Please select the eligibility criteria that correspond to the clinical trial below.
Title: Clinical Efficacy of Phosphodiesterase-5 Inhibitor Tadalafil in Eisenmenger Syndrome - A Randomised, Placebo Controlled, Double Blind, Crossover Study
Brief Summary: A preliminary observational study by the investigators has shown that tadalafil, a selective phosphodiesterase-5 inhibitor (PDE-5) decreases pulmonary vascular resistance(PVR) in patients of eisenmenger syndrome (ES) resulting in increase in pulmonary blood flow (Qp), systemic oxygen saturation (SaO2), functional class and exercise capacity. The aim of this placebo controlled trial was to assess the effect of the drug on exercise capacity and functional class compared to placebo.


Options:
A: Inclusion Criteria:

* Severe aortic stenosis (AVA \< 1.0 cm2)
* Referred for a clinically ordered right and left heart catheterization
* 18 years of age and older
* Able and willing to comply with all requirements of the study

Exclusion Criteria:

* Nitrate use within 24 hours
* SBP \< 110 mmHg or MAP \< 75 mmHg
* Severe mitral regurgitation
* Severe aortic regurgitation
* Increased risk of priapism
* Retinal or optic nerve problems or unexplained visual disturbance
* Alpha antagonists or cytochrome P450 3A4 inhibitors use within 24 hours
* Current or recent (≤ 30 days) acute coronary syndrome
* O2 sat \< 90% on room air
* Females that are pregnant or believe they may be pregnant
* Any condition which the PI determines will place the subject at increased risk or is likely to yield unreliable hemodynamic data
* Unwilling to provide informed consent
B: Inclusion Criteria:

* Age at the date of selection ≥ 18 years
* Mean pulmonary pressure ≥ 30 mmHg, measured by a Swan-Ganz catheter placed in the pulmonary artery
* Heart valve intervention: surgical or percutaneous replacement, repair or dilatation performed at least one year before inclusion
* Stable clinical condition for at least one month, without hospital admissions for heart failure, and on appropriate and stable doses of conventional cardiovascular medications

Exclusion Criteria:

* Requiring or likely to require the following medications: organic nitrates, alpha-blocker therapy, potent cytochrome P450 3A4 inhibitors (erythromycin, ketoconazole, cimetidine, HIV protease inhibitors such ritonavir and saquinavir) Patients who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months.
* Patients with resting hypotension, with systolic blood pressure \< 90 mmHg
* Patients with retinitis pigmentosa
* Anatomical deformation of the penis (such as angulation, cavernosal fibrosis or Peyronie's disease) or patients who have conditions which may predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia)
* Severe renal impairment with creatinine clearance \< 30 ml/min
* Significant hepatic dysfunction
* Prosthesis or valvular dysfunction with hemodynamic repercussion.
* Pregnant or breast-feeding women
* Patients unlikely to cooperate in the study or with inability or unwillingness to give informed consent
* Life expectancy less than 2 years due to non-cardiac disease
C: Inclusion Criteria:

* COPD, FEV1 \< 80% ref. and FEV1/FVC \< 0.7 post bronchodilator
* Age 40-80 years
* Pulmonary hypertension
* Consent to participate in the study

Exclusion Criteria:

* Pulmonary or extrapulmonary disease that modifies gas exchange or pulmonary hemodynamics
* Recent exacerbation (\<4 weeks) (temporally)
* Patients treated with nitrates or CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir)
* Ischemic optic neuropathy
* Patients treated with phosphodiesterase-5 inhibitors
* Patients with ischemic cardiopathy
* Systemic disease that could modified the results
* Patients unable to practise exercise
D: Inclusion Criteria:

* Patients of ES with age greater than or equal to 14 years and weight greater than or equal to 30 kgs in World Health Organisation (WHO) functional class II and III attending our congenital clinic were invited to participate in the study

Exclusion Criteria:

* WHO class IV,
* congestive heart failure or had PCWP \> 15mmHg,
* left ventricular ejection fraction \<40%,
* atrial fibrillation,
* patent ductus arteriosus,
* complex congenital heart defects,
* restrictive lung disease(total lung capacity \< 70% of predicted), obstructive lung disease ( forced expiratory volume in 1 second \[FEV1\] \< 70% of predicted with FEV1/ Forced vital capacity \[FVC\] \< 60%),
* previously diagnosed coronary artery disease requiring nitrate therapy,
* abnormal biochemical profile and
* hypersensitivity to PDE- 5 inhibitors.

Answer: D