NPPB and pericardial effusion: Additional negative prognostic factors are a distance shorter than 300 m on 6MWT, a peak Oxygen consumption < 12 mL/min/kg on cardiopulmonary exercise testing, elevated and increasing BNP/ NT-proBNP plasma levels, pericardial effusions and TAPSE < 1.5 cm on echocardiography and right atrial pressure > 15 mmHg or cardiac index ≤ 2 L/min/m2 on cardiac catheterization [10].