Savale L, Habibi A, Lionnet F, et al. - In this nationwide multicenter, retrospective study, researchers determined the impact of sickle cell disease (SCD) genotype on clinical phenotypes as well as outcomes of precapillary pulmonary hypertension (PH) due to SCD. From the French PH Registry, all patients with SCD-associated precapillary PH were included (n = 58): 41 homozygous for hemoglobin S (SS), 3 S-β₀ thalassemia (S-β₀ thal) and 14 hemoglobin SC disease (SC). Lower 6-minute walk distance and lower pulmonary vascular resistance were detected among SS/S-β₀ thal patients vs SC patients. A total of 85% of SC patients and 9% of SS/S-β₀ thal patients exhibited mismatched segmental perfusion defects on lung scintigraphy, and heterogeneous lung perfusion without segmental defects was seen in 50% of SS/S-β₀ thal. Poor prognosis was observed in patients with precapillary PH associated with SCD. More often in SC patients, thrombotic lesions seemed like a major part of PH related to SCD.