Outcome Study Assessing a 75 Milligrams (mg) Dose of Macitentan in Patients With Pulmonary Arterial Hypertension

The purpose of this study is to demonstrate superiority of macitentan 75 milligrams (mg) in prolonging the time to the first clinical events committee (CEC)-adjudicated morbidity or mortality (M/M) event in participants with symptomatic pulmonary arterial hypertension (PAH) compared to macitentan 10 mg.


Eligibility Criteria:
Inclusion Criteria:

* Target population: greater than or equal to (\>=) 18 (or the legal age of consent in the jurisdiction in which the study is taking place) years of age
* Target population: Symptomatic Pulmonary Arterial Hypertension (PAH) in World Health Organization Functional Class (WHO FC) II, III, or IV
* Target population: PAH subtype falling in one of the below classifications: Idiopathic; Heritable; Drug- or toxin-induced; Related to: Connective tissue disease, HIV infection, Portal hypertension, and Congenital heart disease with small/coincidental cardiac defect with systemic-to-pulmonary shunt (for example atrial septal defect, ventricular septal defect, patent ductus arteriosus, atrioventricular septal defect) which does not account for the elevated pulmonary vascular resistance (PVR) or persistent PAH documented by an Right heart catheterization (RHC) \>= 1 year after simple systemic-to pulmonary shunt repair
* PAH diagnosis confirmed by hemodynamic evaluation at rest at any time prior to screening: Mean pulmonary artery pressure (mPAP) greater than (\>) 20 millimeters of mercury (mm Hg), and; Pulmonary artery wedge pressure (PAWP) or left ventricular end diastolic pressure (LVEDP) less than or equal to (\<=) 15 mm Hg, and PVR \>= 3 Wood Units (that is, \>= 240 dyn\*sec/cm\^5)
* Able to perform the 6-minute walking test (6MWT) with a minimum distance of 50 meters (m) and maximum distance of 440m at screening. Participants able to walk more than 440m at screening are eligible if they are in WHO FC III or IV and n-terminal prohormone of brain natriuretic peptide or n-terminal pro B-type natriuretic peptide (NT-proBNP) level is \>=300 nanograms per liter (ng/L) at screening, based on central laboratory results

Exclusion Criteria:

* Known presence of three or more of the following risk factors for heart failure with preserved ejection fraction at screening, based on records that confirm documented medical history: Body mass index (BMI) \> 30 kilograms per meter square (kg/m\^2), Diabetes mellitus of any type, Essential hypertension (even if well controlled); Coronary artery disease, that is, any of the following: history of stable angina, or known more than 50 percent (%) stenosis in a coronary artery, or history of myocardial infarction, or history of or planned coronary artery bypass grafting and/or coronary artery stenting
* Presence of moderate or severe obstructive lung disease (forced expiratory volume in 1 second \[FEV1\] / forced vital capacity \[FVC\] \< 70%; and FEV1 \< 60% of predicted after bronchodilator administration) ) in participants with a known or suspected history of significant lung disease as documented by a spirometry test performed within 1 year prior to screening
* Known moderate to severe hepatic impairment, defined as Child-Pugh Class B or C, based on records that confirm documented medical history
* Serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) \> 1.5\*upper limit of normal (ULN) at screening
* Hemoglobin \< 100 gram per liter (g/L) (\< 10 gram per deciliter \[g/dL\]) at screening