Efficacy and safety of adding rivaroxaban to the anti-platelet regimen in patients with coronary artery disease: a systematic review and meta-analysis of randomized controlled trials

Preventing Cardiogenic Thromboembolism in Cats: Literature Gaps, Rational Recommendations, and Future Therapies

Cardiogenic arterial thromboembolism (CATE) is a devastating complication in cats with cardiomyopathies with significant morbidity and mortality. Despite recent advances in the diagnosis and treatment of CATE, its recurrence and mortality remain high. This highlights the urgent need for a greater understanding of CATE pathophysiology so that novel diagnostic tests and therapeutics can be developed. This comprehensive review aims to summarize existing literature on pathophysiology, clinical diagnosis, and current recommendations on the prevention and treatment of CATE. It also identifies and describes knowledge gaps and research priorities in the roles of immunothrombosis and procoagulant platelets in the pathogenesis of CATE.

Synergistic inhibitory effects of clopidogrel and rivaroxaban on platelet function and platelet-dependent thrombin generation in cats

BACKGROUND

Dual antithrombotic treatment (DAT) with clopidogrel and rivaroxaban sometimes is prescribed to cats with hypertrophic cardiomyopathy at risk of thromboembolism. To date, no studies have evaluated their combined effects on platelet function.

OBJECTIVES/HYPOTHESIS

Evaluate the safety of DAT in healthy cats and compare, ex vivo, platelet-dependent thrombin generation and agonist-induced platelet activation and aggregation in cats treated with clopidogrel, rivaroxaban, or DAT. We hypothesized that DAT would safely modulate agonist-induced platelet activation and aggregation more effectively than single agent treatment.

ANIMALS

Nine apparently healthy 1-year-old cats selected from a research colony.

METHODS

Unblinded, nonrandomized ex vivo cross-over study. All cats received 7 days of rivaroxaban (0.6 ± 0.1 mg/kg PO), clopidogrel (4.7 ± 0.8 mg/kg PO), or DAT with defined washout periods between treatments. Before and after each treatment, adenosine diphosphate (ADP)- and thrombin-induced platelet P-selectin expression was evaluated using flow cytometry to assess platelet activation. Platelet-dependent thrombin generation was measured by fluorescence assay. Platelet aggregation was assessed using whole blood impedance platelet aggregometry.

RESULTS

No cats exhibited adverse effects. Of the 3 treatments, only DAT significantly decreased the number of activated platelets (P = .002), modulated platelet activation in response to thrombin (P = .01), dampened thrombin generation potential (P = .01), and delayed maximum reaction velocity (P = .004) in thrombin generation. Like clopidogrel, DAT inhibited ADP-mediated platelet aggregation. However, rivaroxaban alone resulted in increased aggregation and activation in response to ADP.

CONCLUSION AND CLINICAL IMPORTANCE

Treatment combining clopidogrel and rivaroxaban (DAT) safely decreases platelet activation, platelet response to agonists, and thrombin generation in feline platelets more effectively than monotherapy with either clopidogrel or rivaroxaban.

Trends in Off-Label Indications of Non-Vitamin K Antagonist Oral Anticoagulants in Acute Coronary Syndrome

Acute coronary syndrome (ACS) is a leading cause of mortality worldwide. Despite optimal antiplatelet therapy recommendation after ischemic events, recurrent thrombotic complications rate remains high. The recurrent events maybe in part due to increased thrombin levels during ACS which may underscore the need for an additional anticoagulation therapy. Given the advantages of non-vitamin K antagonist oral anticoagulants (NOACs) over warfarin, they have the potential to prevent thrombus formation, in the presence or absence of atrial fibrillation, but at the cost of increased risk of bleeding. NOACs have also shown a promising efficacy in managing left ventricular thrombus and a potential benefit in avoiding stent thrombosis after percutaneous coronary revascularization. Taken as a whole, NOACs are increasingly used for off-licence indications, and continue to evolve as essential therapy in preventing and treating thrombotic events. Herein, this review discusses NOACs off-label indications in the setting of ischemic coronary disease.

