1101
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Kolnagou A, Economides C, Eracleous E, Kontoghiorghes GJ. Low serum ferritin levels are misleading for detecting cardiac iron overload and increase the risk of cardiomyopathy in thalassemia patients. The importance of cardiac iron overload monitoring using magnetic resonance imaging T2 and T2*. Hemoglobin 2006; 30:219-27. [PMID: 16798647 DOI: 10.1080/03630260600642542] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The incidence of cardiomyopathy was monitored in a 6-year follow-up study involving 56 transfused thalassemia patients treated with deferoxamine (DFO), deferiprone (L1) or their combination. During this period, five female patients on regular subcutaneous or intravenous DFO presented with cardiac complications. Three patients suffered congestive heart failure and the other two arrhythmias. Four of the five patients maintained serum ferritin levels of about 1 mg/L or below and the fifth about 1.5 mg/L for several years prior to the cardiomyopathy. Cardiac magnetic resonance imaging (MRI) T2* and T2 was performed in four patients after the cardiomyopathy, identifying the presence of moderate-to-heavy siderosis. The treatment of the five patients has since changed, involving mainly the use of L1. Low serum ferritin levels appear to be misleading for detecting cardiac iron overload and this may increase the risk of cardiomyopathy. The MRI T2 and T2* relaxation time measurements are a more accurate method of detecting cardiac iron overload. Chelation therapy using L1 or appropriate L1/DFO combinations can reduce cardiac iron overload and the mortality rate in thalassemia patients.
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Affiliation(s)
- Annita Kolnagou
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol, Cyprus
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1102
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Schocke MFH, Zoller H, Vogel W, Wolf C, Kremser C, Steinboeck P, Poelzl G, Pachinger O, Jaschke WR, Metzler B. Cardiac phosphorus-31 two-dimensional chemical shift imaging in patients with hereditary hemochromatosis. Magn Reson Imaging 2006; 22:515-21. [PMID: 15120171 DOI: 10.1016/j.mri.2004.01.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2003] [Accepted: 01/26/2004] [Indexed: 10/26/2022]
Abstract
Hemochromatosis is a hereditary iron overload syndrome characterized by increased iron storage, followed by liver cirrhosis and is often associated with restrictive cardiomyopathy. The purpose of this study was to detect alterations of cardiac high-energy phosphate metabolism in patients with hereditary hemochromatosis (HHC) prior to the development of structural heart diseases. Therefore cardiac phosphorus-31 two-dimensional chemical shift imaging ((31)P 2D CSI) was employed. Twenty-four male patients (mean age 47.2 +/- 12 years) homozygous for the C282Y mutation in the hemochromatosis associated HFE gene and twenty-four male healthy volunteers (mean age 47 +/- 11 years) as age-matched controls were included in this study. Using a 1.5-Tesla whole-body magnetic resonance scanner, electrocardiograph-triggered transversal 31P 2D CSI was performed. Left ventricle mean phosphocreatine (PCr) to beta-adenosine triphosphate (beta-ATP) ratios of patients with HHC (1.60 +/- 0.41) were significantly decreased in comparison to healthy volunteers (1.93 +/- 0.36; p = 0.004). Furthermore, we detected moderate, negative correlations between left ventricular PCr to beta-ATP ratios and transferrin saturation, cholesterol, low-density lipoprotein as well as triglyceride. This study shows that 31P 2D CSI permits the detection of alterations of cardiac high-energy phosphate metabolism in patients with HHC, but without any evidence for heart disease. The decreased PCr to beta-ATP ratios in HHC might be caused by mitochondrial impairment due to cardiac iron overload.
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Affiliation(s)
- Michael F H Schocke
- Department of Radiology, University Hospital of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Tyrol, Austria.
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1103
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Rose C, Vandevenne P, Bourgeois E, Cambier N, Ernst O. Liver iron content assessment by routine and simple magnetic resonance imaging procedure in highly transfused patients. Eur J Haematol 2006; 77:145-9. [PMID: 16608501 DOI: 10.1111/j.0902-4441.2006.t01-1-ejh2571.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Liver iron content (LIC) assessment by magnetic resonance imaging (MRI) is validated but not standardized. In a single center, we tried to assess the accuracy of a specific, simple MRI procedure adapted to high LIC from a well-established simple and routine procedure known to quantify LIC. METHODS In 27 cases of monthly transfused patients, we compared biochemical values of LIC assessed on liver biopsy specimens and results obtained by two signal intensity ratio of gradient echo imaging (R2*) MRI protocols. The first was Gandon's routine procedure previously validated in liver disease and the second, our own method, was an addition of a gradient echo sequence specifically adapted to high LIC encountered in hematology practice. RESULTS Twenty-seven liver biopsies were performed in 18 adult patients (myelodysplastic syndrome = 5, beta-thalassemia = 13). LIC by biopsy ranged from 1.4 to 54 mg/g liver dry weight (mg/g dw) (median 9.4 mg/g dw). Correlation between LIC by biopsy and by MRI with Gandon's procedure was good (R = 0.80) in patients with LIC falling within the range reported by Gandon. By contrast, a weak correlation was demonstrated (R = 0.52) in patients with high LIC (above 11.2 mg/g dw). With our sequences, the correlation was good both in the entire group of patients (R = 0.83) and in patients with LIC above 11.2 mg/g dw (R = 0.85). CONCLUSION Our results suggest that the addition of a specific shorter-gradient echo sequence to a very simple, fast technique produces an accurate estimation of LIC in post-transfusional iron overload.
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Affiliation(s)
- Christian Rose
- Service d'Hématologie, Groupe Hospitalier de l'Institut Catholique Lillois, GHICL, Hôpital Saint Vincent, Université Catholique de Lille, Lille, France
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1104
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Sheth S, Tang H, Jensen JH, Altmann K, Prakash A, Printz BF, Hordof AJ, Tosti CL, Azabagic A, Swaminathan S, Brown TR, Olivieri NF, Brittenham GM. Methods for noninvasive measurement of tissue iron in Cooley's anemia. Ann N Y Acad Sci 2006; 1054:358-72. [PMID: 16339684 DOI: 10.1196/annals.1345.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
To examine the relationship between myocardial storage iron and body iron burden, as assessed by hepatic storage iron measurements, we studied 22 patients with transfusion-dependent thalassemia syndromes, all being treated with subcutaneous deferoxamine, and 6 healthy subjects. Study participants were examined with a Philips 1.5-T Intera scanner using three multiecho spin echo sequences with electrocardiographic triggering and respiratory navigator gating. Myocardial and hepatic storage iron concentrations were determined using a new magnetic resonance method that estimates total tissue iron stores by separately measuring the two principal forms of storage iron, ferritin and hemosiderin. In a subset of 10 patients with beta-thalassemia major, the hepatic storage iron concentration had been monitored repeatedly for 12-14 years by chemical analysis of tissue obtained by liver biopsy and by magnetic susceptometry. In this subset, we examine the relationship between hepatic iron concentration over time and our current magnetic resonance estimates of myocardial iron stores. No significant relationship was found between simultaneous estimates of myocardial and hepatic storage iron concentrations. By contrast, in the subset of 10 patients with beta-thalassemia major, the correlation between the 5-year average of hepatic iron concentration and the current myocardial storage iron was significant (R = .67, P = .03). In these patients, myocardial storage iron concentrations seem to reflect the control of body iron over a period of years. Magnetic resonance methods promise to provide more effective monitoring of iron deposition in vulnerable tissues, including the liver, heart, and endocrine organs, and could contribute to the development of iron-chelating regimens that more effectively prevent iron toxicity.
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Affiliation(s)
- Sujit Sheth
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, Harkness Pavilion, Room HP5, 180 Fort Washington Avenue, New York, NY 10032, USA.
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1105
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Wood JC, Enriquez C, Ghugre N, Otto-Duessel M, Aguilar M, Nelson MD, Moats R, Coates TD. Physiology and pathophysiology of iron cardiomyopathy in thalassemia. Ann N Y Acad Sci 2006; 1054:386-95. [PMID: 16339687 PMCID: PMC2892916 DOI: 10.1196/annals.1345.047] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Iron cardiomyopathy remains the leading cause of death in patients with thalassemia major. Magnetic resonance imaging (MRI) is ideally suited for monitoring thalassemia patients because it can detect cardiac and liver iron burdens as well as accurately measure left ventricular dimensions and function. However, patients with thalassemia have unique physiology that alters their normative data. In this article, we review the physiology and pathophysiology of thalassemic heart disease as well as the use of MRI to monitor it. Despite regular transfusions, thalassemia major patients have larger ventricular volumes, higher cardiac outputs, and lower total vascular resistances than published data for healthy control subjects; these hemodynamic findings are consistent with chronic anemia. Cardiac iron overload increases the relative risk of further dilation, arrhythmias, and decreased systolic function. However, many patients are asymptomatic despite heavy cardiac burdens. We explore possible mechanisms behind cardiac iron-function relationships and relate these mechanisms to clinical observations.
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Affiliation(s)
- John C Wood
- Division of Cardiology, Mailstop 34, Childrens Hospital of Los Angeles, 4650 Sunset Blvd., Los Angeles, CA 90027, USA.
