan Adverse Drug Reactions Report database from April 2004 to March 2022. In addition, differences in signals between younger and elderly patients, affecting factors, and time-to-onset from initial antiplatelet and anticoagulant treatments were analyzed. Results: Aspirin, clopidogrel, warfarin, apixaban, and rivaroxaban, but not ticagrelor, ticlopidine, prasugrel, dabigatran, and edoxaban showed intraocular hemorrhage signals under monotherapy. In combination therapy, dual therapy (aspirin + P2Y12 inhibitors, warfarin, direct oral anticoagulants, and P2Y12 inhibitors + warfarin) and triple therapy (aspirin + P2Y12 inhibitors + warfarin) resulted in intraocular hemorrhage signals. Intraocular hemorrhage signals were observed in younger patients receiving monotherapy with aspirin and in elderly patients receiving monotherapy and combination therapy with warfarin. Affecting factors were diabetes mellitus in patients with prasugrel, use of medications for intravitreal injections, and posterior sub-Tenon injections with some antiplatelets and anticoagulants. The median period of intraocular hemorrhage occurrence after starting monotherapy with aspirin, clopidogrel, warfarin, or rivaroxaban was within 90 days. Conclusion: In addition to monotherapy with several antiplatelets and anticoagulants, combination therapy using aspirin, P2Y12 inhibitors, and warfarin has the potential risk of intraocular hemorrhage. Particular attention should be paid to the occurrence of intraocular hemorrhages in younger patients taking aspirin, in elderly patients taking warfarin, and within the first 90 days of antiplatelet and anticoagulant use.

Baseline P2Y12 reactivity, kidney function, and CYP2C19 genotype determine clopidogrel responsiveness in acute stroke.

Clopidogrel is the most-widely used platelet P2Y12-inhibitor for secondary-prevention of ischemic stroke. Platelet P2Y12 reactivity before and after inhibitors can be measured with blood sampling by commercialized system. We aimed to evaluate (1) whether high-on-clopidogrel platelet P2Y12 reactivity (HCPR) is associated with short-term vascular events and (2) the predictors of HCPR in acute stroke. The inclusion criterion was patients with acute stroke who received clopidogrel within 12-48 h after the onset. Platelet reactivity was assayed at baseline and after clopidogrel treatment using the VerifyNow system. The primary endpoint was recurrent ischemic events within 21 days after stroke. Among 190 patients, 32(16.9%) had recurrent ischemic stroke. Multivariate analyses showed that HCPR was significantly associated with the short-term events with an odds-ratio of 2.5 (95% CI 1.1-5.7, p = 0.027). Patients with HCPR had significantly higher frequencies of high baseline platelet P2Y12 reactivity, impaired kidney function, and carrying one or two CYP2C19 loss-of-function alleles. A poor clopidogrel response score combining these factors was developed. Ten percent of patients with score 0, 20.3% of those with score 1, 38.3% of those with score 2, and 66.7% of those with score 3 had HCPR (χ2-test, p < 0.001). Multivariate analyses showed that, compared with the score-0 group, the score-2 and -3 groups had higher risks of HCPR with hazard-ratios of 5.4 (95% CI 1.5-20.3, p = 0.012) and 17.4 (95% CI 3.4-88.9, p = 0.001) for developing recurrent ischemic strokes. The study emphasized the role of HCPR in ischemic stroke. We also developed an HCPR risk score, which could be used in clinical practice or trials, potentially with more precision, to weigh the clinical benefit of a tailored antiplatelet-strategy for patients with stroke.

Ticagrelor Loading on ST-Elevation Myocardial Infarction: Interaction With Prodromal Angina on Infarct Size and Clinical Events.

