This trial will include patients who have a heart condition called atrial fibrillation. Atrial fibrillation is an abnormal rhythm (irregular beat) in the heart. Patients with atrial fibrillation have an increased chance for a blood clot to form in the heart and move to other blood vessels in the body and cause obstruction. This obstruction may damage tissue. For example, a blood clot plugging a vessel in the brain could cause a stroke. Therefore, patients with atrial fibrillation may be given anticoagulant (blood-thinning) tablets such as warfarin or acenocoumarol.

This trial will include patients who have a heart condition called atrial fibrillation. Atrial fibrillation is an abnormal rhythm (irregular beat) in the heart. Patients with atrial fibrillation have an increased chance for a blood clot to form in the heart and move to other blood vessels in the body and cause obstruction. This obstruction may damage tissue. For example, a blood clot plugging a vessel in the brain could cause a stroke. Therefore, patients with atrial fibrillation may be given anticoagulant (blood-thinning) tablets such as warfarin or acenocoumarol.The purpose of this study is to compare the safety and effectiveness of a new injectable anticoagulant drug that is administered once weekly, SanOrg34006 (International Nonproprietary Name – idraparinux sodium), with warfarin or acenocoumarol tablets.Assignment to either SanOrg34006 (idraparinux sodium) Injection or vitamin K antagonist (warfarin or acenocoumarol) tablets will be purely by chance and will be known by both patients and their doctors.Condition:- Atrial FibrillationStudy Type: InterventionalStudy Design: Treatment, Randomized, Open Label, Safety/Efficacy StudyOfficial Title: The AMADEUS trial, A multicenter, randomized, open-label, assessor blind, non-inferiority study comparing the efficacy and safety of once-weekly subcutaneous idraparinux (SanOrg34006) with adjusted-dose oral vitamin-K antagonists in the prevention of thromboembolic events in patients with atrial fibrillation.EligibilityAges Eligible for Study: 18 Years and above, Genders Eligible for Study: BothCriteriaInclusion Criteria: * ECG-documented atrial fibrillation (AF) and an indication for long-term vitamin K antagonist (VKA) therapy based on the presence of at least one of the following risk factors: (a.) previous ischemic stroke, transient ischemic attack (TIA) or systemic embolism (b.) hypertension requiring drug treatment (c.) left ventricular dysfunction (left ventricular ejection fraction <45% or symptomatic congestive heart failure) (d.) age >75 years (e.) age between 65-75 years plus diabetes mellitus, or (f.) age between 65-75 years plus symptomatic coronary artery disease (previous myocardial infarction (MI) or angina pectoris) * Written informed consentExclusion Criteria: * Legal lower age limitations (country specific) * Indication for VKA other than AF, including prosthetic heart valves, venous thromboembolism, and planned cardioversion * Transient AF caused by a reversible disorder * Active bleeding or high risk of bleeding * Recent (<15 days) or anticipated invasive procedures with potential for uncontrolled bleeding, including major surgery * Participation in another pharmacotherapeutic study within the prior 30 days * Creatinine clearance <10 mL/min, severe hepatic disease, or bacterial endocarditis * Uncontrolled hypertension: systolic blood pressure > 180 mm Hg and/or diastolic blood pressure > 110 mm Hg * Pregnancy or childbearing potential without proper contraceptive measures * Any other contraindication listed in the labeling of warfarin or acenocoumarol[1] Bondi Junction, Cairns, Camperdown, Miranda, Perth, Australia; Recruiting[2] South Australia, Tasmania, Victoria, Australia; Recruiting[3] Concord Repartiation General Hospital, Concord, Australia; Recruiting