Survival in medically treated patients with homozygous ゲ-thalassemia

Background: The prognosis of patients with homozygous β-thalassemia (thalassemia major) has been improved by transfusion and iron-chelation therapy. We analyzed outcome and prognostic factors among patients receiving transfusions and chelation therapy who had reached the age at which iron-induced cardiac disease, the most common cause of death, usually occurs. Methods: Using the duration of life without the need for either inotropic or antiarrhythmic drugs as a measure of survival without cardiac disease, we studied 97 patients born before 1976 who were treated with regular transfusions and chelation therapy. We used Cox proportional-hazards analysis to assess the effect of prognostic factors and life-table analysis to estimate freedom from cardiac disease over time. Results: Of the 97 patients, 59 (61 percent) had no cardiac disease; 36 (37 percent) had cardiac disease, and 18 of them had died. Univariate analysis demonstrated that factors affecting cardiac disease-free survival were age at the start of chelation therapy (P<0.001), the natural log of the serum ferritin concentration before chelation therapy began (P = 0.01), the mean ferritin concentration (P<0.001), and the proportion of ferritin measurements exceeding 2500 ng per milliliter (P<0.001). With stepwise Cox modeling, only the proportion of ferritin measurements exceeding 2500 ng per milliliter affected cardiac disease-free survival (P<0.001). Patients in whom less than 33 percent of the serum ferritin values exceeded 2500 ng per milliliter had estimated rates of survival without cardiac disease of 100 percent after 10 years of chelation therapy and 91 percent after 15 years. Conclusions: The prognosis for survival without cardiac disease is excellent for patients with thalassemia major who receive regular transfusions and whose serum ferritin concentrations remain below 2500 ng per milliliter with chelation therapy., The prognosis of patients with transfusion-dependent homozygous β-thalassemia (thalassemia major) has been improved by regular transfusion and iron-chelation therapy¹. Before the introduction of therapy with deferoxamine, an iron-chelating agent, in the late 1970s,² iron overload from transfusions was a frequent cause of morbidity and mortality in these patients. Death was often due to cardiac failure, which typically began before the patient reached 20 years of age³. Previous studies have suggested that deferoxamine therapy, begun early in life, prolongs survival without cardiac disease,⁴–⁹ but follow-up was too short for unequivocal conclusions. The need for definitive information about the…