Background—: 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.
Thalassemia syndromes are characterized by the inability to produce normal hemoglobin. Ineffective erythropoiesis and red cell transfusions are sources of excess iron that the human organism is unable to remove. Iron that is not saturated by transferrin is a toxic agent that, in transfusion-dependent patients, leads to death from iron-induced cardiomyopathy in the second decade of life. The availability of effective iron chelators, advances in the understanding of the mechanism of iron toxicity and overloading, and the availability of noninvasive methods to monitor iron loading and unloading in the liver, heart, and pancreas have all significantly increased the survival of patients with thalassemia. Prolonged exposure to iron toxicity is involved in the development of endocrinopathy, osteoporosis, cirrhosis, renal failure, and malignant transformation. Now that survival has been dramatically improved, the challenge of iron chelation therapy is to prevent complications. The time has come to consider that the primary goal of chelation therapy is to avoid 24-h exposure to toxic iron and maintain body iron levels within the normal range, avoiding possible chelation-related damage. It is very important to minimize irreversible organ damage to prevent malignant transformation before complications set in and make patients ineligible for current and future curative therapies. In this clinical case-based review, we highlight particular aspects of the management of iron overload in patients with beta-thalassemia syndromes, focusing on our own experience in treating such patients. We review the pathophysiology of iron overload and the different ways to assess, quantify, and monitor it. We also discuss chelation strategies that can be used with currently available chelators, balancing the need to keep non-transferrin-bound iron levels to a minimum (zero) 24 h a day, 7 days a week and the risk of over-chelation.