Clopidogrel-Mediated P2Y12 Inhibition According to Renal Function in Patients With Diabetes Mellitus and CAD.

This prospective ex vivo and in vitro pharmacodynamic (PD)/pharmacokinetic investigation was conducted in patients with diabetes mellitus with (n = 31) and without chronic kidney disease (n = 30). PD assessments included platelet reactivity index, maximum platelet aggregation, and P2Y12 reaction units. Ex vivo pharmacokinetic assessments included plasma levels of clopidogrel and its active metabolite. In vitro PD assessments were conducted on baseline samples incubated with escalating concentrations of clopidogrel and its active metabolite. Among patients with diabetes mellitus treated with clopidogrel, impaired renal function was associated with increased maximum platelet aggregation. This finding could be attributed partially to upregulation of the P2Y12 activity without differences in drug absorption or metabolism. (Impact of Chronic Kidney Disease on Clopidogrel Effects in Diabetes Mellitus; NCT03774394).

Exploring the landscape of academic retractions in medicine: a comprehensive umbrella review.

INTRODUCTION: The escalating trend of academic article retractions over the last decades raises concerns about scientific integrity, but heterogeneity in retractions and reasons for them pose a major challenge. We aimed to comprehensively overview systematic reviews focusing on retractions in the biomedical literature. EVIDENCE ACQUISITION: We abstracted salient features and bibliometric details from shortlisted articles. The Joanna Briggs Institute (JBI) Checklist for Systematic Reviews and Research Syntheses was used for validity appraisal. EVIDENCE SYNTHESIS: A total of 11 reviews were included, published between 2016 and 2023, and reporting on a total of 1851 retracted studies. Several major reasons for retractions were identified, spanning both misconduct (e.g., falsification, duplication, plagiarism) and non-misconduct issues (e.g., unreliable data, publishing problems). Correlates include author-related factors (number of authors, nationality) and journal-related factors (impact factor), with repeat offenders contributing significantly. Impacts of retractions is profound, affecting scholarly credibility, public trust, and resource utilization. CONCLUSIONS: In order to prevent retractions and amend their adverse effects, rigorous and transparent reporting standards, enhanced training in research ethics, strengthened peer review processes, and the establishment of collaborative and integrated research integrity offices are proposed.

Therapeutic Potential of FXI Inhibitors: Hype or Hope?

Significant advancements have shaped the landscape of anticoagulant therapy in the past two decades, including the introduction of direct oral anticoagulants (DOACs), characterized by favorable safety and efficacy profiles and reduced drug-to-drug or food interaction resulting in excellent patient compliance. However, residual concerns still exist with standard-of-care anticoagulant therapy, including the inability to use DOACs in several clinical settings and the need to further reduce the risk of bleeding. Recent improvements in the understanding of the mechanisms behind thrombus formation have led to the awareness that the intrinsic pathway of the coagulation cascade may play an important role in pathological thrombosis, but not in hemostasis. This has represented the rationale for targeting this pathway with factor XI (FXI) inhibitors, with the aim of uncoupling hemostasis and thrombosis. Clinical evidence from patients with FXI deficiency further supports this concept. A number of compounds with different mechanisms of action have been developed to target FXI (i.e., asundexian, abelacimab, Ionis-FXIRx, milvexian, osocimab, and Xisomab 3G). To date, the majority of available trials have not gone beyond completion of phase 2 and results are conflictive making it difficult to appraise the clinical benefit of these compounds in the different clinical settings where they have been tested (i.e., atrial fibrillation, acute ischemic stroke, acute myocardial infarction, end-stage renal disease, total knee arthroplasty). Moreover, the largest phase 3 randomized trial designed to test the efficacy of asundexian over apixaban in patients with atrial fibrillation, the OCEANIC-AF, has been prematurely stopped as a result of the inferior efficacy of asundexian. In this review we discuss the pharmacological properties and available evidence generated thus far for factor XI inhibitors, providing a perspective on the current state of these drugs.

Antiphospholipid Syndrome: Insights into Molecular Mechanisms and Clinical Manifestations.

