Cardiomyopathy in Duchenne Muscular Distrophy: Clinical Insights and Therapeutic Implications

Duchenne muscular dystrophy cardiomyopathy (DMD-DCM) is characterized by progressive ventricular dilation and dysfunction that can begin at any age and worsens over time. Thanks to the lengthening of life expectancy due to better management of respiratory involvement, end-stage heart failure (HF) is becoming the main cause of death for DMD patients. Therefore, from the time of DMD diagnosis, every effort should be focused to early detect the onset and the worsening of the DMD-DCM, with the aim of starting and modulating the therapy to slow the progression of cardiac dysfunction. In cardiac evaluation, biomarkers, electrocardiograms, and echocardiograms must be considered, but cardiac magnetic resonance (CMR) is now acquiring a leading role due to its sensitivity in the earlier identification of cardiac involvement. The management of DMD-DCM at end stage is a difficult challenge that requires a multidisciplinary team composed of clinical cardiologists, electrophysiologists, cardiac surgeons, neuromuscular specialists, and psychologists. Because of the lack of specific drugs for DMD, we will review the actual cardiovascular armamentarium including drugs used for HF

Insights from cardiopulmonary exercise testing in pediatric patients with hypertrophic cardiomyopathy

The usefulness of cardiopulmonary exercise test (CPET) in adult hypertrophic cardiomyopathy (HCM) patients is well-known, whereas its role in pediatric HCM patients has not yet been explored. The present study investigates possible insights from a CPET assessment in a cohort of pediatric HCM outpatients in terms of functional and prognostic assessment. Sixty consecutive pediatric HCM outpatients aged <18 years old were enrolled, each of them undergoing a full clinical assessment including a CPET; a group of 60 healthy subjects served as controls. A unique composite end-point of heart failure (HF) related and sudden cardiac death (SCD) or SCD-equivalent events was also explored. During a median follow-up of 53 months (25th–75th: 13–84 months), a total of 13 HF- and 7 SCD-related first events were collected. Compared to controls, HCM patients showed an impaired functional capacity with most of them showing peak oxygen uptake (pVO2) values of <80% of the predicted, clearly discrepant with functional New York Heart Association class assessment. The composite end-point occurred more frequently in patients with the worst CPETs’ profiles. At the univariate analysis, pVO2% was the variable with the strongest association with adverse events at follow-up (C-index = 0.72, p = 0.025) and a cut-off value equal to 60% was the most accurate in identifying those patients at the highest risk. In a pediatric HCM subset, the CPET assessment allows a true functional capacity estimation and it might be helpful in identifying early those patients at high risk of events.publishedVersio

Cardiac Manifestations in Children with SARS-COV-2 Infection: 1-Year Pediatric Multicenter Experience

Since the spread of COVID-19, pediatric patients were initially considered less affected by SARS-COV-2, but current literature reported subsets of children with multisystem inflammatory syndrome (MIS-C). This study aims to describe the cardiac manifestation of SARS-COV-2 infection in a large cohort of children admitted to two Italian pediatric referral centers. Between March 2020 and March 2021, we performed a cardiac evaluation in 294 children (mean age 9 ± 5.9 years, male 60%) with active or previous SARS-COV-2 infection. Twenty-six showed ECG abnormalities: 63 repolarization anomalies, 13 Long QTc, five premature ventricular beats, two non-sustained ventricular tachycardia, and one atrial fibrillation. In total, 146 patients underwent cardiac biomarkers: NT-proBNP was elevated in 57, troponin in 34. An echocardiogram was performed in 98, showing 54 cardiac anomalies: 27 left-ventricular dysfunction, 42 pericarditis, 16 coronaritis. MIS-C was documented in 46 patients (mean age 9 ± 4.8 years, male 61%) with cardiac manifestations in 97.8%: 27 ventricular dysfunctions, 32 pericarditis, 15 coronaritis, 3 arrhythmias. All patients recovered, and during follow-up, no cardiac anomalies were recorded. Our experience showed that cardiac involvement is not rare in children with SARS-COV-2, and occurred in almost all patients with MIS-C. However, patients’ recovery is satisfactory and no additional events were reported during FU

Myocardial and Arrhythmic Spectrum of Neuromuscular Disorders in Children

Neuromuscular disorders (NMDs) are highly heterogenous from both an etiological and clinical point of view. Their signs and symptoms are often multisystemic, with frequent cardiac involvement. In fact, childhood onset forms can predispose a person to various progressive cardiac abnormalities including cardiomyopathies (CMPs), valvulopathies, atrioventricular conduction defects (AVCD), supraventricular tachycardia (SVT) and ventricular arrhythmias (VA). In this review, we selected and described five specific NMDs: Friedreich’s Ataxia (FRDA), congenital and childhood forms of Myotonic Dystrophy type 1 (DM1), Kearns Sayre Syndrome (KSS), Ryanodine receptor type 1-related myopathies (RYR1-RM) and Laminopathies. These changes are widely investigated in adults but less researched in children. We focused on these specific topics due their relative frequency and their potential unexpected cardiac manifestations in children. Moreover these conditions present different inheritance patterns and mechanisms of action. We decided not to discuss Duchenne and Becker muscular dystrophies due to extensive work regarding the cardiac aspects in children. For each described NMD, we focused on the possible cardiac manifestations such as different types of CMPs (dilated-DCM, hypertrophic-HCM, restrictive-RCM or left ventricular non compaction-LVNC), structural heart abnormalities (including valvulopathies), and progressive heart rhythm changes (AVCD, SVT, VA). We describe the current management strategies for these conditions. We underline the importance, especially for children, of a serial multidisciplinary personalized approach and the need for periodic surveillance by a dedicated heart team. This is largely due to the fact that in children, the diagnosis of certain NMDs might be overlooked and the cardiac aspect can provide signs of their presence even prior to overt neurological diagnosis

Duchenne Dilated Cardiomyopathy: Cardiac Management from Prevention to Advanced Cardiovascular Therapies

Duchenne muscular dystrophy (DMD) cardiomyopathy (DCM) is characterized by a hypokinetic, dilated phenotype progressively increasing with age. Regular cardiac care is crucial in DMD care. Early recognition and prophylactic use of angiotensin converting enzyme inhibitors (ACEi) are the main stay therapeutic strategy to delay incidence of DMD-DCM. Pharmacological treatment to improve symptoms and left ventricle (LV) systolic function, have been widely implemented in the past years. Because of lack of DMD specific drugs, actual indications for established DCM include current treatment for heart failure (HF). This review focuses on current HF strategies to identify, characterize, and treat DMD-DCM

Heart rate reduction as a marker to optimize carvedilol treatment and enhance myocardial recovery in pediatric dilated cardiomyopathy

Introduction: An elevated heart rate is associated with an increased risk of death or cardiac transplant in children with dilated cardiomyopathy (DCM). Whether heart rate is a clinical marker to address therapy, is poorly investigated in children.Aim: To investigate the relationship between heart rate reduction (HRR) and left ventricular ejection fraction (LVEF) in DCM, treated with carvedilol.Methods: This is a multi center retrospective analysis conducted on all children with DCM (aged &lt; 18 years) between 2013 and 2020, with LVEF &lt; 40% and treated with carvedilol. Carvedilol was up titrated to the maximal tolerated dose or to 1 mg/kg/day. Echocardiographic data on left ventricular function and dimension were collected. The relationship between HRR and LVEF, left ventricular end-diastolic (LVEDd) and end-systolic diameter (LVESd) was assessed before and after HRR with carvedilol, using regression analysis.Results: 100 patients were enrolled (M: 51%; age 7 &amp; PLUSMN; 8 years). The mean LVEF was 30.2 &amp; PLUSMN; 10% before treatment and 43.7 &amp; PLUSMN; 9.6% after treatment, at the maximum therapeutic dose (p &lt; 0.0001). There was a positive relationship between HRR and increase in LVEF (R (2) = 0.06, p = 0.014). A HRR of &gt; 20% correlated with an improvement in LVEF &gt; 13%. At 3 years follow up, HRR demonstrated a significant reduction of LVESd (R2 = 0.1, p = 0.003) LVEDd (R2 = 0.07, p = 0.008) and LVEF recovery up to 15% (p &lt; 0.0001). No deaths or heart transplant occurred during follow-up.Conclusion: This study demonstrates that HRR is safe and improvement in LVEF is related to the degree of HRR. The magnitude of LVEF improvement was enhanced by a major reduction in HR. It provides evidence that HRR could be used as a clinical marker to treat HF in children

Heart rate reduction strategy using ivabradine in end-stage duchenne cardiomyopathy

Background: End-stage dilated cardiomyopathy (DCM) is the leading cause of morbidity and mortality in patients with Duchenne Muscular Dystrophy (DMD). No studies are available on the effect of ivabradine on long-term outcomes in end-stage DMD/DCM. Methods: We prospectively enrolled a cohort of end-stage DMD/DCM patients with LV ejection fraction <40%, on chronic HF treatment with an ACE inhibitor referred consecutively from 2012 to 2017 to Bambino Gesù Children's Hospital. In each patient, before starting HRR strategy and after 1 year, we collected medical records comprehensive of clinical, demographic and imaging parameters, BNP levels, neurological and respiratory assessment. Results: Twenty male patients with DMD/DCM with a mean age of 15.0 ± 3.5 (13–19 IQR) years were enrolled and divided into 2 groups according to ivabradine therapy. This group showed a higher incidence of MACEs compared to others in treatment with ivabradine (87.5% vs 12.5%, p = 0.025). At Kaplan Meier survival analysis curves, the rate free from MACEs was higher in patients treated with ivabradine (log rank p = 0.017). At multivariate Cox regression analysis, ivabradine therapy was an independent predictor of freedom from MACEs (H.R. 0.078, 95% CI 0.007–0.877, p = 0.039). Conclusion: HRR strategy, whether achieved by beta blockers alone or in combination with ivabradine, seemed to be effective in reducing the incidence of acute adverse events, reaching optimal target heart rate and improving left ventricular function in DMD/DCM patients

Insights from cardiopulmonary exercise testing in pediatric patients with hypertrophic cardiomyopathy

The usefulness of cardiopulmonary exercise test (CPET) in adult hypertrophic cardiomyopathy (HCM) patients is well-known, whereas its role in pediatric HCM patients has not yet been explored. The present study investigates possible insights from a CPET assessment in a cohort of pediatric HCM outpatients in terms of functional and prognostic assessment. Sixty consecutive pediatric HCM outpatients aged <18 years old were enrolled, each of them undergoing a full clinical assessment including a CPET; a group of 60 healthy subjects served as controls. A unique composite end-point of heart failure (HF) related and sudden cardiac death (SCD) or SCD-equivalent events was also explored. During a median follow-up of 53 months (25th–75th: 13–84 months), a total of 13 HF- and 7 SCD-related first events were collected. Compared to controls, HCM patients showed an impaired functional capacity with most of them showing peak oxygen uptake (pVO2) values of <80% of the predicted, clearly discrepant with functional New York Heart Association class assessment. The composite end-point occurred more frequently in patients with the worst CPETs’ profiles. At the univariate analysis, pVO2% was the variable with the strongest association with adverse events at follow-up (C-index = 0.72, p = 0.025) and a cut-off value equal to 60% was the most accurate in identifying those patients at the highest risk. In a pediatric HCM subset, the CPET assessment allows a true functional capacity estimation and it might be helpful in identifying early those patients at high risk of events

Clinical presentation and natural history of hypertrophic cardiomyopathy in RASopathies

RASopathies are a heterogeneous group of genetic syndromes characterized by mutations in genes that regulate cellular processes, including proliferation, differentiation, survival, migration, and metabolism. Excluding congenital heart defects, hypertrophic cardiomyopathy is the most frequent cardiovascular defect in patients affected by RASopathies. A worse outcome (in terms of surgical risk and/or mortality) has been described in a specific subset of Rasopathy patients with early onset, severe hypertrophic cardiomyopathy presenting with heart failure. New short-term therapy with a mammalian target of rapamycin inhibitor has recently been used to prevent heart failure in these patients with a severe form of hypertrophic cardiomyopathy