Features Associated With Pulmonary Hypertension In Splenectomized Patients With Hemoglobin E/β-Thalassemia Disease

Pulmonary hypertension (PHT) associated with thalassemia hemoglobinopathy is now an accepted clinical entity. Due to a high prevalence of thalassemia hemoglobinpathy worldwide, it is the most common entity of PHT. Despite the commonness, its pathogenesis is not yet completely understood. Although asplenia is a known risk factor, PHT does not develop in all splenectomized patients. The present study was therefore done to search for other associated features.

Sixty-one clinically stable splenectomized hemoglobin E/β-thalassemia disease (E/β-Thal) adult outpatients, on no medication aside from folic acid and who received no blood transfusion in the preceding 4 weeks, were prospectively studied. All gave written informed consent, and study protocol was approved by the institution ethics committee on studies in humans (#0774/2548). Transthoracic echocardiogram was used to evaluate cardiac function and to estimate pulmonary artery systolic pressure (PASP). PHT was defined as an estimated PASP ≥36 mmHg. Clinical features and laboratory data were dichotomized according to the presence (PHT+) or absence (PHT-) of PHT, and statistical analysis was done by STATA version 10 (Stata Corp, Texas), considering a P value<0.05 as statistically significant.

Of the 61 patients, 32 (52.5%) were PHT+, 14 of whom were female. There was no gender difference between the 2 groups (p=0.246). All had normal left ventricular ejection fraction, and none had positive serology for human immunodeficiency virus. Results expressed in mean ± SD or median (range) of the various measured parameters and their statistically significant differences are shown in the following table.

PHT was found in 52.5% of the 61 splenectomized E/β-Thal patients with no gender preponderance. Although PHT was found mostly after the first decade of splenectomy, its prevalence did not correlate with time elapsed since the procedure. Features associated with PHT in splenectomized E/β-Thal patients were greater transfusion requirement, lower RBC counts, higher serum lactate dehydrogenase (LDH) and lower serum cholesterol levels, as a reflection of more severe disease and more severe ineffective erythropoiesis; together with a higher serum soluble vascular cell adhesion molecule-1 (VCAM-1) levels, likely from chronic hypoxemia.

No relevant conflicts of interest to declare.