Dual-pathway inhibition for secondary and tertiary antithrombotic prevention in cardiovascular disease

Polyvascular Disease: A Narrative Review of Risk Factors, Clinical Outcomes and Treatment

PURPOSE OF REVIEW

Polyvascular disease has a significant global burden and is associated with increased risk of major adverse cardiac events with each additional vascular territory involved. The purpose of this review is to highlight the risk factors, associated outcomes, emerging genetic markers, and evidence for screening and treatment of polyvascular disease.

RECENT FINDINGS

Polyvascular disease is the presence of atherosclerosis in two or more vascular beds. It has a significant global burden, with a prevalence of 30-70% in patients with known atherosclerosis. Patients with polyvascular disease experience elevated rates of cardiovascular death, myocardial infarction and stroke, especially among high-risk subgroups like those with type 2 diabetes mellitus and there is a step-wise increased risk of adverse outcomes with each additional vascular territory involved. Genetic analyses demonstrate that some individuals may carry a genetic predisposition, while others exhibit higher levels of atherogenic lipoproteins and inflammatory markers. Routine screening for asymptomatic disease is not currently recommended by major cardiovascular societies unless patients are high-risk. While there are no established protocols for escalating treatment, existing guidelines advocate for lipid-lowering therapy. Additionally, recent studies have demonstrated benefit from antithrombotic agents, such as P2Y12 inhibitors and low-dose anticoagulation, but the optimal timing and dosage of these agents has not been established, and the ischemic benefit must be balanced against the increased risk of bleeding in the polyvascular population. Due to the high prevalence and risks associated with polyvascular disease, early identification and treatment intensification are crucial to reduce disease progression. Future research is needed to develop screening protocols and determine the optimal timing and dosing of therapy to prevent ischemic events.

Pharmacological and clinical appraisal of factor XI inhibitor drugs

The evolution of anticoagulation therapy, from vitamin K antagonists to the advent of direct oral anticoagulants (DOACs) almost two decades ago, marks significant progress. Despite improved safety demonstrated in pivotal trials and post-marketing observations, persistent concerns exist, particularly regarding bleeding risk and the absence of therapeutic indications in specific subgroups or clinical contexts. Factor XI (FXI) has recently emerged as a pivotal contributor to intraluminal thrombus formation and growth, playing a limited role in sealing vessel wall injuries. Inhibiting FXI presents an opportunity to decouple thrombosis from haemostasis, addressing concerns related to bleeding events while safeguarding against thromboembolic events. Notably, FXI inhibition holds promise for patients with end-stage renal disease or cancer, where clear indications for DOACs are currently lacking. Various compounds have undergone design, testing, and progression to phase 2 clinical trials, demonstrating a generally favourable safety and tolerability profile. However, validation through large-scale phase 3 trials with sufficient power to assess both safety and efficacy outcomes is needed. This review comprehensively examines FXI inhibitors, delving into individual classes, exploring their pharmacological properties, evaluating the latest evidence from randomized trials, and offering insights into future perspectives.

Antithrombotic strategies for preventing graft failure in coronary artery bypass graft

Coronary artery bypass graft (CABG) procedures face challenges related to graft failure, driven by factors such as acute thrombosis, neointimal hyperplasia, and atherosclerotic plaque formation. Despite extensive efforts over four decades, the optimal antithrombotic strategy to prevent graft occlusion while minimizing bleeding risks remains uncertain, relying heavily on expert opinions rather than definitive guidelines. To address this uncertainty, we conducted a review of randomized clinical trials and meta-analyses of antithrombotic therapy for patients with CABG. These studies examined various antithrombotic regimens in CABG such as single antiplatelet therapy (aspirin or P2Y12 inhibitors), dual antiplatelet therapy, and anticoagulation therapy. We evaluated outcomes including the patency of grafts, major adverse cardiovascular events, and bleeding complications and also explored future perspectives to enhance long-term outcomes for CABG patients. Early studies established aspirin as a key component of antithrombotic pharmacotherapy after CABG. Subsequent randomized controlled trials focused on adding a P2Y12 inhibitor (such as clopidogrel, ticagrelor, or prasugrel) to aspirin, yielding mixed results. This article aims to inform clinical decision-making and guide the selection of antithrombotic strategies after CABG.

Dual antithrombotic therapy dose-dependently alters hemostatic plug structure and function

BACKGROUND

Antithrombotic medications carry an inherent risk of bleeding, which may be exacerbated when anticoagulant and antiplatelet therapeutics are combined. Prior studies have shown different effects of antiplatelet vs anticoagulant drugs on the structure and function of hemostatic plugs in vivo.

OBJECTIVES

We examined whether dual antithrombotic treatment consisting of combined antiplatelet and anticoagulant therapeutics alters hemostatic plug structure and function differently from treatment with either therapeutic alone.

METHODS

Mice were treated with the P2Y12 antagonist clopidogrel and the factor Xa inhibitor rivaroxaban across a range of doses, either alone or in combination. The hemostatic response was assessed using a mouse jugular vein puncture injury model. Platelet accumulation and fibrin deposition were evaluated using quantitative multiphoton fluorescence microscopy, and bleeding times were recorded.

RESULTS

Mice treated with clopidogrel alone exhibited a decrease in platelet accumulation at the site of injury, with prolonged bleeding times only at the highest doses of clopidogrel used. Mice treated with rivaroxaban alone instead showed a reduction in fibrin deposition with no impact on bleeding. Mice treated with both clopidogrel and rivaroxaban exhibited platelet and fibrin accumulation that was similar to that with either drug given alone; however, dual antithrombotic therapy resulted in impaired hemostasis at doses that had no impact on bleeding when given in isolation.

CONCLUSION

Combined administration of antiplatelet and anticoagulant therapeutics exacerbates bleeding as compared to that with either drug alone, potentially via combined loss of both adenosine 5'-diphosphate- and thrombin-mediated platelet activation. These findings enhance our understanding of the bleeding risk associated with dual antithrombotic therapy.

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.

World Heart Federation Roadmap for Secondary Prevention of Cardiovascular Disease: 2023 Update

Background

Secondary prevention lifestyle and pharmacological treatment of atherosclerotic cardiovascular disease (ASCVD) reduce a high proportion of recurrent events and mortality. However, significant gaps exist between guideline recommendations and usual clinical practice.

Objectives

Describe the state of the art, the roadblocks, and successful strategies to overcome them in ASCVD secondary prevention management.

Methods

A writing group reviewed guidelines and research papers and received inputs from an international committee composed of cardiovascular prevention and health systems experts about the article's structure, content, and draft. Finally, an external expert group reviewed the paper.

Results

Smoking cessation, physical activity, diet and weight management, antiplatelets, statins, beta-blockers, renin-angiotensin-aldosterone system inhibitors, and cardiac rehabilitation reduce events and mortality. Potential roadblocks may occur at the individual, healthcare provider, and health system levels and include lack of access to healthcare and medicines, clinical inertia, lack of primary care infrastructure or built environments that support preventive cardiovascular health behaviours. Possible solutions include improving health literacy, self-management strategies, national policies to improve lifestyle and access to secondary prevention medication (including fix-dose combination therapy), implementing rehabilitation programs, and incorporating digital health interventions. Digital tools are being examined in a range of settings from enhancing self-management, risk factor control, and cardiac rehab.

Conclusions

Effective strategies for secondary prevention management exist, but there are barriers to their implementation. WHF roadmaps can facilitate the development of a strategic plan to identify and implement local and national level approaches for improving secondary prevention.

Edoxaban treatment in a post-infarction experimental model

BACKGROUND

The sequelae of myocardial infarction (MI) require specific pharmacological therapy to minimise the post-MI remodelling, which in many cases evolves into cardiovascular complications. The aim of this study was to analyse the effect of edoxaban, an oral anticoagulant, on cardiac recovery in a rat model of permanent coronary artery ligation.

METHODS

An experimental method to assess the post-MI remodelling in rats for 4 weeks, based on cardiac magnetic resonance imaging (MRI) and final histological analysis of the hearts was performed. The influence of daily oral treatment with edoxaban (20 mg/kg/day) for 28 days post-MI was analysed in comparison to vehicle.

RESULTS

In our model, edoxaban was shown to be safe and bleeding was observed in 1 of 10 animals. General physical recovery of the treated animals was shown by higher body weight recovery compared with non-treated animals (38.6 ± 2.9 vs. 29.9 ± 3.1 g, respectively, after 28 days). There was not a pronounced effect of edoxaban in post-MI cardiac remodelling, but mitigated fibrosis was observed by the reduced expression of vascular endothelial growth factor and tumour growth factor β1 in the peri-infarct zone.

