2.1 Study population
In this cross-sectional study, a total of 51 asymptomatic participants aged between 18 and 45 with β-TM on regular follow-up were recruited from the haematology clinic. We did not enroll a healty control group. Instead of this, we defined two groups based on their magnetic resonance (MR) T2* values (as ≤20 msec and >20 msec) which is an accepted indicator of cardiovascular involvement. Patients with coronary heart disease, moderate to severe valvular heart disease, congenital heart disease, atrial fibrillation, risk factors for atherosclerosis (hypertension, diabetes, hyperlipidemia, family history and smoking), left ventricular (LV) systolic or diastolic dysfunction, and patients who were using drugs which effect cardiovascular function were excluded from the study. Haematological and biochemical parameters were measured. As anemia can affect cardiac hemodynamic parameters, cardiovascular assessment was performed after transfusion to minimize potential confounding influence of anaemia.
We measured serum ferritin levels, and performed two- dimensional echocardiography (2DE) and real-time three-dimensional echocardiography (RT3DE) at the same session during rest condition. We analyzed T2* cardiac magnetic resonance imaging for determination of myocardial iron load, and assessed endothelial functions by brachial artery flow-mediated dilatation (FMD) and aortic strain.
The Local Ethics Committee approved this study and the informed consents were obtained from all participants.