Left ventricular function in thalassemia major: protective effect of deferoxamine

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.

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

Primary clinic.

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

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.

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.

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.