Determining Nt-proBNP Levels with Diastolic Dysfunction in Thalassemia Major Patients

Beta thalassemia is an autosomal, recessive disorder, characterized by ineffective erythropoiesis. Chronic transfusions and inability of body to eliminate iron lead to an iron overload, thereby causing damage to heart. Natriuretic peptides (NPs) are produced within the heart, which are then released into the circulation in response to ventricular wall stress. We, therefore, aimed to study the relation between ventricular dysfunction and N-terminal pro-B-type natriuretic peptides (NT-proBNPs). We enrolled 105 patients with increased serum ferritin levels and echocardiography was performed. We collected blood samples and NT-proBNP levels were measured in them. Though we found that the studied group had no significant difference in the mean serum NT-proBNP levels, in patients with or without hypertrophy ( n  = 37, p  = 0.992), the NT-proBNP levels were found to be significantly increased in patients with diastolic dysfunction ( n  = 24, p  < 0.0001 with mean values of 577.67 ± 122.01 and 456.50 ± 48.40 pg/mL in patients with and without diastolic dysfunction, respectively). The NT-proBNP levels correlated well with the echocardiography indices, such as left ventricular end-systolic diameter (LVESD), ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/E' ratio), and ratio of the early (E) to late (A) ventricular filling velocities (E/A ratio), and were found to have significant positive correlation with the serum ferritin levels. The NT-proBNP levels correlated significantly with diastolic dysfunction; thus, serum ferritin levels could be useful for assessing the diastolic dysfunction in patients with beta thalassemia.