Prevalence and Risk Factors for Pulmonary Arterial Hypertension in a Large Group of β-Thalassemia Patients Using Right Heart Catheterization A Webthal Study

Background Pulmonary arterial hypertension (PAH) remains a concern in patients with -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 -thalassemia patients (mean age 36.49.3 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 -thalassemia patients as confirmed on right heart catheterization was 2.1%, with an approximate to 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.