Pulmonary Hypertension Associated With Hemoglobinopathies

Hemoglobinopathies constitute a heterogeneous group of hereditary hemoglobin disorders characterized by either reduced (thalassemias) or defective (sickle cell disease) globin chain synthesis that results in chronic hemolytic anemia. They represent the most common monogenetic disorders in humans, and although traditionally confined to specific geographic areas and populations (the Mediterranean Basin and the Middle and Far East in the case of β-thalassemia; Sub-Saharan Africa and African-Americans in the case of sickle cell disease), they have currently expanded to a global distribution because of the immigration of those populations to the Western world.1 Although their clinical severity is variable, the hemoglobinopathies are generally demanding conditions, particularly in the homozygous state, characterized by reduced survival, multiorgan complications, frequent hospitalizations, and need for lifelong management, thus posing a significant medical and socioeconomic burden.Cardiovascular complications are among the leading causes of mortality and morbidity in hemoglobinopathies.1 In the wide spectrum of cardiovascular manifestations of these patients, pulmonary hypertension (PH) holds a prominent place. It has been postulated that hemoglobinopathies, along with HIV infection and schistosomiasis, may be the most common causes of PH worldwide given the high prevalence of PH in those populations.2 β-ThalassemiaPH is a frequent finding in patients with hemoglobinopathies, but the reported prevalence varies in the different conditions and according to the method used for screening (Table 1). In thalassemia intermedia, a form of β-thalassemia that accounts for 20% to 25% of cases, PH has been recognized as the most striking cardiovascular finding and the main cause of heart failure. In a preliminary report, all 7 patients with thalassemia intermedia with heart failure had preserved systolic left ventricular (LV) function and severe PH as shown by right-sided heart catheterization.8 This initial report was followed by a systematic study of 110 patients with thalassemia intermedia with a mean …