Gianluca Forni

On T2* Magnetic Resonance and Cardiac Iron

Background— Measurement of myocardial iron is key to the clinical management of patients at risk of siderotic cardiomyopathy. The cardiovascular magnetic resonance relaxation parameter R2* (assessed clinically via its reciprocal, T2*) measured in the ventricular septum is used to assess cardiac iron, but iron calibration and distribution data in humans are limited. Methods and Results— Twelve human hearts were studied from transfusion-dependent patients after either death (heart failure, n=7; stroke, n=1) or transplantation for end-stage heart failure (n=4). After cardiovascular magnetic resonance R2* measurement, tissue iron concentration was measured in multiple samples of each heart with inductively coupled plasma atomic emission spectroscopy. Iron distribution throughout the heart showed no systematic variation between segments, but epicardial iron concentration was higher than in the endocardium. The mean±SD global myocardial iron causing severe heart failure in 10 patients was 5.98±2.42 mg/g dry weight (range, 3.19 to 9.50 mg/g), but in 1 outlier case of heart failure was 25.9 mg/g dry weight. Myocardial ln[R2*] was strongly linearly correlated with ln[Fe] (R2=0.910, P<0.001), leading to [Fe]=45.0×(T2*)−1.22 for the clinical calibration equation with [Fe] in milligrams per gram dry weight and T2* in milliseconds. Midventricular septal iron concentration and R2* were both highly representative of mean global myocardial iron. Conclusions— These data detail the iron distribution throughout the heart in iron overload and provide calibration in humans for cardiovascular magnetic resonance R2* against myocardial iron concentration. The iron values are of considerable interest in terms of the level of cardiac iron associated with iron-related death and indicate that the heart is more sensitive to iron loading than the liver. The results also validate the current clinical practice of monitoring cardiac iron in vivo by cardiovascular magnetic resonance of the midseptum.

Hepatocellular carcinoma in the thalassaemia syndromes

Hepatocellular carcinoma (HCC) frequently complicates hepatic cirrhosis secondary to viral infection or iron overload. Therefore, patients affected by thalassaemia syndromes have a theoretically high risk of developing the tumour. We collected data on patients attending Italian centres for the treatment of thalassaemia. Twenty‐two cases of HCC were identified; 15 were male. At diagnosis, the mean age was 45 ± 11 years and the mean serum ferritin was 1764 ± 1448 μg/l. Eighty‐six percent had been infected by hepatitis C virus. Nineteen of 22 cases were diagnosed after 1993, suggesting that this problem is becoming more frequent with the aging population of thalassaemia patients.

Myocardial scarring by delayed enhancement cardiovascular magnetic resonance in thalassaemia major

Background: Cardiovascular magnetic resonance (CMR) by delayed enhancement (DE) enables visualisation of myocardial scarring, but no dedicated studies are available in thalassaemia major. Objective: To investigate the prevalence, extent, clinical and instrumental correlates of myocardial fibrosis or necrosis by DE CMR in patients with thalassaemia major. Patients: 115 Patients with thalassaemia major consecutively examined at an MRI laboratory. Methods: DE images were acquired to quantify myocardial scarring. Myocardial iron overload was determined by multislice multiecho T2*. Cine images were obtained to evaluate biventricular function. Results: DE areas were present in 28/115 patients (24%). The mean (SD) extent of DE was 3.9 (2.4)%. In 26 patients the location of fibrosis was not specific and patchy distribution was prevalent. Two patients showed transmural DE following coronary distribution. The DE group was significantly older than the no-DE group (31 (7.7) years vs 26 (7.7) years, p = 0.004). No significant relation with heart T2* values and biventricular function was found. A significant correlation was found between the presence of DE and changes in ECG (ECG abnormal in the DE group 22/28 patients and in the no-DE group 30/87 patients; χ2 = 14.9; p<0.001). Conclusions: In patients with thalassaemia the significant presence of myocardial fibrosis/necrosis seems to be a time-dependent process correlating with cardiovascular risk factors and cardiac complications. Levels of HCV antibodies are significantly higher in the serum of patients with thalassaemia with myocardial fibrosis/necrosis. ECG changes showed a good accuracy in predicting myocardial scarring.

Quantitative ultrasonic analysis of myocardium in patients with thalassemia major and iron overload.

