BACKGROUND: Heart failure resulting from myocardial iron deposition is the most important cause of death in beta-thalassemia major (TM) patients. Cardiac T2*magnetic resonance imaging (MRI), echocardiography, and serum ferritin level serve as diagnostic methods for detecting myocardial iron overload. In this study, we aimed to evaluate the relationship between the above-mentioned methods. METHODS: T2*MRI and echocardiographic measurement of left ventricular (LV) systolic and diastolic function were performed in 63 patients. Serum ferritin level was measured. The relationships between all assessments were evaluated. RESULTS: There were 40 women and 23 men with a mean age of 23.7+/-5.1 years (range, 15-35 years). There was no statistically significant correlation between serum ferritin level and LV systolic and diastolic function (P=0.994 and P=0.475, respectively). T2*MRI results had a significant correlation with ferritin level; 63.6% of patients with serum ferritin level >2,000 ng/mL had abnormal cardiac MRI, while none of the patients with ferritin level <1,000 ng/mL had abnormal cardiac MRI (P=0.001). There was no significant correlation between MRI findings and LV systolic function (P=1.00). However, we detected a significant difference between LV diastolic function and cardiac siderosis (P=0.03) CONCLUSION: MRI findings are a good predictor of future cardiac dysfunction, even in asymptomatic TM patients; however, diastolic dysfunction may happen prior to cardiac siderosis in some patients, and echocardiography is able to diagnose this diastolic dysfunction while T2*MRI shows normal findings.
beta-Thalassemia* ; Cause of Death ; Echocardiography* ; Female ; Ferritins ; Heart Failure ; Humans ; Iron ; Iron Overload ; Magnetic Resonance Imaging* ; Male ; Siderosis

OBJECTIVES: The lower mortality rate of obese patients with heart failure (HF) has been partly attributed to reverse causation bias due to weight loss caused by disease. Using data about weight both before and after HF, this study aimed to adjust for reverse causation and examine the association of obesity both before and after HF with mortality. METHODS: Using the Atherosclerosis Risk in Communities (ARIC) study, 308 patients with data available from before and after the incidence of HF were included. Pre-morbid and post-morbid obesity were defined based on body mass index measurements at least three months before and after incident HF. The associations of pre-morbid and post-morbid obesity and weight change with survival after HF were evaluated using a Cox proportional hazard model. RESULTS: Pre-morbid obesity was associated with higher mortality (hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.04 to 2.49) but post-morbid obesity was associated with increased survival (HR, 0.57; 95% CI, 0.37 to 0.88). Adjusting for weight change due to disease as a confounder of the obesity-mortality relationship resulted in the absence of any significant associations between post-morbid obesity and mortality. CONCLUSIONS: This study demonstrated that controlling for reverse causality by adjusting for the confounder of weight change may remove or reverse the protective effect of obesity on mortality among patients with incident HF.
Atherosclerosis* ; Bias (Epidemiology) ; Body Mass Index ; Heart Failure* ; Heart* ; Humans ; Incidence ; Mortality* ; Obesity* ; Proportional Hazards Models ; Weight Loss