Determination of early cardiac deterioration in beta-thalassaemia major by echocardiography.

OBJECTIVES

Cardiovascular involvement is the leading cause of mortality in patients with beta-thalassaemia major (beta-TM). This cross-sectional study was performed to evaluate the earlier cardiac damage in beta-TM by echocardiography, before left ventricular (LV) systolic dysfunction was observed.

METHODS AND

RESULTS

The study population consisted of 70 patients with beta-TM and was compared with age- and sex-matched healthy controls (n= 47). The study population was divided into subgroups based on serum ferritin levels and the time interval from first diagnosis. All patients and control subjects underwent transthoracic echocardiography. Mean LV ejection fractions were similar between groups (60 +/- 5% vs 62+/- 6%, P= 0.063). beta-TM patients had increased left atrial (LA) volume index, LV mass index, and right ventricle (RV) diameter index (30.3 +/- 9.9 vs 19.9 +/- 4.8, 97.0 +/-17.8 vs 80.2 +/- 13.6, and 1.50 +/- 0.17 vs 1.31 +/- 0.15; P= 0.0001, respectively). Patients with beta-TM had significantly shortened pulmonary acceleration times (133.7+/- 22.4 vs 154.9 +/- 16.5, P= 0.0001). Mitral early inflow (E) velocity and tissue Doppler (TDI) annular velocity (Em) ratios (E/Em) were also elevated (7.5 +/- 3.0 vs 6.2 +/- 1.6, respectively, P= 0.009). Serum levels of ferritin were correlated with interventricular septum (R= 0.308, P= 0.009) and posterior wall (R= 0.312, P= 0.009) thicknesses.

CONCLUSIONS

It is often unsuccessful to reverse iron-induced cardiac deterioration in late-stage disease when cardiac failure is already present. Increased LV mass index, LA volume index, RV diameter index, and decreased pulmonary acceleration time could be earlier parameters featuring premature cardiac remodelling in beta-TM. Increased E/Em ratio may also point out early cardiac deterioration in beta-TM patients.