Effects of rivaroxaban on myocardial mitophagy in the rat heart

Background

This study aims to demonstrate the efficacy of rivaroxaban's pharmacokinetic effects on myocardial mitophagy in rats by inducing apoptosis.

Methods

In this double-blind experiment, Wistar albino male rats were randomly divided into three groups for an experimental ischemia model: the sham group (Group 1; n=7), the control group (Group 2; n=7), and the drug group (Group 3; n=7). Rivaroxaban was perorally administered with gavage at 2 mg/ kg/day for 28 days in Group 3. The heart was surgically exposed, and ischemia was achieved by compressing the vessel around the proximal part of the left anterior descending coronary artery for 10 min. The heart tissue was then transected, removed, and morphologically and immunohistochemically examined under a light microscope.

Results

Heart sections were immunohistochemically marked with caspase 3, caspase 9, APAF1, and Bcl-2 antibodies. Group 1 was compared to the rivaroxaban-treated group, and the pathways inducing apoptosis was increased (caspase 3, caspase 9, APAF1; p<0.015, p<0.004, and p<0.01, respectively) and Bcl-2, the molecule that inhibits apoptosis, was decreased (p<0.01) in Group 3.

Conclusion

The present study provides an evidence that the mitophagy response is less in rivaroxaban-treated rats, showing the protective effect of rivaroxaban against acute ischemia. Rivaroxaban-treated rats may have reduced cell death in cardiomyocytes during myocardial infarction and thus have reduced damage to the heart tissue caused by myocardial infarction.

Chronic Coronary Syndrome: Overcoming Clinical Practice Guidelines. The role of the COMPASS Strategy

Current European guidelines on chronic coronary syndromes recommend the use of low-dose aspirin (or clopidogrel if intolerance or contraindication occurs) throughout life. However, as the risk of recurrent vascular events is high, particularly in some patients (i.e. diffuse multivessel coronary artery disease, diabetes, recurrent myocardial infarction, peripheral artery disease, or chronic kidney disease,…), these guidelines also consider that in those patients at moderate or high risk of ischemic events, but without a high bleeding risk, dual antithrombotic therapy should be considered. According to these guidelines, treatment options for dual antithrombotic therapy in combination with aspirin may include clopidogrel 75 mg/daily, prasugrel 10 mg/daily, ticagrelor 60 mg bid or rivaroxaban 2.5 mg bid. Remarkably, despite the results of the clinical trials that sustain these recommendations clearly diverge, guidelines do not differentiate between them. However, although all these drugs have demonstrated a significant reduction in major cardiovascular events in patients with stable atherosclerotic disease, only the addition of rivaroxaban has been associated with a reduction in cardiovascular and overall mortality in the secondary analysis. This may be related to the fact that the activation of platelets and factor X plays a key role in the development of atherothrombosis, and, consequently, both targets should be considered for the appropriate management of these patients.

In vitro Bioaccessibility, Bioavailability, and Plasma Protein Interaction of New Oral Anticoagulants in the Presence of Macronutrients

BACKGROUND

Over the last years, a new generation of oral anticoagulants (NOACs), including apixaban, rivaroxaban and dabigatran, has been developed for the control of thrombosis and related disorders. The presence of food within the gastrointestinal (GI) tract can potentially affect the oral bioavailability of drugs.

OBJECTIVE

In the present paper, we evaluated the stability of these drugs in in vitro GI digestion, with and without the main macronutrients such as proteins, lipids, carbohydrates, and fibers, and their ability to enter into the systemic circulation. In addition, we examined the percentage of the drug binding to plasma proteins, such as human serum albumin, high density- and low density lipoproteins.

METHODS

The NOACs bioaccessibility was evaluated by an in vitro procedure simulating the gastrointestinal enzymatic system, while their bioavailability was studied by cell culture of Caco-2 cells and in vitro study of transepithelial transport. The in vitro transepithelial permeated NOACs were added to plasma protein solutions simulating the average fasting plasma protein concentrations. The NOACs detection was carried out by HPLC-DAD/ESI-MS analysis.

RESULTS

GI digestion significantly reduces intestinal bioaccessibility and bioavailability of NOACs, especially as regards apixaban and dabigatran. Interestingly, the co-digestion of fibers led to a strong decrease of NOAC intestinal bioaccessibility and bioavailability, while the effects of the other macronutrients, as well as a low fiber standard meal, had no significant influence in this sense.

CONCLUSION

Dabigatran, rivaroxaban and apixaban may be administered independently of a standard meal, provided that it does not include a high amount of dietary fibers.