Comparison of effects of oral deferiprone and subcutaneous desferrioxamine on myocardial iron concentrations and ventricular function in beta-thalassaemia

Abstract

Background: Despite the introduction of the parenteral iron chelator desferrioxamine more than 30 years ago, 50% of patients with thalassaemia major die before the age of 35 years, predominantly from iron-induced heart failure. The only alternative treatment is oral deferiprone, but its long-term efficacy on myocardial iron concentrations is unknown.

Methods: We compared myocardial iron content and cardiac function in 15 patients receiving long-term deferiprone treatment with 30 matched thalassaemia major controls who were on long-term treatment with desferrioxamine. Myocardial iron concentrations were measured by a new magnetic-resonance T2* technique, which shows values inversely related to tissue iron concentration.

Findings: The deferiprone group had significantly less myocardial iron (median 34.0 ms vs 11.4 ms, p=0.02) and higher ejection fractions (mean 70% [SD 6.5] vs 63% [6.9], p=0.004) than the desferrioxamine controls. Excess myocardial iron (T2* <20 ms) was less common in the deferiprone group than in the desferrioxamine controls (four [27%] vs 20 [67%], p=0.025), as was severe (T2* <10 ms) iron overload (one [7%] vs 11 [37%], p=0.04). The odds ratio for excess myocardial iron in the desferrioxamine controls versus the deferiprone group was 5.5 (95% CI 1.2-28.8).

Interpretation: Conventional chelation treatment with subcutaneous desferrioxamine does not prevent excess cardiac iron deposition in two-thirds of patients with thalassaemia major, placing them at risk of heart failure and its complications. Oral deferiprone is more effective than desferrioxamine in removal of myocardial iron.