Iron Overload and Myocardial Restriction

Heart failure still remains the main cause of death in β-thalassemia, despite the progress, which was made by intensification of iron chelation therapy. Iron myocardial deposition, due to regular blood transfusions, can cause congestive heart failure as a result of left- or right-sided heart failure combined with left ventricular myocardial restriction. Regular and intense chelation therapy has improved quality of life and survival by decreasing secondary hemochromatosis. However, heart failure has not been prevented despite the intensification of iron chelation therapy.             Acute myocarditis in β-thalassemia major has been reported to contribute to heart failure in addition to iron overloading. However, apart from myocarditis which may lead to immune mediated chronic left ventricular dysfunction and failure, other factors acting through immunologic or genetically defined mechanisms might also affect the development of left sided heart failure. Multiple transfusions represent a repetitive antigenic stimulus together with iron chelation therapy itself. In this brief overview, the pathogenetic mechanisms of myocardial involvement and heart failure in β-thalassemia major are discussed