Effect of L-type calcium channel blocker (amlodipine) on myocardial iron deposition in patients with thalassaemia with moderate-to-severe myocardial iron deposition: protocol for a randomised, controlled trial

Introduction: Sideroblastic cardiomyopathy secondary to repeated blood transfusions is a feared complication in thalassaemia. Control of myocardial iron is thus becoming the cornerstone of thalassaemia management. Recent evidence suggests a role for L-type Ca2+ channels in mediating iron uptake by the heart. Blocking the cellular iron uptake through these channels may add to the benefit of therapy to standard chelation in reducing myocardial iron. We aim to determine the efficacy of amlodipine (a calcium channel blocker) as an adjunct to standard aggressive chelation in retarding myocardial iron deposition in thalassaemics with or without cardiomyopathy.Outcomes: The primary outcome is to compare the efficacy of amlodipine+chelation (intervention) versus standard chelation (control) in retarding myocardial iron deposition. Secondary outcomes include the effect of amlodipine therapy on systolic and diastolic function, strain and strain rate and liver iron content.Methods and analysis: This is a single-centre, parallel-group, prospective randomised control trial. Twenty patients will be randomised in a 1:1 allocation ratio into the intervention and control arms. In addition to conventional echocardiography, MRI T2* values for assessment of cardiac and liver iron load will be obtained at baseline and at 6 and 12 months. Cardiac T2* will be reported as the geometric mean and per cent coefficient of variation, and an increase in cardiac T2* values from baseline will be used as an end point to compare the efficacy of therapy. A p Value of Study setting: Department of Pediatric and Child Health, Aga Khan University Hospital, Karachi, Pakistan.Ethics and dissemination: This study has been approved by the Ethics Review Committee and Clinical Trials Unit at The Aga Khan University with respect to scientific content and compliance with applicable research and human subjects regulations. Findings will be reported through scientific publications and research conferences and project summary papers for participants

Prenatal detection of impaired corpus callosum growth using two-dimensional neurosonography in growth-restricted fetuses: potential indicator of fetal brain remodeling in-utero

Objectives: Fetal corpus callosum (CC) serves as a sensitive indicator for brain development and maturation. This largest white-matter-fiber-bundle is important for inter-hemispheric communication of sensory, motor and higher-order information. Its altered development in preterm-infants suggests white-matter-injury and its possible association with delayed cognitive and motor development. We aim to compare the growth of CC in appropriate-for-gestational-age (AGA) and growth-restricted-fetuses (GRFs) using two-dimensional-neuroimaging. Methods: 42 pregnant women were examined in the third-trimester (25-37 weeks) from October- December 2013. Inclusion criteria were singleton fetuses with no structural or chromosomal abnormalities and pregnant women with no medical complications. Fetal brain was examined in the mid-sagittal plane. Length of the CC was measured across outer-outer and inner-inner diameters along with its area. Mean of three measurements recorded in millimeters was included in the analysis. Results: Out of 42 fetuses examined, 31 were identified as AGA and 11 as GRFs based on their estimated-fetal-weight. Mid-sagittal view was successfully obtained in all except for 4 AGA fetuses (90%). Mean maternal age, mean gestational age (GA) and mean area of CC did not differ between the groups (p-value \u3e 0.05). Mean outer-outer and mean inner-inner diameters of CC were significantly lower for GRFs [37.12 (S.D. = 4.6) and 31.27 (S.D. = 4)] compared to AGA fetuses [41.2 (S.D. = 3.4) and 35.8 (S.D. = 2.4)] (p-values: 0.006 and 0.001), respectively. However, both the diameters showed a positive correlation with GA in AGA and GRFs. Conclusions: GRFs show a diminished growth of CC. This may be an indicator of fetal brain remodeling in-utero as an adaptation to compromised intra-uterine environment. Further studies with larger sample size and with inclusion of additional neural biomarkers are needed to validate our findings and to evaluate the effect of reduced fetal CC growth on cognitive and motor development during early childhood. Keywords: corpus callosum, two-dimensional neurosonography, growth restricted fetuses, brain remodelin

Calcium channel blockers for preventing cardiomyopathy due to iron overload in people with transfusion-dependent beta thalassaemia

