A Study of Pulmonary Arterial Hypertension Participants Treated With Macitentan or Selexipag

Change from baseline in the number of the non-invasive low-risk criteria will be assessed according to the following parameters: world health organization (WHO)/functional class (FC)- I, II, 6-minute walk distance (6MWD) greater than (>) 440 meters (m), and brain natriuretic peptide (BNP) less than (<) 50 nanogram per liter (ng/l) or N-terminal-pro-hormone brain natriuretic Peptide (NT-proBNP) <300 ng/l.

Risk profile is assessed as improved, stable or worsened where improved indicates 1 or more non-invasive parameters from intermediate to low risk profile; stable indicates no change in the parameters; and worsened indicates 1 or more non-invasive parameters move from low or intermediate to intermediate or high range risk.

Change in risk profile for the low/high intermediate risk participants according to following cut-off values for low intermediate risk/high intermediate risk, respectively: (6MWD [greater than or equal to [>=] or < 300m], Peak oxygen consumption [VO2] [>= or < 50% predicted], BNP [less than or equal to [<=] or > 175 ng/l], or NT-proBNP [<= or > 850 ng/l], right atrial area [RA] [<= or > 22 centimeter [cm]] and right atrial pressure [RAP] [<= or > 11 millimeter of mercury [mmHg]] or stroke volume index (SVI) (> or <= 38 milliliter per meter square [ml/m2])). The low intermediate risk is defined by a presence of at least three low intermediate parameters and a high intermediate risk is defined by a presence of at least three high intermediate parameters.

Change from baseline in 6MWD will be reported.

Change from baseline in BNP or NT-proBNP will be reported.

The REVEAL risk calculator determines the risk status and the scores can be defined as: low risk as a score of <= 6, intermediate risk as a score of 7 or 8, and high risk as a score of >= 9 for the survival rates.

Adherence to ESC/ERS guidelines and 6th WSPH will be reported.

Change in echocardiographic parameters will be reported as assessed by echocardiogram.

Change in hemodynamic parameters will be reported.

The hospitalization rate due to PAH worsening will be calculated based on the number of participants with at least one hospitalization. The calculation of the rate will be based on the number of events over the whole follow-up time that is exposure time.

OS is defined as the duration/time from the start of study treatment to date of death due to any cause.

The emPHasis-10 is a short and easy questionnaire that consists of 10 items which address breathlessness, fatigue, control and confidence. Each item is scored on a semantic differential six-point scale (0-5), with contrasting adjectives at each end. A total emPHasis-10 score is derived using simple aggregation of the 10 items. emPHasis-10 scores range from 0 to 50, higher scores indicate worse quality of life.

Participants will be invited to fill in two narrative plots; one at the enrollment visit and one at the month 12 visit.

Caregivers will be invited to fill in two narrative plots; one at the enrollment visit and one at the month 12 visit.

An AE is any untoward medical occurrence in a participant enrolled in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. An ADR is defined as a response to a medicinal (investigational or non-investigational) product that is noxious and unintended.