Dual therapy with clopidogrel and rivaroxaban in cats with thromboembolic disease

OBJECTIVES

Feline arterial thromboembolism (ATE), an often devastating outcome, was recently shown to affect 11.3% of cats with hypertrophic cardiomyopathy over 10 years. Current American College of Veterinary Internal Medicine guidelines recommend the use of clopidogrel in cats at risk for ATE, with addition of a factor Xa inhibitor in very high risk or post-ATE cases. To date, no studies have examined the safety or efficacy of this combined antithrombotic therapy. This retrospective case series aimed to assess the frequency and type of adverse events that occurred in cats prescribed dual clopidogrel and rivaroxaban therapy. Secondary aims were to evaluate indications for dual therapy and clinical outcome.

METHODS

The study included 32 cats prescribed clopidogrel (18.75 mg PO q24h) and rivaroxaban (2.5 mg PO q24h) on an outpatient basis over a 5-year period.

RESULTS

Cats were prescribed dual therapy for at least one of the following: ATE event (n = 18), presence of an intracardiac thrombi (n = 17) or presence of spontaneous echocardiographic contrast (SEC) (n = 16). Five cats experienced adverse effects that could be attributed to medications, a median of 13 days from initiation (epistaxis, hematemesis, hematochezia or hematuria). No cat required hospitalization as a result of these events. Median survival time from onset of therapy was 257 days (interquartile range [IQR] = 38-497) for all cats, 502 days (IQR = 171-663) for ATE cats, 725 days (IQR = 133-856) for cats with an ATE to two or more limbs and 301 days (IQR = 221-431) for cats with only one limb affected. Recurrence rate of ATE while on dual therapy was 16.7%; no cat newly developed an ATE while on dual therapy.

CONCLUSIONS AND RELEVANCE

Dual antithrombotic therapy with clopidogrel and rivaroxaban resulted in a low reported incidence of adverse events. Cats placed on dual therapy for an ATE event experienced a low rate of recurrence and effective thromboprophylaxis was achieved in cats with intracardiac thrombi or SEC.

Low Dose Rivaroxaban for Atherosclerotic Cardiovascular Diseases: A Systematic Review and Meta-analysis

Background: This study aims to explore the role of low-dose rivaroxaban (≤10 mg daily) for the treatment of atherosclerotic cardiovascular disease (ASCVD). Methods: PubMed, Embase and the Cochrane Library were searched for randomized controlled trials (RCTs) of low-dose rivaroxaban in patients with ASCVD including coronary artery disease (CAD) and peripheral artery disease (PAD). Literature screening, data extraction, and risk of bias assessment were carried out independently by two researchers. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using random-effect models to determine risks of outcomes in ASCVD patients treated with rivaroxaban and comparators, and meta-analysis was conducted via Review Manager 5.3.5 software. Results: 3,768 records were obtained through literature search, and 9 articles representing 6 RCTs ultimately qualified for this study. The meta-analysis indicated that for patients with CAD, the addition of rivaroxaban (5 mg daily) to aspirin could significantly reduce the risk of major adverse cardiovascular events (MACEs) compared with aspirin alone (HR 0.81, 95% CI, 0.72 to 0.91, p = 0.0004, I² = 60%, 4 studies). For PAD patients receiving rivaroxaban (5 mg daily) plus aspirin, there was no significant reduction in the risk of MACEs (HR 0.84, 95% CI, 0.63 to 1.13, p = 0.25, I² = 74%, 2 studies); however, there was significant reduction in major adverse limb events (MALEs) (HR 0.54, 95% CI, 0.35 to 0.83, p = 0.005, one studies) and in the composite of MACEs or MALEs (HR 0.78, 95% CI, 0.64 to 0.95, p = 0.02, I² = 66%, 2 studies) when compared with patients receiving aspirin alone. Meanwhile, rivaroxaban combined with aspirin significantly increased the risk of International Society on Thrombosis and Haemostasis (ISTH) major bleeding compared with aspirin alone in patients with CAD (HR 1.74, 95% CI, 1.43 to 2.13, p < 0.00001, I² = 0%, 2 studies) and PAD (HR 1.47, 95% CI, 1.19 to 1.83, p = 0.0004, I² = 0%, 2 studies). Conclusions: Compared with standard antiplatelet therapy, the addition of a 5 mg daily dose of rivaroxaban to standard antiplatelet therapy may improve cardiovascular or limb outcomes of patients with ASCVD, with an increase in major bleeding. Patients who would benefit from the addition of low-dose rivaroxaban to antiplatelet agents and appropriate dual-pathway antithrombotic strategies should be identified in clinical practice to individualize antithrombotic therapy.

