NPPB and pericardial effusion: Treatment of patients with PAH aims to achieve the following therapeutic goals: WHO FC I/II; normalization of right heart size and RV function, defined as a right atrial area (RAA) < 18 cm2 and the absence of pericardial effusion; mean right atrial pressure (mRAP) < 8 mmHg; cardiac index (CI) ≥ 2.5 L/min/m2; 6-min walking distance (6MWD) > 440 m; peak oxygen consumption (VO2 peak) > 15 mL/kg/min; ventilatory equivalents for carbon dioxide (VE/VCO2 slope) < 36; and normalization of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels.