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

Direct oral anticoagulants versus Vitamin K antagonists in antiphospholipid syndrome: A systematic review and meta-analysis

BACKGROUND

Randomized controlled trials (RCTs) comparing the efficacy and safety of direct oral anticoagulants (DOACs) versus Vitamin K antagonists (VKAs) in patients with thrombotic antiphospholipid syndrome (APS) have yielded inconsistent results, partly due to the inherent challenges of conducting RCTs in populations with rare medical conditions. We conducted a systematic review and meta-analysis to evaluate the comparative effects of DOACs versus VKAs in thrombotic APS.

METHODS

RCTs and observational studies comparing DOACs versus VKAs in patients with thrombotic APS were included. The primary endpoint was a composite of arterial (ATE) and venous thrombotic events (VTE). Incidence rate ratios (IRRs) and associated 95 % confidence intervals (CI) were used to account for different follow-up durations. GRADE was used for rating the certainty of evidence.

FINDINGS

Twelve studies, four randomized and eight observational, encompassing a total of 1307 APS patients were included. The use of DOACs was associated with an increase in the primary endpoint (IRR 2.33; 95 % CI 1.18-4.58; GRADE=moderate) driven by increased ATE (IRR 2.70; 95 % CI 1.42-5.13; GRADE=low), compared with the use of VKA. VTE (IRR 0.98; 95 % CI 0.59-1.64; GRADE=low), major (IRR 0.83; 95 % CI 0.48-1.43; GRADE=low) and non-major (IRR 1.32; 95 % CI 0.81-2.14; GRADE=very low) bleeding did not differ significantly between groups. Compared with VKAs, DOACs were associated with an increase in myocardial infarction (IRR 4.71; 95 % CI 1.00-22.21; GRADE=very low) and stroke (IRR 7.48; 95 % CI 1.27-44.13; GRADE=very low). The increased risk of arterial thrombotic events with DOACs was consistently observed in a dedicated analysis of RCTs and was mitigated by the concomitant use of single antiplatelet therapy.

INTERPRETATION

In patients with thrombotic APS, the use of DOACs is associated with increased thrombotic events compared with VKAs, mainly driven by arterial thrombotic events. A single antiplatelet therapy combined with DOACs maight offer a promising alternative to VKAs, warranting further dedicated investigations.

PRIMARY FUNDING SOURCE

The study was not funded.

PROTOCOL REGISTRATION

This study is registered in PROSPERO (CRD42024582033).

Combining Colchicine and Antiplatelet Therapy to Tackle Atherothrombosis: A Paradigm in Transition?

Atherothrombosis, the primary driver of acute cardiovascular (CV) events, is characterized by the activation of three key pathophysiological pathways: platelets, coagulation, and inflammation. Dual antiplatelet therapy (DAPT) is the current standard of care for patients with acute coronary syndrome, providing significant reductions in cardiovascular (CV) events, albeit with an associated increased risk of bleeding. However, the high residual risk of recurrent events among these patients highlights the need for alternative strategies to treat and prevent atherothrombosis. To this extent, several approaches aimed at targeting atherothrombosis have been proposed. Among these, a strategy of dual-pathway inhibition simultaneously targeting platelets, using single or DAPT, and coagulation, using a low-dose anticoagulant such as rivaroxaban 2.5 mg twice daily, has shown to reduce CV events but at the expense of increased bleeding. Targeting inflammatory pathways has the potential to be a highly effective strategy to tackle atherothrombosis without increasing bleeding risk. Several anti-inflammatory agents have been tested in patients with coronary artery disease, but to date only colchicine is approved for secondary prevention on top of standard care, including antiplatelet therapy. However, many aspects of colchicine's mechanism of action, including its antiplatelet effects and how it synergizes with antiplatelet therapy, remain unclear. In this review, we summarize the available clinical and pre-clinical evidence on the antiplatelet effects of colchicine and its synergistic interactions with antiplatelet therapy, highlighting their potential role in addressing atherothrombosis.

Aspirin Hypersensitivity in Patients With Atherosclerotic Cardiovascular Disease

Low-dose aspirin remains the most commonly used antiplatelet agent among patients with atherosclerotic cardiovascular disease. Aspirin hypersensitivity occurs in 1% to 5% of patients and is among the most frequent causes for prohibiting the use of aspirin, posing a significant dilemma on how to manage these patients in clinical practice. Aspirin hypersensitivity is often misinterpreted and confused with aspirin intolerance, with treatment approaches being often unclear and lacking specific recommendations. Aspirin desensitization and low-dose aspirin challenge have emerged as pragmatic, effective, and safe approaches in patients with suspected or confirmed aspirin hypersensitivity who require aspirin therapy, but they are underused systematically in clinical practice. Furthermore, there is confusion over alternative antiplatelet agents to be used in these patients. The pathophysiological mechanisms and classification of aspirin hypersensitivity, as well as alternative strategies and practical algorithms to overcome the need for aspirin use in patients with atherosclerotic cardiovascular disease with suspected aspirin hypersensitivity, are discussed.

Antithrombotic Therapy in High Bleeding Risk, Part II: Noncardiac Percutaneous Interventions

Over the past decades, there have been great advancements in the antithrombotic management of patients undergoing percutaneous interventions, but most of the available evidence derives from studies conducted in the setting of cardiac interventions. Antithrombotic treatment regimens used in patients undergoing percutaneous cardiac interventions, in particular coronary, are frequently extrapolated to patients undergoing noncardiac interventions. However, the differences in risk profile of the population treated and the types of interventions performed may translate into differences is the safety and efficacy associated with antithrombotic therapy. Noncardiac percutaneous interventions are commonly performed in patients at high bleeding risk, which may indeed impact outcomes, hence underscoring the importance of risk stratification to guide clinical decision-making processes. In this review, we appraise the available evidence on antithrombotic therapy in high-bleeding-risk patients undergoing noncardiac percutaneous interventions.

Aspirin Hypersensitivity in Patients with Coronary Artery Disease: An Updated Review and Practical Recommendations

Acetylsalicylic acid (ASA) represents a cornerstone of antiplatelet therapy for the treatment of atherosclerotic coronary artery disease (CAD). ASA is in fact indicated in case of an acute coronary syndrome or after a percutaneous coronary intervention with stent implantation. Aspirin hypersensitivity is frequently reported by patients, and this challenging situation requires a careful evaluation of the true nature of the presumed sensitivity and of its mechanisms, as well as to differentiate it from a more frequent (and more easily manageable) aspirin intolerance. Two main strategies are available to allow ASA administration for patients with CAD and suspected ASA hypersensitivity: a low-dose ASA challenge, aimed at assessing the tolerability of ASA at the antiplatelet dose of 100 mg, and desensitization, a therapeutic procedure which aims to induce tolerance to ASA. For those patients who cannot undergo ASA challenge and desensitization due to previous serious adverse reactions, or for those in whom desensitization was unsuccessful, a number of further alternative strategies are available, even if these have not been validated and approved by guidelines. The aim of this state-of-the-art review is therefore to summarize the established evidence regarding pathophysiology, clinical presentation, diagnosis, and management of aspirin hypersensitivity and to provide a practical guide for cardiologists (and clinicians) who have to face the not uncommon situation of a patient with concomitant coronary artery disease and aspirin hypersensitivity.

Antithrombotic Therapy in High Bleeding Risk, Part I: Percutaneous Cardiac Interventions

Antithrombotic therapy after cardiac percutaneous interventions is key for the prevention of thrombotic events but is inevitably associated with increased bleeding, proportional to the number, duration, and potency of the antithrombotic agents used. Bleeding complications have important clinical implications, which in some cases may outweigh the expected benefit of reducing thrombotic events. Because the response to antithrombotic agents varies widely among patients, there has been a relentless effort toward the identification of patients at high bleeding risk (HBR), in whom modulation of antithrombotic therapy may be needed to optimize the balance between safety and efficacy. Among patients undergoing cardiac percutaneous interventions, recent advances in technology have allowed for strategies of de-escalation to reduce bleeding without compromising efficacy, and HBR patients are expected to benefit the most from such approaches. Guidelines do not extensively expand upon the topic of de-escalation strategies of antithrombotic therapy in HBR patients. In this review, we discuss the evidence and provide practical recommendations on optimal antithrombotic therapy in HBR patients undergoing various cardiac percutaneous interventions.

Switching Platelet P2Y12 Receptor Inhibiting Therapies

Antiplatelet therapy involving aspirin and a P2Y12 receptor inhibitor is fundamental in managing patients with atherothrombotic disease. Switching between P2Y12 inhibitors is frequently observed in clinical settings for various reasons, such as safety, efficacy, patient adherence, or cost concerns. Although it occurs often, the optimal method for switching remains a concern owing to potential drug interactions, which can result in either inadequate platelet inhibition and subsequent thrombotic events or low platelet reactivity and increased bleeding risks due to therapy overlap. This review offers practical guidance on switching P2Y12 inhibitors, drawing from pharmacodynamic and clinical data.

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.

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.

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).