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1106
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Abstract
Magnetic resonance T2* values of the myocardium are directly related to tissue iron levels. Minor effects from myocardial oxygenation and fibrosis are overwhelmed by the highly dominant iron effect in clinically relevant levels of myocardial iron overload. Myocardial T2* values less than 20 ms indicate iron overload, and this is considered severe when T2* is less than 10 ms. Decreasing myocardial T2* levels are associated with systolic and diastolic ventricular dysfunction. Most recorded cases of heart failure in thalassemia to date have occurred in patients with very low T2* values (in the severe range). Exceptions to this have occurred in patients with other causes of heart failure such as concomitant congenital heart disease. In patients presenting with heart failure who undergo aggressive chelation with continuous intravenous deferoxamine, longitudinal studies show that myocardial T2* increases, and this is accompanied by increases in ejection fraction and relief of heart failure. In cross-sectional studies, the myocardial T2* and ejection fraction of patients on deferiprone was superior to that of patients on deferoxamine. Randomized controlled prospective trials comparing these two drugs for their action in clearing myocardial iron, as measured by myocardial T2*, are under way and should report in 2005/2006. These trials will clarify the role of different chelators in the management of myocardial iron overload and may be valuable in reducing the toll of death in thalassemia from heart failure.
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Affiliation(s)
- Dudley J Pennell
- CMR Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK.
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1107
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Abstract
For a number of patients it is difficult to diagnose the cause of cardiac disease. In such patients cardiac magnetic resonance is useful for helping to make a differential diagnosis between ischaemic and dilated cardiomyopathy; identifying patients with myocarditis; diagnosing cardiac involvement in sarcoidosis and Chagas' disease; identifying patients with unusual forms of hypertrophic cardiomyopathy and those with continuing myocardial damage; and defining the sequelae of ablation treatment for hypertrophic obstructive cardiomyopathy.
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Affiliation(s)
- U Sechtem
- Division of Cardiology and Pulmology, Robert-Bosch-Krankenhaus, Auerbachstrasse 110, D-70376 Stuttgart, Germany.
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1108
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Piga A, Roggero S, Marletto F, Sacchetti L, Longo F. Combined use of oral chelators and desferrioxamine in thalassemia. ACTA ACUST UNITED AC 2006; 10 Suppl 1:89-91. [PMID: 16188646 DOI: 10.1080/10245330512331389737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- A Piga
- Thalassemia Center, Department of Pediatric Hematology-Oncology, University of Torino, Italy.
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1109
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Pepe A, Lombardi M, Positano V, Cracolici E, Capra M, Malizia R, Prossomariti L, De Marchi D, Midiri M, Maggio A. Evaluation of the efficacy of oral deferiprone in beta-thalassemia major by multislice multiecho T2*. Eur J Haematol 2006; 76:183-92. [PMID: 16451393 DOI: 10.1111/j.1600-0609.2005.00587.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Oral deferiprone (L1) appears to be promising in the treatment of beta-thalassemia major (TM) patients. T2* magnetic resonance imaging (MRI) with a single measurement in the mid-ventricular septum was validated as a quantitative evaluation of myocardial iron overload. Previous studies suggested a marked heterogeneity of iron distribution in the myocardium. We set up a multislice multiecho T2* MRI for the detection of this heterogeneity. The aim of our study was to investigate differences between the L1 vs. the subcutaneous desferrioxamine (DF)-treated patients using this new approach. METHODS Thirty-six beta-TM patients (age 29 +/- 8 yr) underwent MRI. Eighteen patients received long-term L1, and 18 other patients matched for age and sex received DF. T2* multiecho sequences on three short axis views of the left ventricle were obtained and analyzed by custom-made software. In each slice, the myocardium was automatically segmented into four segments. Cine-dynamic images were also obtained to evaluate biventricular function. RESULTS For multislice T2* technique, the coefficient of variation for intra- and inter-observer, and inter-study reproducibility was 3.9%, 4.7%, and 5.5%, respectively. The global heart T2* value was significantly higher in the L1 vs. DF group (35 +/- 7 vs. 27 +/- 2 ms; P = 0.02). The number of segments with normal T2* value (>20 ms) was significantly higher in the L1 vs. the DF group (11 +/- 1 vs. 8 +/- 5 segments; P = 0.03). We did not detect significant differences in biventricular function parameters. CONCLUSIONS This new approach confirms that L1 could be more effective than DF in removal of myocardial iron.
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Affiliation(s)
- Alessia Pepe
- MRI Laboratory, Institute of Clinical Physiology, CNR, Pisa, Italy.
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1110
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Alexopoulou E, Stripeli F, Baras P, Seimenis I, Kattamis A, Ladis V, Efstathopoulos E, Brountzos EN, Kelekis AD, Kelekis NL. R2 relaxometry with MRI for the quantification of tissue iron overload in beta-thalassemic patients. J Magn Reson Imaging 2006; 23:163-70. [PMID: 16374880 DOI: 10.1002/jmri.20489] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To evaluate the usefulness of a time-efficient MRI method for the quantitative determination of tissue iron in the liver and heart of beta-thalassemic patients using spin-spin relaxation rate, R2, measurements. MATERIALS AND METHODS Images were obtained at 1.5 T from aqueous Gd-DTPA solutions (0.106-8 mM) and from the liver and heart of 46 beta-thalassemic patients and 10 controls. The imaging sequence used was a respiratory-triggered 16-echo Carr-Purcell-Meiboom-Gill (CPMG) spin-echo (SE) pulse sequence (TR = 2000 msec, TE(min) = 5 msec, echo spacing (ES) = 5 msec, matrix = 192 x 256, slice thickness = 10 mm). Liver iron concentration (LIC) measurements were obtained for 22 patients through biopsy specimens excised from the relevant liver segment. Biopsy specimens were also evaluated regarding iron grade and fibrosis. Serum ferritin (SF) measurements were obtained in all patients. RESULTS A statistically significant difference was found between patients and healthy controls in mean liver (P < 0.004) and myocardium (P < 0.004) R2 values. The R2 values correlated well with Gd DTPA concentration (r = 0.996, P < 0.0001) and LIC (r = 0.874, P < 0.0001). A less significant relationship (r = 0.791, P < 0.0001) was found between LIC measurements and SF levels. R2 measurements appear to be significantly affected (P = 0.04) by different degrees of hepatic fibrosis. The patients' liver R2 values did not correlate with myocardial R2 values (r = 0.038, P < 0.21). CONCLUSION Tissue iron deposition in beta-thalassemic patients may be adequately quantified using R2 measurements obtained with a 16-echo MRI sequence with short ES (5 msec), even in patients with a relatively increased iron burden.
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Affiliation(s)
- Efthymia Alexopoulou
- Second Department of Radiology, National and Kapodistrian University of Athens, Athens, Greece
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1111
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Christoforidis A, Haritandi A, Tsitouridis I, Tsatra I, Tsantali H, Karyda S, Dimitriadis AS, Athanassiou-Metaxa M. Correlative study of iron accumulation in liver, myocardium, and pituitary assessed with MRI in young thalassemic patients. J Pediatr Hematol Oncol 2006; 28:311-5. [PMID: 16772883 DOI: 10.1097/01.mph.0000212915.22265.3b] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Clinical complications resulting from unevenly iron accumulation in individual organs of patients with beta-thalassemia major can affect both expectancy and quality of life. Magnetic resonance imaging (MRI) offers a quantitative, noninvasive, accurate method for estimating iron levels in various tissues, not easily accessible with other techniques. The aim of this study was to evaluate and correlate the level of iron accumulation in different organs (anterior pituitary, myocardium, and liver) assessed with MRI, in children and young adults with beta-thalassemia major. Thirty children and young adults (13 female and 17 male patients) with homozygous beta-thalassemia, treated conventionally, were studied with hepatic, myocardial, and hypophyseal MRI. For liver and myocardium, we calculated the natural logarithm of the signal-to-air ratio in flash 2-dimensional sequences with electrocardiogram gating, whereas for anterior pituitary, the signal intensity was measured in sagittal T2 sequences. All scans were performed within 3 months. In 13 patients, data regarding liver iron concentrations (LIC) assessed by percutaneous liver biopsy were available. The mean of serum ferritin concentrations for 1 year before scans was calculated for each patient. MRI values in myocardium and liver showed a significant negative correlation to age (r=-0.73 and -0.69, respectively). For pituitary MRI, a linear regression with age was recorded in patients over 14 years of age (r=-0.67), whereas a relatively increased signal intensity reduction was recorded in pubertal subjects. Mean serum ferritin concentrations ranged from 252 to 5872 mug/L with an average of 1525+/-1047 mug/L. No statistical significant correlation was noted between mean ferritin levels versus liver, pituitary, and cardiac MRI values (r=-0.49, -0.28, and -0.1, respectively). Mean LIC values assessed by percutaneous biopsy were 13.76+/-11.6 mg/g of dry tissue. A statistically significant negative correlation was observed between liver MRI readings and LIC determined by biopsy (r=-0.89). None of the 3 organs studied with MRI were significantly correlated to each other. Pituitary to liver MRI values and liver to myocardial MRI values were moderately correlated (r=0.34 and 0.42, respectively). Pituitary MRI was not correlated at all to myocardial MRI (r=-0.001). In conclusion, iron accumulation in thalassemic patients is a procedure progressing with age, which seems to act independently in different organs. MRI represents a reliable, noninvasive method for assessing iron overload in various tissues, non-easily accessible with other techniques. Regular scanning, to recognize preclinically excessive iron deposits and intensified chelation therapy, can prevent serious and fatal complications.