BackgroundPatients with f-thalassemia major present with severe anemia and need continuous transfusion therapy. The consequent iron overload leads to hemochromatosis. Initial cardiac dysfunction has been documented even in thalassemics without clinical manifestations of heart failure as well as by conventional echocardiographic-Doppler techniques. The purpose of this study was to assess the acoustic quantitative properties of myocardium in patients with iron overload. Methods and ResultsThirty-eight patients with (3-thalassemia major, without clinical signs of cardiac failure, and 20 age- and sex-matched young controls were studied by echocardiography. An on-line analysis of the ultrasonic radiofrequency signal was performed to obtain quantitative operator-independent measurements of the integrated backscatter (IB) signal of the ventricular septum and the posterior wall. The integrated values of the radiofrequency signal were normalized for the pericardial interface and expressed in percent (IB%). Thalassemic patients had been receiving transfusion therapy for 16±5 years and had received 313±+138 transfusion units; they all had received chelation treatment (desferroxiamine) for 9±2 years. Patients and controls showed comparable values of echocardiographically assessed percent fractional shortening (32±3% versus 36±4%, p=NS), whereas thalassemics showed higher values of left ventricular mass index (118±30 versus 98 ± 15 g/m2, p<0.05). The IB% values were higher in patients with thalassemia major than in controls for both septum (35±14% versus 21+6%, p<0.001) and posterior wall (16±6% versus 11±3%, p<0.001). In thalassemic patients, no significant correlation was found between the septum IB% value and hematological parameters, such as the total number of transfusions (r=0.2, p=NS) or the mean ferritin value (r=0.1, p=NS). No significant correlation was also found between the septum IB% value and the echocardiographically assessed left ventricular mass index (r=0.2, p=NS). ConclusionThese data demonstrate that myocardial reflectivity is abnormally increased in patients with thalassemia major under transfusion treatment, probably due to myocardial iron deposits and/or secondary structural changes. These quantitatively assessed abnormalities in regional reflectivity can be detected when conventional echocardiographic parameters of systolic left ventricular function are undistinguishable from normal controls.

Standardized T2* map of a normal human heart to correct T2* segmental artefacts; myocardial iron overload and fibrosis in thalassemia intermedia versus thalassemia major patients and electrocardiogram changes in thalassemia major patients.

Studies of the standardized, 3D, 16-segments map of the circumferential distribution of T2* values, of cardiovascular magnetic resonance (CMR) in thalassemia major (TM) and thalassemia intermedia (TI) patients and of electrocardiogram (ECG) changes associated with TM, have been carried out. Similarly, the segment-dependent correction map of the T2* values and the artifactual variations in normal subjects and the T2* correction map to correct segmental measurements in patients with different levels of myocardial iron burden have been evaluated. Cardiovascular magnetic resonance can be a suitable guide to cardiac management in TI, as well as in TM; TI patients show lower myocardial iron burden and more pronounced high cardiac output findings than TM patients. Moreover, it is proposed that, due to its good positive predictive value (PPV) and low cost, ECG can be a suitable guide to orient towards CMR examination in TM cases.

Congenital Dyserythropoietic Anemia Type II: molecular analysis and expression of the SEC23B Gene

BackgroundCongenital dyserythropoietic anemia type II (CDAII), the most common form of CDA, is an autosomal recessive condition. CDAII diagnosis is based on invasive, expensive, and time consuming tests that are available only in specialized laboratories. The recent identification of SEC23B mutations as the cause of CDAII opens new possibilities for the molecular diagnosis of the disease. The aim of this study was to characterize molecular genomic SEC23B defects in 16 unrelated patients affected by CDAII and correlate the identified genetic alterations with SEC23B transcript and protein levels in erythroid precursors.MethodsSEC23B was sequenced in 16 patients, their relatives and 100 control participants. SEC23B transcript level were studied by quantitative PCR (qPCR) in peripheral erythroid precursors and lymphocytes from the patients and healthy control participants. Sec23B protein content was analyzed by immunoblotting in samples of erythroblast cells from CDAII patients and healthy controls.ResultsAll of the investigated cases carried SEC23B mutations on both alleles, with the exception of two patients in which a single heterozygous mutation was found. We identified 15 different SEC23B mutations, of which four represent novel mutations: p.Gln214Stop, p.Thr485Ala, p.Val637Gly, and p.Ser727Phe. The CDAII patients exhibited a 40-60% decrease of SEC23B mRNA levels in erythroid precursors when compared with the corresponding cell type from healthy participants. The largest decrease was observed in compound heterozygote patients with missense/nonsense mutations. In three patients, Sec23B protein levels were evaluated in erythroid precursors and found to be strictly correlated with the reduction observed at the transcript level. We also demonstrate that Sec23B mRNA expression levels in lymphocytes and erythroblasts are similar.ConclusionsIn this study, we identified four novel SEC23B mutations associated with CDAII disease. We also demonstrate that the genetic alteration results in a significant decrease of SEC23B transcript in erythroid precursors. Similar down-regulation was observed in peripheral lymphocytes, suggesting that the use of these cells might be sufficient in the identification of Sec23B gene alterations. Finally, we demonstrate that decreased Sec23B protein levels in erythroid precursors correlate with down-regulation of the SEC23B mRNA transcript.