CONCLUSIONS

Our analysis provided the experimental basis to support the feasibility of MRI to study cardiac function and characterise myocardial scarring in a rat model. Overall data suggested the safety of edoxaban in the model, and compared to placebo, it showed a better post-MI recovery, probably by reducing fibrosis of the heart. Further research on mid-term cardiac recovery with edoxaban after MI is justified.

Comparison of rivaroxaban-based dual antithrombotic and antiplatelet therapies for symptomatic patients with lower-extremity peripheral artery disease post-revascularization: a retrospective cohort study

Background

Patients with symptomatic lower-extremity peripheral artery disease (LE-PAD) are prone to serious cardiovascular and limb events. Few studies have evaluated the effect of rivaroxaban-based dual antithrombotic therapy in high-risk patients with LE-PAD in Asian populations.

Objectives

To investigate the efficacy and safety of rivaroxaban-based dual antithrombotic therapy in symptomatic patients with LE-PAD.

Design

Retrospective cohort study.

Methods

This study included patients with LE-PAD treated at the Nanjing Drum Tower Hospital from 1 January 2018 to 31 December 2021. These participants were divided into antiplatelet (APT) or antiplatelet therapy combined with rivaroxaban (RAPT) groups. The efficacy outcomes in this study were the occurrence of major adverse cardiovascular events (MACE), including myocardial infarction, ischemic stroke, or death from cardiovascular causes, and major adverse limb events (MALE), including urgent revascularization, acute limb ischemia, and major amputation. The safety outcomes included major and clinically relevant non-major (CRNM) bleeding. Patients were followed up until the time of death or the end of the study (31 March 2023).

Results

We included 1144 patients with LE-PAD (APT: 502 patients; RAPT: 642 patients). The RAPT group had a lower risk of primary composite efficacy outcomes [hazard ratio (HR): 0.40] and a nonsignificant increase in major bleeding risk (HR: 2.33) than the APT group. The RATP group also had a significantly lower risk of secondary efficacy outcomes, including ischemic stroke (HR: 0.41), myocardial infarction (HR: 0.31), cardiovascular death (HR: 0.40), and MALE (HR: 0.65), than the APT group. The CRNM bleeding incidence varied between the two groups (HR: 3.96). Moreover, no significant interactions were observed between the subgroups and treatment groups in the composite efficacy analysis.

Conclusion

Rivaroxaban-based dual antithrombotic therapy significantly reduced the occurrence of MACE in patients with LE-PAD without increasing major bleeding events. High-risk patients benefited from the dual antithrombotic therapy.

Bibliometric analysis of residual cardiovascular risk: trends and frontiers

BACKGROUND

The presence of residual cardiovascular risk is an important cause of cardiovascular events. Despite the significant advances in our understanding of residual cardiovascular risk, a comprehensive analysis through bibliometrics has not been performed to date. Our objective is to conduct bibliometric studies to analyze and visualize the current research hotspots and trends related to residual cardiovascular risk. This will aid in understanding the future directions of both basic and clinical research in this area.

METHODS

The literature was obtained from the Web of Science Core Collection database. The literature search date was September 28, 2022. Bibliometric indicators were analyzed using CiteSpace, VOSviewer, Bibliometrix (an R package), and Microsoft Excel.

RESULT

A total of 1167 papers were included, and the number of publications is increasing rapidly in recent years. The United States and Harvard Medical School are the leading country and institution, respectively, in the study of residual cardiovascular risk. Ridker PM and Boden WE are outstanding investigators in this field. According to our research results, the New England Journal of Medicine is the most influential journal in the field of residual cardiovascular risk, whereas Atherosclerosis boasts the highest number of publications on this topic. Analysis of keywords and landmark literature identified current research hotspots including complications of residual cardiovascular risk, risk factors, and pharmacological prevention strategies.

CONCLUSION

In recent times, global attention toward residual cardiovascular risk has significantly increased. Current research is focused on comprehensive lipid-lowering, residual inflammation risk, and dual-pathway inhibition strategies. Future efforts should emphasize strengthening international communication and cooperation to promote the comprehensive evaluation and management of residual cardiovascular risk.

Management of Residual Risk in Chronic Coronary Syndromes. Clinical Pathways for a Quality-Based Secondary Prevention

Chronic coronary syndrome (CCS), which encompasses a broad spectrum of clinical presentations of coronary artery disease (CAD), is the leading cause of morbidity and mortality worldwide. Recent guidelines for the management of CCS emphasize the dynamic nature of the CAD process, replacing the term "stable" with "chronic", as this disease is never truly "stable". Despite significant advances in the treatment of CAD, patients with CCS remain at an elevated risk of major cardiovascular events (MACE) due to the so-called residual cardiovascular risk. Several pathogenetic pathways (thrombotic, inflammatory, metabolic, and procedural) may distinctly contribute to the residual risk in individual patients and represent a potential target for newer preventive treatments. Identifying the level and type of residual cardiovascular risk is essential for selecting the most appropriate diagnostic tests and follow-up procedures. In addition, new management strategies and healthcare models could further support available treatments and lead to important prognostic benefits. This review aims to provide an overview of the diagnostic and therapeutic challenges in the management of patients with CCS and to promote more effective multidisciplinary care.

Personalised antiplatelet therapies for coronary artery disease: what the future holds

Coronary artery disease (CAD) is one of the leading causes of death globally, and antiplatelet therapy is crucial for both its prevention and treatment. Antiplatelet drugs such as aspirin and P2Y12 inhibitors are commonly used to reduce the risk of thrombotic events, including myocardial infarction, stroke, and stent thrombosis. However, the benefits associated with the use of antiplatelet drugs also come with a risk of bleeding complications. The ever-growing understanding of the poor prognostic implications associated with bleeding has set the foundations for defining strategies that can mitigate such safety concern without any trade-off in antithrombotic protection. To this extent, personalised antiplatelet therapy has emerged as a paradigm that optimizes the balance between safety and efficacy by customizing treatment to the individual patient's needs and risk profile. Accurate risk stratification for both bleeding and thrombosis can aid in selecting the optimal antiplatelet therapy and prevent serious and life-threatening outcomes. Risk stratification has traditionally included clinical and demographic characteristics and has expanded to incorporate angiographic features and laboratory findings. The availability of bedside platelet function testing as well as rapid genotyping assays has also allowed for a more individualized selection of antiplatelet therapy. This review provides a comprehensive overview of the current state of the art and future trends in personalised antiplatelet therapy for patients with CAD, with emphasis on those presenting with an acute coronary syndrome and undergoing percutaneous coronary revascularization. The aim is to provide clinicians with a comprehensive understanding of personalised antiplatelet therapy and facilitate informed clinical decision-making.

Dual Antiplatelet Therapy or Antiplatelet Plus Anticoagulant Therapy in Patients with Peripheral and Chronic Coronary Artery Disease: An Updated Review

Despite evidence-based therapies, patients presenting with atherosclerosis involving more than one vascular bed, such as those with peripheral artery disease (PAD) and concomitant coronary artery disease (CAD), constitute a particularly vulnerable group characterized by enhanced residual long-term risk for major adverse cardiac events (MACE), as well as major adverse limb events (MALE). The latter are progressively emerging as a difficult outcome to target, being correlated with increased mortality. Antithrombotic therapy is the mainstay of secondary prevention in both patients with PAD or CAD; however, the optimal intensity of such therapy is still a topic of debate, particularly in the post-acute and long-term setting. Recent well-powered randomized clinical trials (RCTs) have provided data in favor of a more intense antithrombotic therapy, such as prolonged dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor or a therapy with aspirin combined with an anticoagulant drug. Both approaches increase bleeding and selection of patients is a key issue. The aim of this review is, therefore, to discuss and summarize the most up-to-date available evidence for different strategies of anti-thrombotic therapies in patients with chronic PAD and CAD, particularly focusing on studies enrolling patients with both types of atherosclerotic disease and comparing a higher- versus a lower-intensity antithrombotic strategy. The final objective is to identify the optimal tailored approach in this setting, to achieve the greatest cardiovascular benefit and improve precision medicine.

Intracranial Hemorrhage in Hospitalized Patients Following Percutaneous Coronary Intervention: A Large Cohort Analysis from a Single Center

BACKGROUND

There are several reports on the prevalence and characteristics of intracranial hemorrhage (ICH) following percutaneous coronary intervention (PCI), which is a rare but severe complication with high mortality. However, the clinical landscapes of computed tomography (CT)-confirmed, symptomatic ICH in hospitalized patients are not fully characterized.

