High risk features in pulmonary arterial hypertension impacting agent selection*

RV: right ventricle; PaCO₂: partial arterial pressure of carbon dioxide; RAp: right atrial pressure; CI: cardiac index; WHO: World Health Organization; 6MWD: 6-minute walk distance; VO₂: oxygen consumption on cardiopulmonary exercise testing; BNP: brain natriuretic peptide; NT-pro BNP: N-terminal pro-brain natriuretic peptide; CTD: connective tissue disease; PAH: pulmonary arterial hypertension.
* While factors such as age >50 years, CTD PAH, and failure to improve or clinical worsening during treatment do not affect initial agent selection, they may influence the decision to add or change therapy.
¶ Examples include pericardial effusion, RV dysfunction, and right atrial enlargement.