Background: Beta-thalassaemia is an inherited blood disorder that reduces the production of haemoglobin. The most severe form requires recurrent blood transfusions, which can lead to iron overload. Cardiovascular dysfunction caused by iron overload is the leading cause of morbidity and mortality in people with transfusion-dependent beta-thalassaemia. Iron chelation therapy has reduced the severity of systemic iron overload, but removal of iron from the myocardium requires a very proactive preventive strategy. There is evidence that calcium channel blockers may reduce myocardial iron deposition. This is an update of a Cochrane Review first published in 2018.Objectives: To assess the effects of calcium channel blockers plus standard iron chelation therapy, compared with standard iron chelation therapy (alone or with a placebo), on cardiomyopathy due to iron overload in people with transfusion-dependent beta thalassaemia.Search methods: We searched the Cochrane Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books, to 13 January 2022. We also searched ongoing trials databases and the reference lists of relevant articles and reviews.Selection criteria: We included randomised controlled trials (RCTs) of calcium channel blockers combined with standard chelation therapy versus standard chelation therapy alone or combined with placebo in people with transfusion-dependent beta thalassaemia.Data collection and analysis: We used standard Cochrane methods. We used GRADE to assess certainty of evidence.Main results: We included six RCTs (five parallel-group trials and one cross-over trial) with 253 participants; there were 126 participants in the amlodipine arms and 127 in the control arms. The certainty of the evidence was low for most outcomes at 12 months; the evidence for liver iron concentration was of moderate certainty, and the evidence for adverse events was of very low certainty. Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may have little or no effect on cardiac T2* values at 12 months (mean difference (MD) 1.30 ms, 95% confidence interval (CI) -0.53 to 3.14; 4 trials, 191 participants; low-certainty evidence) and left ventricular ejection fraction (LVEF) at 12 months (MD 0.81%, 95% CI -0.92% to 2.54%; 3 trials, 136 participants; low-certainty evidence). Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may reduce myocardial iron concentration (MIC) after 12 months (MD -0.27 mg/g, 95% CI -0.46 to -0.08; 3 trials, 138 participants; low-certainty evidence). The results of our analysis suggest that amlodipine has little or no effect on heart T2*, MIC, or LVEF after six months, but the evidence is very uncertain. Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may increase liver T2* values after 12 months (MD 1.48 ms, 95% CI 0.27 to 2.69; 3 trials, 127 participants; low-certainty evidence), but may have little or no effect on serum ferritin at 12 months (MD 0.07 μg/mL, 95% CI -0.20 to 0.35; 4 trials, 187 participants; low-certainty evidence), and probably has little or no effect on liver iron concentration (LIC) after 12 months (MD -0.86 mg/g, 95% CI -4.39 to 2.66; 2 trials, 123 participants; moderate-certainty evidence). The results of our analysis suggest that amlodipine has little or no effect on serum ferritin, liver T2* values, or LIC after six months, but the evidence is very uncertain. The included trials did not report any serious adverse events at six or 12 months of intervention. The studies did report mild adverse effects such as oedema, dizziness, mild cutaneous allergy, joint swelling, and mild gastrointestinal symptoms. Amlodipine may be associated with a higher risk of oedema (risk ratio (RR) 5.54, 95% CI 1.24 to 24.76; 4 trials, 167 participants; very low-certainty evidence). We found no difference between the groups in the occurrence of other adverse events, but the evidence was very uncertain. No trials reported mortality, cardiac function assessments other than echocardiographic estimation of LVEF, electrocardiographic abnormalities, quality of life, compliance with treatment, or cost of interventions.Authors\u27 conclusions: The available evidence suggests that calcium channel blockers may reduce MIC and may increase liver T2* values in people with transfusion-dependent beta thalassaemia. Longer-term multicentre RCTs are needed to assess the efficacy and safety of calcium channel blockers for myocardial iron overload, especially in younger children. Future trials should also investigate the role of baseline MIC in the response to calcium channel blockers, and include a cost-effectiveness analysis.Trialregistration: ClinicalTrials.gov NCT01125254 NCT01395199 NCT00061750 NCT00749515 NCT02671695 NCT00800761 NCT00115349 NCT00712738 NCT01927913 NCT02173951 NCT01186419 NCT02065492 NCT02474420

Reduction of cardiac iron overload by optimising iron chelation therapy in transfusion dependent thalassaemia using cardiac T2* MRI: A quality improvement project from Pakistan

Objectives: Cardiac T2* MRI (T2*CMR), for accurate estimation of myocardial siderosis, was introduced as part of a QI collaborative to optimise chelation therapy in order to improve cardiac morbidity in transfusion dependent thalassaemia (TDT) patients. We report the impact of this QI initiative from two thalassaemia centres from this collaborative.Design and setting: A key driver based quality initiative was implemented to improve chelation in TDT patients registered at these two centres in Karachi, Pakistan. Protocol optimisation and compliance to treatment through training, communication and feedback were used as the drivers for QI intervention. Preintervention variables (demographics, chelation history, T2*CMR, echocardiography and holters) were collected from January 2015 to December 2016) and compared with variables in the post implementation phase (January to December 2019). A standardised adverse event severity for chelators and its management was devised for safe drug therapy as well as ensuring compliance to the regimen. Preintervention and postintervention variables were compared using non-parametric test. P value\u3c0.05 was statistically significant.Results: 100 patients with TDT, median age 17 (9-34) years, were included. An increase or stabilisation of T2*CMR was documented in 82% patients in the postintervention phase especially in patients with severe myocardial iron overload (5.5 vs 5.3 ms, p \u3c0.01). Significantly fewer patients had abnormal echocardiographic findings (3.5% vs 26%, p \u3c0.05) in the postintervention versus preintervention period.Conclusion: This QI initiative improved the chelation therapy leading to improved cardiac status in TDT patients at the participating centres