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Affiliation(s)
- Athanasios Christoforidis
- Thalassaemia Unit, 1st Paediatric Department, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki.
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1112
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Neufeld EJ. Oral chelators deferasirox and deferiprone for transfusional iron overload in thalassemia major: new data, new questions. Blood 2006; 107:3436-41. [PMID: 16627763 PMCID: PMC1895765 DOI: 10.1182/blood-2006-02-002394] [Citation(s) in RCA: 216] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 03/03/2006] [Indexed: 01/19/2023] Open
Abstract
For nearly 30 years, patients with transfusional iron overload have depended on nightly deferoxamine infusions for iron chelation. Despite dramatic gains in life expectancy in the deferoxamine era for patients with transfusion-dependent anemias, the leading cause of death for young adults with thalassemia major and related disorders has been cardiac disease from myocardial iron deposition. Strategies to reduce cardiac disease by improving chelation regimens have been of the highest priority. These strategies have included development of novel oral iron chelators to improve compliance, improved assessment of cardiac iron status, and careful epidemiologic assessment of European outcomes with deferiprone, an oral alternative chelator available for about a decade. Each of these strategies is now bearing fruit. The novel oral chelator deferasirox was recently approved by the Food and Drug Administration (FDA); a randomized clinical trial demonstrates that deferasirox at 20 to 30 mg/kg/d can maintain or improve hepatic iron in thalassemia as well as deferoxamine. A randomized trial based on cardiac T2* magnetic resonance imaging (MRI) suggests that deferiprone can unload myocardial iron faster than deferoxamine. Retrospective epidemiologic data suggest dramatic reductions in cardiac events and mortality in Italian subjects exposed to deferiprone compared with deferoxamine. These developments herald a new era for iron chelation, but many unanswered questions remain.
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Affiliation(s)
- Ellis J Neufeld
- Division of Hematology, Children's Hospital, Karp 08210, 300 Longwood Ave, Boston, MA 02115, USA.
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1113
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Raney AR, Bello D. Cardiovascular Magnetic Resonance Assessment of Ischemic and Nonischemic Cardiomyopathies. Heart Fail Clin 2006; 2:145-61. [PMID: 17386886 DOI: 10.1016/j.hfc.2006.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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1114
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Westwood MA, Firmin DN, Gildo M, Renzo G, Stathis G, Markissia K, Vasili B, Pennell DJ. Intercentre reproducibility of magnetic resonance T2* measurements of myocardial iron in thalassaemia. Int J Cardiovasc Imaging 2006; 21:531-8. [PMID: 16175443 DOI: 10.1007/s10554-005-0651-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2004] [Accepted: 01/14/2005] [Indexed: 01/19/2023]
Abstract
In transfusion-dependent thalassemia major, iron-induced cardiomyopathy is the predominant cause of morbidity and mortality. Assessment of myocardial iron loading using MRI gradient echo T2* measurements have been described, but has only been performed at one centre in London. We assessed the transferability of this method by comparing the results from three different MR scanners in three different countries. Ten patients with thalassemia major underwent myocardial T2* assessment using a Siemens Sonata Scanner in London. Patients were also scanned with either a similar T2* sequence on a GE Systems CVI scanner in Athens, or a GE Systems signa echospeed scanner in Cagliari. Two scans were performed at the respective site in all patients to assess interstudy reproducibility at each site. The mean difference and coefficient of variability for the heart between scanners was 0.08 ms and 9.7% between London and Athens; and 0.30 ms and 1.6% between London and Cagliari. The interstudy mean difference and coefficient of variability for the heart in Athens was 0.6 ms and 3.5%, and 0.2 ms and 2.4% in Cagliari. In conclusion, the myocardial iron estimations were consistent between the three centres with scanners of differing manufacture, suggesting that this technique may have widespread application in the assessment of patients with iron overload conditions such as thalassaemia.
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Affiliation(s)
- Mark A Westwood
- CMR Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK.
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1115
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Anderson LJ, Westwood MA, Prescott E, Walker JM, Pennell DJ, Wonke B. Development of thalassaemic iron overload cardiomyopathy despite low liver iron levels and meticulous compliance to desferrioxamine. Acta Haematol 2006; 115:106-8. [PMID: 16424659 DOI: 10.1159/000089475] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Accepted: 05/10/2005] [Indexed: 01/13/2023]
Abstract
It is believed that myocardial iron deposition and the resultant cardiomyopathy only occur in the presence of severe liver iron overload. Using cardiovascular magnetic resonance, it is now possible to assess myocardial and liver iron levels as well as cardiac function in the same scan, allowing this supposition to be examined. We describe a patient with progressive myocardial iron deposition and the development of early iron overload cardiomyopathy despite excellent compliance to standard subcutaneous desferrioxamine, minimal liver iron and well-controlled serum ferritin levels. These indirect markers remained far below the thresholds conventionally believed to be associated with increased cardiac risk.
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1116
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Butwick A, Findley I, Wonke B. Management of pregnancy in a patient with beta thalassaemia major. Int J Obstet Anesth 2006; 14:351-4. [PMID: 16140004 DOI: 10.1016/j.ijoa.2005.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2004] [Revised: 02/01/2005] [Accepted: 02/01/2005] [Indexed: 11/15/2022]
Abstract
beta thalassaemia is one of the world's most wide-spread monogenetic disorders. Advances in the management of beta thalassaemia major by extensive blood transfusions and chelation therapy have improved survival of patients into adult life. Due to the prolonged life expectancy and improvements in quality of life, pregnancy has now become an important issue for patients and clinicians. We report a case of a pregnant patient with beta thalassaemia major who underwent a successful caesarean section under spinal anaesthesia. The multidisciplinary approach to management of beta thalassaemia major and pregnancy is discussed.
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Affiliation(s)
- A Butwick
- Department of Anaesthesia, St. George's Hospital, London, UK
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1117
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Isbell DC, Kramer CM. The Evolving Role of Cardiovascular Magnetic Resonance Imaging in Nonischemic Cardiomyopathy. Semin Ultrasound CT MR 2006; 27:20-31. [PMID: 16562569 DOI: 10.1053/j.sult.2005.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Over the last several years, the role of cardiac magnetic resonance imaging in the diagnosis and management of heart failure has been rapidly expanding. The techniques unrivaled flexibility, accuracy in defining ventricular structure and function, and capacity to characterize tissue makes it particularly well suited for the study of the nonischemic cardiomyopathies. In this article, we provide an overview of the existing literature highlighting the diagnostic utility and prognostic power of cardiac magnetic resonance imaging in the nonischemic cardiomyopathies.
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Affiliation(s)
- David C Isbell
- Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA.
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1118
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Daar S, Pathare AV. Combined therapy with desferrioxamine and deferiprone in beta thalassemia major patients with transfusional iron overload. Ann Hematol 2006; 85:315-9. [PMID: 16450126 DOI: 10.1007/s00277-005-0075-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2005] [Accepted: 12/22/2005] [Indexed: 01/16/2023]
Abstract
Iron overload is the main cause of morbidity and mortality especially from heart failure in patients with beta thalassemia major (TM). Successful iron chelation is therefore essential for the optimal management of TM. Although desferrioxamine (DFX) has been the major iron-chelating treatment of transfusional iron overload, compliance is a major hindrance in achieving optimal therapeutic results. The availability of oral iron chelation with deferiprone (L(1)) since 1987 is useful but showed poor efficacy when used alone as compared to DFX. We therefore decided to compare DFX alone with a prospective combined therapy with DFX and L(1) in beta thalassemia major patients with iron overload. We studied 91 patients with beta thalassemia major (mean age+/-SD, 15.02+/-5.8; range 2-30 years) attending the day care unit for regular transfusional support. They received packed red cells every 3-4 weeks to maintain pretransfusion hemoglobin concentration above 9 g/dl. They had been receiving DFX at a daily dose of 40 mg kg(-1) day(-1) by subcutaneous infusion for 8-10 h on 4-5 nights each week for the past several years. However, due to various reasons, they had developed considerable transfusional iron overload. These patients were allocated to prospectively receive additional therapy with oral iron chelator L(1) at 75 mg kg(-1) day(-1) body weight in three divided doses with food after informed consent and continued to receive treatment with DFX as per the above dosage. Of the 91 patients, six developed severe gastrointestinal (GI) upset, two agranulocytosis, two arthropathy, one persistently raised liver enzymes, two died owing to sepsis, and two received allogeneic bone marrow transplantation. Amongst the remaining 76 patients, 21 were found noncompliant (not taking DFX regularly, but taking L(1) regularly). Thus, in the 55 evaluable patients {6-48 months on combination therapy; mean [(+/-SD)22+/-12 months]}, the mean serum ferritin (+/-SD) fell dramatically from 3,088 (+/-1,299) ng/ml (DFX alone) to 2,051 (+/-935) ng/ml (DFX and L(1); p<0.001). It is interesting to note that there was also a significant improvement in the myocardial function as assessed by the ejection fraction (p<0.004) and fractional shortening (p<0.05) in those patients (n=42) who could be studied after being on combination therapy for a minimum of 1 year. The study emphasizes that beta thalassemia major patients with transfusional iron overload can be successfully treated with a combination of DFX and L(1). Our results also demonstrate a significant statistical improvement after as little as 6 months of combination therapy. Furthermore, these improvements lead to a progressive fall in the mean serum ferritin. Lastly, the study also demonstrates significant improvement in the echocardiographic parameters of myocardial performance in these patients receiving combination therapy.
