Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Phase 3, Active (Warfarin) Controlled, Randomized, Double-Blind, Parallel Arm Study to Evaluate Efficacy and Safety of Apixaban in Preventing Stroke and Systemic Embolism in Subjects With Nonvalvular Atrial Fibrillation
Brief Summary: The trial seeks to determine if apixaban, an investigational anticoagulant (blood-thinner) is as effective as standard therapy (warfarin) in preventing stroke and systemic embolism in subjects with atrial fibrillation and risk factors for stroke.


Options:
A: 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
B: 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.
C: Inclusion Criteria:

* Males and females ≥ 18 yrs with atrial fibrillation (AF) and one or more of the following risk factors for stroke:
* Age ≥ 75, previous stroke
* transient ischemic attack (TIA) or Systemic Embolism (SE)
* Symptomatic congestive heart failure or left ventricular dysfunction with left ventricular ejection fraction (LVEF) ≤ 40%
* Diabetes mellitus or hypertension requiring pharmacological treatment
D: Inclusion criteria

1. Acute deep vein thrombosis (DVT) of the leg involving proximal veins, and/or pulmonary embolism (PE) iin patients for whom at least 6 months of anticoagulant therapy is considered appropriate
2. Male or female, being 18 years of age or older
3. Written informed consent for study participation

Exclusion criteria

1. Overt symptoms of VTE for longer than 2 weeks prior to enrolment
2. PE satisfying at least one of the following criteria: Haemodynamic instability, embolectomy is indicated or performed, thrombolytic therapy is indicated or performed, or suspected source of PE is other than the legs
3. Actual or anticipated use of vena cava filter
4. Contraindications to anticoagulant therapy
5. Patients who in the investigators opinion should not be treated with warfarin
6. Allergy to heparins or other alternate approved therapy used for initial treatment, warfarin or dabigatran, or to one of the excipients included in these medications
7. Patients who in the investigators judgement are perceived as having an excessive risk of bleeding
8. Known anaemia
9. Need of anticoagulant treatment for disorders other than VTE
10. Recent unstable cardiovascular disease
11. Elevated AST or ALT \> 2x ULN
12. Liver disease expected to have any potential impact on survival
13. Patients who have developed transaminase elevations upon exposure to ximelagatran
14. Severe renal impairment
15. Women who are pregnant, nursing, or of childbearing potential who refuse to use a medically acceptable form of contraception
16. Participation in another clinical trial with an investigational drug during the last 30 days or previous participation in this study
17. Patients considered unsuitable for inclusion by the investigator

Answer: C