INTRODUCTION: Ticagrelor might reduce infarct size by exerting a more potent antiplatelet effect or by promoting a potential conditioning stimulus in ST-elevation myocardial infarction (STEMI) patients. Pre-infarction angina (PIA) is an effective preconditioning stimulus that reduces ischemia-reperfusion injury. Because little is known on the interaction of PIA in STEMI-patients loaded with ticagrelor, we sought to determine if patients loaded with ticagrelor had improved clinical outcomes as compared to clopidogrel and to study if it is modulated by the presence of PIA. METHODS: From 1272 STEMI patients submitted to primary percutaneous coronary intervention and treated with clopidogrel or ticagrelor from January 2008 to December 2018, 826 were analyzed after propensity score matching. Infarct size was estimated using peak creatine kinase (CK) and troponin T (TnT), and clinical impact was evaluated through cumulative major cardiac and cerebrovascular events (MACCE) at 1-year follow-up. Matched patients and their interaction with PIA were analyzed. RESULTS: Patients loaded with ticagrelor had lower peak CK [1405.50 U/L (730.25-2491.00), P < .001] and TnT [3.58 ng/mL (1.73-6.59), P < .001)], regardless of PIA. The presence of PIA was associated with lower CK (P = .030), but not TnT (P = .097). There was no interaction between ticagrelor loading and PIA (P = .788 for TnT and P = .555 for CK). There was no difference in MACCE incidence between clopidogrel or ticagrelor loading (P = .129). Cumulative survival was also similar between clopidogrel or ticagrelor, regardless of PIA (P = .103). CONCLUSION: Ticagrelor reduced infarct sizes independently and without a synergic effect with PIA. Despite reducing infarct size, clinical outcomes were similar across both groups.

Monitoring of Antiplatelet Therapy.

In the late 1990s, the antithrombotic antiplatelet agent, clopidogrel, a P2Y12 inhibitor, was introduced. Around the same time, there was an increase in a number of new methods to measure platelet function (e.g., PFA-100 in 1995), and this has continued. It became evident that not all patients responded to clopidogrel in the same way and that some patients had a relative "resistance" to therapy, termed "high on-treatment platelet reactivity." This then led to some publications to advocate platelet function testing being used for patients on antiplatelet therapy. Platelet function testing was also suggested for use in patients awaiting cardiac surgery after stopping their antiplatelet therapy as a way of balancing thrombotic risk pre-surgery and bleeding risk perioperatively. This chapter will discuss some of the commonly used platelet function tests used in these settings, particularly those that are sometimes referred to as point-of-care tests or that require minimal laboratory sample manipulation. The latest guidance and recommendations for platelet function testing will be discussed following several clinical trials looking at the usefulness of platelet function testing in these clinical settings.

Effects of Pooled Platelet Concentrate After Coronary Artery Bypass Graft Surgery in Patients With Dual Antiplatelet Therapy.

BACKGROUND: Dual antiplatelet therapy (DAPT) has become standard first-line treatment of acute coronary syndrome; however, it increases the risk of bleeding complications. The aim of this study was to investigate the benefits of pooled platelet concentrate (PPC) in reducing postoperative bleeding in patients undergoing off-pump coronary artery bypass graft (CABG) after a DAPT loading dose. METHODS: One hundred nine patients who underwent emergent CABG within the first 24 hours after receiving a DAPT loading dose were included in the study and divided into 2 groups: patients who were (group 1, n = 63) and were not (group 2, n = 46) given PPC during the surgery. The amount of bleeding in the postoperative period and the need for blood transfusions were recorded. RESULTS: The mean (SD) surgical drainage amounts were 475.39 (101.94) mL in group 1 and 679.34 (232.03) mL in group 2 (P = .001). The need for surgical revisions was 0% and 15.2% in groups 1 and 2, respectively (P = .002). The median (range) duration of hospitalization after surgery was 4 (4-6) days in group 1 and 6 (4-9) days in group 2 (P = .001). Total transfusions per patient were higher in group 2 than in group 1 (1 [range, 1-4] and 3 [range, 2-7] units, respectively; P = .001). CONCLUSION: Perioperative PPC in patients who had received DAPT reduces postoperative bleeding, the need for blood products, and hospital stay. As a result, it has beneficial effects for early mobilization and improves patient comfort.

Recanalization of external iliac artery occlusion in a patient with spinal stenosis using medications: a case report.

BACKGROUND: Iliac artery occlusion accompanied by spinal canal stenosis is rare. All reported cases were treated with endovascular stenting for iliac artery occlusion. We report the first case of external iliac artery occlusion accompanied by spinal stenosis, which was successfully treated with conservative treatment. CASE PRESENTATION: A 66-year-old man with lower extremity pain and claudication visited the outpatient spine clinic. He complained of a tingling sensation in the L5 dermatome of the right leg and L4 dermatome of the left leg. Magnetic resonance imaging showed central stenosis in at the L4-5 and L5-S1 levels, and lateral recess stenosis at the L5-S1 level. The patient's symptoms were ambiguous with mixed neurological claudication and vascular claudication. Computed tomography of the lower extremity artery showed complete occlusion in the right external iliac artery. Conservative treatment with clopidogrel and beraprost sodium was performed. After treatment, his symptoms gradually improved. Clopidogrel and beraprost sodium were continued for 4 years. Follow-up computed tomography at 4 years showed recanalization of the right external iliac artery occlusion. CONCLUSIONS: We describe a rare case of external iliac artery occlusion and spinal stenosis. External iliac artery occlusion may be successfully treated only with conservative treatment using medication.

