Prolonged survival in patients with beta-thalassemia major treated with deferoxamine
To determine whether survival of patients with beta-thalassemia major has been prolonged by management that utilizes hypertransfusion and chelation with deferoxamine, we analyzed longevity by the Kaplan-Meier product-limit method. Group 1 patients (n = 71) followed between 1960 and 1976 with a low-transfusion regimen (pretransfusion hemoglobin level 7 to 8 gm/dl) and no chelation had an estimated median age of survival of 17.4 years, whereas it was 31.0 years for group 2 subjects (n = 80), who began hypertransfusion between 1976 and 1978 (pretransfusion hemoglobin level 10.5 to 11.5 gm/dl) and chelation with deferoxamine (20 to 60 mg/kg per day) (p less than 0.0001). For 70 patients who were treated with hypertransfusion and deferoxamine, we had data to calculate the ratio of total milligrams of transfusional iron to cumulative grams of deferoxamine. The 24 patients who died had a total iron burden of greater than 1.05 gm/kg; the ratio for them exceeded 31. These patients were characterized by poor compliance with chelation or by late start of therapy, with inability to receive enough deferoxamine before death. Death was preceded by arrhythmia requiring therapy in all but one, and by cardiac failure in all. Of 41 similarly iron-loaded survivors, 33 had a ratio of less than 31; only three had an arrhythmia, and five had cardiac failure. We conclude that treatment with deferoxamine, when used in amounts proportional to iron burden, delayed cardiac complications and improved longevity.