Prevalence of thromboembolic events among 8,860 patients with thalassaemia major and intermedia in the Mediterranean area and Iran.

Beta-thalassaemia is a congenital haemolytic anaemia characterized by partial (intermedia, TI) or complete (major, TM) deficiency in the production of beta-globin chains. The primary aim of this study was to determine the prevalence of thromboembolic events in patients with beta-thalassaemia. To achieve this, a multiple choice questionnaire was sent to 56 tertiary referral centres in eight countries (Lebanon, Italy, Israel, Greece, Egypt, Jordan, Saudi Arabia and Iran), requesting specific information on patients who had experienced a thromboembolic event. The study demonstrated that thromboembolic events occurred in a clinically relevant proportion (1.65%) of 8,860 thalassaemia patients (TI - 24.7% or TM - 75.3%) from the Mediterranean and Iran. Thromboembolism occurred 4.38 times more frequently in TI than TM (p < 0.001), with more venous events occurring in TI and more arterial events occurring in TM. Thrombosis in thalassaemia was also more common in females, splenectomized patients and those with profound anaemia (haemoglobin <9 g/dl). Due to the increased risk of thromboembolic events, the rationale for splenectomy should perhaps be re-assessed and the role of transfusion therapy for the prophylaxis of thrombosis, among other complications, be evaluated prospectively.