METHODS

Among 121,066 patients receiving PCI treatment in the Fu Wai Hospital between 2013 and 2022, there were 18 CT-defined, symptomatic patients with ICH occurring during post-PCI hospitalization. Symptomatic ICH was defined as clinical suspicion of hemorrhage and/or new focal neurological signs. We analyzed ICH timing, clinical and imaging features, and subsequent outcomes.

RESULTS

Overall, in this retrospective analysis, the incidence of CT-defined, symptomatic ICH was 0.015% (18/121,066). More than half of the cases (55.6%) occurred within the first 12 h following PCI. The most common initial manifestation of ICH patients was disturbance of consciousness. Thirteen patients (72.2%) had a hematoma volume ≥ 30 cm³. Additionally, the ICH was observed in the cerebral lobe (66.7%), cerebellum (22.2%), and the basal ganglia and thalamus (11.1%). The 90-day mortality of ICH patients undergoing PCI was very high (72.2%). Consciousness disturbance (p = 0.036), intracerebral hemorrhage volume > 30 mm³ (p = 0.001), and intracerebral hemorrhage originating from the infratentorial origin (p = 0.044) were significantly higher in patients who died.

CONCLUSIONS

Symptomatic ICH events occur with a rate of around 0.015%, with significantly higher short-term mortality risk in our cohort receiving PCI, which has not yet been demonstrated in other cohorts.

Eligibility to Intensified Antithrombotic Regimens for Secondary Prevention in Patients Who Underwent Percutaneous Coronary Intervention

Single antiplatelet therapy (SAPT) and intensified antithrombotic regimens (prolonged dual antiplatelet therapy [DAPT] or dual pathway inhibition [DPI]) are recommended for secondary prevention in patients who underwent percutaneous coronary intervention (PCI) after initial DAPT. We aimed to characterize eligibility to such strategies and to explore to what extent guidelines are applied in clinical practice. Patients who underwent PCI for acute or chronic coronary syndrome who completed initial DAPT were analyzed from a prospective registry. Patients were categorized into SAPT, prolonged DAPT/DPI, or DPI groups as per guideline indication by using a risk stratification algorithm. Predictors of receiving intensified regimens and the divergency of practice from guidelines were investigated. Between October 2019 and September 2021, a total of 819 patients were included. Based on the guidelines, 83.7% of patients qualified for SAPT, 9.6% for any intensified regimen (i.e., prolonged DAPT or DPI), and 6.7% for DPI only. At multivariable analysis, patients were more likely to receive an intensified regimen if they had diabetes, dyslipidemia, peripheral artery disease, multivessel disease, or previous myocardial infarction. Conversely, they were less likely to receive an intensified regimen if they had atrial fibrillation, chronic kidney disease, or previous stroke. Guidelines were not followed in 18.3% of cases. In particular, only 14.3% of candidates to intensified regimens were treated accordingly. In conclusion, although the majority of patients who underwent PCI after the initial period of DAPT were eligible for SAPT, 1 out of 6 had an indication to intensified regimens. However, such intensified regimens were underused among eligible patients.

Bleeding in acute coronary syndrome: from definitions, incidence, and prognosis to prevention and management

INTRODUCTION

In patients with acute coronary syndrome (ACS), the ischemic benefit of antithrombotic treatment is counterbalanced by the risk of bleeding. The recognition that bleeding events have prognostic implications (i.e. mortality) similar to recurrent ischemic events led to the development of treatment regimens aimed at balancing both ischemic and bleeding risks.

AREAS COVERED

This review aims at describing definitions, incidence, and prognosis related to bleeding events in ACS patients as well as bleeding-avoidance strategies for their prevention and management of bleeding complications.

EXPERT OPINION

Management of ACS patients has witnessed remarkable progress after the shift in focusing on the trade-off between ischemia and bleeding. Efforts in standardizing bleeding definitions will allow for better defining the prognostic impact of different types of bleeding events and enable to identify the high-bleeding risk patient. Such efforts will allow to balance the trade-off between the thrombotic and bleeding risk of the individual patient translating into better downward diagnostic and therapeutic decision-making. Novel strategies aiming at maximizing the safety and efficacy of antithrombotic regimens as well as the development of novel antithrombotic drugs and reversal agents and technological advances will allow for optimization of bleeding-avoidance strategies and management of bleeding complications.

Low dose rivaroxaban for the management of atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease is characterized by some risk of major adverse events despite the availability of effective medical therapies for secondary prevention. There is emerging evidence suggesting that thrombin partly contributes to this residual risk. In fact, thrombin (i.e., activated coagulation factor II) triggers not only the conversion of fibrinogen to fibrin but also platelet activation and various pathways responsible for pro-atherogenic and/or pro-inflammatory effects through interaction with protease activated receptors. To reduce the risk associated with thrombin activation, oral anticoagulants antagonists of vitamin K showed promise, but were associated with unacceptable bleeding rates. Direct oral anticoagulants targeting the activated factors X and II carry a lower risk of bleeding than vitamin K antagonists. Rivaroxaban, a direct inhibitor of activated factor X approved at the dose of 20 mg once daily for the prevention of thromboembolic events, has been also investigated at a reduced dose of 2.5 mg twice daily in several alternative scenarios of atherosclerotic cardiovascular disease, in combination with standard of care. Current guidelines recommend that low-dose rivaroxaban is given in an adjunct to standard therapy to patients with stable atherosclerosis and acute coronary syndromes at low bleeding risk. Several studies are underway to evaluate its putative benefits in other clinical settings.

Dual-pathway Inhibition with Low-dose Aspirin and Rivaroxaban versus Aspirin Monotherapy in Patients with Coronary Artery Disease and Peripheral Artery Disease: Systematic Literature Review and Meta-analysis

Background

Low-dose aspirin lowers cardiovascular event risk; dual-pathway inhibition (DPI) using low-dose aspirin with low-dose rivaroxaban may reduce this risk further. A systematic literature review and meta-analysis compared the efficacy, safety and net clinical benefit (NCB) of DPI with aspirin.

Methods

PubMed and Embase were searched for randomised controlled trials reporting clinical efficacy, safety and NCB of DPI compared with aspirin alone in patients with coronary artery disease (CAD) and/or peripheral artery disease. Six articles representing four trials were included.

Results

DPI versus aspirin alone significantly reduced major adverse cardiovascular events (HR 0.77; 95% CI [0.69-0.87]; p<0.01), increased International Society on Thrombosis and Haemostasis major bleeding events (HR 1.67; 95% CI [1.37-2.02]; p<0.01) and resulted in a significant NCB (HR 0.79; 95% CI [0.70-0.90]; p<0.01).

Conclusion

These results underscore the potential benefit of DPI in patients with CAD, including those in the immediate post-acute coronary syndrome stage and with established CAD, as well as patients with peripheral artery disease.

Factor XI Inhibitors in Early Clinical Trials: A Meta-analysis

BACKGROUND

 Phase II randomized controlled trials (RCTs) on factor(F)XI inhibitors have shown promising results but they were burdened by low statistical power for clinical outcomes.

METHODS

 We performed a systematic review and meta-analysis of RCT comparing FXI inhibitors versus other anticoagulants (enoxaparin or direct oral anticoagulants, DOACs) or versus placebo on top of antiplatelet therapy.

RESULTS

 Eight RCTs testing FXI inhibitors (ISIS 416858, osocimab, abelacimab, milvexian, asundexian) and enrolling 9,216 patients were included. Compared with enoxaparin, FXI inhibitors were associated with reduced any-bleeding (risk ratio [RR]: 0.49, 95% confidence interval [CI]: 0.31-0.77), no difference in major bleeding (RR: 0.96, 95% CI: 0.41-2.28), and reduced trial-defined efficacy endpoint (RR: 0.62, 95% CI: 0.49-0.79), the latter driven by the high-dose regimens. Compared with DOACs, FXI inhibitors were associated with a trend toward reduced any-bleeding (RR: 0.66, 95% CI: 0.31-1.38) and no difference in major bleeding (RR: 1.03, 95% CI: 0.22-4.78) or in trial-defined efficacy endpoint (RR: 1.23, 95% CI: 0.88-1.70). Compared with placebo, FXI inhibitors were associated with increased any-bleeding (RR: 1.25, 95% CI: 1.08-1.43) and a trend toward increased major bleeding (RR: 1.21, 95% CI: 0.75-1.93), both driven by high-dose regimens, with no difference in trial-defined efficacy endpoint (RR: 1.02, 95% CI: 0.92-1.13).

