Prognostic Significance of Left Ventricular Diastolic Indexes in β-Thalassemia Major

Objective To define the prognostic significance of left ventricular diastolic function in patients with beta-thalassemia major by noninvasive M-mode echocardiography and Doppler measurements. Design Cohort analytic study. Setting A university hospital in Taipei, Taiwan. Patients Forty-five patients (age range, 4 to 25 years) with transfusion-dependent beta-thalassemia major followed up for 5 years. Interventions None. Measurements and main results M-mode and Doppler echocardiography were used to determine the left systolic time interval; ejection fraction; left atrium emptying index; isovolumetric relaxation period; diastolic total period; the duration, slope, and height of the early diastolic flow-velocity peak; and the ratio between the heights of early and atrial diastolic flow-velocity peaks. All patients had normal systolic ventricular function initially, but impaired diastolic function developed, especially in the older age group who had more evidence of iron loading. In nine of those with abnormal diastolic total period (n = 10) and duration of the early diastolic flow-velocity peak (n = 12) values, regardless of age, congestive heart failure developed during the period of follow-up. Of these nine, four died within 2 years after the advent of heart failure and five remained compensated after anticongestive treatment and use of deferoxamine mesylate. The presence of an abnormal diastolic total period and duration of the early diastolic flow-velocity peak values correlated well with the prognosis. Conclusions Left ventricular diastolic filling variables by echocardiography are important predictors of the outcome of patients with transfusion-dependent beta-thalassemia major and could provide useful measures in determining the effects of medication during long-term follow-up.