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Affiliation(s)
- S Daar
- Day Care Unit, Department of Haematology, College of Medicine, Sultan Qaboos University, Muscat, 123, Sultanate of Oman
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1119
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Ghugre NR, Coates TD, Nelson MD, Wood JC. Mechanisms of tissue-iron relaxivity: nuclear magnetic resonance studies of human liver biopsy specimens. Magn Reson Med 2006; 54:1185-93. [PMID: 16215963 PMCID: PMC2892963 DOI: 10.1002/mrm.20697] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
MRI is becoming an increasingly important tool to assess iron overload disorders, but the complex nature of proton-iron interactions has troubled noninvasive iron quantification. Intersite and intersequence variability as well as methodological inaccuracies have been limiting factors to its widespread clinical use. It is important to understand the underlying proton relaxation mechanisms within the (human) tissue environment to address these differences. In this respect, NMR relaxometry was performed on 10 fresh human liver biopsy specimens taken from patients with transfusion-dependent anemia. T1 (1/R1) inversion recovery, T2 (1/R2) single echo, and multiecho T2 CPMG measurements were performed on a 60-MHz Bruker Minispectrometer. NMR parameters were compared to quantitative iron levels and tissue histology. Relaxivities R1 and R2 both increased linearly with hepatic iron content, with R2 being more sensitive to iron. CPMG data were well described by a chemical-exchange model and predicted effective iron center dimensions consistent with hemosiderin-filled lysosomes. Nonexponential relaxation was evident at short refocusing intervals with R2 and amplitude behavior suggestive of magnetic susceptibility-based compartmentalization rather than anatomic subdivisions. NMR relaxometry of human liver biopsy specimens yields unique insights into the mechanisms of tissue-iron relaxivity.
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Affiliation(s)
- Nilesh R. Ghugre
- Division of Cardiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Thomas D. Coates
- Department of Hematology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Marvin D. Nelson
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - John C. Wood
- Division of Cardiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Correspondence to: John C. Wood, Division of Cardiology, Mailstop 34, Children’s Hospital Los Angeles, 4650 Sunset Boulevard, Los Angeles, CA 90027-0034, USA.
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1120
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Ghugre NR, Enriquez CM, Coates TD, Nelson MD, Wood JC. Improved R2* measurements in myocardial iron overload. J Magn Reson Imaging 2006; 23:9-16. [PMID: 16329085 PMCID: PMC2892961 DOI: 10.1002/jmri.20467] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To optimize R2*(1/T2*) measurements for cardiac iron detection in sickle cell and thalassemia patients. MATERIALS AND METHODS We studied 31 patients with transfusion-dependent sickle cell disease and 48 patients with thalassemia major; myocardial R2* was assessed in a single midpapillary slice using a gated gradient-echo pulse sequence. Pixel-wise maps were coregistered among the patients to determine systematic spatial fluctuations in R2*. The contributions of minimum TE, echo spacing, signal-decay model, and region-of-interest (ROI) choice were compared in synthetic and acquired images. RESULTS Cardiac relaxivity demonstrated characteristic circumferential variations regardless of the degree of iron overload. Within the interventricular septum, a gradient in R2* from right to left ventricle was noted at high values. Pixel-wise and ROI techniques yielded nearly identical values. Signal decay was exponential but a constant offset or second exponential term was necessary to avoid underestimation at high iron concentration. Systematic underestimation of R2* was observed for higher minimum TE, limiting the range of iron concentrations that can be profiled. Fat-water oscillations, although detectable, represented only 1% of the total signal. CONCLUSION Clinical cardiac R2* measurements should be restricted to the interventricular septum and should have a minimum TE < or = 2 msec. ROI analysis techniques are accurate; however, offset-correction is essential.
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Affiliation(s)
- Nilesh R. Ghugre
- Division of Cardiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Cathleen M. Enriquez
- Division of Cardiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Thomas D. Coates
- Department of Hematology-Oncology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Marvin D. Nelson
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - John C. Wood
- Division of Cardiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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1121
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He T, Gatehouse PD, Anderson LJ, Tanner M, Keegan J, Pennell DJ, Firmin DN. Development of a novel optimized breathhold technique for myocardial T2 measurement in thalassemia. J Magn Reson Imaging 2006; 24:580-5. [PMID: 16892203 DOI: 10.1002/jmri.20681] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
PURPOSE To develop a reproducible fast spin-echo (FSE) technique for accurate myocardial T2 measurement with application to iron overload assessment in thalassemia. MATERIALS AND METHODS An FSE sequence was developed to permit acquisition of multiple TE images in one breathhold (BH-FSE). A dynamic black-blood scheme was introduced to better cancel blood signal. A nonselective refocusing train was also adopted to suppress stimulated echoes. The optimized technique was tested on phantoms and then applied to 10 normal volunteers and 10 thalassemia patients. Interstudy reproducibility was measured on all the 20 subjects. RESULTS The mean difference in T2 values was 1.7% from phantom experiments between BH-FSE and the conventional spin-echo (SE) technique. High contrast BH-FSE images were acquired from human subjects, with minimal stimulated echoes and effective blood suppression (P = 0.0005). The coefficient of variation for interstudy reproducibility was 4.3%. T2 values from thalassemia patients were substantially lower than those from the normal subjects (45.2 +/- 26.1 msec vs. 56.9 +/- 8.4 ms, P = 0.02). CONCLUSION The dynamic black-blood T2 sequence is a fast reproducible acquisition that compares favorably with conventional techniques, is robust to motion artifacts, and yields high blood-myocardium contrast. This technique may provide a useful tool in thalassemia and other scenarios requiring myocardial T2 quantification.
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Affiliation(s)
- Taigang He
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital and Imperial College, London, UK.
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1122
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Martín M, Estornell J, Orero M, Pérez JL, Ridoccid F, Martínez V. Evidencia por resonancia magnética de la eficacia del tratamiento quelante combinado en la miocardiopatía por depósito férrico. Rev Esp Cardiol (Engl Ed) 2006. [DOI: 10.1157/13083654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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1123
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Rochitte CE, Tassi EM, Shiozaki AA. The emerging role of MRI in the diagnosis and management of cardiomyopathies. Curr Cardiol Rep 2006; 8:44-52. [PMID: 16507236 DOI: 10.1007/s11886-006-0010-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cardiac magnetic resonance (CMR) has emerged as an important tool for the evaluation of cardiomyopathies, providing highly accurate information on the macroscopic changes of cardiac morphology, function, and tissue composition. For myocardial tissue characterization, the technique of myocardial delayed enhancement is a potentially promising tool for diagnosis, management, and prognosis. Several CMR approaches are now available to better diagnose and prognosticate dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular disease, myocarditis, and other cardiomyopathies.
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1124
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Westwood MA, Wonke B, Maceira AM, Prescott E, Walker JM, Porter JB, Pennell DJ. Left ventricular diastolic function compared with T2* cardiovascular magnetic resonance for early detection of myocardial iron overload in thalassemia major. J Magn Reson Imaging 2005; 22:229-33. [PMID: 16028255 DOI: 10.1002/jmri.20379] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To compare left ventricular (LV) diastolic function with myocardial iron levels in beta thalassemia major (TM) patients, using cardiovascular magnetic resonance (CMR). MATERIALS AND METHODS We studied 67 regularly transfused patients with TM and 22 controls matched for age, gender, and body surface area. The early peak filling rate (EPFR) and atrial peak filling rate (APFR) were determined from high-temporal-resolution ventricular volume-time curves. Myocardial iron estimation was achieved using myocardial T2* measurements. RESULTS Myocardial iron loading was found in 46 TM patients (69%), in whom the EPFR correlated poorly with T2* (r = -0.20, P = 0.19). The APFR (r = 0.49, P < 0.001) and EPFR/APFR ratio (r = -0.62, P < 0.001) correlated better with T2*. The sensitivity of the diastolic parameters for detecting myocardial iron loading ranged from 4% (EPFR and APFR) to 17% (EPFR/APFR ratio). CONCLUSION Myocardial iron overload results in diastolic myocardial dysfunction, but low sensitivity limits the use of a single estimation for early detection of iron overload, for which T2* has a superior categorical limit of normality.
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Affiliation(s)
- Mark A Westwood
- Cardiovascular MR Unit, Royal Brompton Hospital and Imperial College, Sydney Street, London SW3 6NP, UK
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1125
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Fischer R, Piga A, Harmatz P, Nielsen P. Monitoring Long-Term Efficacy of Iron Chelation Treatment with Biomagnetic Liver Susceptometry. Ann N Y Acad Sci 2005; 1054:350-7. [PMID: 16339683 DOI: 10.1196/annals.1345.043] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In patients with thalassemia, the assessment of liver iron concentration (LIC) can be used to initiate chelation treatment with desferrioxamine (DFO), deferiprone (DFP), or novel chelators (deferasirox); to adjust chelation dose according to the actual blood transfusion rate; and to monitor chelation efficacy. The results from measurements by SQUID biomagnetic liver susceptometry in the LIC range 17-11,500 microg/g of liver in about 1000 patients were used to derive nonstandard parameters, which may be useful in the treatment monitoring of patients with thalassemia. From these measurements, including liver volumes, the documented chelation dose rates, and the blood transfusion rates, the chelator index (equivalent Therapeutical Index), the total body iron elimination rate, and the molar efficacy were calculated. Chelator indices (CIs) ranged from 0.1 to 11.7 mmol/d/g of Fe for DFO, with a threshold of CI greater than 1.2 mmol/d/g of Fe indicating DFO toxicity. For DFP, CI ranged from 0.1 to 23.2 mmol/d/g of Fe. In long-term studies (2 and 4 years), mean molar efficacies of DFO and DFP were found to be quite stable with 17.6 +/- 4.8% and 4.9 +/- 1.4%, respectively. Currently, specific chelation dose is based upon body weight. Because liver iron measurements by biosusceptometry are now regularly available in Europe and America, as well as quantitative MRI worldwide, these methods may be used to adjust chelation treatment regimens to body iron stores.
