Prevalence and risk factors for pulmonary hypertension in patients with hemoglobin E/β‐thalassemia disease

Objectives To find the prevalence and risk factors of pulmonary hypertension ( PHT ) in adult patients with hemoglobin E /β‐thalassemia disease ( E /β‐Thal). Methods One hundred and ten clinically stable E /β‐ T hal outpatients, sixty‐one of whom had undergone splenectomy, were prospectively studied using their clinical profiles, selected blood tests, chest roentgenogram, and transthoracic echocardiogram. Based on the pulmonary artery systolic pressure ( PASP ) values estimated by the echocardiogram of ≥36 mmHg, they were dichotomized into those with ( PHT +) and without ( PHT −) PHT . Results PHT was found in 41 (37.3%) patients without gender preponderance. It was not due to the left heart and was not severe ( PASP  = 46.3 ± 10.4 mmHg). PASP was higher in splenectomized patients (48.0 ± 11 vs. 40.3 ± 4.7 mmHg ( P  =   0.004)). PHT was found in 32 of 61 (52.5%) splenectomized patients, mostly (53%) in the second decade, and rarely (6.3%) during the first 5 yr after splenectomy. PHT + patients had more hemolysis ( P  =   0.001–0.04 depending on the parameters), more asplenic cases ( P  <   0.001), and higher serum soluble vascular cell adhesion molecule‐1 (s VCAM ‐1) and high‐sensitivity C‐reactive protein levels ( P  =   0.004 and 0.008, respectively). Strong risk factors by univariate analysis were serum s VCAM ‐1 levels ≥1600 ng/mL, serum cell‐free Hb ≥ 3 mg/dL, asplenia, and amount of NRBC s/100 WBC s >40. Conclusions Prevalence of PHT in E/β‐ T hal patients was 37.3% without gender preponderance. Those with severe hemolysis and asplenia invariably had severer PHT . Strong risk factors were asplenia and associated markedly elevated values of s VCAM ‐1, cell‐free H b, and NRBC s in blood.