CONCLUSION

 Results of this meta-analysis on FXI inhibitors suggest increased safety and efficacy compared with enoxaparin and modest increased safety compared with DOACs. The use of FXI inhibitors in adjunct to antiplatelet therapy versus placebo appears to be associated with a dose-dependent increase in bleeding without any difference in efficacy.

STUDY REGISTRATION

 This study is registered in PROSPERO (CRD42022367706).

Advances in the available pharmacotherapy for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation

INTRODUCTION

Non-ST-segment elevation acute coronary syndromes (NSTE-ACS), including non-ST-segment-elevation myocardial infarction (NSTEMI) and unstable angina, represent a leading cause of mortality worldwide, with important socio-economic consequences. NSTEMI accounts for the majority of acute coronary syndromes and usually develops on the background of a nonocclusive thrombus. We searched for relevant literature in the field in PubMed and clinicaltrials.gov as of July 2022.

AREAS COVERED

A number of pharmacotherapies are currently available for treatment and secondary prevention, mainly including antithrombotic, lipid-lowering and anti-inflammatory drugs. Pretreatment with aspirin, anticoagulant and statin therapy is of key importance in the preprocedural phase, while pretreating with an oral P2Y12 inhibitor is not routinely indicated in patients undergoing early invasive management. For patients undergoing percutaneous coronary revascularization, pharmacotherapy essentially consists of antithrombotic drugs, which should be carefully selected. Finally, antithrombotic, lipid-lowering and anti-inflammatory drugs are important components of long-term secondary prevention after a NSTE-ACS.

EXPERT OPINION

This article reviews the evidence supporting recommendation on pharmacotherapy in patients presenting with a NSTE-ACS. Several randomized clinical trials are still ongoing and are expected to further inform scientific knowledge and clinical practice, with the final aim to improve the treatment of NSTE-ACS patients.

Bleeding Events After Transcatheter Aortic Valve Replacement: JACC State-of-the-Art Review

Transcatheter aortic valve replacement (TAVR) has gained over time a major reduction in procedural complications. Despite this, clinically relevant bleeding still occurs in a non-negligible proportion of patients and adversely affects prognosis. Patients with severe aortic stenosis are at heightened risk for spontaneous bleeding due to advanced age and a high comorbidity burden. Also, procedural factors and antithrombotic management contribute to define individual bleeding susceptibility. Bleeding prevention represents an emerging area for improving patient care. Because of the tight hemorrhagic/ischemic balance, a tailored approach based on individual bleeding-risk profile, such as a less invasive antithrombotic regimen or appropriate diagnostic preprocedural evaluation, should be pursued to avoid bleeding events. This review aims to provide an in-depth overview of bleeding events in the TAVR field, including definitions, timing and the extent of risk, and clinical impact, as well as updates on antithrombotic management and its potential influence on bleeding complications.

Timing, Selection, Modulation, and Duration of P2Y12 Inhibitors for Patients With Acute Coronary Syndromes Undergoing PCI

Dual antiplatelet therapy with aspirin and the oral P2Y₁₂ inhibitor clopidogrel as the cornerstone of treatment for patients with an acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) was firstly established in 2001. Soon thereafter, the newer-generation P2Y₁₂ inhibitors prasugrel and ticagrelor became commercially available. The clinical management of ACS patients undergoing PCI has evolved significantly in the last 2 decades, with a shift toward more rapid invasive management, broader use of drug-eluting stents, and the increasing recognition that major bleeding due to antiplatelet therapy is detrimental. In this ever-changing scenario, numerous studies have addressed 4 main questions regarding P2Y₁₂ inhibition in ACS patients undergoing PCI: timing, selection, modulation, and duration. This paper reviews the latest evidence surrounding these topical questions, with a focus on efficacy and safety data, practice guidelines, and residual areas of uncertainty.

Antithrombotic Strategy in Secondary Prevention for High-Risk Patients with Previous Acute Coronary Syndrome: Overlap between the PEGASUS Eligibility and the COMPASS Eligibility in a Large Multicenter Registry

BACKGROUND

Patients with previous acute coronary syndrome (ACS) are at high risk of recurrent adverse cardiovascular events. Recently, prolonged dual antiplatelet therapy (DAPT) and oral anticoagulation therapy (OAT) have been shown to reduce recurrent ischemic events to the expense of an increase in bleeding events. The number of patients potentially eligible for these therapies in real life remains to be determined.

METHODS

Among ACS patients from five registries and one randomized controlled trial, we assessed the proportion of patients eligible for the PEGASUS strategy only and the proportion of patients eligible for the COMPASS strategy only, and set out the proportion of patients with an overlap between the strategies.

FINDINGS

Among the 10,048 evaluable patients, we found that 5373 (53.4%) were eligible for the PEGASUS strategy and 3841 (38.2%) were eligible for the COMPASS strategy, with a group of 3444 (34.4%) overlapping between the two strategies. The number of patients eligible for the PEGASUS strategy only was 1929 (19.2%) and the number eligible for the COMPASS strategy only was 397 (4.0%); 4278 (42.6%) were eligible for neither a PEGASUS strategy nor a COMPASS strategy.

INTERPRETATION

In a large cohort of ACS patients, one in three patients was eligible for either a prolonged DAPT with ticagrelor 60 mg and low-dose aspirin or a dual pathway inhibition approach with rivaroxaban 2.5 mg and low-dose aspirin.

Dual pathway inhibition in patients with atherosclerotic disease: pharmacodynamic considerations and clinical implications

INTRODUCTION

The persistence of elevated rates of ischemic recurrences despite the use of antiplatelet therapy among patients with atherosclerotic disease together with the understanding of the pivotal role of coagulation in the thrombo-inflammatory processes involved in the pathogenesis of atherosclerosis and its complications has fostered the development of treatments targeting both platelets and coagulation, a strategy known as dual-pathway inhibition (DPI).

AREAS COVERED

In this review we discuss the recent advancements in the understanding of the interplay between coagulation, platelets and inflammation involved in the pathophysiology of atherosclerosis and atherothrombosis, as the rationale for the implementation of a DPI strategy. We also discuss the available pharmacodynamic (PD) evidence and clinical implications with the use of DPI in patients with atherosclerotic disease.

EXPERT OPINION

The implementation of a DPI by adding the so-called 'vascular dose of rivaroxaban' (i.e. 2.5 mg bis in die), on top of antiplatelet therapy has consistently been associated with reduced levels of thrombin generation in PD studies and with reduced ischemic event rates at the cost of increased bleeding compared to antiplatelet therapy alone. Further research is warranted to best define patients in whom a DPI regimen has the best safety and efficacy profile.

Gender-differences in antithrombotic therapy across the spectrum of ischemic heart disease: Time to tackle the Yentl syndrome?

The incidence and clinical presentation of ischemic heart disease (IHD), as well as thrombotic and bleeding risks, appear to differ between genders. Compared with men, women feature an increased thrombotic risk, probably related to an increased platelet reactivity, higher level of coagulation factors, and sex-associated unique cardiovascular risk factors, such as pregnancy-related (i.e., pre-eclampsia and gestational diabetes), gynecological disorders (i.e., polycystic ovary syndrome, early menopause) and autoimmune or systemic inflammatory diseases. At the same time, women are also at increased risk of bleeding, due to inappropriate dosing of antithrombotic agents, smaller blood vessels, lower body weight and comorbidities, such as diabetes and chronic kidney disease. Pharmacological strategies focused on the personalization of antithrombotic treatment may, therefore, be particularly appealing in women in light of their higher bleeding and ischemic risks. Paradoxically, although women represent a large proportion of cardiovascular patients in our practice, adequate high-quality clinical trial data on women remain scarce and inadequate to guide decision-making processes. As a result, IHD in women tends to be understudied, underdiagnosed and undertreated, a phenomenon known as a "Yentl syndrome." It is, therefore, compelling for the scientific community to embark on dedicated clinical trials to address underrepresentation of women and to acquire evidence-based knowledge in the personalization of antithrombotic therapy in women.

