Prediction of long-term survival in patients with transfusion-dependent hemoglobinopathies: Insights from cardiac imaging and ferritin.

AIMS: The current study evaluated the association of echocardiography, cardiac magnetic resonance (CMR), and ferritin data with 10-year survival in thalassemia patients. METHODS: Demographics, ferritin, echocardiography, and CMR parameters of stable consecutive thalassemia patients were prospectively collected. RESULTS: In total, 75 patients (mean age 37 ± 11 years, 45% male) with thalassemia were included and dichotomized based on their survival status after a median follow-up period of 10.3 [9.6-10.9] years. Older age (HR: 1.071, p = 0.001), ferritin ≥2000 ng/ml (HR: 4.682, p = 0.007) and ≥1700 ng/ml (HR: 7.817, p = 0.002), elevated LV end-diastolic pressure (HR: 1.019, p = 0.044), TR Vmax >2.8 m/s (HR: 6.845, p = 0.005), and CMR T2∗ ≤20 msec (HR: 3.602, p = 0.043) and ≤34 msec (HR: 5.854, p = 0.026) were associated with increased all-cause mortality (primary endpoint). A baseline model including age was created and became more predictive of worse survival by adding TR Vmax >2.8 m/s instead of elevated LV end-diastolic pressure (C index 0.767 vs. 0.760, respectively), ferritin ≥1700 ng/ml instead of ≥2000 ng/ml (C index 0.890 vs. 0.807, respectively), or CMR T2∗≤34 msec instead of ≤20 msec (C index 0.845 vs. 0.839, respectively). Parameters associated with the combined endpoint of cardiac mortality/cardiac hospitalization (secondary endpoint) after adjusting for age were ferritin ≥1700 ng/ml (HR 3.770, p = 0.014), ratio E/A wave >2 (HR 3.565, p = 0.04), TR Vmax >2.8 m/s (HR 4.541, p = 0.049), CMR T2∗ ≤20 ms (HR 9.462, p = 0.001), and CMR T2∗ ≤34 ms (HR 11.735, p = 0.002). The model including age and T2∗ ≤34 ms instead of T2∗ ≤20 ms was more predictive of the secondary endpoint (C-index 0.844 vs 0.838, respectively). CONCLUSIONS: In thalassemia patients, TR Vmax >2.8 m/s, ferritin ≥2000 ng/ml, and CMR T2∗ ≤20 ms were associated with worse long-term survival. In the current era of advanced chelation therapy, aiming for ferritin ≤1700 ng/ml and CMR T2∗ ≥34 ms may improve their prognosis.

Cardiomyopathy in Thalassemia: Quick Review from Cellular Aspects to Diagnosis and Current Treatments.

BACKGROUND: Cardiomyopathic manifestations induced by continuous blood transfusion are the leading cause of death among patients with thalassemia major (TM). Despite introduction of chelation therapy, heart failure after cardiomyopathic manifestations is still a major threat to patients. METHODS: We performed a search of relevant English-language literature, retrieving publications from the PubMed database and the Google Scholar search engine (2005-2018). We used "thalassemia major", "cardiomyopathy", "iron overload", "cardiac magnetic resonance T2" "chelation therapy", and "iron burden" as keywords. RESULTS: The results of the studies we found suggest that cardiac hepcidin is a major regulator of iron homeostasis in cardiac tissue. Unlike previous assumptions, the heart appears to have a limited regeneration capability, originating from a small population of hypoxic cardiomyocytes. CONCLUSIONS: Oxygen levels determine cardiomyocyte gene-expression patterns. Upregulation of cardiac hepcidin in hypoxia preserves cardiomyocytes from forming out of reactive oxygen species catalyzed by free cellular iron in cardiomyocytes. Using the limited regeneration capacity of cardiac cells and gaining further understanding of the cellular aspects of cardiomyopathic manifestations may help health care professionals to develop new therapeutic strategies.

Left Ventricular Diastolic Dysfunction in ß-Thalassemia Major with Heart Failure.