Clinical utility of endocrine markers predicting myocardial siderosis in transfusion dependent thalassemia major

Background: Endocrinopathy due to iron overload is the most common morbidity whereas myocardial siderosis causing toxic cardiomyopathy is the leading cause of mortality among patients with transfusion dependent thalassemia major (TDTM). If detected early, this can be treated with aggressive chelation. T2* cardiac magnetic resonance imaging (CMR) guided chelation protocols are now the gold standard but have limited availability in low and middle-income countries. We hypothesized that markers of endocrine dysfunction would correlate with T2* CMR and can be used to predict the severity of myocardial siderosis and guide chelation therapy.Methodology: We undertook a multicenter retrospective study of 280 patients with TDTM to assess the prevalence of endocrinopathies and the predictive value of a number of individual and composite markers of endocrinopathy with T2* CMR.Results: The prevalence of hypogonadism, stunting, hypoparathyroidism, and hypothyroidism was 82%, 69%, 40%, and 30%, respectively. The sensitivity of hypogonadism and stunting predicting severe myocardial siderosis was 90% and 80%, respectively.Conclusion: We conclude that clinical markers of endocrine dysfunction, especially hypogonadism (positive likelihood ratio [LR+] = 1.4, 95% confidence interval [CI] = 1.0-1.9; positive predictive value [PPV] = 77%, 95% CI = 70-82; negative predictive value [NPV] = 57%, 95% CI = 34-77] and stunting (LR+ = 1.3, 95% CI = 1.1-1.6; PPV = 64%, 95% CI = 60-69; NPV = 55%, 95% CI = 45-64) in TDTM can predict severe myocardial siderosis and can potentially guide chelation therapy, especially where access to T2* CMR is limited

Burden of Cardiac Siderosis in a Thalassemia-Major Endemic Population: A Preliminary Report From Pakistan

Objective: To describe the initial experience and demographics of T2* cardiac magnetic resonance-based myocardial-iron quantification of transfusion-dependent thalassemia-major (TM) patients from Pakistan and the correlation with serum ferritin.Methods: Eligible TM patients presenting between April 2014 and April 2015 to Aga Khan University Hospital, Pakistan, for T2*CMR were included. The severity of myocardial-iron deposition was defined as follows: normal T2*\u3e20 ms, mild-moderate T2*10 to 20 ms, and severe T2*\u3c10 ms. Cardiac symptoms were classified using the NYHA functional classification. Echocardiographic systolic and diastolic functions were performed. Continuous variables were presented as the median (minimum-maximum value). Correlation was measured using the Spearman rank correlation. Multivariate logistic regression was used to determine factors associated with the NYHA functional class.Results: A total of 83 patients (49 male and 34 female) with TM, age 19 (5 to 45) years at presentation for T2*CMR, were reviewed. At presentation, 70% of the patients were classified as NYHA class II or worse. T2*\u3c20 ms was observed in 62.6% of the patients, with 47% showing severe iron deposition (T2\u3c10 ms). No correlation of T2*\u3c20 ms (r=-0.157, P=0.302) and T2*\u3c10 ms (r=-0.128, P=0.464) was observed with serum ferritin. On multivariate analysis, lower T2* values correlated with a worsening NYHA functional class.CONCLUSIONS: There is a high prevalence of severe myocardial iron load in Pakistani TM patients. Serum ferritin did not correlate with T2* values. Lower T2* was the only clinical factor associated with the NYHA functional class

Establishment of a thalassaemia major quality improvement collaborative in Pakistan

Objectives: The aim of this study was to establish multidisciplinary care for patients with transfusion-dependent thalassaemia (TDT) by creating a TDT quality improvement (QI) collaborative in a resource-constrained setting. This study presents our initial experience of creating this collaborative, the baseline characteristics of the participants, the proposed QI interventions and the outcome metrics of the collaborative.Design and Setting: TDT QI collaborative is a database comprising patients with TDT from four centres in Karachi, Pakistan. Study variables included symptoms of cardiac or endocrine dysfunction, physical examination including anthropometry and Tanner staging, chelation therapy, results of echocardiography, T2* cardiac MRI (CMR) and serum ferritin. The main outcome of this collaborative was improvement in TDT-related morbidity and mortality. Interventions addressing the key drivers of outcome were designed and implemented.Results: At the time of reporting, the total number of patients in this database was 295. Most patients reported cardiac symptoms corresponding to New York Heart Association class 2. Approximately half (52%, n=153) of the patients demonstrated severe myocardial iron overload (T2* \u3c10 ms). Majority of the patients (58%, n=175) were not on adequate chelation therapy. There was no difference in echocardiographic measures of systolic and diastolic left ventricle among the different spectrums of iron overloaded myocardium.Conclusion: Using T2* CMR and endocrine testing, we have identified significant burden of iron siderosis in our patients with TDT. Lack of adequate iron load assessment and standardised management was observed. Interventions designed to target these key drivers of outcome are the unique part of this QI-based TDT registry