Electrochemical peptide nucleic acid functionalized α-Fe2O3/Fe3O4 nanosheets for detection of CYP2C19*2 gene.

The CYP2C19*2 gene carriers and non-carriers are closely related to the dosage of clopidogrel. To correctly guide the use of clopidogrel and promote individualized therapy, an ultra-sensitive electrochemical biosensor was developed for the detection of CYP2C19*2 gene. The heterogeneous α-Fe2O3/Fe3O4 nanosheets were prepared via the hydrothermal-calcination process, and the preparation parameters were optimized. The average diameter and thickness of the nanosheets were approximately 150 nm and 53 nm, respectively; and the saturation magnetization was 80.2 emu/g. The α-Fe2O3/Fe3O4@Au nanosheets were prepared by sodium borohydride reduction method, and self-assembled to the electrode surface with magnetic field. Ultra-sensitive detection of CYP2C19*2 gene was realized through the recognition ability of strong single base mismatching of peptide nucleic acid and signal amplification effect of magnetic α-Fe2O3/Fe3O4@Au nanosheets. Under optimal detection conditions, the current had a good linear correlation with the negative logarithm of CYP2C19*2 gene concentration in the range 1 pM-1 nM, and the detection limit was 0.64 pM (S/N = 3). Meanwhile, the electrochemical signals of target DNA and incomplete complementary DNA were detected. The constructed biosensor exhibited good selectivity, reproducibility, and stability, providing a promising strategy for the detection of other gene mutations by electrochemical biosensors.

Genetic-Guided Oral P2Y12 Inhibitor Selection and Cumulative Ischemic Events After Percutaneous Coronary Intervention.

BACKGROUND: Genetic-guided P2Y12 inhibitor selection has been proposed to reduce ischemic events by identifying CYP2C19 loss-of-function (LOF) carriers at increased risk with clopidogrel treatment after percutaneous coronary intervention (PCI). A prespecified analysis of TAILOR-PCI (Tailored Antiplatelet Therapy Following PCI) evaluated the effect of genetic-guided P2Y12 inhibitor therapy on cumulative ischemic and bleeding events. OBJECTIVES: Here, the authors detail a prespecified analysis of cumulative endpoints. The primary endpoint was cumulative incidence rate of ischemic events at 12 months. Cumulative incidence of major and minor bleeding was a secondary endpoint. Cox proportional hazards models as adapted by Wei, Lin, and Weissfeld were used to estimate the effect of this strategy on all observed events. METHODS: The TAILOR-PCI trial was a prospective trial including 5,302 post-PCI patients with acute and stable coronary artery disease (CAD) who were randomized to genetic-guided P2Y12 inhibitor or conventional clopidogrel therapy. In the genetic-guided group, LOF carriers were prescribed ticagrelor, whereas noncarriers received clopidogrel. TAILOR-PCI's primary analysis was time to first event in LOF carriers. RESULTS: Among 5,276 patients (median age 62 years; 25% women; 82% acute CAD; 18% stable CAD), 1,849 were LOF carriers (903 genetic-guided; 946 conventional therapy). The cumulative primary endpoint was significantly reduced in the genetic-guided group compared with the conventional therapy (HR: 0.61; 95% CI: 0.41-0.89; P = 0.011) with no significant difference in cumulative incidence of major or minor bleeding (HR: 1.36; 95% CI: 0.67-2.76; P = 0.39). CONCLUSIONS: Among CYP2C19 LOF carriers undergoing PCI, a genetic-guided strategy resulted in a statistically significant reduction in cumulative ischemic events without a significant difference in bleeding. (Tailored Antiplatelet Therapy Following PCI [TAILOR-PCI]; NCT01742117).

Clinical Impact of CYP2C19 Genotype on Clopidogrel-Based Antiplatelet Therapy After Percutaneous Coronary Intervention.

