Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effects of Combination of Bosentan and Sildenafil Versus Sildenafil Monotherapy on Morbidity and Mortality in Symptomatic Patients With Pulmonary Arterial Hypertension - A Multicenter, Double-blind, Randomized, Placebo-controlled, Parallel Group, Prospective, Event Driven Phase IV Study
Brief Summary: COMPASS-2 is a Phase 4, prospective, randomized, double-blind, placebo-controlled, event-driven study evaluating the effect of bosentan on the time to first confirmed morbidity/mortality event in patients with symptomatic PAH already receiving sildenafil therapy. Patients must have been receiving doses of sildenafil equal to or greater than 20 mg t.i.d. for at least 12 weeks prior to being randomized.

The study continued until the predefined target number of morbidity/mortality events was reached.


Options:
A: Inclusion Criteria:

1. Signed informed consent prior to initiation of any study-mandated procedure
2. Males or females \>=12 years of age (except for countries where this age limit is contrary to specific regulatory requirements).

   - Women of childbearing potential must have a negative pretreatment pregnancy test and must use a reliable method of contraception during study treatment and for at least 3 months after study treatment termination.

   ·Reliable methods of contraception are:

   O Barrier type devices (e.g., female condom, diaphragm, contraceptive sponge) only in combination with a spermicide.

   O Intrauterine devices. O Oral, transdermal, injectable or implantable contraceptives only in combination with a barrier method.
   * Hormone-based contraceptives alone, regardless of the route of administration, are not considered as reliable methods of contraception.
   * Abstention, rhythm method, and contraception by the partner alone are not acceptable methods of contraception.

     * Women not of childbearing potential are defined as postmenopausal (i.e., amenorrhea for at least 1 year), or documented surgically or naturally sterile.
3. Patients with symptomatic PAH
4. Patients with the following types of PAH belonging to WHO Group I:

   * Idiopathic (IPAH)
   * Familial (FPAH)
   * Associated with (APAH):

     i. Collagen vascular disease with normal left ventricular function (ejection fraction (EF) \> 50%) ii. Congenital systemic-to-pulmonary shunts at least 2 years post surgical repair iii. Drugs and toxins
5. PAH diagnosed by right heart catheter showing:

   * Mean pulmonary arterial pressure (mPAP) \>= 25 mm Hg AND
   * Pulmonary capillary wedge pressure (PCWP) =\< 15 mm Hg or left ventricular end diastolic pressure (LVEDP) =\< 15 mmHg If both PCWP and LVEDP are available then the LVEDP value is retained for inclusion.
6. Treatment with a stable dose of sildenafil equal to or greater than 20 mg t.i.d. for at least 12 weeks prior to randomization (no sildenafil dosage adjustment should occur in this period) 7)150 m =\< 6-minute walk test (6MWT) =\< 480 m, documented by 2 tests with second 6MWT within 15% of first 6MWT distance or a third test required

Exclusion Criteria :