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Affiliation(s)
- Roland Fischer
- University Medical Center Hamburg-Eppendorf, Department of Molecular Cell Biology, Hamburg, Germany.
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1126
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Abstract
This overview describes the history of transfusion therapy and consequent iron overload in thalassemia. It emphasizes the importance of measurement of hepatic iron and reviews the history of chelation therapy. It briefly describes the discoveries of the genetic basis of thalassemia and the application of that knowledge in prenatal diagnosis. The review goes on to emphasize pharmaceutical efforts to induce fetal hemoglobin synthesis in thalassemic red cells and ends with a discussion of oral iron chelators, stem cell transplant, and the status of gene therapy.
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Affiliation(s)
- David G Nathan
- Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.
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1127
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St Pierre TG, Clark PR, Chua-Anusorn W. Measurement and Mapping of Liver Iron Concentrations Using Magnetic Resonance Imaging. Ann N Y Acad Sci 2005; 1054:379-85. [PMID: 16339686 DOI: 10.1196/annals.1345.046] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Measurement of liver iron concentration (LIC) is an important clinical procedure in the management of transfusional iron overload with iron chelation. LIC gives an indication of over- or underchelation. Although chemical assay of needle biopsy samples from the liver has been considered the "gold standard" of LIC measurement, needle biopsy sampling errors can be surprisingly large owing to the natural spatial variation of LIC throughout the liver and the small size of biopsy specimens. A magnetic resonance imaging technique has now been developed that enables safe noninvasive measurement and imaging of LIC with a known accuracy and precision. Measurements of LIC can be made over the range of LIC encountered in clinical practice. The technique is based on the measurement and imaging of proton transverse relaxation rates (R2) within the liver. The R2 imaging technique can be implemented on most clinical 1.5-T MRI instruments, making it readily available to the clinical community.
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Affiliation(s)
- Timothy G St Pierre
- School of Physics, M013, University of Western Australia, Crawley, Western Australia 6009, Australia.
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1128
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Porter JB, Rafique R, Srichairatanakool S, Davis BA, Shah FT, Hair T, Evans P. Recent Insights into Interactions of Deferoxamine with Cellular and Plasma Iron Pools: Implications for Clinical Use. Ann N Y Acad Sci 2005; 1054:155-68. [PMID: 16339661 DOI: 10.1196/annals.1345.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Despite the availability of deferoxamine (DFO) for more than three decades, its rates of interaction with cellular iron pools in different tissues, and the effects of its pharmacokinetics on the interaction with plasma iron pools, remain incompletely understood. The positive charge of DFO, together with the negative resting potential in vertebrate cells, favors cellular uptake, whereas the low lipophilicity and high molecular weight counter this effect. The findings presented suggest a facilitated uptake of DFO into hepatocytes, being several hundred-fold faster than into red cells. Antibodies that selectively recognize ferrioxamine (FO) show that initial hepatocellular iron chelation is cytosolic, but later transposes to lysosomal and ultimately canalicular compartments. Strong FO staining is visible in myocytes within 4-8 h after commencing a subcutaneous DFO infusion, indicating effective chelation of myocyte iron. A methodology was developed to study the interaction of DFO and its metabolites with plasma iron pools by stabilizing DFO with aluminum ions, thereby preventing iron shuttling from non-transferrin-bound iron (NTBI) onto DFO after plasma collection. DFO removes only about a third of NTBI rapidly, and NTBI is rarely cleared completely. Increasing DFO dosing does not increase NTBI removal, but instead leads to a greater rebound in NTBI on cessation of intravenous infusion. Thus, intermittent infusions of high-dose DFO are less desirable than continuous infusions at low doses, particularly in high-risk patients. Here the benefits of continuous DFO on heart function occur before changes in T2*-visible storage iron, consistent with early removal of a toxic labile iron pool within myocytes.
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Affiliation(s)
- J B Porter
- Department of Haematology, University College London, London, United Kingdom.
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1129
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Piga A, Roggero S, Vinciguerra T, Sacchetti L, Gallo V, Longo F. Deferiprone: New Insight. Ann N Y Acad Sci 2005; 1054:169-74. [PMID: 16339662 DOI: 10.1196/annals.1345.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Recent results from independent studies suggest that deferiprone is more cardioprotective than deferoxamine. Patients on long-term treatment with deferiprone have a better myocardial magnetic resonance imaging pattern and less chance to develop a new cardiac disease or worsen an existing one. Most of these observations are retrospective and require confirmation from randomized controlled trials. Other new observations regard the effects of combining the two chelators. Most results indicate an additional effect on iron excretion and a significant reduction of the time required to mitigate severe iron overload and to reverse clinical heart disease. Again, these data require confirmation, as they were mostly obtained on individual cases or small groups of patients treated with a wide range of combinations of the two chelators, but the univocity of results is impressive. After many years of controversy, deferiprone is emerging as a useful oral iron chelator that enhances the chances for the patient to have optimal treatment. Well-designed and -conducted studies will help in answering the questions still open.
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Affiliation(s)
- A Piga
- Department of Pediatric Hematology/Oncology, University of Turin, Turin, Italy.
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1130
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Tsironi M, Polonifi K, Deftereos S, Farmakis D, Andriopoulos P, Moyssakis I, Aessopos A. Transfusional hemosiderosis and combined chelation therapy in sickle thalassemia. Eur J Haematol 2005; 75:355-8. [PMID: 16146544 DOI: 10.1111/j.1600-0609.2005.00528.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Although the indications for transfusions in sickle cell syndromes are well listed, and chronic transfusion has become practicable since the recent advances in chelation therapy have essentially eliminated the risk of secondary iron overload, multi-transfused, non-compliant to long-term chelation therapy patients confront the complication of iron overload and secondary hemosiderosis. In thalassemia major patients, combined therapy with desferrioxamine and deferiprone has maximized tissue iron removal and may reduce the overall occurrence of hemosiderotic heart failure. Despite this, safety and contradictions of chelating agents are still controversial. The aim of this report is to present the results of this combination in a long-term transfused sickle beta-thalassemic patient suffering from severe heart failure and liver dysfunction.
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Affiliation(s)
- M Tsironi
- First Department of Internal Medicine, University of Athens, Medical School, Laiko Hospital, Athens, Greece.
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1131
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Papakonstantinou O, Maris TG, Kostaridou S, Ladis V, Vasiliadou A, Gourtsoyiannis NC. Abdominal lymphadenopathy in beta-thalassemia: MRI features and correlation with liver iron overload and posttransfusion chronic hepatitis C. AJR Am J Roentgenol 2005; 185:219-24. [PMID: 15972427 DOI: 10.2214/ajr.185.1.01850219] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of our study was to describe the MRI features of abdominal lymphadenopathy in patients with beta-thalassemia major and investigate the relation of abdominal lymphadenopathy with the severity of iron overload and posttransfusion chronic hepatitis C. MATERIALS AND METHODS Abdominal MRI studies of 60 consecutive patients with beta-thalassemia major, performed for quantification of liver iron overload at a single institution, were retrospectively studied for the presence of lymph nodes and their distribution, size, and number. The signal intensity ratios of liver, spleen, and the largest lymph node to the right paraspinous muscle (L/M, S/M, and LN/M, respectively) were calculated on T1-weighted gradient-echo images. MRI findings for the lymph nodes were compared with the histologically assigned activity level of chronic hepatitis C that was available in 17 patients who had undergone liver biopsy within 1 month of the MRI examination. RESULTS Hypointense abdominal lymph nodes larger than 7 mm were seen in 19 (32%) of 60 thalassemic patients in perihepatic and paraortic distributions. Lymphadenopathy was related to both the severity of hepatic siderosis, as expressed by the L/M values, and the presence of chronic hepatitis C, given that 18 (95%) of the 19 thalassemic patients with lymphadenopathy had chronic hepatitis C. Moreover, thalassemic patients with a moderate or severe level of hepatic inflammation presented with abdominal lymphadenopathy more frequently than those with mild hepatic inflammation. CONCLUSION The development of hypointense abdominal lymphadenopathy in patients with beta-thalassemia major who have received multiple transfusions depends both on the severity of liver iron overload and on the presence and the activity level of coexistent chronic hepatitis C.
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Affiliation(s)
- Olympia Papakonstantinou
- Department of Radiology, MRI Unit, University Hospital of Heraklion, University of Crete Medical School, Crete, Greece.