We studied the clinical, electrocardiographic, echocardiographic, Doppler and T2* cardiac magnetic resonance (CMR) data of all adult ß-thalassemia major (ß-TM) patients with heart failure (HF) consecutively observed at our referral center of the Sicilian region between 2008 and 2016. There were 16 patients enrolled in the study. Echocardiographic examination showed that only one patient had HF with systolic dysfunction of the left ventricle (HFrEF), whereas the others had HF with preserved systolic function of the left ventricle (HFpEF). Systolic dysfunction of the right ventricle (RV) was observed in 13 cases. Furthermore, 30.0% of the patients presented T2* CMR values consistent with intermediate risk of systolic dysfunction of the left ventricle (LV) due to iron overload, whereas 70.0% had normal values. Typical electrocardiographic abnormalities (wide T wave inversion and low voltages) were observed in 11 out of 16 patients. In conclusion, in the adult ß-TM patients with HF recently observed at our center, the predominant form was that with diastolic dysfunction of the LV, and with systolic dysfunction of the RV. Only 30.0% had low values of T2* CMR. Typical electrocardiographic abnormalities were found in 69.0%.

Myocardial deformation in iron overload cardiomyopathy: speckle tracking imaging in a beta-thalassemia major population.

Traditional echocardiography is unable to detect neither the early stages of iron overload cardiomyopathy nor myocardial iron deposition. The aim of the study is to determine myocardial systolic strain indices in thalassemia major (TM), and assess their relationship with T2*, a cardiac magnetic resonance index of the severity of cardiac iron overload. 55 TM cases with recent cardiac magnetic resonance (CMR-T2*) underwent speckle tracking analysis to assess regional myocardial strains and rotation. The results were compared with a normal control group (n = 20), and were subsequently analyzed on the basis of the CMR-T2* values. Two TM groups were studied: TM with significant cardiac iron overload ("low" T2*, ≤20 ms; n = 21), and TM with normal T2* values ("normal" T2*, >20 ms; n = 34). TM patients show significant, uniform decrease in circumferential and radial strain (P < 0.05), and a remarkable reduction in end-systolic rotation, both global, and for all segments (P < 0.001). No significant differences were found between the low- and the normal T2* group either in regional strains and rotation or in standard echocardiographic and CMR parameters. Spearman's correlation coefficient shows no significant correlation between myocardial strains, rotation and cardiac T2* values. In conclusion, our results are in accordance with recent evidence that myocardial iron overload is not the only mechanism underlying iron cardiomyopathy in TM. Strain imaging can predict subclinical myocardial dysfunction irrespective of CMR-T2* values, although it cannot replace CMR-T2* in assessing cardiac iron overload. Finally, it might be useful to appropriately time cardioactive treatment.

Myocardial and liver iron overload, assessed using T2* magnetic resonance imaging with an excel spreadsheet for post processing in Tunisian thalassemia major patients.

Thalassemia is a common genetic disorder in Tunisia. Early iron concentration assessment is a crucial and challenging issue. Most of annual deaths due to iron overload occurred in underdeveloped regions of the world. Limited access to liver and heart MRI monitoring might partially explain these poor prognostic results. Standard software programs are not available in Tunisia. This study is the first to evaluate iron overload in heart and liver using the MRI T2* with excel spreadsheet for post processing. Association of this MRI tool results to serum ferritin level, and echocardiography was also investigated. One hundred Tunisian-transfused thalassemia patients older than 10 years (16.1 ± 5.2) were enrolled in the study. The mean myocardial iron concentration (MIC) was 1.26 ± 1.65 mg/g dw (0.06-8.32). Cardiac T2* (CT2*) was under 20 ms in 30 % of patients and under 10 ms in 21 % of patients. Left ventricular ejection function was significantly lower in patients with CT2* <10 ms. Abnormal liver iron concentration (LIC >3 mg/g dw) was found in 95 % of patients. LIC was over 15 mg/g dw in 25 % of patients. MIC was more correlated than CT2* to LIC and serum ferritin. Among patients with SF <1000 µg/l, 13 % had CT2* <20 ms. Our data showed that 30 % of the Tunisian thalassemia major patients enrolled in this cohort had myocardial iron overload despite being treated by iron chelators. SF could not reliably predict iron overload in all thalassemia patients. MRI T2* using excel spreadsheet for routine follow-up of iron overload might improve the prognosis of thalassemia major patients in developing countries, such as Tunisia, where standard MRI tools are not available or expensive.