Antiphospholipid syndrome (APS) is a complex systemic autoimmune disorder characterized by a hypercoagulable state, leading to severe vascular thrombosis and obstetric complications. The 2023 ACR/EULAR guidelines have revolutionized the classification and understanding of APS, introducing broader diagnostic criteria that encompass previously overlooked cardiac, renal, and hematologic manifestations. Despite these advancements, diagnosing APS remains particularly challenging in seronegative patients, where traditional tests fail, yet clinical symptoms persist. Emerging non-criteria antiphospholipid antibodies offer promising new diagnostic and management avenues for these patients. Managing APS involves a strategic balance of cardiovascular risk mitigation and long-term anticoagulation therapy, though the use of direct oral anticoagulants remains contentious due to varying efficacy and safety profiles. This article delves into the intricate pathogenesis of APS, explores the latest classification criteria, and evaluates cutting-edge diagnostic tools and therapeutic strategies.

P2Y12 Inhibitor Monotherapy After Short DAPT in Acute Coronary Syndrome: A Systematic Review and Meta-analysis.

BACKGROUND: P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy (DAPT) may balance ischemic and bleeding risks in patients with acute coronary syndrome (ACS). However, it remains uncertain how different P2Y12 inhibitors used as monotherapy affect outcomes. METHODS: Randomized controlled trials comparing P2Y12 inhibitor monotherapy after a short course of DAPT (≤3 months) versus 12-month DAPT in ACS were included. The primary endpoint was major adverse cardiovascular events (MACE). All analyses included an interaction term for the P2Y12 inhibitor used as monotherapy. Trial sequential analysis were run to explore whether the effect estimate of each outcomes may be affected by further studies. RESULTS: Seven trials encompassing 27,284 ACS patients were included. Compared with 12-month DAPT, P2Y12 inhibitor monotherapy after a short course of DAPT was associated with no difference in MACE (OR 0.92, 95% CI 0.76-1.12) and a significant reduction in net adverse clinical events (NACE) (OR 0.75; 95% CI 0.60-0.94), any bleeding (OR 0.54, 95% CI 0.43-0.66) and major bleeding (OR 0.47, 95% CI 0.37-0.60). Significant interactions for subgroup difference between ticagrelor and clopidogrel monotherapy were found for MACE (pint=0.016), all-cause death (pint=0.042), NACE (pint=0.018), and myocardial infarction (pint=0.028). Trial sequential analysis showed conclusive evidence of improved NACE with ticagrelor, but not with clopidogrel monotherapy, compared with standard DAPT. CONCLUSIONS: In patients with ACS, P2Y12 inhibitor monotherapy after short DAPT halves bleeding without increasing ischemic events compared with standard DAPT. Ticagrelor, but not clopidogrel monotherapy, reduced MACE, NACE and mortality compared with standard DAPT, supporting its use after aspirin discontinuation. Protocol registration: This study is registered in PROSPERO (CRD42023494797).

Stratified medicine for acute and chronic coronary syndromes: A patient-tailored approach.

The traditional approach to management of cardiovascular disease relies on grouping clinical presentations with common signs and symptoms into pre-specified disease pathways, all uniformly treated according to evidence-based guidelines ("one-size-fits-all"). The goal of precision medicine is to provide the right treatment to the right patients at the right time, combining data from time honoured sources (e.g., history, physical examination, imaging, laboratory) and those provided by multi-omics technologies. In patients with ischemic heart disease, biomarkers and intravascular assessment can be used to identify endotypes with different pathophysiology who may benefit from distinct treatments. This review discusses strategies for the application of stratified management to patients with acute and chronic coronary syndromes.

Comparative effects of different antiplatelet strategies in carriers of CYP2C19 loss-of-function alleles: a network meta-analysis.

