Background: Heart disease represents the main determinant of survival in β-thalassemia, but its particular features in the two clinical forms of the disease, thalassemia major (TM) and thalassemia intermedia (TI), are not completely clarified.
Methods: We compared clinical and echocardiographic global parameters in 131 TM patients who received regular chelation transfusions and were highly compliant with treatment (mean age, 28 ± 6 years [± SD]), and 74 age-matched, TI patients who did not receive chelation transfusions.
Results: Congestive heart failure was encountered in five patients with TM (3.8%; age range, 25 to 29 years) and in two patients with TI (2.7%; age range, 37 to 40 years). Systolic left ventricular (LV) dysfunction (ejection fraction < 55% or shortening fraction < 35%) was only encountered in patients with TM (8.4%). Considerable pulmonary hypertension (systolic tricuspid gradient > 35 mm Hg) was only present in TI (23.0%). In the remaining patients without evident heart disease, cardiac dimensions, LV mass, LV shortening and ejection fractions, and cardiac output were significantly higher in patients with TI. LV afterload was higher in patients with TM. LV diastolic early transmitral diastolic peak flow velocity (E)/late transmitral diastolic peak flow velocity (A) ratio was also higher in TM. Systolic and mean pulmonary artery pressures and total pulmonary resistance were higher in both young and old TI patients.
Conclusion: Regular lifelong transfusion and chelation therapy in TM prevented premature heart disease and pulmonary hypertension, although LV dysfunction still occurred and led to heart failure. The absence of regular therapy in TI, in contrast, preserved systolic LV function but allowed pulmonary hypertension development, which also led to heart failure, starting within the fourth decade of life, a decade later compared to TM.