Please select the eligibility criteria that correspond to the clinical trial below.
Title: REcurrent VEnous Thromboembolism Risk Stratification Evaluation A Study to Develop a Clinical Prediction Rule to Predict Low Recurrence Risk in Patients With Idiopathic Venous Thromboembolism.
Brief Summary: The purpose of this study is to develop a way to predict which patients diagnosed with idiopathic blood clots can safely stop warfarin therapy after six months. We will use patient characteristics, blood test results and imaging test results to identify those patients who have the lowest risk of developing a new blood clot after warfarin is stopped.


Options:
A: Inclusion Criteria:

1. Objectively proven (as previously described (8)) proximal idiopathic deep vein thrombosis or pulmonary embolism. Idiopathic will be defined as VTE occurring in the absence of fracture, plaster cast, immobilization greater than 3 days or a general anesthetic in the last three months prior to VTE diagnosis; a known deficiency of antithrombin, protein C or protein S; and malignancy in the last five years
2. Patients treated initially with a minimum of five days of heparin or low molecular weight heparin and oral anticoagulants with a target intensity of 2.0 - 3.0 with no recurrence in the subsequent six months.
3. Patients currently on oral anticoagulants

Exclusion Criteria:

1. Recurrent idiopathic VTE (i.e. \&#8805; 2 previous idiopathic VTE). Previous secondary VTE is not an exclusion criterion;
2. Age \&lt;18;
3. Known deficiency of proteins S, protein C or antithrombin;
4. Known, persistently positive anticardiolipin antibodies (titers \&gt; 30U/ml);
5. Known, persistently positive lupus anticoagulant;
6. Combined thrombophilic defects (e.g. homozygous for FVL or PGM, or compound heterozygous for FVL and PGM);
7. Refusal of informed consent.
B: Inclusion Criteria:

* Men and women ≥ 18 years of age;
* Clinical diagnosis of Deep Vein Thrombosis (DVT) or Pulmonary Embolism (PE);
* Anticoagulant treatment completed
* No recurrence of Venous Thromboembolism (VTE)

Exclusion Criteria:

* Subjects with indications for long-term treatment with a vitamin K antagonist
* Active bleeding or high risk for serious bleeding
* Short life expectancy
* Uncontrolled high blood pressure
* Impaired kidney or liver function
C: Inclusion Criteria:

* first episode of symptomatic, objectively confirmed idiopathic proximal deep vein thrombosis and/or pulmonary embolism;
* initial treatment with unfractionated heparin or low-molecular-weight heparin (or effective alternative) followed by a vitamin K antagonist (target INR 2.0-3.0). All patients will receive 6 or 12 months of oral anticoagulant treatment. Patients initially treated with thrombolytic therapy who received warfarin therapy are eligible for inclusion.

Exclusion Criteria:

* permanent risk factors for venous thromboembolism: patients known to have antiphospholipid antibodies or lupus anticoagulant (based on local laboratory criteria) or to have homozygous factor V Leiden or homozygous prothrombin G21210A or heterozygous factor V Leiden plus heterozygous prothrombin G21210A or antithrombin III deficiency; patients with active malignancy
* temporary risk factors for venous thromboembolism
* any recurrence of venous thromboembolism or bleeding episode during the established 6-month period of oral anticoagulant treatment
* allergy or intolerance of aspirin
* clear indication for aspirin or other anti-platelet therapy (e.g. clopidogrel, ticlopidine)
* clear indication for long-term anticoagulant therapy (e.g. recurrent idiopathic venous thromboembolism, prosthetic heart valve)
* treatment with non-selective COX-1/2 non-steroidal anti-inflammatory drugs
* life expectancy less than 6 months
* active bleeding or at high risk of bleeding (gastrointestinal bleeding within the past 12 months; endoscopic diagnosis of peptic ulcer disease or ulcerative esophagitis within the past 6 months unless there is documented endoscopic evidence of healing; intracranial bleeding within the past year; known bleeding diathesis)
* anticipated non-adherence to study medications
* inability to attend follow up because of geographic inaccessibility
* failure to provide informed consent
D: Inclusion criteria:

Inclusion_Criteria

* Acute symptomatic deep vein thrombosis (DVT)
* Pulmonary embolism (PE) 3-12 months prior to screening, which has been documented by objective testing

Exclusion criteria:

Exclusion_Criteria

* Symptomatic DVT or PE at screening Interruption of anticoagulant therapy for 2 or more weeks during the 3-12 months of treatment for the prior VTE.
* Patients who in the investigators judgement are perceived as having an excessive risk of bleeding Elevated Aspartate aminotransferase (AST) or Alanine tranminase (ALT) \> 2x ULN
* Severe renal impairment (estimated creatinine clearance \<= 30 ml/min)

Answer: A