BACKGROUND: Carriers of cytochrome 2C19 (CYP2C19) loss of function (LoF) alleles treated with clopidogrel have impaired drug metabolism resulting in reduced active metabolite levels, high platelet reactivity (HPR), and an increased risk of thrombotic events. Several alternative antiplatelet therapies have been proposed to overcome HPR in these patients, but their comparative effects remain poorly explored. METHODS: Randomized controlled trials (RCTs) comparing different oral antiplatelet therapies in carriers of CYP2C19 LoF alleles undergoing percutaneous coronary interventions (PCI) were included. A frequentist network meta-analysis was conducted to estimate mean difference (MD) or odds ratios (OR) and 95% confidence intervals (CI). The primary outcome was platelet reactivity assessed by VerifyNow and reported as P2Y12 reaction unit (PRU). The secondary outcome was the rate of HPR. Standard-dose of clopidogrel (75 mg daily) was used as reference treatment. RESULTS: A total of 12 RCTs testing 6 alternative strategies (i.e., clopidogrel 150 mg, prasugrel 3.75 mg, 5 mg, and 10 mg, ticagrelor 90 mg bid, and adjunctive cilostazol 100 mg bid) were included in the network. Compared with standard-dose clopidogrel, the greatest reduction in PRU was observed with prasugrel 10 mg (MD -127.91; 95% CI -141.04; -114.78) and ticagrelor 90 mg bid (MD -124.91; 95% CI -161.78; -88.04), followed by prasugrel 5 mg (MD -76.33; 95% CI -98.01; -54.65) and prasugrel 3.75 mg (MD -73.00; 95% CI -100.28; -45.72). Among other strategies, adjunctive cilostazol (MD-42.64; 95% CI -64.72; -20.57) and high-dose clopidogrel (MD -32.11; 95% CI -51.33; -12.90) were associated with a modest reduction in PRU compared with standard-dose clopidogrel. CONCLUSION: Among carriers of CYP2C19 LoF alleles undergoing PCI, standard-dose prasugrel or ticagrelor are most effective in reducing platelet reactivity, while double-dose clopidogrel and additional cilostazol showed modest effects. Reduced-dose of prasugrel may represent a balanced strategy to overcome HPR without a significant increase in bleeding. The clinical implications of these pharmacodynamic findings warrant further investigation.

P2Y12 Inhibition in Patients Requiring Oral Anticoagulation After Percutaneous Coronary Intervention: The SWAP-AC-2 Study.

BACKGROUND: Among patients treated with a novel oral anticoagulant (NOAC) undergoing percutaneous coronary intervention (PCI), combination therapy with clopidogrel (ie, known as dual antithrombotic therapy [DAT]) is the treatment of choice. However, there are concerns for individuals with impaired response to clopidogrel. OBJECTIVES: The authors sought to assess the pharmacodynamic (PD) effects of clopidogrel vs low-dose ticagrelor in patients with impaired clopidogrel response assessed by the ABCD-GENE score. METHODS: This was a prospective, randomized PD study of NOAC-treated patients undergoing PCI. Patients with an ABCD-GENE score ≥10 (n = 39), defined as having impaired clopidogrel response, were randomized to low-dose ticagrelor (n = 20; 60 mg twice a day) or clopidogrel (n = 19; 75 mg once a day). Patients with an ABCD-GENE score <10 (n = 42) were treated with clopidogrel (75 mg once a day; control cohort). PD assessments at baseline and 30 days post-randomization (trough and peak) were performed to assess P2Y12 signaling (VerifyNow P2Y12 reaction units [PRU], light transmittance aggregometry, and vasodilator-stimulated phosphoprotein); makers of thrombosis not specific to P2Y12 signaling were also assessed. The primary endpoint was PRU (trough levels) at 30 days. RESULTS: At 30 days, PRU levels were reduced with ticagrelor-based DAT compared with clopidogrel-based DAT at trough (23.0 [Q1-Q3: 3.0-46.0] vs 154.5 [Q1-Q3: 77.5-183.0]; P < 0.001) and peak (6.0 [Q1-Q3: 4.0-14.0] vs 129.0 [Q1-Q3: 66.0-171.0]; P < 0.001). Trough PRU levels in the control arm (104.0 [Q1-Q3: 35.0-167.0]) were higher than ticagrelor-based DAT (P = 0.005) and numerically lower than clopidogrel-based DAT (P = 0.234). Results were consistent by light transmittance aggregometry and vasodilator-stimulated phosphoprotein. Markers measuring other pathways leading to thrombus formation were largely unaffected. CONCLUSIONS: In NOAC-treated patients undergoing PCI with an ABCD-GENE score ≥10, ticagrelor-based DAT using a 60-mg, twice-a-day regimen reduced platelet P2Y12 reactivity compared with clopidogrel-based DAT. (Tailoring P2Y12 Inhibiting Therapy in Patients Requiring Oral Anticoagulation After PCI [SWAP-AC-2]; NCT04483583).

