Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Prospective, Randomized, Double-Blind, Parallel-Group, Multicenter, Non-inferiority Study Comparing the Efficacy and Safety of Rivaroxaban (BAY 59-7939) With Warfarin for the Prevention of Stroke and Non-Central Nervous System Systemic Embolism in Subjects With Non-Valvular Atrial Fibrillation
Brief Summary: The purpose of this study is to compare the efficacy and safety of rivaroxaban with warfarin for the prevention of blood clots in the brain (referred to as stroke) and blood clots in other parts of the body referred to as non-central nervous system systemic embolism) in patients with non-valvular atrial fibrillation (a heart rhythm disorder).


Options:
A: Inclusion criteria:

1. Patients aged 18-75
2. Patients who have received a bileaflet mechanical heart valve

Exclusion criteria:

1. Prior valve surgery
2. Uncontrolled hypertension
3. severe renal impairment
4. active liver disease
5. increased risk of bleeding
B: Inclusion criteria Patients with non-valvular atrial fibrillation (AF), at moderate to high risk of stroke, or systemic embolism with at least one additional risk factor (i.e. previous ischemic stroke, TIA, or systemic embolism, left ventricular dysfunction, age \>=75 years, age \>=65 with either diabetes mellitus, history of coronary artery disease or hypertension)

Exclusion criteria

1. Prosthetic heart valves requiring anticoagulation per se, or hemodynamically relevant valve disease that is expected to require surgical intervention during the course of the study
2. Severe, disabling stroke within the previous 6 months, or any stroke within the previous 14 days
3. Conditions associated with an increased risk of bleeding
4. Contraindication to warfarin treatment
5. Reversible causes of atrial fibrillation (e.g., cardiac surgery, pulmonary embolism, untreated hyperthyroidism).
6. Plan to perform a pulmonary vein ablation or surgery for cure of the AF
7. Severe renal impairment (estimated creatinine clearance \<=30 mL/min)
8. Active infective endocarditis
9. Active liver disease
10. Women who are pregnant, lactating, or of childbearing potential who refuse to use a medically acceptable form of contraception throughout the study
11. Anaemia (haemoglobin \<100g/L) or thrombocytopenia (platelet count \<100 x 109/L)
12. Patients who have developed transaminase elevations upon exposure to ximelagatran
13. Patients who have received an investigational drug in the past 30 days or are participating in another drug study
14. Patients considered unreliable by the investigator concerning the requirements for follow-up during the study and/or compliance with study drug administration, has a life expectancy less than the expected duration of the trial due to concomitant disease, or has any condition which in the opinion of the investigator, would not allow safe participation in the study (e.g., drug addiction, alcohol abuse)
15. Any known hypersensitivity to galactose if the warfarin used contains galactose.
C: Inclusion Criteria:

* Patients must have documented atrial fibrillation on 2 separate occasions within 6 months before screening
* History of a prior stroke, transient ischemic attack or non-neurologic systemic embolism believed to be cardiac in origin, or at least two of the following risk factors: heart failure, hypertension, age 75 years or greater, diabetes mellitus

Exclusion Criteria:

* Significant mitral stenosis
* Transient atrial fibrillation caused by a reversible disorder
* Active internal bleeding
* Severe disabling stroke
* History of intracranial bleeding
* Hemorrhagic disorders
D: Inclusion criteria:

* Patients scheduled to undergo primary, unilateral, elective total hip arthroplasty.
* Male or female 18 years of age or older.
* Patients giving written informed consent for study participation.

Exclusion criteria:

* Patients weighing less than 40 kg.
* History of bleeding diathesis.
* Patients who in the investigators judgement are perceived as having an excessive risk of bleeding, for example, constitutional or acquired coagulation disorders or because of anticipated need of quinidine, verapamil or other restricted medication during the treatment period (see Section 4.2.2).
* Major surgery or trauma (e.g., hip fracture) within 3 months of enrolment.
* Recent unstable cardiovascular disease (in the investigators opinion) such as uncontrolled hypertension, that is ongoing at the time of enrolment or history of myocardial infarction within 3 months of enrolment.
* Any history of haemorrhagic stroke or any of the following intracranial pathologies: bleeding, neoplasm, Atriovenous (AV) malformation or aneurysm.
* Ongoing treatment for Venous Thromboembolism (VTE).
* Clinically relevant bleeding (gastrointestinal, pulmonary, intraocular or urogenital bleeding) within 6 months of enrolment.
* Gastric or duodenal ulcer within one year of enrolment.
* Liver disease expected to have any potential impact on survival (ie, hepatitis B or C, cirrhosis). This does not include Gilberts syndrome or hepatitis A with complete recovery.
* Active liver disease or liver disease decreasing survival (e.g, acute hepatitis, chronic active hepatitis, cirrhosis) or Alanine Aminotransferase (ALT) \>3 x ULN.
* Known severe renal insufficiency (CrCl \<30 ml/min). Note: CrCl should be calculated only if serum creatinine is elevated or renal insufficiency is suspected. See Appendix 10.1 for calculation.
* Elevated creatinine that, in the investigators opinion, contraindicates venography.
* Treatment with anticoagulants, clopidogrel, ticlopidine, abciximab, aspirin \>162.5 mg/day or NSAID with t 1/2 \>12 hours within 7 days prior to hip replacement surgery OR anticipated need while the patient is receiving study medication and prior to 24 hours after the last administration of any blinded study medication (COX-2 selective inhibitors are allowed).
* Anticipated required use of intermittent pneumatic compression and electric stimulation of lower limb.
* Pre-menopausal women (last menstruation within 1 year prior to signing informed consent) who:

  * Are pregnant.
  * Are nursing.
  * Are of child-bearing potential and are NOT practicing acceptable methods of birth control, or do NOT plan to continue practicing an acceptable method throughout the study. Acceptable methods of birth control include intrauterine device; oral, implantable or injectable contraceptives and surgical sterility.
* Known allergy to radio opaque contrast media.
* History of thrombocytopenia, including heparin-induced thrombocytopenia, or a platelet count \<100,000 cells/microliter at randomisation.
* Allergy to heparins or dabigatran etexilate.
* Active malignant disease or current cytostatic treatment. Patients should be disease free for at least 5 years.
* Participation in a clinical trial within 30 days of randomisation.
* Leg amputee.
* Known alcohol or drug abuse which would interfere with completion of the study.
* Contraindications to enoxaparin.
* Previous participation in this study.

Answer: C