Antithrombotic Treatment Patterns of Patients with Symptomatic Peripheral Arterial Occlusive Disease in Germany: Evidence from Health Insurance Claims Data

Objectives: Patients with peripheral arterial occlusive disease (PAOD) are at risk of worsening limb symptoms, major adverse cardiovascular events and exhibit an impaired life expectancy. There is a lack of evidence on the extent of pharmacological secondary prevention in PAOD patients. This study assesses treatment patterns of antithrombotic agents in symptomatic PAOD patients. Methods: This is a retrospective cohort study using data from the second largest insurance fund in Germany, BARMER. We included symptomatic PAOD patients undergoing in-hospital treatment with an index admission between 1 January 2010 and 31 December 2017. Outcomes were proportions of single antiplatelets (SAPT), dual antiplatelets (DAPT), vitamin-K antagonists (VKA), or direct oral anticoagulants (DOAC) in the 12 months prior and 6 months after the index hospitalization. Non-parametric cumulative incidence for competing risks was estimated to account for censoring and death after discharge from hospital stay. Patient flows were visualised by alluvial diagrams. All analyses were stratified by intermittent claudication (IC) and chronic limb-threatening ischaemia (CLTI). The protocol was registered to ClinicalTrials.gov (NCT03909022). Results: A total of 80,426 unique patient encounters were identified. Mean age was 72.7 (46.3% female). Amongst all patients, 25.6% were on SAPT, 4.1% on DAPT, 9.1% on VKA, 3.9% on DOAC, 3.9% on both antiplatelets and oral anticoagulation, and 53.3% without any antithrombotic therapy during the 12 months before index stay. The estimated cumulative incidence was 37.9% SAPT, 14.8% DAPT, 7.5% VKA, 4.3% DOAC, 7.4% both, and 28.1% without any antithrombotic therapy during the 6 months after index stay. The considerable increases in antiplatelet therapy were mainly driven by the group of patients without antithrombotics before index stay. As compared with IC, patients who suffered from CLTI received less often antiplatelets but more often anticoagulants both before and after index stay. Conclusions: Utilisation rates of antithrombotic therapy increased considerably after in-hospital treatment for PAOD. Yet, remarkably high rates of symptomatic patients without any blood-thinning therapy constitute a major concern with respect to adequate secondary prevention of PAOD patients.

Endoplasmic reticulum stress: A common pharmacologic target of cardioprotective drugs

Despite the advances made in cardiovascular disease prevention, there is still substantial residual risk of adverse cardiovascular events. Contemporary evidence suggests that additional reduction in cardiovascular disease risk can be achieved through amelioration of cellular stresses, notably inflammatory stress and endoplasmic reticulum (ER) stress. Only two clinical trials with anti-inflammatory agents have supported the role of inflammatory stress in cardiovascular risk. However, there are no clinical trials with selective ER stress modifiers to test the hypothesis that reducing ER stress can reduce cardiovascular disease. Nevertheless, the ER stress hypothesis is supported by recent pharmacologic studies revealing that currently available cardioprotective drugs share a common property of reducing ER stress. These drug classes include angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, mineralocorticoid receptor blockers, β-adrenergic receptor blockers, statins, and select antiglycemic agents namely, metformin, glucagon like peptide 1 receptor agonists and sodium glucose cotransporter 2 inhibitors. Although these drugs ameliorate common risk factors for cardiovascular disease, such as hypertension, hypercholesterolemia and hyperglycemia, their cardioprotective effects may be partially independent of their principal effects on cardiovascular risk factors. Clinical trials with selective ER stress modifiers are needed to test the hypothesis that reducing ER stress can reduce cardiovascular disease.

Rationale and design of the AXIOMATIC-SSP phase II trial: Antithrombotic treatment with factor XIa inhibition to Optimize Management of Acute Thromboembolic events for Secondary Stroke Prevention

BACKGROUND

Individuals with ischemic stroke or transient ischemic attack (TIA) have a high early risk of ischemic stroke despite dual antiplatelet therapy. The risk of ischemic stroke, and associated disability, represents a significant unmet clinical need. Genetic variants resulting in reduced factor XI levels are associated with reduced risk for ischemic stroke but are not associated with increased intracranial bleeding. Milvexian is an oral small-molecule inhibitor of FXIa that binds activated factor XI with high affinity and selectivity and may reduce the risk of stroke when added to antiplatelet drugs without significant bleeding. We aimed to evaluate the dose-response relationship of milvexian in participants treated with dual antiplatelets.

METHODS

We began a phase II, double-blinded, randomized, placebo-controlled trial at 367 sites in 2019. Participants (N = 2366) with ischemic stroke (National Institutes of Health Stroke Scale score ≤7) or high-risk TIA (ABCD² score ≥6) were randomized to 1 of 5 doses of milvexian or placebo for 90 days. Participants also received clopidogrel 75 mg daily for the first 21 days and aspirin 100 mg for 90 days. The efficacy endpoint was the composite of ischemic stroke or incident infarct on magnetic resonance imaging. Major bleeding, defined as type 3 or 5 bleeding according to the Bleeding Academic Research Consortium, was the safety endpoint. Participant follow-up will end in 2022.

CONCLUSION

The AXIOMATIC-SSP trial will evaluate the dose-response of milvexian for ischemic stroke occurrence in participants with ischemic stroke or TIA.

Discovery of 7, 4'-dimethoxy-3-hydroxyflavone as a protease-activated receptor 4 antagonist with antithrombotic activity and less bleeding tendency in mice

There is growing evidence of the importance of protease-activated receptor 4 (PAR4), one of thrombin receptors, as a therapeutic target in thrombotic cardiovascular diseases. In the present study, we utilized ligand-based virtual screening, bioassay, and structure-activity relationship study to discover PAR4 antagonists with new chemical scaffolds from natural origin, and examined their application as antiplatelet agents. By using these approaches, we have identified a flavonoid, 7, 4'-dimethoxy-3-hydroxyflavone, that exhibits anti-PAR4 activity. 7, 4'-Dimethoxy-3-hydroxyflavone inhibited PAR4-mediated human platelet aggregation, GPIIb/IIIa activation, and P-selectin secretion. Also, it inhibited PAR4 downstream signaling pathways, including Ca2+/protein kinase C, Akt, and MAP kinases ERK and p38, in human platelets, and suppressed PAR4-mediated β-arrestin recruitment in CHO-K1 cells exogenously expressed human PAR4. In a microfluidic system, 7, 4'-dimethoxy-3-hydroxyflavone reduced thrombus formation on collagen-coated chambers at an arterial shear rate in recalcified whole blood. Furthermore, mice treated with 7, 4'-dimethoxy-3-hydroxyflavone were significantly protected from FeCl3-induced carotid arterial occlusions, without significantly affecting tail bleeding time. In conclusion, 7, 4'-dimethoxy-3-hydroxyflavone represents a new class of nature-based PAR4 antagonist, it shows effective in vivo antithrombotic properties with less bleeding tendency, and could be a potential candidate for developing new antiplatelet agents.

Theaflavin: a natural candidate to restrain thrombosis

Many clinical studies have demonstrated the beneficial effects of black tea on cardiovascular diseases. However, the antiplatelet and antithrombotic activities of theaflavin (TF-1) remain unknown. In this study, we aimed to investigate the beneficial effects of TF-1 on platelet activation and thrombosis formation both in vitro and in vivo. Firstly, the in vitro antiplatelet activity of TF-1 was analyzed using platelets isolated from human blood via aggregometry, flow cytometry, the ELISA kit, western blot and fluorescence microscopy. Subsequently, the in vivo analysis of the hemostatic state and thrombosis formation was carried out in C57BL/6 mice based on the tail bleeding time and an FeCl₃-induced arterial thrombus model. The results showed that TF-1 could prominently inhibit platelet aggregation in a dose-dependent manner, and attenuate P-selectin expression, fibrinogen binding, spreading and thromboxane A2 (TxA2) formation. Western blot analysis showed that TF-1 potently inhibited spleen tyrosine kinase (Syk) and Akt (ser473/474) phosphorylation. The in vivo data further confirmed the inhibition of platelet activation by TF-1 with a prolonged arterial occlusion time (from 15.0 ± 1.1 minutes to 40.0 ± 5.4 minutes). All the results indicated that TF-1 is a powerful inhibitor of platelet activation and thrombosis formation in C57BL/6 mice, and could be developed as a novel food-based inhibitor of thrombotic disorders.

Opportunità cliniche e impatto sul sistema sanitario di un trattamento ottimale del paziente post-sindrome coronarica acuta

Despite the improvement of revascularization procedures, patients with acute coronary syndrome often develop recurrent ischemic events, suggesting a high residual cardiovascular risk in these patients, which requires a strict clinical monitoring as well as an optimal control of modifiable risk factors.

To this aim, an optimal management of index event and appropriate preventive measures are equally important. Hospital care by cardiologists should be followed by outpatient management by general practitioners, as established by specific diagnostic and therapeutic pathways, which should warrant an optimal support to the patient. A strict collaboration between hospital and primary care is crucial to monitor and adapt drug therapy after the acute event and improve adherence of the patients to prescribed treatments and implementation of life-style modifications, with benefits also in term of cost-effectiveness. In this context, individualized rehabilitation programs should also be offered to patients with acute coronary syndromes, in order to improve survival and quality of life.

