Left ventricular function in thalassemia major: protective effect of deferoxamine.

Objective: To test the hypothesis that chelation therapy with deferoxamine would prevent alterations in left ventricular systolic and diastolic function due to transfusional iron overload in patients with thalassemia major.

Design: A consecutive series of patients receiving chronic transfusional and chelation therapy were studied by two-dimensional and Doppler echocardiography.

Setting: Primary clinic.

Patients: Eight thalassemic patients (four men and four women), mean age 22 years (range 14 to 28) and seven age and sex matched control subjects.

Interventions: All patients had received transfusional therapy since birth, with mean annual load of red blood cells of 200 mL/kg. Iron chelation therapy with deferoxamine, using a subcutaneous infusion pump, was administered from age two years in the younger patients and from age 16 years in the two older cases. Doses were 25 mg/kg/day in children and 1.5 to 4 g per 12 h in adults to maintain ferritin blood levels at 1000 to 1500 ng/L.

Main Results: No significant differences were found in the following Doppler diastolic indexes: isovolumic relaxation time, early flow velocity (E wave), late flow velocity (A wave), E:A ratio, rate of deceleration of flow velocity in early diastole (EF slope), flow velocity deceleration time and end-diastolic volume. Ejection fraction was similar in the two groups (59 +/- 7 versus 64 +/- 5%), but contractility, expressed as end-systolic pressure/end-systolic volume index, appeared slightly depressed (4.6 +/- 1 versus 6.7 +/- 0.8) in the thalassemic group.

Conclusions: Deferoxamine prevents alteration of left ventricular diastolic function in chronic transfusional therapy for thalassemia major. Depression of contractility, in spite of a normal ejection fraction, may be an early sign of worsening systolic performance, unavoidable even with chelation therapy.