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1132
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Affiliation(s)
- J B Porter
- University College London, Department of Haematology, London, UK.
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1133
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Hahalis G, Alexopoulos D, Kremastinos DT, Zoumbos NC. Heart failure in beta-thalassemia syndromes: a decade of progress. Am J Med 2005; 118:957-67. [PMID: 16164878 DOI: 10.1016/j.amjmed.2005.02.021] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The thalassemias are common monogenic disorders of hemoglobin synthesis. beta-thalassemias are the most important among the thalassemia syndromes and have become a worldwide clinical problem due to an increasing immigrant population. In beta-thalassemia major, regular blood transfusions are necessary early in life. Beta-thalassemia intermedia refers to a less severe phenotype, whereas beta-thalassemia/hemoglobin E disease encompasses a broad phenotypic spectrum. Blood transfusions and increased gastrointestinal iron absorption result in iron overload and tissue damage. Among patients with beta-thalassemia major, biventricular, dilated cardiomyopathy remains the leading cause of mortality. In some patients, a restrictive type of left ventricular cardiomyopathy or pulmonary hypertension is noted. The clinical course, although variable and occasionally fulminant, is more benign in recent than in older series. Myocarditis has been described as a cause of left-sided heart failure in younger patients. Pulmonary arterial hypertension is the principal cause of heart failure in beta-thalassemia intermedia. Chelation therapy has improved prognosis in beta-thalassemia major both by reducing the incidence of heart failure and by reversing cardiomyopathy. Estimation of the patient's cardiac risk is mainly based on clinical criteria and serial echocardiography. A new cardiovascular magnetic resonance technique will probably fulfill the need for more precise risk stratification in beta-thalassemia syndromes. By increasing the proportion of patients on optimal chelation, survival in beta-thalassemia major may further improve. Recent advances in gene therapy are expected to result in the long-awaited cure of this disease.
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Affiliation(s)
- George Hahalis
- Department of Cardiology, Patras University Medical School, Rio Patras, Greece
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1134
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Mavrogeni SI, Markussis V, Kaklamanis L, Tsiapras D, Paraskevaidis I, Karavolias G, Karagiorga M, Douskou M, Cokkinos DV, Kremastinos DT. A comparison of magnetic resonance imaging and cardiac biopsy in the evaluation of heart iron overload in patients with beta-thalassemia major. Eur J Haematol 2005; 75:241-7. [PMID: 16104881 DOI: 10.1111/j.1600-0609.2005.00474.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To apply magnetic resonance imaging (MRI) for the assessment of myocardial iron deposition in patients with beta-thalassemia and compare the results with cardiac biopsy data. BACKGROUND Myocardial iron accumulation is the main cause for cardiac complications in beta-thalassemia. METHODS Twenty-five consecutive thalassemic patients were studied using a 0.5-T (Tesla) system, ECG-gated, with echo time (TE) = 17-68 ms. T2 relaxation time of the interventricular septum was calculated assuming simple monoexponential decay. A heart T2 relaxation time value of 32 ms was used for the discrimination between high and low iron deposition. Heart biopsy was performed within a week after the MRI study. Patients with stainable iron in more than 50% of the myofibrils were graded as having severe iron deposition. A serum ferritin level below 2000 ng/mL was considered as an indication of successful chelation. RESULTS Seven of the 25 patients had heart biopsy indicative of low iron deposition (Group L) and the remaining 18 patients had heart biopsy indicative of high iron deposition (Group H). T2 relaxation time of the heart (T2H) was lower in Group H compared to Group L (31.5 +/- 3.9 (range: 28-40) ms vs. 35.7 +/- 3.7 (range: 29-40) ms, P = 0.026). The T2H was in agreement with heart biopsy in 86% of the patients in Group L and in 78% of the patients in Group H (overall agreement 80%). Similarly, serum ferritin levels were in agreement with heart biopsy in 28% and 88%, respectively (overall agreement 72%). In Group L, MRI was in better agreement with biopsy compared to serum ferritin (86% vs. 28%, P < 0.05). A receiver operating characteristic curve (ROC) analysis confirmed that a T2 relaxation time of 32 ms had the highest discriminating ability for the corresponding biopsy outcome. CONCLUSIONS Heart T2 relaxation time appears in agreement with cardiac biopsy, both in high and low iron deposition, and may become a useful non-invasive index in beta-thalassemia.
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1135
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Drakonaki E, Papakonstantinou O, Maris T, Vasiliadou A, Papadakis A, Gourtsoyiannis N. Adrenal glands in beta-thalassemia major: magnetic resonance (MR) imaging features and correlation with iron stores. Eur Radiol 2005; 15:2462-8. [PMID: 16086182 DOI: 10.1007/s00330-005-2855-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2005] [Revised: 06/01/2005] [Accepted: 07/01/2005] [Indexed: 11/30/2022]
Abstract
This study aimed at describing the magnetic resonance (MR) imaging features of the adrenal glands in beta-thalassemic patients and at investigating the relation between adrenal and hepatic siderosis. Adrenal signal intensity (SI) was retrospectively assessed on abdominal MR studies of 35 patients with beta-thalassemia major undergoing quantification of hepatic siderosis and 12 healthy controls, using T1-(120/4/90), intermediate-(120/4/20), and T2*-(120/15/20) weighted GRE sequences. Adrenal SI was graded as grade 0 (normal SI on all sequences), grade 1 (hypointensity on T2* alone), or grade 2 (hypointensity on at least T2*). Adrenal size was measured in the thalassemic patients and compared with normative data. Liver-to-muscle (L/M) SI ratios, expressing hepatic siderosis, were estimated on each sequence. Serum ferritin levels were recorded. Adrenal hypointensity (grades 1 and 2) was noted in 24/35 (68.6%) patients. L/M ratios correlated significantly with adrenal SI in all sequences. Patients with grade 1 and grade 2 adrenal SI had significantly decreased L/M ratios compared with grade 0. Serum ferritin correlated significantly with L/M values but not with adrenal SI. Adrenal size was within normal limits. Diffuse hypointensity in normal-sized adrenals is a common MR finding in beta-thalassemic patients and correlates with the degree of hepatic siderosis.
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Affiliation(s)
- Eleni Drakonaki
- Department of Radiology, University Hospital of Heraklion, Stavrakia, P.O. Box 1325, 71110, Heraklion, Crete, Greece.
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1136
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Wood JC, Enriquez C, Ghugre N, Tyzka JM, Carson S, Nelson MD, Coates TD. MRI R2 and R2* mapping accurately estimates hepatic iron concentration in transfusion-dependent thalassemia and sickle cell disease patients. Blood 2005; 106:1460-5. [PMID: 15860670 PMCID: PMC1895207 DOI: 10.1182/blood-2004-10-3982] [Citation(s) in RCA: 793] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Accepted: 04/15/2005] [Indexed: 12/13/2022] Open
Abstract
Measurements of hepatic iron concentration (HIC) are important predictors of transfusional iron burden and long-term outcome in patients with transfusion-dependent anemias. The goal of this work was to develop a readily available, noninvasive method for clinical HIC measurement. The relaxation rates R2 (1/T2) and R2* (1/T2*) measured by magnetic resonance imaging (MRI) have different advantages for HIC estimation. This article compares noninvasive iron estimates using both optimized R2 and R2* methods in 102 patients with iron overload and 13 controls. In the iron-overloaded group, 22 patients had concurrent liver biopsy. R2 and R2* correlated closely with HIC (r2 > or = .95) for HICs between 1.33 and 32.9 mg/g, but R2 had a curvilinear relationship to HIC. Of importance, the R2 calibration curve was similar to the curve generated by other researchers, despite significant differences in technique and instrumentation. Combined R2 and R2* measurements did not yield more accurate results than either alone. Both R2 and R2* can accurately measure hepatic iron concentration throughout the clinically relevant range of HIC with appropriate MRI acquisition techniques.
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Affiliation(s)
- John C Wood
- Department of Pediatrics, Children's Hospital Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027-0034, USA.
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1137
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Wood JC, Otto-Duessel M, Aguilar M, Nick H, Nelson MD, Coates TD, Pollack H, Moats R. Cardiac iron determines cardiac T2*, T2, and T1 in the gerbil model of iron cardiomyopathy. Circulation 2005; 112:535-43. [PMID: 16027257 PMCID: PMC2896311 DOI: 10.1161/circulationaha.104.504415] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Transfusional therapy for thalassemia major and sickle cell disease can lead to iron deposition and damage to the heart, liver, and endocrine organs. Iron causes the MRI parameters T1, T2, and T2* to shorten in these organs, which creates a potential mechanism for iron quantification. However, because of the danger and variability of cardiac biopsy, tissue validation of cardiac iron estimates by MRI has not been performed. In this study, we demonstrate that iron produces similar T1, T2, and T2* changes in the heart and liver using a gerbil iron-overload model. METHODS AND RESULTS Twelve gerbils underwent iron dextran loading (200 mg . kg(-1) . wk(-1)) from 2 to 14 weeks; 5 age-matched controls were studied as well. Animals had in vivo assessment of cardiac T2* and hepatic T2 and T2* and postmortem assessment of cardiac and hepatic T1 and T2. Relaxation measurements were performed in a clinical 1.5-T magnet and a 60-MHz nuclear magnetic resonance relaxometer. Cardiac and liver iron concentrations rose linearly with administered dose. Cardiac 1/T2*, 1/T2, and 1/T1 rose linearly with cardiac iron concentration. Liver 1/T2*, 1/T2, and 1/T1 also rose linearly, proportional to hepatic iron concentration. Liver and heart calibrations were similar on a dry-weight basis. CONCLUSIONS MRI measurements of cardiac T2 and T2* can be used to quantify cardiac iron. The similarity of liver and cardiac iron calibration curves in the gerbil suggests that extrapolation of human liver calibration curves to heart may be a rational approximation in humans.