New Paradigms in Antithrombotic Strategies: A Leap into the Future of Cardiovascular Medicine

During the last decades, significant improvements have changed the landscape of antithrombotic treatment strategies and, more generally, the treatment of thrombotic and cardiovascular diseases [...].

Platelet P2Y12 inhibiting therapy in adjunct to vascular dose of rivaroxaban or aspirin: A pharmacodynamic study of dual pathway inhibition versus dual antiplatelet therapy

AIM

Dual-pathway inhibition (DPI) by adding a vascular dose of rivaroxaban to a single antiplatelet agent has emerged as a promising antithrombotic strategy. However, in most studies the antiplatelet agent of choice used in adjunct to a vascular dose of rivaroxaban was aspirin, and data with a P2Y12 inhibitor and how this DPI regimen compares with standard dual antiplatelet therapy (DAPT) is limited.

METHODS AND RESULTS

This investigation was a sub-study analysis conducted in selected cohorts of patients with stable atherosclerotic disease enrolled from a larger prospective, open-label, parallel-group pharmacodynamics (PD) study. We analyzed data from 40 patients treated with either clopidogrel or ticagrelor-based DAPT first, and clopidogrel or ticagrelor-based DPI thereafter. PD measures explored key pathways involved in thrombus formation and included markers of: 1) P2Y12 reactivity, 2) platelet-mediated global thrombogenicity, 3) cyclooxygenase-1 activity, 3) TRAP-induced platelet aggregation; 4) tissue factor (TF)-induced platelet aggregation, and 5) thrombin generation. As compared to DAPT, on a background of the same P2Y12 inhibitor (clopidogrel or ticagrelor), DPI was associated with reduced thrombin generation, increased markers of cyclooxygenase-1 activity and TRAP-induced platelet aggregation and no differences in markers of P2Y12 signaling, platelet-mediated global thrombogenicity and TF-induced platelet aggregation. In an analysis according to P2Y12 inhibitor type, ticagrelor reduced markers of platelet-mediated global thrombogenicity, P2Y12 signaling and rates of high platelet reactivity compared to clopidogrel.

CONCLUSIONS

Compared to DAPT with aspirin and a P2Y12 inhibitor, the use of a P2Y12 inhibitor in adjunct to a vascular dose of rivaroxaban as part of a DPI strategy is associated with similar effects on platelet-mediated global thrombogenicity but reduced thrombin generation. A DPI strategy with ticagrelor is associated with enhanced antithrombotic efficacy, the clinical implications of which warrant larger scale investigations.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03718429.

Bleeding avoidance strategies in percutaneous coronary intervention

For many years, bleeding has been perceived as an unavoidable consequence of strategies aimed at reducing thrombotic complications in patients undergoing percutaneous coronary intervention (PCI). However, the paradigm has now shifted towards bleeding being recognized as a prognostically unfavourable event to the same extent as having a new or recurrent ischaemic or thrombotic complication. As such, in parallel with progress in device and drug development for PCI, there is clinical interest in developing strategies that maximize not only the efficacy but also the safety (for example, by minimizing bleeding) of any antithrombotic treatment or procedural aspect before, during or after PCI. In this Review, we discuss contemporary data and aspects of bleeding avoidance strategies in PCI, including risk stratification, timing of revascularization, pretreatment with antiplatelet agents, selection of vascular access, choice of coronary stents and antithrombotic treatment regimens.

Effective, disease-modifying, clinical approaches to patients with mild-to-moderate hypertriglyceridaemia

Plasma triglyceride concentration is easily, inexpensively, and accurately measured, and when elevated is a highly informative disease marker that identifies individuals who frequently have a host of underlying metabolic, inflammatory, and atherogenic risk factors. Although this concept aligns with much that has been discussed regarding the metabolic syndrome, individuals identified with mild-to-moderate hypertriglyceridaemia on a screening lipid profile are not necessarily recognised as having features of the metabolic syndrome and frequently do not receive definitive, meaningful, disease-modifying therapy. This treatment would include (1) lifestyle modification; (2) LDL-lowering therapies to aggressively treat elevated apolipoprotein B-containing particles; (3) antihypertensive therapies that have optimal therapeutic profiles for those individuals with metabolic syndrome; (4) icosapent ethyl for those individuals at high risk, particularly patients with established atherosclerotic cardiovascular disease who have residual hypertriglyceridaemia despite treatment with appropriate LDL-lowering therapies; (5) preferential use of cardiovascular protective diabetes therapies, in individuals with diabetes; and (6) antithrombotic therapies for secondary prevention of atherosclerotic cardiovascular disease in the context of high vascular disease risk and diabetes. Several emerging therapies, such as novel weight reducing, anti-inflammatory, lipid-modifying therapies, and therapies targeting the progression of non-alcoholic fatty liver disease, could also soon enter the clinical arena for patients with mild-to-moderate hypertriglyceridaemia and associated metabolic syndrome.

Atypical Roles of the Chemokine Receptor ACKR3/CXCR7 in Platelet Pathophysiology

The manifold actions of the pro-inflammatory and regenerative chemokine CXCL12/SDF-1α are executed through the canonical GProteinCoupledReceptor CXCR4, and the non-canonical ACKR3/CXCR7. Platelets express CXCR4, ACKR3/CXCR7, and are a vital source of CXCL12/SDF-1α themselves. In recent years, a regulatory impact of the CXCL12-CXCR4-CXCR7 axis on platelet biogenesis, i.e., megakaryopoiesis, thrombotic and thrombo-inflammatory actions have been revealed through experimental and clinical studies. Platelet surface expression of ACKR3/CXCR7 is significantly enhanced following myocardial infarction (MI) in acute coronary syndrome (ACS) patients, and is also associated with improved functional recovery and prognosis. The therapeutic implications of ACKR3/CXCR7 in myocardial regeneration and improved recovery following an ischemic episode, are well documented. Cardiomyocytes, cardiac-fibroblasts, endothelial lining of the blood vessels perfusing the heart, besides infiltrating platelets and monocytes, all express ACKR3/CXCR7. This review recapitulates ligand induced differential trafficking of platelet CXCR4-ACKR3/CXCR7 affecting their surface availability, and in regulating thrombo-inflammatory platelet functions and survival through CXCR4 or ACKR3/CXCR7. It emphasizes the pro-thrombotic influence of CXCL12/SDF-1α exerted through CXCR4, as opposed to the anti-thrombotic impact of ACKR3/CXCR7. Offering an innovative translational perspective, this review also discusses the advantages and challenges of utilizing ACKR3/CXCR7 as a potential anti-thrombotic strategy in platelet-associated cardiovascular disorders, particularly in coronary artery disease (CAD) patients post-MI.

Appraising the contemporary role of aspirin for primary and secondary prevention of atherosclerotic cardiovascular events

INTRODUCTION

Although the role of aspirin for primary prevention of atherosclerotic cardiovascular disease (ASCVD) has been disputed, its use in secondary ASCVD prevention is well established. Recent trials of primary prevention do not suggest a significant net benefit with aspirin, whereas accruing evidence supports adopting aspirin-free strategies in the context of potent P2Y₁₂ inhibition for the secondary prevention of selected patients undergoing percutaneous coronary intervention.

AREAS COVERED

This updated review aims at summarizing and appraising the pharmacological characteristics and the contemporary role of aspirin for the primary and secondary prevention of ASCVD.

EXPERT OPINION

Recent trials and metanalyses in the context of primary prevention highlighted a modest reduction in ischemic events with aspirin use, counterbalanced by a significant increase in bleeding events. However, ongoing studies on cancer prevention could modify the current paradigm of the unfavorable benefit-risk ratio of aspirin in patients with no overt ASCVD. Conversely, aspirin use is crucial for secondary ASCVD prevention, both in chronic and acute coronary syndromes. Nevertheless, after a brief period of dual antiplatelet therapy, patients at high bleeding risk may benefit from discontinuation of aspirin if a P2Y₁₂ inhibitor is used, hence reducing the bleeding risk with no rebound in thrombotic events.

