Objective: Beta-thalassemia hemoglobin E (beta-thal/HbE) is the commonest beta-thalassemia disease. Cardiovascular complications are still the leading cause of death in these patients. Regular transfusion with iron chelation has been currently more employed. Yet studies on hemodynamic and cardiovascular changes in this particular patients are still lacking. We aimed to define hemodynamic and cardiovascular characteristics in beta-thal/HbE patients receiving regular transfusion concomitant with iron chelation compared to healthy controls.

Materials and Methods: Cross-sectional study of 40 beta-thal/HbE patients receiving regular transfusion and iron chelation over one year and 40 age-sex-matched healthy controls was conducted. Hemodynamic and echocardiographic parameters were evaluated.

Results: The age (mean ± SD) of patients was 34±10 years. Beta-thal/HbE patients demonstrated significant differences in following parameters compared to healthy controls (all p<0.001): mean blood pressure (76.7±8.7 vs. 86.8±10.8 mmHg), stroke index (51.3±12.7 vs. 36.7±8.3 ml/m2), cardiac output index (3.9±1.1 vs. 2.5±0.6 L/min), vascular resistance index (9.81±3.28 vs. 12.42±2.26 mm·min/L·m2), systemic arterial compliance index (1.26±0.48 vs. 0.69±0.22ml/m2/mmHg), left ventricular systolic and diastolic volume index (48.2±14.0 vs. 37.4±9.2 and19.1±5.7 vs. 13.2±4.2 ml/m2). Biventricular systolic and left ventricular diastolic functions were well-preserved. Pulmonary arterial pressure was significantly elevated in beta-thal/HbE. However, the prevalence of pulmonary arterial hypertension (PAH) was 20% which was lower than previous populations receiving occasional transfusion.

Conclusion: Cardiovascular features compensating for longstanding anemia remain detectable in beta-thal/HbE patients receiving regular transfusion and iron chelation. Higher cardiac output, lower systemic vascular resistance and an enlarged left ventricular chamber were found in this particular population. However, systolic and diastolic functions remained well-preserved despite chronic transfusion.

Keywords: β-thalassemia/HbE, regular transfusion, echocardiography, hemodynamics