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Myocardial iron loading in transfusion-dependent thalassemia and sickle cell disease

John C. Wood, J. Michael Tyszka, Susan Carson, Marvin D. Nelson and Thomas D. Coates

Article Figures & Data

Figures

  • Figure 1.

    Relationship among LV ejection fraction, myocardial T2*, and transfusion duration. (A) Plot of ejection fraction by MRI versus cardiac T2* in patients with thalassemia (•) and those with SCD (□). Dotted lines represent reference range for ejection fraction.12-14 Embedded Image indicates need for cardiac medications. Two patients had ventricular tachycardia, indicated by the letters VT. (B) Plot of cardiac T2* as a function of transfusion duration. Patients with SCD were predominantly receiving transfusions for less than 13 years (13 of 17), whereas the majority (10 of 19) of patients with thalassemia had transfusions for longer periods. None of the thalassemia patients receiving transfusions for less than 13 years had abnormal cardiac T2*, whereas 8 of 10 patients receiving transfusions for longer periods had abnormal T2*.

Tables

  • Table 1.

    Demographics and MRI data from patients with SCA and TM.

    ParameterSCATMPNormal reference range
    Age, y 17.6 ± 1.3 15.7 ± 1.4 .23
    Sex, M/F 9/8 10/9 .999
    Hepatic iron concentration, mg/g dry weight 19.3 ± 3.7 18.4 ± 3.8 .997
    Ferritin concentration 5422 ± 855 3648 ± 1378 .37
    Transfusion duration, y 9.3 ± 1.3 12.2 ± 1.5 .20
    Chelation duration, y 6.9 ± 1.2 9.8 ± 1.5 .23
    BSA, m2 1.57 ± 0.09 1.25 ± 0.06 .002*
    Pretransfusion hemoglobin level, g/L 94 ± 1 92 ± 1 .08
    Heart rate, bpm 89.6 ± 3.6 84.1 ± 3.5 .18
    Systolic blood pressure, mm Hg 116.9 ± 2.5 105 ± 2.3 .001*
    Diastolic blood pressure, mm Hg 63.5 ± 1.9 60.2 ± 1.8 .02*
    T2*, ms 38.1 ± 2.5 26.1 ± 4.6 .005* 25-46
    LV ejection fraction, % 71 ± 2 67 ± 2 .14 61-7714
    LV end-diastolic volume index, mL/m2 90.0 ± 5.4 85.9 ± 3.9 .53 36-8014
    LV end-systolic volume index, mL/m2 26.1 ± 2.2 29.1 ± 2.8 .41 5-3114
    LV mass index, g/m2 77.0 ± 4.8 63.4 ± 3.2 .008* 6-9514
    Cardiac index, L/min/m2 5.9 ± 0.5 4.6 ± 0.2 .03* 1.7-4.013
    • Data represent the mean value ± SE. Right hand column demonstrates 95% confidence intervals for MRI values; however, all statistical comparisons are between the two patient populations. — indicates not assessed.

    • * Significant P value.