Proposed algorithm for evaluation of pulmonary hypertension related to sickle cell disease. 6MWD, 6-minute walk distance; ANA, anti-nuclear antibody; CXR, chest X-ray; EKG, electrocardiogram; LFTs, liver function tests; mPAP, mean pulmonary artery pressure; NT-pro-BNP, N-terminal pro–brain natriuretic peptide; PAWP, pulmonary artery wedge pressure; PH, pulmonary hypertension; PVR, pulmonary vascular resistance; SCD, sickle cell disease; TRV, tricuspid regurgitation velocity. Note: Echocardiography should be performed while patients are clinically stable. PAH therapy is to be considered on the basis of a weak recommendation and very low-quality evidence. Reprinted with permission of the American Thoracic Society.84 The American Journal of Respiratory and Critical Care Medicine is an official journal of the American Thoracic Society.