Cardiovascular complications of thalassemia major and thalassemia intermedia

ABSTRACT

Cardiac complications due to Iron overload are the most common cause of death in beta-thalassemic patients. Although regular blood transfusions in thalassemia major [TM] patients have improved the quality of life of the patients but the most important complication of such transfusions is iron overload in cardiac tissues. In spite of iron overload in untransfused thalassemia intermedia [TI] patients, the intestinal absorption of iron increases in these patients because of ineffective erythropoesis. The aim of this study was to evaluate cardiac status in thalassemia major and intermedia patients and the investigation of the possible effect of iron overload in the heart of beta-thalassemic patients. 46 patients entered into this study. 26 patients had thalassemia major with regular blood and also chelator transfusions and 20 patients with thalassemia intermedia who had not received regular transfusions. The age of the patients in the 2 groups were similar. The results of clinical evaluation and echocardiographies of the patients of the 2 groups were compared with each other. Collected data were analyzed by means of Chi square and man whitney U tests. Heart failure occurred in two patients with TM [9.52%] and one patient with TI [4.76%]. Considerable pulmonary hypertension [systolic tricuspid gradient >35mmHg] was only present in 3 patients with TI [14.28%]. But systolic dysfunction of left ventricle [ejection fraction<55% or shortening fraction<35%] occurred in 5 patients with TM [23.8%]. In the patients without apparent heart disease, cardiac dimensions, LV mass, LV shortening and ejection fractions, cardiac output and valvular involvement were significantly more in patients with TI. But the maximum speed of systolic flow out of mitral valve in primary phase was higher significantly in TM patients than TI patients. Regular lifelong transfusion and chelation therapy in TM patients prevents premature heart disease and pulmonary hypertension, but LV dysfunction can occur and lead to heart failure. In contrast in TI patients left ventricular function is normal but pulmonary hypertension occurs which may lead to heart failure. Left ventricular performance is better preserved when chelation treatment is adjusted to maintain the serum ferritin concentration at <1000 nanogram/ml