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Affiliation(s)
- John C Wood
- Division of Pediatric Cardiology, Department of Pediatrics and Radiology, Children's Hospital of Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027, USA.
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1138
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Haacke EM, Cheng NYC, House MJ, Liu Q, Neelavalli J, Ogg RJ, Khan A, Ayaz M, Kirsch W, Obenaus A. Imaging iron stores in the brain using magnetic resonance imaging. Magn Reson Imaging 2005; 23:1-25. [PMID: 15733784 DOI: 10.1016/j.mri.2004.10.001] [Citation(s) in RCA: 728] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Accepted: 10/07/2004] [Indexed: 02/06/2023]
Abstract
For the last century, there has been great physiological interest in brain iron and its role in brain function and disease. It is well known that iron accumulates in the brain for people with Huntington's disease, Parkinson's disease, Alzheimer's disease, multiple sclerosis, chronic hemorrhage, cerebral infarction, anemia, thalassemia, hemochromatosis, Hallervorden-Spatz, Down syndrome, AIDS and in the eye for people with macular degeneration. Measuring the amount of nonheme iron in the body may well lead to not only a better understanding of the disease progression but an ability to predict outcome. As there are many forms of iron in the brain, separating them and quantifying each type have been a major challenge. In this review, we present our understanding of attempts to measure brain iron and the potential of doing so with magnetic resonance imaging. Specifically, we examine the response of the magnetic resonance visible iron in tissue that produces signal changes in both magnitude and phase images. These images seem to correlate with brain iron content, perhaps ferritin specifically, but still have not been successfully exploited to accurately and precisely quantify brain iron. For future quantitative studies of iron content we propose four methods: correlating R2' and phase to iron content; applying a special filter to the phase to obtain a susceptibility map; using complex analysis to extract the product of susceptibility and volume content of the susceptibility source; and using early and late echo information to separately predict susceptibility and volume content.
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Affiliation(s)
- E Mark Haacke
- The MRI Institute for Biomedical Research, 440 East Ferry Street, Detroit, MI 48202, USA.
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1139
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Bluemke DA, Liddell RP. Can MR imaging provide a noninvasive "biopsy" of the heart to measure iron levels? Radiology 2005; 234:647-8. [PMID: 15734922 DOI: 10.1148/radiol.2343041670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- David A Bluemke
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, 600 N Wolfe St, MRI Room 143, Baltimore, MD 21287, USA.
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1140
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Wang ZJ, Lian L, Chen Q, Zhao H, Asakura T, Cohen AR. 1/T2 and magnetic susceptibility measurements in a gerbil cardiac iron overload model. Radiology 2005; 234:749-55. [PMID: 15734931 DOI: 10.1148/radiol.2343031084] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To measure the transverse relaxation rate (1/T2) and magnetic susceptibility of the heart in conditions of iron overload by using magnetic resonance (MR) imaging and to correlate these with the tissue iron concentration in a gerbil model. MATERIALS AND METHODS With prior approval by the institutional animal care and use committee, iron overload was induced with one to 15 weekly subcutaneous injections of iron dextran. Nine gerbils had one to five injections, 10 had six to 10, and eight had 13-15. T2 of the whole heart was measured ex vivo (n=27), and the magnetic susceptibility of the tissue was estimated through measurement of the tissue lysate (n=25). The iron level was measured (in milligrams of iron per gram of wet tissue) with chemical analysis after MR imaging. While 1/T2 and magnetic susceptibility are not equivalent measures of the chemically determined tissue iron level, correlations were expected and were identified by using linear regression models. RESULTS Iron concentration range was 0.28-1.95 mg/g wet tissue. Iron concentration was strongly correlated with 1/T2 (r=0.92, P <.001, and the root of the mean squares error of the linear prediction, epsilonRMS, was 0.17 mg Fe/g wet tissue with a repetition time of 700 msec). Iron concentration also was strongly correlated with magnetic susceptibility (r=0.90, P <.001, epsilonRMS=0.19 mg Fe/g wet tissue). Multiple regression analysis with combined 1/T2 (with repetition time of 700 msec) and magnetic susceptibility data led to a slight increase in r and decrease in epsilon(RMS) (r=0.93, P <.001, epsilonRMS=0.16 mg Fe/g wet tissue). CONCLUSION The results of this animal model study demonstrate that 1/T2 and magnetic susceptibility values can be used for estimation of the iron level in the heart.
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Affiliation(s)
- Zhiyue J Wang
- Department of Radiology, Divisions of Hematology and Biostatistics and Epidemiology, Department of Pediatrics, Children's Hospital of Philadelphia, PA, USA.
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1141
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Voskaridou E, Douskou M, Terpos E, Stamoulakatou A, Meletis J, Ourailidis A, Papassotiriou I, Loukopoulos D. Deferiprone as an oral iron chelator in sickle cell disease. Ann Hematol 2005; 84:434-40. [PMID: 15809885 DOI: 10.1007/s00277-005-1015-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2004] [Accepted: 01/26/2005] [Indexed: 01/13/2023]
Abstract
Iron overload is not uncommon in sickle cell disease (SCD) and requires regular chelation therapy in several instances. The present study evaluates the effect of deferiprone in 15 adult patients with SCD (ten beta(s)/beta(0)thalassemia and five beta(s)/beta(s)) and iron overload. Deferiprone was given at a dose of 75 mg/kg daily for 12 months. The evaluation considered pre- and post-treatment values of serum ferritin, urinary iron excretion, and T2 values of liver and heart obtained by magnetic resonance imaging (MRI). Eleven patients had a liver biopsy prior to starting therapy to evaluate iron concentration (LIC). Twelve patients completed the study with satisfactory compliance. In ten of them (83.3%) the serum ferritin levels decreased significantly at the end of the trial; in eight patients (66.6%) the reduction of serum ferritin was accompanied by a significant increase of their liver T2 values. All patients had a significant increase of urinary iron excretion in response to the drug. Ferritin levels and liver T2 values correlated with liver iron concentration; on the contrary, ferritin levels and liver T2 values failed to show any correlation with heart T2 values. Heart T2 values did not also show any correlation with left ventricular ejection fraction. Deferiprone was well tolerated and did not cause any significant adverse effects. These results suggest that deferiprone may effectively decrease the iron deposition in patients with SCD; moreover, T2 MRI proves to be a reliable and rapid, noninvasive method for assessing the liver iron load in patients with SCD.
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Affiliation(s)
- Ersi Voskaridou
- Thalassemia Center, Laikon General Hospital, 16 Sevastoupoleos Street, 11526, Athens, Greece.
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1142
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Soriano CJ, Ridocci F, Estornell J, Jimenez J, Martinez V, De Velasco JA. Noninvasive diagnosis of coronary artery disease in patients with heart failure and systolic dysfunction of uncertain etiology, using late gadolinium-enhanced cardiovascular magnetic resonance. J Am Coll Cardiol 2005; 45:743-8. [PMID: 15734620 DOI: 10.1016/j.jacc.2004.11.037] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Revised: 10/24/2004] [Accepted: 11/01/2004] [Indexed: 01/27/2023]
Abstract
OBJECTIVES We evaluated the feasibility of using late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) to distinguish left ventricular (LV) systolic dysfunction related or not to coronary artery disease (CAD) in patients with heart failure (HF) but without clinical suspicion of CAD as the underlying cause. BACKGROUND In patients with known CAD, LGE-CMR is capable of distinguishing LV systolic dysfunction related to CAD from dilated cardiomyopathy. METHODS Seventy-one patients with HF and LV systolic dysfunction, without a previous history of myocardial infarction, with neither Q waves nor clinical data suggesting CAD, underwent both LGE-CMR and coronary angiography. RESULTS Twenty-six patients (37%) had angiographically proven CAD (>/=70% stenosis of a major epicardial vessel) (angio [+] group), and 45 (63%) had unobstructed coronary arteries (angio [-] group). Twenty-one patients in the angio (+) group (21 of 26, 81%) showed subendocardial and/or transmural enhancement, whereas only 4 (9%) of 45 in the angio (-) group showed it (p < 0.001). In 7 patients (7 of 71, 10%), we found a different pattern of mid-wall enhancement-namely, 3 of 26 patients in the angio (+) group and 4 of 45 in the angio (-) group (11% vs. 9%, p = 0.7). Mid-wall enhancement in the angio (+) group was distributed in segments other than those which had subendocardial enhancement. CONCLUSIONS In patients with HF and LV systolic dysfunction without clinical suspicion of CAD, LGE-CMR is an excellent tool for classifying patients in relation to the presence or absence of underlying CAD. Thus, CMR might offer a valid alternative to coronary angiography for the detection of CAD in these patients.
