On improvement in ejection fraction with iron chelation in thalassemia major and the risk of future heart failure

Journal of Cardiovascular Magnetic Resonance

Research

JP Carpenter¹  DJ Pennell¹  M Roughton²  ZI Cabantchik³ 

[1] Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, UK;National Heart and Lung Institute, Imperial College, London, UK;Department of Statistics, University College London, UK;Life Sciences Institute, Hebrew University of Jerusalem, Safra Campus-Givat Ram, Jerusalem, Israel;

关键词: Ejection Fraction;    Left Ventricular Ejection Fraction;    Cardiovascular Magnetic Resonance;    Iron Overload;    Iron Chelator;   

DOI  :  10.1186/1532-429X-13-45

 received in 2011-09-06, accepted in 2011-09-12,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundTrials of iron chelator regimens have increased the treatment options for cardiac siderosis in beta-thalassemia major (TM) patients. Treatment effects with improved left ventricular (LV) ejection fraction (EF) have been observed in patients without overt heart failure, but it is unclear whether these changes are clinically meaningful.MethodsThis retrospective study of a UK database of TM patients modelled the change in EF between serial scans measured by cardiovascular magnetic resonance (CMR) to the relative risk (RR) of future development of heart failure over 1 year. Patients were divided into 2 strata by baseline LVEF of 56-62% (below normal for TM) and 63-70% (lower half of the normal range for TM).ResultsA total of 315 patients with 754 CMR scans were analyzed. A 1% absolute increase in EF from baseline was associated with a statistically significant reduction in the risk of future development of heart failure for both the lower EF stratum (EF 56-62%, RR 0.818, p < 0.001) and the higher EF stratum (EF 63-70%, RR 0.893 p = 0.001).ConclusionThese data show that during treatment with iron chelators for cardiac siderosis, small increases in LVEF in TM patients are associated with a significantly reduced risk of the development of heart failure. Thus the iron chelator induced improvements in LVEF of 2.6% to 3.1% that have been observed in randomized controlled trials, are associated with risk reductions of 25.5% to 46.4% for the development of heart failure over 12 months, which is clinically meaningful. In cardiac iron overload, heart mitochondrial dysfunction and its relief by iron chelation may underlie the changes in LV function.

【 授权许可】

CC BY   
© Pennell et al; licensee BioMed Central Ltd. 2011