Long-term outcome of continuous 24-hour deferoxamine infusion via indwelling intravenous catheters in high-risk β-thalassemia

Abstract

The optimal regimen of intravenous deferoxamine for iron overload in high-risk homozygous β-thalassemia is unknown because only short-term follow-up has been described in small patient groups. We report the outcome over a 16-year period of a continuous 24-hour deferoxamine regimen, with dose adjustment for serum ferritin, delivered via 25 indwelling intravenous lines for 17 patients. Treatment indications were cardiac arrhythmias, left ventricular dysfunction, gross iron overload, and intolerability of subcutaneous deferoxamine. Cardiac arrhythmias were reversed in 6 of 6 patients, and the left ventricular ejection fraction improved in 7 of 9 patients from a mean (± SEM) of 36 ± 2% to 49 ± 3% (P = .002, n = 9). The serum ferritin fell in a biphasic manner from a pretherapy mean of 6281 ± 562 μg/L to 3736 ± 466 μg/L (P = .001), falling rapidly and proportionally to the pretreatment ferritin (r2 = 0.99) for values >3000 μg/L but falling less rapidly below this value (at 133 ± 22 μg/L/mo). The principal catheter-related complications were infection and thromboembolism (1.15 and 0.48 per 1000 catheter days, respectively), rates similar to other patient groups. Only one case of reversible deferoxamine toxicity was observed (retinal) when the therapeutic index was briefly exceeded. An actuarial survival of 61% at 13 years with no treatment-related mortality provides evidence of the value of this protocol.