Royal Brompton Hospital and Imperial College, London, UK.
J Cardiovasc Magn Reson. 2011 Jan 17;13(1):8. doi: 10.1186/1532-429X-13-8.
Heart failure remains a major cause of mortality in thalassaemia major. The possible role of cardiac fibrosis in thalassemia major in the genesis of heart failure is not clear. It is also unclear whether cardiac fibrosis might arise as a result of heart failure.
We studied 45 patients with thalassaemia major who had a wide range of current cardiac iron loading and included patients with prior and current heart failure. Myocardial iron was measured using T2* cardiovascular magnetic resonance (CMR), and following this, late gadolinium enhancement (LGE) was used to determine the presence of macroscopic myocardial fibrosis.
The median myocardial T2* in all patients was 22.6 ms (range 5.3-58.8 ms). Fibrosis was detected in only one patient, whose myocardial T2* was 20.1 ms and left ventricular ejection fraction 57%. No fibrosis was identified in 5 patients with a history of heart failure with full recovery, in 3 patients with current left ventricular dysfunction undergoing treatment, or in 18 patients with myocardial iron loading with cardiacT2* < 20 ms at the time of scan.
This study shows that macroscopic myocardial fibrosis is uncommon in thalassemia major across a broad spectrum of myocardial iron loading. Importantly, there was no macroscopic fibrosis in patients with current or prior heart failure, or in patients with myocardial iron loading without heart failure. Therefore if myocardial fibrosis indeed contributes to myocardial dysfunction in thalassemia, our data combined with the knowledge that the myocardial dysfunction of iron overload can be reversed, indicates that any such fibrosis would need to be both microscopic and reversible.
心力衰竭仍然是重型地中海贫血患者死亡的主要原因。心脏纤维化在重型地中海贫血导致心力衰竭中的可能作用尚不清楚。也不清楚心脏纤维化是否可能是心力衰竭的结果。
我们研究了 45 名患有各种当前心脏铁负荷的重型地中海贫血患者，包括既往和当前心力衰竭的患者。使用 T2*心血管磁共振（CMR）测量心肌铁，之后使用晚期钆增强（LGE）确定是否存在宏观心肌纤维化。
所有患者的心肌 T2中位数为 22.6 ms（范围 5.3-58.8 ms）。仅在一名心肌 T2为 20.1 ms 和左心室射血分数为 57%的患者中检测到纤维化。在 5 名有心力衰竭病史且已完全恢复的患者、3 名正在接受治疗的当前左心室功能障碍患者或 18 名心肌铁负荷且扫描时心脏 T2*<20 ms 的患者中，未发现纤维化。
本研究表明，在广泛的心肌铁负荷范围内，重型地中海贫血中很少出现宏观心肌纤维化。重要的是，当前或既往心力衰竭或无心力衰竭的心肌铁负荷患者中没有宏观纤维化。因此，如果心肌纤维化确实导致地中海贫血患者的心肌功能障碍，我们的数据结合铁过载导致的心肌功能障碍可以逆转的知识表明，任何这种纤维化都需要是微观和可逆转的。