Benefit and risk of adding rivaroxaban in patients with coronary artery disease: A systematic review and meta-analysis

Background

Although the European Medicines Agency and the US Food and Drug Administration have, respectively, approved rivaroxaban for the prevention of recurrent major adverse cardiovascular events in patients with myocardial infarction and stable coronary artery disease, its efficacy and safety is unclear. This meta‐analysis aimed to evaluate the benefit and risk of adding rivaroxaban in coronary artery disease (CAD) patients, focusing on treatment effects stratified by different baseline clinical presentations.

Hypothesis

There are differences in treatment effects of adding rivaroxaban among CAD patients with different baseline clinical presentations.

Methods

Medline, EMBASE, and Cochrane Databases were systematically searched from inception to 21 July 2020 for randomized controlled trials (RCTs) comparing rivaroxaban in CAD patients. The primary efficacy endpoint and safety endpoint were assessed by using Mantel–Haenszel pooled risk ratios (RRs) and 95% confidence intervals (CIs).

Results

Five RCTs that included 43 650 patients were identified. Patients receiving rivaroxaban had a significantly lower risk of the primary efficacy endpoint (RR, 0.86; 95% CI, 0.76–0.97, p = .01) accompanied by increased risk of the primary safety endpoint (RR, 1.83; 95% CI, 1.10–3.05, p = .02). Subgroup analyses showed that in males the risk–benefit appears to be more favorable while in patients ≥65 years, in females, in patients with diabetes, those with mild to moderate impaired renal function, and region of Asia/other seems unfavorable.

Conclusion

Rivaroxaban may provide an additional choice for secondary prevention in CAD patients. However, careful estimation of the risk of ischemic and bleeding events using patient characteristics are critical to achieving net benefit.

Safety and Efficacy of Oral Anticoagulants Therapies in Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention: A Network Meta-Analysis

Background:

Different antithrombotic treatments, from vitamin K antagonists to direct oral anticoagulants (DOACs), are available to reduce ischemic risks in patients with atrial fibrillation (AF) after percutaneous coronary intervention (PCI). Objective: To synthetize evidence about the benefit–risk ratio of antithrombotic treatments and their combinations in patients with AF and PCI.

Methods:

A network meta-analysis and a stochastic multicriteria acceptability analysis (SMAA) were performed including randomized controlled trials (RCT) that evaluate antithrombotic treatments in adults with AF and PCI. Searches were conducted in PubMed and Scopus (updated November-2019). Outcomes compared included bleeding, stroke, and death (Prospero registration: CRD42019146813).

Results:

Five RCTs were included (11 532 patients). Vitamin K antagonists + dual antiplatelet therapy was associated with major bleeding (odds ratio: 0.52 [95% CI: 0.32-0.86]) compared to DOAC + P2Y12. No statistical differences were found among DOAC regimens for the main outcomes, including bleeding, stroke, and death. Surface under the cumulative ranking curve analysis (SUCRA) and SMAA demonstrated edoxaban 60 mg + P2Y12 inhibitor as the worst option (28%). Apixaban 5 mg + P2Y12 inhibitor was the safest alternative (63%) in all scenarios.

Conclusions:

Insufficient evidence on the clinical superiority among anticoagulant regimens exists, although apixaban slightly stands out. Edoxaban was associated with more adverse events. To strength this evidence, well-designed, low risk of bias clinical trials are needed. Cost-minimization analyses are required to provide further information for clinical decision-making.