Document Detail


Relationship of magnetic resonance imaging estimation of myocardial iron to left ventricular systolic and diastolic function in thalassemia.
MedLine Citation:
PMID:  19356483     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: We sought to evaluate whether echocardiographic diastolic function indices correlate with myocardial iron and systolic function in patients with transfusion-dependent thalassemia (TDT) who are at risk for cardiomyopathy. BACKGROUND: In thalassemia syndromes, there is an important clinical need to risk stratify patients for the development of iron-overload cardiomyopathy so that chelation therapy can be adjusted and cardiac morbidity averted. This purpose may be served by measuring the magnetic resonance imaging (MRI)-derived parameter T2*, which varies inversely with tissue iron concentration but has limited availability. As diastolic dysfunction may precede systolic dysfunction, we sought to directly compare more readily available echocardiographic indices of diastolic function to myocardial T2* and ejection fraction (EF). METHODS: We identified 47 paired echocardiography and MRI examinations in 24 patients with TDT. Echocardiographic measurements of transmitral flow velocities (E, A), tissue Doppler velocities (E'), and left ventricular volume and EF were compared with MRI measurements of myocardial T2*, ventricular volume, and EF. RESULTS: All patients had a restrictive filling pattern (E/A >or=1.5 and deceleration time <140 ms) and normal relaxation. There was no significant correlation between E/E' or the Tei index versus EF. Although E/A and E' had statistically significant correlations with EF, the relationships were weak with all correlation coefficients <0.52. The parameters E/A, E', E/E', and the Tei index did not significantly correlate with myocardial iron concentration as assessed by MRI T2*. Increased myocardial iron as measured by T2* was strongly associated with lower left ventricular EF, with a T2* <9 ms having a sensitivity of 100% and specificity of 89% for MRI EF <50%. CONCLUSIONS: In patients with TDT, echocardiographic diastolic function parameters correlated poorly with EF and myocardial T2* and were thus not well-suited for risk stratification. Myocardial T2* had a strong relationship with EF and appears to be a promising approach for predicting the development of heart failure and for iron chelator dose adjustment.
Authors:
Benedetta Leonardi; Renee Margossian; Steven D Colan; Andrew J Powell
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  JACC. Cardiovascular imaging     Volume:  1     ISSN:  1876-7591     ISO Abbreviation:  JACC Cardiovasc Imaging     Publication Date:  2008 Sep 
Date Detail:
Created Date:  2009-04-09     Completed Date:  2009-04-23     Revised Date:  2009-05-21    
Medline Journal Info:
Nlm Unique ID:  101467978     Medline TA:  JACC Cardiovasc Imaging     Country:  United States    
Other Details:
Languages:  eng     Pagination:  572-8     Citation Subset:  IM    
Affiliation:
Department of Cardiology, Children's Hospital Boston, Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.
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MeSH Terms
Descriptor/Qualifier:
Adolescent
Adult
Cardiomyopathies / chemically induced,  metabolism,  physiopathology
Child
Echocardiography, Doppler
Female
Heart Diseases / chemically induced*,  metabolism,  physiopathology
Heart Failure / chemically induced,  metabolism,  physiopathology
Humans
Iron / metabolism*
Iron Chelating Agents / administration & dosage,  adverse effects*
Iron Overload / chemically induced,  diagnosis*,  metabolism,  physiopathology
Magnetic Resonance Imaging*
Male
Middle Aged
Myocardium / metabolism*
Predictive Value of Tests
ROC Curve
Retrospective Studies
Risk Assessment
Stroke Volume / drug effects
Thalassemia / drug therapy*,  metabolism,  pathology
Ventricular Dysfunction, Left / chemically induced,  metabolism,  physiopathology
Ventricular Function, Left / drug effects*
Young Adult
Chemical
Reg. No./Substance:
0/Iron Chelating Agents; 7439-89-6/Iron
Comments/Corrections
Comment In:
JACC Cardiovasc Imaging. 2008 Sep;1(5):579-81   [PMID:  19356484 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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