1. PAH belonging to WHO group II-V
2. PAH associated with portal hypertension and HIV infection
3. PAH associated with thyroid disorders, glycogen storage disease, Gaucher disease, hereditary hemorrhagic telangiectasia, hemoglobinopathies, myeloproliferative disorders and splenectomy
4. PAH associated with significant venous or capillary involvement (PCWP \> 15 mmHg): pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis
5. Persistent pulmonary hypertension of the newborn
6. Significant valvular disease with valvular lesions to be excluded by echocardiogram within 2 years prior to randomization (i.e. patients with tricuspid or pulmonary insufficiency secondary to PAH can be included)
7. Restrictive lung disease: total lung capacity (TLC) \< 60% of normal predicted value (see Appendix 3)
8. Obstructive lung disease: forced expiratory volume/forced vital capacity (FEV1/FVC) \< 0.5
9. Moderate to severe hepatic impairment, i.e., Child-Pugh Class B or C
10. Known HIV infection
11. Acute or chronic impairment (other than dyspnea), limiting the ability to comply with study requirements or that may interfere with the safety or the evaluation of the study, such as chronic infection, chronic renal failure etc.
12. Psychotic, addictive or other disorder limiting the ability to provide informed consent or to comply with study requirements
13. Pregnancy or breast-feeding
14. Condition that prevents compliance with the protocol or adherence to therapy
15. Systolic blood pressure \< 85 mmHg
16. Body weight \< 40 kg
17. Hemoglobin \<75% of the lower limit of the normal range
18. Aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) \> 1.5 times the upper limit of normal ranges
19. Known hypersensitivity or history of drug-related adverse events with bosentan (e.g. increase in liver function test results), or any of the excipients of its formulation
20. Receipt of an investigational product other than sildenafil within 3 months before start of study treatment
21. Treatment with endothelin receptor antagonists (ERAs), prostanoids or phosphodiesterase (PDE) 5 inhibitors other than sildenafil within 3 months prior to randomization
22. Concomitant systemic treatment within 1 week prior to randomization with

    * calcineurin inhibitors (e.g., cyclosporine A and tacrolimus), sirolimus and everolimus
    * glibenclamide (glyburide)
    * both cytochrome P2C9 (CYP2C9) and cytochrome P3A4 (CYP3A4) (e.g., fluconazole, amiodarone, voriconazole)
    * combination of drugs that inhibit CYP2C9 and CYP3A4
23. Treatment with nitrates and alpha-blockers at time of randomization
24. In the opinion of the investigator - patients in need for treatment with any prostanoid up to Visit 4
25. Significant left ventricular dysfunction
B: Inclusion Criteria:

* Between 18 and 60 years of age inclusive, at the time of signing the informed consent.
* Healthy as determined by a responsible and experienced physician, based on a medical evaluation including medical history, physical examination, laboratory tests, vital signs and cardiac monitoring (ECG and 24 hour Holter). A subject with a clinical abnormality or laboratory parameter(s) which is/are not specifically listed in the inclusion or exclusion criteria, outside the reference range for the population being studied may be included only if the Investigator, in consultation with Medical Monitor if required, judges and documents that the finding is unlikely to introduce additional risk factors and will not interfere with the study procedures.
* Body weight \>= 50 Kilogram (kg) (110 pounds \[lbs\]) for men and \>= 45 kg (99lbs) for women and body mass index (BMI) within the range 18 - 30 kg per square metre (m\^2) (inclusive)
* Male or Female. Female with non-reproductive potential defined as, Pre-menopausal females with one of the following: Documented tubal ligation or Documented hysteroscopic tubal occlusion procedure with follow-up confirmation of bilateral tubal occlusion or Hysterectomy or Documented Bilateral Oophorectomy, Documented Postmenopausal defined as 12 months of spontaneous amenorrhea
* Capable of giving signed informed consent.

Exclusion Criteria:

