The role of brain natriuretic peptide and tissue doppler echocardiography in the management of transfusion dependent thalassaemia patients.
Doctoral thesis, UCL (University College London).
Available under License : See the attached licence file.
Background: Iron induced heart failure is the commonest cause of death in thalssaemia major. The cardiomyopathy is reversible when treated early, but once symptomatic heart failure occurs, the outlook is poor. A recent technique using magnetic resonance myocardial T2* (T2 star) has been validated for the assessment of early myocardial iron deposition. Worldwide however, transthoracic echocardiography is the mainstay of assessment for these patients. Conventional echo parameters are poor at identifying those with cardiac iron loading who are at risk of cardiac failure, only becoming abnormal once significant iron loading has occurred. Newer techniques involving tissue Doppler imaging (TDI) have been promising. Our aim was to explore the role of these techniques and that of brain natriuretic peptide (BNP), a biomarker released in heart failure, in the management of Thalassaemia major patients. Methods/Results: 167 patients with thalassaemia major were screened with cardiac T2* MRI to quantify iron loading. Those with severe cardiac iron, T2* <8ms, (n=15) were treated with both desferrioxamine and deferiprone chelation. Those with mild to moderate cardiac iron, T2* 8- 20ms, (n=65) were randomised to desferrioxamine plus either deferiprone or placebo. Both groups were treated for 12 months. At baseline, 6 and 12 months all those in the combination therapy trial and in the severe group were assessed with T2*, full transthoracic echocardiography including TDI and BNP levels. BNP only became abnormal in those with obvious clinical heart failure. TDI systolic velocities in the septum and RV were significantly lower in those with severe cardiac iron and improved over 12 months, correlating with an improvement in T2*. Conclusion: In thalassaemia patients, BNP is unhelpful in assessing cardiac iron status. Systolic tissue velocities can give an indication as to an individuals cardiac iron status and could help to monitor their progress during chelation therapy.
|Title:||The role of brain natriuretic peptide and tissue doppler echocardiography in the management of transfusion dependent thalassaemia patients|
|Open access status:||An open access version is available from UCL Discovery|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Medical Sciences > Medicine (Division of)|
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