Investigating the Anti-Inflammatory Properties of Apixaban for the Prevention of Thromboembolic Complications in Patients with Non-Valvular Atrial Fibrillation: A Proof of Concept Study (Preprint)

Abstract

BACKGROUND Atherosclerotic vascular disease is the primary cause of myocardial infarction, stroke, unstable angina (ischemic heart pain), and sudden cardiac death. Over the last decade, appreciation of the role of inflammation in atherosclerosis has burgeoned. Apixaban is a highly selective orally bioavailable reversible direct inhibitor of both free and clot-bound coagulation Factor Xa (FXa) recommended for the prevention of stroke and systemic embolism in people with non-valvular atrial fibrillation (NVAF). Existing studies indicate that FXa-induced intracellular signaling is correlated with inflammation, which allude to the fact that direct inhibition of FXa may impede atherosclerosis. OBJECTIVE In line, the present proposal aims to investigate if administration of apixaban in patients with NVAF ameliorates atherosclerosis through impediment of FXa-mediated PAR-2. METHODS Recruitment of NVAF patients: Thirty-five patients with NVAF will be recruited according to a defined recruitment criterion. Blood samples will be collected from these 35 patients with NVAF prior to the initiation of apixaban therapy, and three-months post apixaban therapy. Blood sample analysis: Peripheral blood mononuclear cells (PBMCs) will be isolated from the samples using ficoll-gradient separation, according to a defined protocol. CD14+ monocyte will be isolated from PBMCs and will be differentiated into macrophages. Western blot will be performed to quantify the inflammatory modulator, mitogen activated protein kinase (MAPK). RNA extraction and relative quantitative PCR assay: The total RNA of the macrophages will be extracted. cDNA will be obtained from RNA by reverse transcription. Relative quantitative PCR will be performed to measure the mRNA levels of pro-inflammatory cytokines. RESULTS The study is yet to commence. Although the funding for this study has been approved by the funding organisation (Pfizer Global) following extensive review. Ethical approval for this study was obtained from the Research Ethics Committees at all the participating centers. All participants will sign informed consent prior to study enrolment. The attending clinician will share and discuss the study results with their patients. CONCLUSIONS As inflammation has been implicated in atherosclerosis and associated ailments, the current proposal explores an aspect of apixaban function that can be translated for ameliorating mortality and morbidity associated with atherosclerotic cardiovascular disease through the design of novel treatment/management strategies. STRENGTHS AND LIMITATIONS > First study to explore the anti-atherosclerotic activity of apixaban in a clinical setting, which can be translated to other NOACs. > Study outcomes will identify a novel paradigm of apixaban function employing systematic in vitro and in vivo experimentation protocols, which will assist clinicians and other healthcare decision makers to make a more informed choice regarding patient treatment. > This is a proof-of-concept study with only 35 patients from a relatively genetically homogenous population, therefore, obtained results will require validation and substantiation in a larger cohort of genetically heterogenous patients. CLINICALTRIAL As this study is a proof of concept study, it is therefore not a clinical trial and for this reason trial registration is not required.