Platelet ACKR3/CXCR7 Favors Anti-Platelet Lipids over an Atherothrombotic Lipidome and Regulates Thrombo-inflammation

Platelet ACKR3/CXCR7 surface expression is enhanced and influences prognosis in coronary artery disease-(CAD) patients, who exhibit a distinct atherothrombotic platelet lipidome. Current investigation validates the potential of ACKR3/CXCR7 in regulating thrombo-inflammatory response, through its impact on the platelet lipidome. CAD patients-(n=230) with enhanced platelet-ACKR3/CXCR7 expression exhibited reduced aggregation. Pharmacological CXCR7-agonist-(VUF11207) significantly reduced pro-thrombotic platelet response in blood from ACS patients-(n=11) ex vivo. CXCR7-agonist administration reduced thrombotic functions and thrombo-inflammatory platelet-leukocyte interactions post myocardial infarction-(MI) and arterial injury in vivo. ACKR3/CXCR7-ligation did not affect surface availability of GPIbα, GPV, GPVI, GPIX, αv-integrin, β3-integrin, coagulation profile-(APTT, PT), bleeding time, plasma-dependent thrombin generation-(thrombinoscopy) or clot formation-(thromboelastography), but counteracted activation-induced phosphatidylserine exposure and procoagulant platelet-assisted thrombin generation. Targeted-(micro-UHPLC-ESI-QTrap-MS/MS) and untargeted-(UHPLC-ESI-QTOF-MS/MS) lipidomics analysis revealed that ACKR3/CXCR7-ligation favored generation of anti-thrombotic lipids-(dihomo-γ-linolenic acid-DGLA, 12-hydroxyeicosatrienoic acid-12-HETrE) over cyclooxygenase-COX-1-(thromboxane-TxA2), or 12-lipoxygenase-LOX-(12-HETE) metabolized pro-thrombotic, and phospholipase derived atherogenic-(lysophosphatidylcholine-LPC) lipids, in healthy subjects and CAD patients, contrary to anti-platelet therapy. Through 12-HETrE, ACKR3/CXCR7-ligation coordinated with Gαs-coupled prostacyclin receptor-(IP) to trigger cAMP-PKA mediated platelet inhibition. ACKR3/CXCR7-ligation reduced generation of lipid agonists-(arachidonic acid-AA,TxA2), lipid signaling intermediates-(lyophosphatidylinositol-LPI, diacylglycerol-DG), which affected calcium mobilization, intracellular signaling, consequently platelet interaction with physiological matrices and thrombo-inflammatory secretion-(IL1β,IFN-γ,TGF-β,IL-8), emphasizing its functional dichotomy from pro-thrombotic CXCR4. Moreover, CXCR7-agonist regulated heparin-induced thrombocytopenia-(HIT)-sera/IgG-induced platelet and neutrophil activation, heparin induced platelet aggregation-(HIPA), generation of COX-1-(TxA2), 12-LOX-(12-HETE) derived thrombo-inflammatory lipids, platelet-neutrophil aggregate formation, and thrombo-inflammatory secretion (sCD40L, IL-1β, IFN-γ, TNF-α, sP-selectin, IL-8, tissue factor-TF) ex vivo. Therefore, ACKR3/CXCR7 may offer a novel therapeutic strategy in acute/chronic thrombo-inflammation exaggerated cardiovascular pathologies, and CAD.

Unexplained arterial thrombosis: approach to diagnosis and treatment

Arterial thrombotic events in younger patients without a readily apparent etiology present significant diagnostic and management challenges. We present a structured approach to diagnosis with consideration of common causes, including atherosclerosis and embolism, as well as uncommon causes, including medications and substances, vascular and anatomic abnormalities, systemic disorders, and thrombophilias. We highlight areas of management that have evolved within the past 5 years, including the use of dual-pathway inhibition in atherosclerotic disease, antithrombotic therapy selection in embolic stroke of undetermined source and left ventricular thrombus, the role of closure of patent foramen ovale for secondary stroke prevention, and the thrombotic potential of coronavirus disease 2019 infection and vaccination. We conclude with a representative case to illustrate the application of the diagnostic framework and discuss the importance of consideration of bleeding risk and patient preference in determining the appropriate management plan.

The enhanced photoelectrochemical platform constructed by N-doped ZnO nanopolyhedrons and porphyrin for ultrasensitive detection of brain natriuretic peptide

Nowadays, brain natriuretic peptide (BNP-32) is fundamental to early cardiovascular clinical diagnosis, whose accurate assay is of significance by photoelectrochemistry (PEC) for the low background and high precision. Herein, a novel enhanced PEC platform was built by successive deposition of N-doped ZnO nanopolyhedra (N-ZnO NP) and protoporphyrin IX (PPIX). Specifically, the N-ZnO NP with a narrow bandgap of 2.60 eV was synthesized by direct calcination of zeolitic imidazole framework-8 (ZIF-8), and performed as the substrate to enhance the photocurrents of PPIX (as photosensitizer) whose photoelectron transfer pathway and enhanced PEC mechanism were studied in detail. Under such foundation, a label-free PEC aptasensor was developed by deposition of DNA aptamer onto the PEC platform and then ultrasensitive assay of BNP-32 based on a "signal off" model. The biosensor showed a wide linear range (1 pg mL^-1- 0.1 μg mL^-1) with a limit of detection (LOD) as low as 0.14 pg mL^-1. This doping technique of ZnO nanomaterials provides some valuable guidelines for synthesis of advanced PEC probes in bioanalysis.

Nonvalvular atrial fibrillation patients anticoagulated with rivaroxaban compared with warfarin exhibit reduced circulating extracellular vesicles with attenuated pro-inflammatory protein signatures

BACKGROUND

Rivaroxaban, a direct oral factor Xa inhibitor, mediates anti-inflammatory and cardiovascular-protective effects besides its well-established anticoagulant properties; however, these remain poorly characterized. Extracellular vesicles (EVs) are important circulating messengers regulating a myriad of biological and pathological processes and may be highly relevant to the pathophysiology of atrial fibrillation as they reflect alterations in platelet and endothelial biology. However, the effects of rivaroxaban on circulating pro-inflammatory EVs remain unknown.

OBJECTIVES

We hypothesized that rivaroxaban's anti-inflammatory properties are reflected upon differential molecular profiles of circulating EVs.

METHODS

Differences in circulating EV profiles were assessed using a combination of single vesicle analysis by Nanoparticle Tracking Analysis and flow cytometry, and proteomics.

RESULTS

We demonstrate, for the first time, that rivaroxaban-treated non-valvular atrial fibrillation (NVAF) patients (n=8) exhibit attenuated inflammation compared with matched warfarin controls (n=15). Circulating EV profiles were fundamentally altered. Moreover, quantitative proteomic analysis of enriched plasma EVs from six pooled biological donors per treatment group revealed a profound decrease in highly pro-inflammatory protein expression and complement factors, together with increased expression of negative regulators of inflammatory pathways. Crucially, a reduction in circulating levels of soluble P-selectin was observed in rivaroxaban-treated patients (compared with warfarin controls), which negatively correlated with the patient's time on treatment.

CONCLUSION

Collectively, these data demonstrate that NVAF patients anticoagulated with rivaroxaban (compared with warfarin) exhibit both a reduced pro-inflammatory state and evidence of reduced endothelial activation. These findings are of translational relevance toward characterizing the anti-inflammatory and cardiovascular-protective mechanisms associated with rivaroxaban therapy.

Eighty years of oral anticoagulation: Learning from history

In the year 2021 we celebrate the 80th anniversary of the first clinical use of vitamin K antagonists (VKAs), the mainstay of prevention and long-term treatment of thromboembolic disease. The discovery and development of oral anticoagulants is one of the most important chapters in the history of medicine, a goal pursued by physicians trying to combat the clinical manifestations of thrombosis since ancient times. Until the last decade, VKAs were the only oral anticoagulants available and used in clinical practice. Today, their clinical use has progressively shrunk, as the non-vitamin K antagonist oral anticoagulants (NOACs) are increasingly replacing VKAs in various conditions after the successful completion of several large randomized controlled trials. Currently, new research is tackling upstream components of the intrinsic pathway - particularly factor XI and factor XII - for the development of new, even safer anticoagulants promising to reduce bleeding without compromising efficacy. This review highlights the evolution of oral anticoagulant therapy tracing the key stages of a long and fascinating history that has unfolded from the first part of the twentieth century until today, indeed an intriguing journey where serendipity is intertwined with the tenacious work of many researchers.

