Role of oral anticoagulant therapy for secondary prevention in patients with stable atherothrombotic disease manifestations

Rivaroxaban versus enoxaparin plus clopidogrel therapy for hypertrophic cardiomyopathy-associated thromboembolism in cats

Background and Aim

Cardiogenic embolism (CE) is a common complication of feline hypertrophic cardiomyopathy (HCM), leading to severe clinical symptoms. This study compared the effects of rivaroxaban and enoxaparin combined with clopidogrel on cats.

Materials and Methods

This was a single-center, prospective, randomized controlled trial. In this study, rivaroxaban or enoxaparin plus clopidogrel was prescribed to 23 cats for at least one of the following events: Abnormal movement of the anterior mitral leaflet during systole, enlargement of the left atrium, spontaneous echocardiographic contrast, or presence of arterial thromboembolism. Oral rivaroxaban (2.5 mg, q24 h) was prescribed to six cats. Subcutaneous injections of enoxaparin (1 mg/kg, q24 h) plus oral clopidogrel (3 mg/kg, PO q24 h) for 60 days were administered to 17 cats. Renal insufficiency and bleeding complications were observed. Plasma concentrations of D-dimer, prothrombin time (PT), partial thromboplastin time, and international normalized ratio (INR) were evaluated. We analyzed the relationship between echocardiography parameters and the effects of coagulation. Blood samples were collected from all cats at baseline and at 1 and 2 months post-treatment.

Results

Rivaroxaban alone and in combination with enoxaparin and clopidogrel significantly affected PT and INR. In cats treated with 2.5 mg/kg rivaroxaban for 60 days, no bleeding or recurrence of thrombus formation was observed. These data support the use of rivaroxaban for the treatment of HCM-associated thromboembolism in cats.

Conclusion

Treatment of HCM-associated thromboembolism with rivaroxaban alone demonstrated clinical effectiveness with no clinical complications in cats.

Clinical experience with dual pathway inhibition therapy: case series and mini review

Background

Dual pathway inhibition (DPI) with rivaroxaban 2.5 mg twice daily plus aspirin has demonstrated reductions in major adverse cardiovascular and limb events in eligible patients with chronic coronary artery disease (CAD), peripheral artery disease, or both. Patients with polyvascular disease, heart failure, renal impairment, or diabetes can benefit particularly from this therapy. We present our clinical experience to elucidate practical issues regarding the selection of patients eligible for DPI and the timing of initiation.

Case summary

The first patient was at high risk of recurrent cardiovascular events due to his history of multi-vessel CAD, myocardial infarction, heart failure, and diabetes. Following a period of post-myocardial infarction dual antiplatelet therapy, he was transitioned to DPI therapy. The second patient was at high risk of cardiovascular events due to his history of polyvascular disease, diffuse CAD, and diabetes. He was hospitalized for unstable angina, which was medically managed because no target lesion was identified. DPI was initiated a day after admission. The third patient was at high risk of cardiovascular events due to an extensive history of polyvascular disease, revascularization, and renal impairment. Although the patient was asymptomatic at routine follow-up, DPI was initiated to reduce the risk of further cardiovascular events.

Discussion

In eligible patients who are at high risk of cardiovascular events, DPI therapy with low-dose rivaroxaban should be considered. Treatment can be started at various times, including at the end of dual antiplatelet therapy, at routine follow-up, or after new events or diagnoses.

Novel Oral Anticoagulants Following Percutaneous Coronary Intervention

Antiplatelet and anticoagulant medications are the cornerstone of therapy for patients with acute coronary syndrome and have also been shown to reduce recurrent cardiovascular events in patients with stable coronary disease. Whereas antiplatelet medications have been the preferred therapy for long-term secondary prevention, the development of novel oral anticoagulants has renewed interest in the use of anticoagulation to prevent atherosclerotic events. In patients with atrial fibrillation or other indications for anticoagulation, recent clinical trials have shown the benefit of double therapy with full-dose novel oral anticoagulants and P2Y12 inhibitors compared with regimens with vitamin K antagonists. In patients without an indication for anticoagulation, the use of low doses of the factor Xa inhibitor, rivaroxaban, has shown benefit. Clinicians have many pharmacological options when treating patients following percutaneous coronary intervention. This review discusses the evidence for the use of novel oral anticoagulants, with an emphasis on patient selection, choice of therapy, and appropriate dosing of anticoagulant and antiplatelet agents, in secondary prevention strategies for atherosclerosis following coronary revascularization for patients with and without a traditional indication for anticoagulation.

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

Advances in antiplatelet therapies for patients with cardiovascular disease have improved patient outcomes over time, but the challenge of balancing the risks of ischaemia and bleeding remains substantial. Moreover, many patients with cardiovascular disease have a residual risk of ischaemic events despite receiving antiplatelet therapy. Therefore, novel strategies are needed to prevent clinical events through mechanisms beyond platelet inhibition and with an acceptable associated risk of bleeding. The advent of non-vitamin K antagonist oral anticoagulants, which attenuate fibrin formation by selective inhibition of factor Xa or thrombin, has renewed the interest in dual-pathway inhibition strategies that combine an antiplatelet agent with an anticoagulant drug. In this Review, we highlight the emerging pharmacological rationale and clinical development of dual-pathway inhibition strategies for the prevention of atherothrombotic events in patients with different manifestations of cardiovascular disease, such as coronary artery disease, cerebrovascular disease and peripheral artery disease.