Please select the eligibility criteria that correspond to the clinical trial below.
Title: Eighteen Months of Oral Anticoagulant Therapy Versus Placebo After 6 Six Months of Anticoagulation for a First Episode of Idiopathic Pulmonary Embolism: a Multicentre Double-blind Randomized Controlled Trial. "PADIS-PE" Study.
Brief Summary: Rational: After 3 or 6 months of oral anticoagulation for an episode of acute venous thromboembolism (VTE), the risk of recurrent VTE is high (10 to 15% per year) in comparison with a low risk of recurrence if VTE was provoked by a major transient risk factor such as recent surgery (3% per year) independently of the initial presentation (deep vein thrombosis or pulmonary embolism). After a first episode of idiopathic VTE, 3 months of anticoagulation is associated with a very high risk of recurrence (27% per year); however, the benefit-risk of extended duration of anticoagulation (1 to 2 years) remains uncertain, mainly in relation with an increased risk of anticoagulant related bleeding. Therefore, the last ACCP conference group recommended 6 months of oral anticoagulant therapy after a first episode of idiopathic VTE. However, this recommendation is likely to be inadequate for at least two main reasons: (1) no studies compared 2 years to 6 months of anticoagulation after idiopathic VTE; and (2), if the frequency of recurrent VTE is similar after deep vein thrombosis and pulmonary embolism, however, the case fatality rate of recurrent VTE is higher after pulmonary embolism (12%) than after deep vein thrombosis (5%).

Objective : the main objective is to demonstrate that, after 6 months of oral anticoagulation for a first episode of idiopathic pulmonary embolism, 18 months of warfarin therapy is associated with a lower cumulative risk of recurrent VTE and major bleeding in comparison with that on 18 months of placebo. The secondary objectives are: (1) to determine the risk of recurrent VTE after 6 months of warfarin therapy and the presence or the absence of residual lung scan perfusion defect and the persistence or not of elevated D-dimer test; and (2), to determine the impact of extended duration of anticoagulation on the risk of VTE after stopping anticoagulant therapy on a follow-up of 2 years.

Method : French multicenter double blind randomized controlled trial. Inclusion and exclusion criteria and pulmonary diagnostic criteria have been defined. After completing 6 months of oral anticoagulation, a lung scan and D-dimer testing are performed; the investigators and the patients will be unaware of the results of these tests. Then, patients are randomized to receive 18 months of warfarin therapy or 18 months of placebo (the dose of placebo will be adapted according to false computer generated INR). The investigators, the radiologists and the patients are blinded of the treatment allocation. The project will be submitted to national ethical committee and written consent will be obtained from all included patients.

Required number of patients: the expected cumulative frequency of recurrent VTE and major bleeding over 18 months is 4.5% while on warfarin therapy and 16% while on placebo. For a α risk of 5% (to falsely conclude to a true difference) and a β risk of 10% (to falsely conclude to an absence of difference), 178 patients per group should be included. As 5% of patients are expected to be loss, a total of 374 patients is required.

Feasibility: about 50 patients per year are hospitalized in our department of medicine in Brest for an acute episode of idiopathic pulmonary embolism. Four additional centers will participate to the study and have a similar recruitment: HEGP (Pr Meyer, Dr Sanchez), CHU Antoine Béclère (Dr Parent, Pr Simmoneau), CHU Saint Etienne (Pr Mismetti, Pr Décousus), CHU Grenoble (Pr Pison, Pr Carpentier). The study will be coordinated by the Clinical Center of Investigation of Brest Hospital; "true" and "false" INR will be generated by the clinic of anticoagulant of "Ile de France" (Dr Cambus).

Clinical implications: the first consequence of the study is to demonstrate that 6 months of warfarin therapy is inadequate and should be continued for at least 18 additional months after a first episode of idiopathic pulmonary embolism. This study has also the potential to confirm or not the contribution of lung scan and D-dimer testing to appreciate the risk of recurrent VTE after stopping anticoagulant therapy. Lastly, the medical economical impact of such therapeutic management will be evaluated.


Options:
A: Inclusion criteria:

1. Patients with confirmed symptomatic PE or proximal DVT of the leg(s) who have been treated for 6 to 18 months with therapeutic dosages (intended INR between 2-3) of an oral VKA (e.g. warfarin, acenocoumarol, phenprocoumon, or fluindione) or RE-COVER study medication up to the moment of screening for the current study.
2. Written informed consent

Exclusion criteria:

1. Younger then 18 years of age
2. Indication for VKA other than DVT and/or PE
3. Patients in whom anticoagulant treatment for their index PE or DVT should be continued
4. Active liver disease or liver disease decreasing survival (e.g. acute hepatitis, chronic active hepatitis, cirrhosis) or ALAT \> 3 x ULN
5. Creatinine clearance \< 30 ml/min
6. Acute bacterial endocarditis
7. Active bleeding or high risk for bleeding.
8. Uncontrolled hypertension (investigators judgement)
9. Intake of another experimental drug within the 30 days prior to randomization into the study
10. Life expectancy \<6 months
11. Childbearing potential without proper contraceptive measures\*, pregnancy or breast feeding
B: 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
C: Inclusion Criteria:

* Patients with confirmed symptomatic PE and/or DVT who have been treated for 6 to 12 months and did not interrupt anticoagulation for longer than 1 week

Exclusion Criteria:

* Legal lower age limitations (country specific) Indication for therapeutic-dosed anticoagulants Indication for antiplatelet therapy or a conventional non-steroid anti-inflammatory drug (NSAID) Hepatic disease which is associated with coagulopathy leading to a clinically relevant bleeding risk Calculated creatinine clearance \< 30 mL/min
D: Inclusion Criteria:

* Patients with a first episode of idiopathic pulmonary embolism who have been treated during 6 months (Plus 30 days or minus 15 days) using Vitamin K antagonist with a INR between 2 and 3.

Exclusion Criteria:

* Age \< 18
* warfarin hypersensibility
* unwilling or unable to give written informed consent
* distal or proximal deep vein thrombosis
* Pulmonary embolism which was provoked by a reversible major risk factor
* major thrombophilia (protein C, S or antithrombin deficiency, antiphospholipids antibodies, homozygous factor V Leiden)
* previous documented episode of proximal deep vein thrombosis or pulmonary embolism
* other indication for anticoagulant therapy (e.g.:atrial fibrillation, mechanic valve)
* patient on antithrombotic agent in whom antithrombotic agent should be started again after stopping anticoagulation
* pregnancy
* women without contraception
* planned major surgery in the next 18 months
* ongoing cancer or cured cancer in less than 2 years
* serious bleeding risk (e.g.: gastric ulcer)
* platelet count less than 100 Giga/l
* Life expectancy less than 18 months

Answer: D