Indicators of a poorer prognosis include Lack of response to vasodilators Hypoxemia Reduced overall physical functioning Low 6-minute walk distance High plasma levels of NT-pro-BNP or BNP Echocardiographic indicators of right heart systolic dysfunction (eg, a tricuspid annular plane systolic excursion of < 1.6 cm, dilated right ventricle, flattened interventricular septum with paradoxical septal motion, and pericardial effusion) Right heart catheterization showing low cardiac output, very high mean pulmonary artery pressures, and / or high right atrial pressures Patients with systemic sclerosis, sickle cell disease, or HIV infection with pulmonary arterial hypertension (PAH) have a worse prognosis than those without PAH.