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Affiliation(s)
- Carlos J Soriano
- Servicio de Cardiología, Consorcio Hospital General Universitario de Valencia, Spain
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1143
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Abstract
PURPOSE OF REVIEW For three decades, deferoxamine has been the only approved iron chelator. This drug has an extremely short-half life and is not orally absorbed; thus, a search has been ongoing for alternative chelators with less onerous delivery. Recently, several oral iron chelators and variations of deferoxamine to prolong the half-life have been developed. These and the methods of monitoring iron overload are the subjects of this review. RECENT FINDINGS New chelators, combinations of chelators and regimens for known chelators and their safety and efficacy are being studied in important preclinical and clinical trials. SUMMARY The care and clinical outcomes of patients with thalassemia and other iron-overload disorders may be markedly improved by recent discoveries and novel approaches to chelation therapy.
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1144
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1145
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Abstract
Cardiovascular magnetic resonance (CMR) has established itself as probably the single best way of phenotyping the failing heart. It is the accepted gold standard for measuring cardiac function, volumes, and mass, but within the same scan session additional techniques are available for greater definition. Tissue characterization with the contrast agent gadolinium is well validated and allows the precise visualization and quantification of myocardial infarction. This can be used for viability assessment and to determine heart failure etiology. Dobutamine stress CMR and CMR perfusion hold advantages over conventional techniques. The new frontiers of CMR in heart failure hold the promise of unique insights quantifying myocardial iron, nonischemic fibrosis, microvascular perfusion, plaque characterization, and CMR-targeted intervention. The development and validation of these techniques represent major research challenges for the future. From a clinical perspective, an equal challenge is in increasing the availability of the modality for patients and physicians.
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Affiliation(s)
- James C C Moon
- Department of Cardiovascular Magnetic Resonance, Royal Brompton Hospital, London, SW3 6NP, UK.
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1146
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Anderson LJ, Westwood MA, Holden S, Davis B, Prescott E, Wonke B, Porter JB, Walker JM, Pennell DJ. Myocardial iron clearance during reversal of siderotic cardiomyopathy with intravenous desferrioxamine: a prospective study using T2* cardiovascular magnetic resonance. Br J Haematol 2004; 127:348-55. [PMID: 15491298 DOI: 10.1111/j.1365-2141.2004.05202.x] [Citation(s) in RCA: 299] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Heart failure from iron overload causes 71% of deaths in thalassaemia major, yet reversal of siderotic cardiomyopathy has been reported. In order to determine the changes in myocardial iron during treatment, we prospectively followed thalassaemia patients commencing intravenous desferrioxamine for iron-induced cardiomyopathy during a 12-month period. Cardiovascular magnetic resonance assessments were performed at baseline, 3, 6 and 12 months of treatment, and included left ventricular (LV) function and myocardial and liver T2*, which is inversely related to iron concentration. One patient died. The six survivors showed progressive improvements in myocardial T2* (5.1 +/- 1.9 to 8.1 +/- 2.8 ms, P = 0.003), liver iron (9.6 +/- 4.3 to 2.1 +/- 1.5 mg/g, P = 0.001), LV ejection fraction (52 +/- 7.1% to 63 +/- 6.4%, P = 0.03), LV volumes (end diastolic volume index 115 +/- 17 to 96 +/- 3 ml, P = 0.03; end systolic volume index 55 +/- 16 to 36 +/- 6 ml, P = 0.01) and LV mass index (106 +/- 14 to 95 +/- 13, P = 0.01). Iron cleared more slowly from myocardium than liver (5.0 +/- 3.3% vs. 39 +/- 23% per month, P = 0.02). These prospective data confirm that siderotic heart failure is often reversible with intravenous iron chelation with desferrioxamine. Myocardial T2* improves in concert with LV volumes and function during recovery, but iron clearance from the heart is considerably slower than from the liver.
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Affiliation(s)
- Lisa J Anderson
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, UK
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1147
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Kwiatkowski JL, Cohen AR. Iron chelation therapy in sickle-cell disease and other transfusion-dependent anemias. Hematol Oncol Clin North Am 2004; 18:1355-77, ix. [PMID: 15511620 DOI: 10.1016/j.hoc.2004.06.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Regular red cell transfusion therapy may be life-saving or may reduce complications substantially in several hematological disorders. The inevitable consequence of repeated transfusions is iron loading, which, if untreated, leads to organ failure and death. Chelation therapy with deferoxamine is the standard of care for patients who have transfusional iron overload. The necessity to administer this drug parenterally limits compliance; this has prompted the search for a safe and effective orally-administered chelator. Deferiprone, the first extensively studied orally active chelator, is now licensed for use in Europe for patients who are unable to use deferoxamine effectively or safely. ICL670, a newer oral chelator, is being tested in large clinical trials. Combined therapies, potentially including transfusional methods to reduce iron loading with parenteral and oral chelators, may improve compliance and efficacy in some patients who are transfused chronically.
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Affiliation(s)
- Janet L Kwiatkowski
- Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
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1148
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St Pierre TG, Clark PR, Chua-Anusorn W. Single spin-echo proton transverse relaxometry of iron-loaded liver. NMR IN BIOMEDICINE 2004; 17:446-458. [PMID: 15523601 DOI: 10.1002/nbm.905] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A single-spin-echo methodology is described for the measurement and imaging of proton transverse relaxation rates (R2) in iron-loaded and normal human liver tissue in vivo. The methodology brings together previously reported techniques dealing with (i) the changes in gain between each spin-echo acquisition, (ii) signal level offset due to background noise, (iii) estimation of signal intensities in decay curves at time zero to enable reliable extraction of relaxation times from tissues with very short T2 values, (iv) bi-exponential modelling of decay curves with a small number of data points, and (v) reduction of respiratory motion artefacts. The accuracy of the technique is tested on aqueous manganese chloride solutions yielding a relaxivity of 74.1+/-0.3 s-1 (mM)-1, consistent with previous reports. The precision of the in vivo measurement of mean liver R2 values is tested through duplicate measurements on 10 human subjects with mean liver R2 values ranging from 26 to 220 s-1. The random uncertainty on the measurement of mean liver R2 was found to be 7.7%.
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Affiliation(s)
- Timothy G St Pierre
- School of Physics, M013, The University of Western Australia, Crawley, WA 6009, Australia.
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1149
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Aessopos A, Farmakis D, Hatziliami A, Fragodimitri C, Karabatsos F, Joussef J, Mitilineou E, Diamanti-Kandaraki E, Meletis J, Karagiorga M. Cardiac status in well-treated patients with thalassemia major. Eur J Haematol 2004; 73:359-66. [PMID: 15458515 DOI: 10.1111/j.1600-0609.2004.00304.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To assess cardiac status in a large group of patients with thalassemia major who had been treated in a standard way since their early infancy with intensive transfusions and deferoxamine chelation therapy and who had good compliance with this regimen. METHODS AND RESULTS We assessed clinically and echocardiographically 202 thalassemia major patients aged 27.3 +/- 6.3 yr and 75 age and sex-matched healthy controls. Overt cardiac disease was encountered in 14 patients (6.9%), including 5 (2.5%) with congestive heart failure, aged 26-37 yr, and 9 with systolic left ventricular (LV) dysfunction, aged 23-37 yr. Ten patients (5.0%) had a history of pericarditis. Left atrial and LV diameters, LV mass and cardiac output were significantly higher in patients than in controls, while peripheral resistance and LV afterload were significantly lower. Relative LV wall thickness did not differ between patients and controls, but it was significantly lower in patients with overt cardiac disease compared to those without (P < 0.05). Restrictive LV filling was observed in 37.6% of patients and was significantly more frequent in cases with overt cardiac disease (P < 0.01). Pulmonary hypertension was practically absent. Hematological parameters and pulmonary artery pressure levels were not independently associated with the presence of overt cardiac disease. CONCLUSION Strict lifelong adherence to the standard transfusion and deferoxamine therapy reduces considerably the occurrence of heart failure, LV dysfunction and pericarditis, prevents early heart failure and pulmonary hypertension, but does not eliminate completely cardiac disease in patients with thalassemia major.
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Affiliation(s)
- Athanasios Aessopos
- Cardiac Outpatient Clinic for Hemoglobinopathies, First Department of Internal Medicine, University of Athens Medical School, Laiko Hospital, Athens, Greece.
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1150
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Abstract
BACKGROUND/AIMS The so-called volume/outcome relationship postulates that a higher caseload and specialization results in an improved outcome. The existence of such a relationship, however, is still debated in the literature. The objective of this review is to discuss the available data on this relationship in surgical oncology. METHODS A Medline analysis was performed using the following terms: volume, outcome, cancer, and surgery. The bibliography of each relevant article was screened for further studies. RESULTS For most malignancies a volume/outcome relationship was demonstrated in recent years. Components of this improved outcome are decreased perioperative morbidity and mortality, higher quality of life after surgery, improved economic outcome, and a better long-term prognosis for patients with cancer. The magnitude of this relationship, however, varies greatly among different malignancies. The exact reason for the volume/outcome relationship is still unknown. CONCLUSION Concentrating high-risk procedures in high-volume hospitals might prevent thousands of perioperative deaths per year. This concept seems feasible for rare and high-risk diseases; however, it is unclear what threshold should be used for the definition of a high-volume provider. For common and low-risk diagnoses, it seems more realistic to educate the medical community in order to improve the outcome for the patients.
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Affiliation(s)
- Jürgen Weitz
- Department of Surgery, University of Heidelberg, DE-69120 Heidelberg, Germany
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