MR Imaging of Diffuse Myocardial Fibrosis in Transfusion-Dependent Anemias (MAFIO)
Chronic Blood Transfusion Related Iron Overload
|Study Design:||Observational Model: Case Control
Time Perspective: Prospective
|Official Title:||Quantification of Diffuse Myocardial Iron Overload Related Interstitial Fibrosis With Cardiac Magnetic Resonance Imaging in Patients With Transfusion-Dependent Anemias|
- Evidence of diffuse myocardial fibrosis (elevated extracellular volume fraction) confirmed by MRI [ Time Frame: at time of cardiac MR examination for each individual ] [ Designated as safety issue: No ]At the time of MRI respective imaging data will be collected to assess the extracellular volume fraction as a marker for diffuse myocardial fibrosis.
- Regional myocardial dysfunction as assessed by global longitudinal strain Echocardiography measurement [ Time Frame: at time of echocardiography examination for each individual ] [ Designated as safety issue: No ]At the time of echocardiography (same day as MRI) respective strain data with be gathered for outcome assessment.
|Study Start Date:||July 2013|
|Study Completion Date:||June 2014|
|Primary Completion Date:||May 2014 (Final data collection date for primary outcome measure)|
Myocardial Iron Overload
chronic blood transfusion related myocardial iron overload
age matched healthy volunteers
Cardiac failure is the major cause of death in patients with transfusion-related iron overload. Histopathologic studies indicate that patients with myocardial siderosis have diffuse interstitial fibrosis. Cardiac MR assessment of the extracellular volume (ECV) fraction in other disease processes has been shown to accurately characterize diffuse myocardial fibrosis and to correlate with changes in diastolic function. No prior studies have assessed for diffuse interstitial myocardial fibrosis in patients with iron overload utilizing the proposed imaging techniques.
In this study, the investigators will assess the presence and extent of interstitial fibrosis in patients with transfusion-dependent anemias using cardiac MR techniques of T1 mapping and determination of ECV fraction. ECV values will be correlated with the severity of myocardial iron deposition determined by multi-echo T2*-weighted imaging, systolic ventricular function as determined by cardiac MR and diastolic function assessed by echocardiography. The investigators will recruit 35 patients with transfusion-related iron overload. Ten age-matched healthy subjects will be included as controls, to establish baseline values of myocardial T1 and ECV values. A modified Look-Locker with inversion recovery (MOLLI) sequence will be used to determine T1 values pre-, and post-administration of a gadolinium-based contrast agent (GBCA) at 1.5 Tesla. Calculated ECV values will be compared between iron-overload subjects and healthy controls, and will be correlated with left ventricular ejection fraction, measures of diastolic dysfunction and T2* values.
Detection of myocardial fibrosis in patients with iron overload would allow for improved prognostication and risk stratification. Elucidation of the relationship between myocardial fibrosis and myocardial iron deposition as well as cardiac functional parameters would provide valuable mechanistic insights and improved pathophysiological understanding of the disease. The results of the proposed study have the potential to significantly impact patient management including recommendations for earlier or more aggressive chelation therapy based on changes in ECV values.
Please refer to this study by its ClinicalTrials.gov identifier: NCT02090699
|Toronto General Hospital|
|Toronto, Ontario, Canada, M5G 2N2|