Changing patterns of splenectomy in transfusion-dependent thalassemia patients†

radiographs and MRI, Stage I: normal plain radiographs, but MRI findings of OFH, Stage II, sclerosis and lucencies of the femoral head, Stage III, subchondral collapse without flattening of the femoral head, Stage IV, flattening of the femoral head, normal joint space, Stage V, joint space narrowing with acetabular changes, and Stage VI, advanced degenerative changes [5]. Patients identified as having OFH were further evaluated with MRI of the pelvis. MRI studies were performed on a 1.5 T MRI (GE) and consisted of axial T1, axial T2 fast spin echo with fat saturation, coronal T2 with fat saturation, T1 coronal of both hips, and coronal and sagital proton density of the symptomatic side, without gadolinium administration.

Prediction of cardiac complications for thalassemia major in the widespread cardiac magnetic resonance era: a prospective multicentre study by a multi-parametric approach

Aims Cardiovascular magnetic resonance (CMR) has dramatically changed the clinical practice in thalassemia major (TM), lowering cardiac complications. We prospectively reassessed the predictive value of CMR parameters for heart failure (HF) and arrhythmias in TM. Methods and results We considered 481 white TM patients (29.48 ± 8.93 years, 263 females) enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) network. Myocardial and liver iron overload were measured by T2* multiecho technique. Atrial dimensions and biventricular function were quantified by cine images. Late gadolinium enhancement images were acquired to detect myocardial fibrosis. Mean follow-up was 57.91 ± 18.23 months. After the first CMR scan 69.6% of the patients changed chelation regimen. We recorded 18 episodes of HF. In the multivariate analysis the independent predictive factors were myocardial fibrosis (HR = 10.94, 95% CI = 3.28-36.43, P < 0.0001), homogeneous MIO (compared with no MIO) (HR = 5.56, 95% CI = 1.37-22.51, P  = 0.016), ventricular dysfunction (HR = 4.33, 95% CI = 1.39-13.43, P  = 0.011). Arrhythmias occurred in 16 patients. Among the CMR parameters only the atrial dilation was identified as univariate prognosticator (HR = 4.26 95% CI=1.54-11.75, P  = 0.005). Conclusions CMR guided the change of chelation therapy in nearly 70% of patients, leading to a lower risk of iron-mediated HF and of arrhythmias than previously reported. Homogeneous MIO remained a risk factor for HF but also myocardial fibrosis and ventricular dysfunction identified patients at high risk. Arrhythmias were independent of MIO but increased with atrial dilatation. CMR by a multi-parametric approach dramatically improves cardiac outcomes and provides prognostic information beyond cardiac iron estimation.

Dual therapy with peg-interferon and ribavirin in thalassemia major patients with chronic HCV infection: Is there still an indication?

BACKGROUND Iron overload and hepatitis C virus (HCV) infection together can lead to chronic liver damage in thalassemia major (TM) patients. AIMS We investigated viral, genetic, and disease factors influencing sustained virological response (SVR) after peg-interferon and ribavirin therapy in TM patients with HCV infection. METHODS We analyzed 230 TM patients with HCV infection (mean age 36.0±6.3 years; 59.1% genotype 1; 32.2% genotype 2; 3.4% genotype 3; and 5.3% genotype 4; 28.7% carried CC allele of rs12979860 in IL28B locus; 79.6% had chronic hepatitis and 20.4% cirrhosis; 63.5% naive and 36.5% previously treated with interferon alone) treated in 14 Italian centers. RESULTS By multivariate regression analysis SVR was independently associated with CC allele of IL28B SNP (OR 2.98; CI 95% 1.29-6.86; p=0.010) and rapid virologic response (OR 11.82; CI 95% 3.83-36.54; p<0.001) in 136 genotype 1 patients. Combining favorable variables the probability of SVR ranged from 31% to 93%. In genotype 2 patients, only RVR (OR 8.61; CI 95% 2.85-26.01; p<0.001) was associated with SVR higher than 80%. In 3 patients with cirrhosis a decompensation of liver or heart disease were observed. Over 50% of patients increased blood transfusions. CONCLUSION Dual therapy in TM patients with chronic HCV infection is efficacious in patients with the best virological, genetic and clinical predictors. Patients with cirrhosis have an increased risk of worsening liver or heart disease.

Worldwide survey of T2* cardiovascular magnetic resonance in Thalassaemia

Results Overall, 57.5% of patients had no significant iron loading (T2* >20ms), 22.6% had moderate cardiac iron (10ms 50%) in South-East Asia had cardiac iron (T2* >20ms) at baseline. At the time of the first scan, 100 patients (3.3%) had confirmed heart failure, the majority of whom (77.0%) had myocardial T2* <10ms with almost all (99%) having T2* <20ms. There were 113 patients who subsequently developed heart failure. 92.0% of these had T2* <10ms and 99.1% had a T2* <20ms. There were 39 deaths. Cardiac T2* values were <10ms in 79.5%, with 92.3% <20ms. Conclusions Even in this well-treated cohort with access to transfusion, chelation and CMR, there is a large proportion of TM patients with moderate to severe cardiac iron loading. Low T2* (<10ms) is associated with cardiac failure and death. There is a huge unmet worldwide need in terms of access to specialist medical care (including transfusion and chelation therapy) together with advanced monitoring techniques (such as CMR).