Impact of coronary microvascular dysfunction in heart failure with preserved ejection fraction: a meta-analysis.

AIMS: Several mechanisms have been identified in the aetiopathogenesis of heart failure with preserved ejection fraction (HFpEF). Among these, coronary microvascular dysfunction (CMD) may play a key pathophysiological role. We performed a systematic review and meta-analysis to investigate the prevalence, echocardiographic correlates, and prognostic implications of CMD in patients with HFpEF. METHODS AND RESULTS: A systematic search for articles up to 1 May 2023 was performed. The primary aim was to assess the prevalence of CMD. Secondary aims were to compare key echocardiographic parameters (E/e' ratio, left atrial volume index [LAVi], and left ventricular mass index [LVMi]), clinical outcomes [death and hospitalization for heart failure (HF)], and prevalence of atrial fibrillation (AF) between patients with and without CMD. Meta-regressions according to baseline patient characteristics and study features were performed to explore potential heterogeneity sources. We identified 14 observational studies, enrolling 1138 patients with HFpEF. The overall prevalence of CMD was 58%. Compared with patients without CMD, patients with HFpEF and CMD had larger LAVi [mean difference (MD) 3.85 confidence interval (CI) 1.19-6.5, P < 0.01)], higher E/e' ratio (MD 2.76 CI 1.54-3.97; P < 0.01), higher prevalence of AF (odds ratio 1.61 CI 1.04-2.48, P = 0.03) and higher risk of death or hospitalization for HF [hazard ratio 3.19, CI 1.04-9.57, P = 0.04]. CONCLUSIONS: CMD is present in little more than half of the patients with HFpEF and is associated with echocardiographic evidence of more severe diastolic dysfunction and a higher prevalence of AF, doubling the risk of death or HF hospitalization.

Atherosclerotic Plaque Erosion: Mechanisms, Clinical Implications, and Potential Therapeutic Strategies-A Review.

ABSTRACT: Atherosclerosis is an insidious and progressive inflammatory disease characterized by the formation of lipid-laden plaques within the intima of arterial walls with potentially devastating consequences. While rupture of vulnerable plaques has been extensively studied, a distinct mechanism known as plaque erosion (PE) has gained recognition and attention in recent years. PE, characterized by the loss of endothelial cell lining in the presence of intact fibrous cap, contributes to a significant and growing proportion of acute coronary events. However, despite a heterogeneous substrate underlying coronary thrombosis, treatment remains identical. This article provides an overview of atherosclerotic PE characteristics and its underlying mechanisms, highlights its clinical implications, and discusses potential therapeutic strategies.

Switching from Dual Antiplatelet Therapy with Aspirin Plus a P2Y12 Inhibitor to Dual Pathway Inhibition with Aspirin Plus Vascular-Dose Rivaroxaban: The Switching Anti-Platelet and Anti-Coagulant Therapy (SWAP-AC) Study.

