THE EFFECT OF IRON OVERLOAD IN THE HEARTS OF PATIENTS WITH BETA-THALASSEMIA

Background and hypothesis: An important complication of beta-thalassem ia is iron deposition in cardiac tissues resulting in fibrosis and dys function. Our aim was the investigation of the possible clinical effec t of iron loading in the heart of patients with beta-thalassemia prior to the appearance of symptoms of depressed systolic function. Methods : Thirty-five patients with beta-thalassemia, of whom 24 had the major type (Group 1) and 11 had the intermedia type (Group 2) were studied. Eleven age- and gender-matched controls were also studied (Group 3). All patients were evaluated echocardiographically and were shown to ha ve normal left ventricular systolic function and dimensions. Serum fer ritin, atrial natriuretic peptide (ANP), left atrial diameter (LAD), p eak early mitral inflow velocity (E), peak late mitral inflow velocity (A), E/A ratio, deceleration time of the mitral inflow E wave (DT), an d isovolumic relaxation time (IVRT) were measured. Results: Univariate analysis showed that both groups of patients had similarly increased LAD and ANP plasma lev els. Group 1 had a higher E/A ratio (2.27 +/- 0 .88) SS than Group 2(1.69 +/- 0.47, p = 0.05) and Group 3 (1.50 +/- 0. 38, p = 0.01). Serum ferritin was significantly higher in Group 1 (3.5 26 +/- 0.352) than in Group 2 (2.808 +/- 0.288, p < 10(-5)) and Group 3 (2.139 +/- 0.124, p<10(-5)).Multivariate analysis showed that ANP is a factor that is affected by the LAD and E/A ratio and that serum fer ritin levels affect the LAD and E/A ratio. Conclusions: Although LAD a nd ANP levels are increased in patients with beta-thalassemia, the inc reased serum ferritin levels of patients seem to affect left atrial si ze and E/A ratio. ANP secretion is consecutively affected by these fac tors.