Please select the eligibility criteria that correspond to the clinical trial below.
Title: BARIVA:Short Versus Extended Prophylaxis of Rivaroxaban for Venous Thromboembolism After Bariatric Surgery
Brief Summary: The aim of this study is to investigate the efficacy and safety of rivaroxaban in obese patients undergoing bariatric surgery.

The objectives are to assess the safety and feasibility of venous thromboembolism (VTE) prophylaxis and lung embolism with Rivaroxaban 10mg as an oral anticoagulant. After bariatric surgery patients receive the study medication Xarelto 10mg QD for 7, resp. 28 days.

All clinically thromboembolic events will be assessed by ultrasound or CT, respectively, as soon as apparent. In addition, patients are screened for VTE at day 28 by ultrasound to detect clinically inapparent thromboses.

In a subgroup of study patients (patients from the University Hospital Inselspital, Bern) PK/PD parameters are assessed following the last intake of rivaroxaban at day 28.


Options:
A: Inclusion Criteria:

* Adult patient (≥ 18 years of age)
* Positive COVID-test
* Under mechanical ventilation
* D-Dimers\>1.2 mg/L

Exclusion Criteria:

* Pregnancy
* Allergy to the drug (bivalirudin)
* Inherited coagulation abnormalities
* No informed consent
B: Inclusion Criteria:

* Patients with scheduled elective bariatric surgery or redo surgery after bariatric interventions
* Written informed consent

Exclusion Criteria:

* DVT and/or PE in the patient history
* Myocardial infarction, transient ischemic attack or stroke within 6 months of study entry
* Uncontrolled hypertension
C: Inclusion Criteria:

* Written informed consent.
* Age\>18 years old.
* Negative serum pregnancy test (in women of childbearing only).
* Patients submitted to endovascular procedures below-the-knee by not exclusively.
* Patient understands and is willing and able to comply with the study instructions and follow-up visit.
* More than 70% stenosis or occlusion of the three distal arteries including or not the tibiofibular trunk (TFT).
* Tissue loss (Rutherford 5).
* One or more patent vessel of pedal arch.

Exclusion Criteria:

* TASC II D femoral and/or popliteal occlusion.
* Life expectancy less than 1 year.
* Allergy or contraindication to apixaban treatment.
* Allergy or contraindication to dual antiplatelet treatment.
* Creatinine clearance less than 30mL/min.
* Planned major amputation before procedure.
* Hybrid procedure (open and endovascular).
* Use of fibrinolytic in the past 10 days.
* Known HIV infection.
* Liver disease (acute or chronic hepatitis and cirrhosis).
* Drug addiction or alcohol abuse 12 months before the randomization.
* Concomitant medications thatinhibit the CYP 3A4 cytochrome and P glycoprotein (ketoconazole, Iitraconazole, ritonavir).
* Platelets count inferior to 100x109/L.
* INR more than 1.5.
* History or condition with high risk of bleeding: Eg. Trauma within 30 days before randomization, gastrointestinal bleeding 6 month before the randomization, intra-ocular, spinal, intra-articular bleeding (any time before), AV malformation, cerebral aneurysm and hypertension without control.
D: Inclusion Criteria:

* Maximum IMT \>1.2 mm and 3.5 mm at any location in the carotid ultrasound studies conducted at both Visit 2 (Week -4) and Visit 3 (Week -2)
* Subjects with age and no other risk factor: Fasting LDL-C at Visit 1 (Week -6) is \>120 mg/dL (3.1mmol/L) and \<190 mg/dL (4.9 mmol/L)
* Subjects with 2 or more risk factors and a 10-year coronary heart disease (CHD) risk \< 10%: Fasting LDL-C at Visit 1 (Week -6) is \>120 mg/dL (3.1 mmol/L) and \<160 mg/dL (4.1 mmol/L)

Exclusion Criteria:

* Use of pharmacologic lipid-lowering medications (eg, HMG-CoA reductase inhibitors, fibrate derivatives, bile acid binding resins, niacin or its analogues at doses \>400 mg) within 12 months prior to Visit 1 (Week -6).
* Clinical evidence of coronary artery disease or any other atherosclerotic disease such as angina, MI, TIA, symptomatic carotid artery disease, CVA, CABG, PTCA, peripheral arterial disease, AAA.

Answer: B