BACKGROUND: Although there is a growing body of evidence that CYP2C19 genotyping can be beneficial when considering treatment with clopidogrel after percutaneous coronary intervention (PCI), whether a genotype-guided strategy can be generally adopted in routine practice remains unclear among East Asians. OBJECTIVES: This study sought to investigate long-term outcomes of patients undergoing clopidogrel-based antiplatelet therapy after drug-eluting stent (DES) implantation according to CYP2C19 genotypes. METHODS: From the nationwide multicenter PTRG-DES (Platelet function and genoType-Related long-term proGnosis in DES-treated patients) consortium, patients who underwent CYP2C19 genotyping were selected and classified according to CYP2C19 loss-of-function allele: rapid metabolizers (RMs) or normal metabolizers (NMs) vs intermediate metabolizers (IMs) or poor metabolizers (PMs). The primary outcome was a composite of cardiac death, myocardial infarction, and stent thrombosis at 5 years after the index procedure. RESULTS: Of 8,163 patients with CYP2C19 genotyping, 56.7% presented with acute coronary syndrome. There were 3,098 (37.9%) in the RM or NM group, 3,906 (47.9%) in the IM group, and 1,159 (14.2%) in the PM group. IMs or PMs were associated with an increased risk of 5-year primary outcome compared with RMs or NMs (HRadj: 1.42; 95% CI: 1.01-1.98; P = 0.041), and the effect was more pronounced in the first year (HRadj: 1.67; 95% CI: 1.10-2.55; P = 0.016). The prognostic implication of being an IM and PM was significant in acute coronary syndrome patients (HRadj: 1.88; 95% CI: 1.20-2.93; P = 0.005) but not in those with stable angina (HRadj: 0.92; 95% CI: 0.54-1.55; P = 0.751) (interaction P = 0.028). CONCLUSIONS: Among East Asians with clopidogrel-based antiplatelet therapy after DES implantation, CYP2C19 genotyping could stratify patients who were likely to have an increased risk of atherothrombotic events. (Platelet Function and genoType-Related Long-term progGosis in DES-treated Patients: A Consortium From Multi-centered Registries [PTRG-DES]; NCT04734028).

Clinical and Pre-Clinical Pharmacokinetics and Pharmacodynamics of Bentracimab.

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

Decreased platelet miR-199a-5p level might lead to high on-clopidogrel platelet reactivity in patients with coronary artery disease.

Clopidogrel combined with aspirin is widely used in coronary artery disease (CAD) patients, while some patients exhibit high platelet activity when receiving the combined treatment. Current environmental and genetic factors could only explain part of the variability in clopidogrel efficacy. Human platelets harbor abundant miRNAs which might affect clopidogrel efficacy by regulating the expression of key proteins in the clopidogrel antiplatelet signaling pathway. This study aimed to investigate the association between platelet miRNA levels and clopidogrel efficacy. Here we recruited 508 CAD patients who underwent clopidogrel antiplatelet therapy and determined the platelet reactivity index (PRI) to evaluate antiplatelet reactivity responses to clopidogrel. Subsequently, 22 patients with extreme clopidogrel response were selected for platelet small RNA sequencing. Another 41 CAD patients taking clopidogrel were collected to verify the differentially expressed candidate miRNAs. We found the metabolic types of the CYP2C19 enzyme (based on CYP2C19 * 2 and * 3 polymorphisms) could significantly affect the PRI of CAD patients with or without percutaneous coronary intervention (PCI) in Chinese. A total of 43 miRNAs were differentially expressed in the platelets from the 22 extreme clopidogrel response samples, and 109 miRNAs were differentially expressed in the 13 CYP2C19 extensive metabolizers with extreme clopidogrel response. Platelet miR-199a-5p levels were correlated negatively with PRI after clopidogrel therapy. Studies in cultured cells revealed that miR-199a-5p inhibited the expression of VASP, a key effector protein downstream of the P2Y12 receptor. In conclusion, we found the expression of VASP could be inhibited by miR-199a-5p, and decreased platelet miR-199a-5p was associated with high on-clopidogrel platelet reactivity in CAD patients.

What is the context?● Clopidogrel combined with aspirin is widely used in coronary artery disease (CAD) patients, while some patients exhibit high platelet activity when receiving the combined treatment.● Current environmental and genetic factors could only explain part of the variability in clopidogrel efficacy.● Human platelets harbor abundant miRNAs which might affect clopidogrel efficacy by regulating the expression of key proteins in the clopidogrel antiplatelet signaling pathway.What is new?● We found that decreased platelet miR-199a-5p level was associated with high on-clopidogrel platelet reactivity.● Overexpression of miR-199a-5p significantly down-regulated the expression of VASP protein in cultured cells.What is the impact?● The current study provided new insights into the exploration of interindividual variability in clopidogrel response from the perspective of miR-199a-5p and VASP interaction.