BACKGROUND: To date, there are no data on switching to dual pathway inhibition (DPI) patients who have completed a guideline-recommended dual antiplatelet therapy (DAPT) regimen. OBJECTIVES: To assess the feasibility of switching from DAPT to DPI and to compare the pharmacodynamic (PD) profiles of these treatments. METHODS: This was a prospective, randomized, PD study conducted in 90 patients with chronic coronary syndrome (CCS) on DAPT with aspirin (81 mg/qd) plus a P2Y12 inhibitor (clopidogrel [75 mg/qd; n = 30], ticagrelor [90 mg/bid; n = 30], or prasugrel [10 mg/qd; n = 30]). Patients in each cohort were randomized to maintain DAPT or switch to DPI (aspirin 81 mg/qd plus rivaroxaban 2.5 mg/bid). PD assessments included: VerifyNow P2Y12 reaction units; light transmittance aggregometry following stimuli with adenosine diphosphate (ADP), tissue factor (TF), and a combination of collagen, ADP, and TF (maximum platelet aggregation %); thrombin generation (TG). Assays were performed at baseline and 30 days postrandomization. RESULTS: Switching from DAPT to DPI occurred without major side effects. DAPT was associated with enhanced P2Y12 inhibition, while DPI with reduced TG. Platelet-mediated global thrombogenicity (primary endpoint) showed no differences between DAPT and DPI in the ticagrelor (14.5% [0.0-63.0] vs. 20.0% [0.0-70.0]; p = 0.477) and prasugrel (20.0% [0.0-66.0] vs. 4.0% [0.0-70.0]; p = 0.482), but not clopidogrel (27.0% [0.0-68.0] vs. 53.0% [0.0-81.0]; p = 0.011), cohorts. CONCLUSION: In patients with CCS, switching from different DAPT regimens to DPI was feasible, showing enhanced P2Y12 inhibition with DAPT and reduced TG with DPI, with no differences in platelet-mediated global thrombogenicity between DPI and ticagrelor- and prasugrel-, but not clopidogrel-, based DAPT. CLINICAL TRIAL REGISTRATION: http://www. CLINICALTRIALS: gov Unique Identifier: NCT04006288.

Impact of ethnicity on antiplatelet treatment regimens for bleeding reduction in acute coronary syndromes: a systematic review and pre-specified subgroup meta-analysis.

AIMS: Randomized controlled trials (RCTs) testing bleeding reduction strategies using antiplatelet treatment regimens (BRATs) in acute coronary syndromes (ACS) have shown promising results, but the generalizability of these findings may be significantly influenced by the ethnicity of the patients enrolled, given that East Asian (EA) patients show different ischaemic-bleeding risk profile compared to non-EA patients. METHODS AND RESULTS: RCTs comparing a BRAT vs. standard 12-month dual antiplatelet therapy (DAPT) in patients with ACS undergoing percutaneous coronary intervention (PCI) were selected. The primary efficacy endpoint was major adverse cardiovascular events (MACE) as defined in each trial and the primary safety endpoint was minor or major bleeding. Twenty-six RCTs testing seven different BRATs were included. The only strategy associated with a trade-off in MACE was 'upfront unguided de-escalation' in the subgroup of non-EAs (risk ratio 1.16, 95% confidence interval 1.09-1.24). All but aspirin monotherapy-based strategies (i.e. 'short and very short DAPT followed by aspirin') were associated with reduced bleeding compared with standard DAPT in both EA and non-EA patients. There were no significant differences between subgroups, but the lack of RCTs in some of the included strategies and the difference in the certainty of evidence between EA and non-EA patients revealed that the evidence in support of different BRATs in ACS undergoing PCI is influenced by ethnicity. Moreover, absolute risk reduction estimation revealed that some BRATs might be more effective than others in reducing bleeding according to ethnicity. CONCLUSION: The majority of BRATs are associated with reduced bleeding without any trade-off in hard ischaemic endpoints regardless of ethnicity. However, the supporting evidence and relative safety profiles of different BRATs might be significantly affected by ethnicity, which should be taken into account in clinical practice. STUDY REGISTRATION: This study is registered in PROSPERO (CRD42023416710).

Coronary microvascular obstruction and dysfunction in patients with acute myocardial infarction.

Despite prompt epicardial recanalization in patients presenting with ST-segment elevation myocardial infarction (STEMI), coronary microvascular obstruction and dysfunction (CMVO) is still fairly common and is associated with poor prognosis. Various pharmacological and mechanical strategies to treat CMVO have been proposed, but the positive results reported in preclinical and small proof-of-concept studies have not translated into benefits in large clinical trials conducted in the modern treatment setting of patients with STEMI. Therefore, the optimal management of these patients remains a topic of debate. In this Review, we appraise the pathophysiological mechanisms of CMVO, explore the evidence and provide future perspectives on strategies to be implemented to reduce the incidence of CMVO and improve prognosis in patients with STEMI.