Distinction of the various forms of β-thalassemia relies on clinical grounds. Patients with β-thalassemia major present to medical attention in early childhood with severe anemia requiring life-long transfusion and iron chelation therapy for survival.2 Conversely, patients with β-thalassemia intermedia present later in childhood with milder anemia and remain largely transfusion-independent.3 Such variation in phenotype has been attributed to several environmental and genetic factors that alter the α/β-chain imbalance and subsequent ineffective erythropoiesis and peripheral hemolysis, the hallmarks of disease process in β-thalassemia. 4 Clinical Perspective on p 345Among the sequelae associated with a diagnosis of β-thalassemia, pulmonary arterial hypertension (PAH) has received great attention in recent years.5 PrevalenceBackground-Pulmonary arterial hypertension (PAH) remains a concern in patients with β-thalassemia major (TM) and intermedia (TI); however, studies evaluating its prevalence and risk factors using systematic confirmation on right heart catheterization are lacking. Methods and Results-This was a multicenter cross-sectional study of 1309 Italian β-thalassemia patients (mean age 36.4±9.3 years; 46% men; 74.6% TM, 25.4% TI). Patients with a tricuspid-valve regurgitant jet velocity ≥3.2 m/s (3.6%) on transthoracic echocardiography further underwent right heart catheterization to confirm the diagnosis of PAH (mean pulmonary arterial pressure ≥25 mm Hg and pulmonary capillary wedge pressure ≤15mm Hg). The confirmed PAH prevalence on right heart catheterization was 2.1% (95% confidence interval [CI], 1.4-3.0) and was higher in TI (4.8%; 95% CI, 3.0-7.7) than TM (1.1%; 95% CI, 0.6-2.0). The positive predictive value for the tricuspid-valve regurgitant jet velocity ≥3.2 m/s threshold for the diagnosis of pulmonary hypertension was 93.9%. Considerable functional limitation and decrease in the 6-minute walk distance were noted in patients with confirmed PAH. On multivariate logistic regression analysis, independent risk factors for confirmed PAH were age (odds ratio, 1.102 per 1-year increase; 95% CI, 1.06-1.15) and splenectomy (odds ratio, 9.31; 95% CI, 2.57-33.7). Conclusions-The prevalence of PAH in β-thalassemia patients as confirmed on right heart catheterization was 2.1%, with an ≈5-fold higher prevalence in TI than TM. Advanced age and splenectomy are risk factors for PAH in this patient population. Clinical Trial Registration-URL: http://www.ClinicalTrials.gov. Unique identifier: NCT01496963.(Circulation. 2014;129:338-345.)

Thalassemia major is an inherited hemoglobin disorder resulting in a chronic hemolytic anemia. Transfusion therapy together with elevated gastrointestinal absorption of iron determines iron overload, which causes most of the mortality and morbidity associated with the disease. Heart complications represent the leading cause of mortality in this disease, although, because of an improvement in chelation treatment, an important and progressive increase of life expectancy mainly as a result of a reduction in mortality due to cardiac dysfunction has been demonstrated in recent years. Clinical pictures of heart damage range from the involvement of the ventricles to pulmonary hypertension or symptomatic ventricular or supra-ventricular arrhythmias. For this reason, the possibility of having specific recommendations is noteworthy. These recommendations outline the definition, the follow-up and the treatment of the main heart complications in this group of patients. The identification of topics and the nomination of the committee were made on behalf of the Society for the Study of Thalassemia and Hemoglobinopathies (SoSTE). The document obtained the auspices of ANMCO, SIC, SIRM and the Cardiovascular Magnetic Resonance Working Groups of the ANMCO, SIC and SIRM. All recommendations provided in this document have been performed according to the American Cardiology College (ACC) and American Heart Association (AHA) guidelines. Moreover, the recommendations were reviewed by two external referees before the definitive approval.