* A blood pressure \<100/55 millimetre of Mercury (mm Hg).
* Haemoglobin (Hb) below normal range: Hb \<133 (gram per litre) g/L for males and Hb \<114 g/L for females
* Alanine amino transferase (ALT) and bilirubin \>1.5 x upper limit of normal (ULN) (isolated bilirubin \>1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin is \<35 percentage \[%\]).
* Current or chronic history of liver disease, or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones)
* Corrected QT (QTc) \>450 milliseconds (msec). The QTc is the QT interval corrected for heart rate according to Bazett's formula (QTcB), Fridericia's formula (QTcF), and/or another method, machine-read or manually over-read.
* Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements (including St John's Wort) within 7 days (or 14 days if the drug is a potential enzyme inducer) or 5 half-lives (whichever is longer) prior to the first dose of study medication, unless in the opinion of the Investigator and Medical Monitor the medication will not interfere with the study procedures or compromise subject safety.
* History of regular alcohol consumption within 6 months of the study defined as: An average weekly intake of \>21 units for males or \>14 units for females. One unit is equivalent to 8 gram (g) of alcohol: a half-pint (\~240 millilitre \[mL\]) of beer, 1 glass (125 mL) of wine or 1 (25 mL) measure of spirits.
* Smoking more than 5 cigarettes per week and subjects must be able to abstain from smoking for a 24 hour period prior to dose and any time whilst in the clinical unit.
* History of sensitivity to any of the study medications, or components thereof or a history of drug or other allergy that, in the opinion of the Investigator or Medical Monitor, contraindicates their participation.
* Presence of hepatitis B surface antigen (HBsAg), positive hepatitis C antibody test result at Screening or within 3 months prior to first dose of study treatment.
* A positive test for human immuno-deficiency virus (HIV) antibody
* A positive pre-study drug/alcohol screen.
* Where participation in the study would result in donation of blood or blood products in excess of 500 mL within previous 3 months
* The subject has participated in a clinical trial and has received an investigational product within the following time period prior to the first dosing day in the current study: 3 months, 5 half-lives or twice the duration of the biological effect of the investigational product (whichever is longer).
* Exposure to more than four new chemical entities within 12 months prior to the first dosing day.
C: Inclusion Criteria:

* aged 10 to 80
* treatment naive symptomatic PAH
* 6-MWD of 100-425 m
* resting mean pulmonary artery pressure greater than 25 mm Hg, pulmonary capillary wedge pressure less than 15 mm Hg, and pulmonary vascular resistance of 240 dyn.s.cm-5 or greater.

Exclusion Criteria:

* Patients with thromboembolic disease,
* untreated obstructive sleep apnea,
* portal hypertension,
* chronic liver disease or renal insufficiency,
* left-sided or unrepaired congenital heart disease,
* substantial obstructive (FEV1/FVC\<50% predicted) or restrictive (total lung capacity\<60% predicted) lung disease
* Patients receiving phosphodiesterase inhibitors or other prostanoids and endothelin receptor antagonists
D: Inclusion Criteria:

* Subjects must have a diagnosis of Pulmonary Arterial Hypertension (PAH) due to the following:

  a. idiopathic or heritable PAH b. PAH associated with: i. connective tissue disease (e.g., limited scleroderma, diffuse scleroderma, mixed connective tissue disease, systemic lupus erythematosus, or overlap syndrome) ii. drugs or toxins iii. Human Immunodeficiency Virus (HIV) infection iv. congenital heart defects repaired greater than 1 year prior to screening (i.e., atrial septal defects, ventricular septal defects, and patent ductus arteriosus) NB: subjects with portopulmonary hypertension and pulmonary veno-occlusive disease are NOT eligible for the study
* Subject must have a current diagnosis of being in World Health Organisation (WHO) Functional Class II or III.
* Subject must meet all of the following haemodynamic criteria by means of a right heart catheterization prior to screening:

  i. mPAP of ≥25 mmHg ii. PVR ≥ 300 dynes/sec/cm5 iii. PCWP or LVEDP of ≤12 mmHg if PVR ≥300 to \<500 dyne/sec/cm5 , or PCWP/LVEDP ≤ 15 mmHg if PVR ≥500 dynes/sec/cm5
* Subject must walk a distance of ≥125m and ≤500m at the screening visit

Exclusion Criteria:

* Subject received previous PAH therapy (phosphodiesterase type 5 inhibitor (PDE5i), endothelin receptor antagonist (ERA), chronic prostanoid\*) within 4 weeks prior to the screening visit (\*Chronic prostanoid use is considered \>7 days of treatment)
* Subject received ERA treatment (e.g., bosentan or sitaxentan) or PDE5i treatment (e.g. Sildenafil) at any time AND discontinued due to tolerance issues other than those associated with liver function abnormalities
* Subjects who have previously discontinued ambrisentan or tadalafil in either another clinical study or commercial product (Volibris/Letairis or Adcirca) for safety or tolerability reasons.

Answer: A