Oral antithrombotic therapy for the prevention of recurrent cerebrovascular events

Stroke is frequently a disabling and even life-threatening condition that has an ischemic cause in most cases. Transient ischemic attack (TIA) is a lower-risk condition that still exposes to the risk of future major cardiovascular events. The causes of stroke can be classified as cardioembolic disease, large vessel disease, small vessel disease, undetermined, or others. Cardioembolic disease and atherothrombosis of large arteries are the most common underlying processes of ischemic stroke and TIA. Therefore, antithrombotic therapy is a central strategy in the pharmacological management of these patients. However, because antithrombotic therapy provides ischemic protection at the price of increased bleeding, defining the fine balance between efficacy and safety is a clinical challenge. Numerous trials have recently defined the current indications to the use of anticoagulant and antiplatelet therapy in patients with various subtypes of ischemic stroke or TIA. In this review, we provide an updated appraisal of the currently available evidence on the use of various oral antithrombotic agents for prevention of recurrent events after an ischemic stroke or TIA.

Antithrombotic Therapy After Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is a treatment option for symptomatic patients with severe aortic stenosis who are candidates for a bioprosthesis across the entire spectrum of risk. However, TAVR carries a risk for thrombotic and bleeding events, underscoring the importance of defining the optimal adjuvant antithrombotic regimen. Antithrombotic considerations are convoluted by the fact that many patients undergoing TAVR are generally elderly and present with multiple comorbidities, including conditions that may require long-term oral anticoagulation (OAC) (eg, atrial fibrillation) and antiplatelet therapy (eg, coronary artery disease). After TAVR among patients without baseline indications for OAC, recent data suggest dual-antiplatelet therapy to be associated with an increased risk for bleeding events, particularly early postprocedure, compared with single-antiplatelet therapy with aspirin. Concerns surrounding the potential for thrombotic complications have raised the hypothesis of adjunctive use of OAC for patients with no baseline indications for anticoagulation. Although effective in modulating thrombus formation at the valve level, the bleeding hazard has shown to be unacceptably high, and the net benefit of combining antiplatelet and OAC therapy is unproven. For patients with indications for the use of long-term OAC, such as those with atrial fibrillation, the adjunctive use of antiplatelet therapy increases bleeding. Whether direct oral anticoagulant agents achieve better outcomes than vitamin K antagonists remains under investigation. Overall, single-antiplatelet therapy and OAC appear to be reasonable strategies in patients without and with indications for concurrent anticoagulation. The aim of the present review is to appraise the current published research and recommendations surrounding the management of antithrombotic therapy after TAVR, with perspectives on evolving paradigms and ongoing trials.

Efficacy and safety of dual pathway inhibition in patients with cardiovascular disease: a systematic review and Meta-analysis

BACKGROUND

Low-dose direct oral anticoagulants (DOACs) in adjunct to antiplatelet therapy, known as dual pathway inhibition (DPI), have been tested to prevent ischaemic events in patients with cardiovascular disease (CVD). We conducted a systematic review and meta-analysis to determine the overall safety and efficacy of low-dose DOACs vs. placebo on a background of antiplatelet therapy.

METHODS

All randomized controlled trials (RCTs) comparing low-dose DOAC (defined as a dosage below the lowest approved for stroke prevention) vs. placebo among patients with CVD receiving single or dual antiplatelet therapy in at least 50% of the population and followed for at least 6 months, were included. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were used to overcome different follow-up durations across trials. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the primary safety endpoint major bleeding. A pre-specified subgroup analysis was performed for different DOAC-dose regimens.

RESULTS

A total of 55,782 patients from 7 RCTs were included. Low-dose DOACs vs placebo were associated with significant reductions in MACE (IRR 0.85, 95% CI 0.78-0.91) and myocardial infarction (IRR 0.86, 95% CI 0.78-0.95) and significant increases of major (IRR 2.05, 95% CI 1.50-2.80) or all bleeding (IRR 1.82, 95% CI 1.49-2.22). CV death (IRR 0.90, 95% CI 0.79-1.03), intracranial (IRR 1.18, 95% CI 0.71-1.96) and fatal bleeding (IRR 1.13, 95% CI 0.76-1.69) did not differ significantly between strategies. Non-significant reductions of all-cause death (IRR 0.90, 95% CI 0.80-1.01) and stroke (IRR 0.73, 95% CI 0.53-1.01) favoured low-dose DOACs. Meta-regression analyses showed a significant interaction between percentage of DAPT use and increased risk of major bleeding (p = 0.04), intracranial Haemorrhage (p = 0.035) and stroke (p = 0.0003). Subgroup analysis of very low-dose DOAC, defined as ≤ 1/3 of the lowest approved dose for stroke prevention (i.e., rivaroxaban 2.5 mg twice daily) seems to mitigate the risk of bleeding without any trade-off in efficacy compared to other low-dose DOAC regimens.

CONCLUSIONS

In patients with CVD, a low-dose DOAC regimen vs. placebo, on a background of antiplatelet therapy, is effective in reducing ischaemic events at the expense of increased major and all bleeding, but without significantly increasing intracranial or fatal bleeds, while the reduction of cardiovascular and total mortality is not statistically significant. A DPI with very low-dose DOAC (i.e. rivaroxaban 2.5 mg twice daily) appears particularly advantageous, especially when combined with a single antiplatelet agent and used among patients at high ischaemic and low bleeding risk.

STUDY REGISTRATION

This study is registered in PROSPERO (CRD42021232744).

Dual Pathway of Inhibition and Vascular Protection in Patients with Atherosclerotic Disease

Несмотря на широкое внедрение в клиническую практику современной антитромботической стратегии (моно- или двойной антитромбоцитарной терапии), резидуальный риск неблагоприятных сердечно-сосудистых событий у пациентов с ишемической болезнью сердца (ИБС) и заболеваниями периферических артерий (ЗПА) по-прежнему остается высоким. До настоящего времени двойная антитромбоцитарная терапия является «золотым стандартом» вторичной профилактики при остром коронарном синдроме (ОКС), а монотерапия рекомендована пациентам с симптоматическим течением ЗПА, стабильной ИБС и цереброваскулярной болезнью. Вместе с тем разрыв атеросклеротической бляшки приводит не только к активации тромбоцитов, но также, вследствие экспозиции тканевого фактора, потенцирует образование тромбина. Поэтому терапевтическая стратегия, направленная на одновременное подавление генерации тромбина и активации тромбоцитов и называемая «двойной путь ингибирования», представляется более эффективной, чем известные варианты лечения, связанные с торможением только одного из двух путей. Как показали результаты исследования COMPASS, комбинация 2,5 мг ривароксабана дважды в сутки со 100 мг/сутки аспирина оказалась более эффективной по сравнению с монотерапией 100 мг/сутки аспирина в части снижения риска серьезных сердечно-сосудистых событий, незапланированных госпитализаций и летальности без увеличения количества фатальных и интракраниальных геморрагических осложнений. Преимущества режима двойного ингибирования, апробированного в исследовании COMPASS, были продемонстрированы в популяции пациентов с недавним ОКС, стабильной ИБС и ЗПА, а также после реваскуляризации нижних конечностей. На сегодняшний день ривароксабан является единственным антикоагулянтом, подтвердившим безусловные преимущества в сочетании с антитромбоцитарной терапией в указанных группах пациентов. Комбинированная терапия низкими дозами ривароксабана (2,5 мг/дважды/сутки) и аспирином (100 мг/сутки) уже включена в последние международные рекомендации как вариант вторичной профилактики у пациентов с патологией коронарных и периферических артерий.

Patients with cardiovascular (CV) disease are at high residual risk of CV events (including peripheral ischemic events), even when they receive the current antithrombotic strategies (single/dual antiplatelet therapy). Until now, dual antiplatelet therapy is the standard of care for the secondary prevention in patients with acute coronary syndrome (ACS), whereas the single antiplatelet therapy, generally with aspirin, is the standard of care for the secondary prevention in stable patients with coronary artery disease (CAD), peripheral artery disease (PAD), or cerebrovascular disease. Meanwhile, atherosclerotic plaque disruption not only induces the platelet activation, but also results in thrombin generation because of tissue factor exposure. Therefore, interrupting both pathways by combining antiplatelet therapy with an anticoagulant (dual pathway inhibition [DPI]), has the potential to be more effective than inhibiting either pathway alone. The COMPASS trial showed that in comparison with aspirin 100 mg, rivaroxaban 2.5 mg twice a day plus aspirin 100 mg reduced the risk of major cardiac events, CV hospitalization, and mortality, without the increase of intracranial or fatal bleedings. The benefit of DPI using the COMPASS regimen was demonstrated in patients with the recent ACS, in chronic CAD and PAD patients, and after the lower extremity revascularization. So far, rivaroxaban is the only anticoagulant, which is effective in combination with antiplatelet therapies in the mentioned groups. The combination of low-dose rivaroxaban (2.5 mg twice daily) and aspirin (100 mg once daily) has been included recently into the latest international recommendations for the secondary prevention in patients with coronary or peripheral artery disease.