Kahnooji Masoumeh, Rashidinejad Hamid Reza, Yazdanpanah Mohammad Shahram, Azdaki Nahid, Naghibzadeh-Tahami Ahmad
Assistant Professor, Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.
Associate Professor, Cardiovascular Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran.
ARYA Atheroscler. 2016 Sep;12(5):226-230.
The assessment of cardiac iron overload in thalassemia major has been considered as an important predictive factor of heart injury. The magnetic resonance imaging (MRI)-derived relaxation time parameter (T2*) varies inversely with iron level, and elevated myocardial iron levels by T2* are associated with depressed left ventricular (LV) ejection fraction (EF). We compared echocardiographic (ECHO) indices of systolic function to myocardial T2* in these patients.
A cross-sectional database review identified 200 consecutive patients with thalassemia who underwent both ECHO and MRI T2* assessment.
There was a negative correlation between T2* measurement and ECHO EF (r = -0.389, P < 0.001). Using a cutoff value of 50% for differentiating LV normal and abnormal function by ECHO, T2* MRI had a sensitivity of 57.1%, a specificity of 89.9%, and an accuracy of 86.5% for predicting LV dysfunction. Receiver operating characteristic analysis showed that cardiac iron measurement had an acceptable value for discriminating normal and abnormal LV function (area under the curve = 0.769, 95% confidence interval: 0.653-0.885). With respect to the relationship between serum ferritin level and cardiac iron value, the level of serum ferritin was positively correlated with the level of cardiac iron load (r = 0.257, P < 0.001).
Myocardial iron load assessed by MRI T2* is associated with deterioration of the LV function assessed by ECHO with a high specificity and moderate sensitivity. It is important to identify the thalassemic patients with a risk of iron overloaded cardiomyopathy and heart failure.
重型地中海贫血患者心脏铁过载的评估一直被视为心脏损伤的重要预测因素。磁共振成像（MRI）得出的弛豫时间参数（T2*）与铁水平呈负相关，通过T2测得的心肌铁水平升高与左心室（LV）射血分数（EF）降低有关。我们比较了这些患者收缩功能的超声心动图（ECHO）指标与心肌T2。
一项横断面数据库回顾确定了200例连续接受ECHO和MRI T2*评估的地中海贫血患者。
T2测量值与ECHO EF之间存在负相关（r = -0.389，P < 0.001）。使用ECHO区分LV正常和异常功能的临界值为50%时，T2 MRI预测LV功能障碍的敏感性为57.1%，特异性为89.9%，准确性为86.5%。受试者工作特征分析表明，心脏铁测量对于区分正常和异常LV功能具有可接受的值（曲线下面积 = 0.769，95%置信区间：0.653 - 0.885）。关于血清铁蛋白水平与心脏铁值之间的关系，血清铁蛋白水平与心脏铁负荷水平呈正相关（r = 0.257，P < 0.001）。
通过MRI T2*评估的心肌铁负荷与通过ECHO评估的LV功能恶化相关，具有高特异性和中等敏感性。识别有铁过载性心肌病和心力衰竭风险的地中海贫血患者很重要。
