Myocardial deformation in pediatric patients with mucopolysaccharidoses: A two-dimensional speckle tracking echocardiography study

Pre-operative Considerations in Adult Mucopolysaccharidosis Patients Planned for Cardiac Intervention

Mucopolysaccharidoses (MPS) are rare lysosomal storage diseases characterized by multiorgan involvement and shortened longevity. Due to advances in therapies such as enzyme replacement therapy and haematopoietic stem cell therapy, life expectancy has increased posing newer challenges to patients and health professionals. One such challenge is cardiovascular manifestations of MPS, which can be life limiting and cause reduction in quality of life. Any cardiovascular intervention mandates comprehensive, multi-systemic work-up by specialist teams to optimize outcome. We highlight the importance of multidisciplinary evaluation of adult MPS patients requiring cardiovascular intervention. Clinical assessments and investigations are discussed, with a focus on the cardiac, anesthetic, airway, respiratory, radiological and psychosocial factors.

Anorexia nervosa-related cardiopathy in children with physical instability: prevalence, echocardiographic characteristics and reversibility at mid-term follow-up

Prompt detection of cardiovascular abnormalities in children with anorexia nervosa and physical instability requiring hospitalization is essential to identify patients at higher cardiovascular risk. We studied all anorexia nervosa children requiring admission at Paediatric Institute in the period 2015-2019. Anorexia nervosa cardiopathy at admission was defined by the presence of at least two of the following clinical findings: pericardial effusion, mitral regurgitation, bradycardia, mitral billowing, aortic regurgitation, altered LV morphology and ECG abnormalities. Echocardiographic data were compared with those registered at 3-8-month follow-up and with data from a healthy population. Thirty-eight anorexia nervosa children were examined. Prevalence of anorexia nervosa cardiopathy at admission was 63% (24 patients). Pericardial effusion, bradycardia and mitral regurgitation were present together in 26% of patients. Most cardiovascular changes recovered at follow-up. Anorexia nervosa cardiopathy was associated with significantly lower left ventricle end-diastolic diameters and mass, and higher E wave, E/A and E/e' ratios and left ventricle sphericity index values vs healthy population and vs anorexia nervosa children without cardiopathy (p<0.05). Left ventricle global longitudinal strain was significantly reduced only in anorexia nervosa cardiopathy patients but recovered, whereas end-diastolic diameters, E/A ratio and sphericity index values remained impaired.Conclusion: Among anorexia nervosa children requiring hospitalization, those presenting several cardiac findings together express an acute anorexia nervosa cardiopathy which is characterized by worse LV filling, geometry and subclinical myocardial deformation impairment. Despite treatment, in those patients, some alterations persist at mid-term follow-up. What is Known: • Cardiac and electrocardiographic changes are present in anorexia nervosa children at diagnosis or during stable disease, and most recover after body-weight treatment. • It is unknown if anorexia nervosa children with more severe cardiac impairment during hospitalization present higher cardiovascular-risk profile despite treatment. What is New: • In anorexia nervosa children needing hospitalization for physical reasons, prevalence of acute anorexia nervosa cardiopathy at admission is high, around 60%. • By advanced echocardiography, children with anorexia nervosa cardiopathy at admission have a worse cardiac filling, impaired cardiac geometry and systolic deformation that only partially recover at mid-term follow-up.

Aortopathies in mouse models of Pompe, Fabry and Mucopolysaccharidosis IIIB lysosomal storage diseases

Introduction

Lysosomal storage diseases (LSDs) are rare inherited metabolic diseases characterized by an abnormal accumulation of various toxic materials in the cells as a result of enzyme deficiencies leading to tissue and organ damage. Among clinical manifestations, cardiac diseases are particularly important in Pompe glycogen storage diseases (PD), in glycosphingolipidosis Fabry disease (FD), and mucopolysaccharidoses (MPS). Here, we evaluated the occurrence of aortopathy in knock out (KO) mouse models of three different LSDs, including PD, FD, and MPS IIIB.

Methods

We measured the aortic diameters in 15 KO male mice, 5 for each LSD: 5 GLA^-/- mice for FD, 5 NAGLU^-/- mice for MPS IIIB, 5 GAA^-/- mice for PD, and 15 wild type (WT) mice: 5 for each strain. In order to compare the aortic parameters between KO and WT mice deriving from the same colonies, different diameters were echocardiographically measured: aortic annulus, aortic sinus, sino-tubular junction, ascending aorta, aortic arch and descending aorta. Storage material content and aortic defects of the KO mice were also analyzed by histology, when available.

Results

Compared to their correspondent WT mice: GAA^-/- mice showed greater diameters of ascending aorta (1.61mm vs. 1.11mm, p-value = 0.01) and descending aorta (1.17mm vs 1.02mm, p-value 0.04); GLA^-/- mice showed greater diameters of aortic annulus (1.35mm vs. 1.22mm, p-value = 0.01), sinus of Valsalva (1.6mm vs. 1.38mm, p-value<0.01), ascending aorta (1.57mm vs. 1.34mm, p-value<0.01), aortic arch (1.36mm vs. 1.22mm, p-value = 0.03) and descending aorta (1.29mm vs. 1.11mm, p-value<0.01); NAGLU^-/- mice showed greater diameters of sinus of Valsalva (1.46mm vs. 1.31mm, p-value = 0.05), ascending aorta (1.42mm vs. 1.29mm, p-value<0.01), aortic arch (1.34mm vs. 1.28mm, p-value<0.01) and descending aorta (1.18mm vs. 1.1mm, p-value 0.01).

Conclusions

We evaluated for the first time the aortic diameters in 3 LSD mouse models and identified different aortopathy patterns, in concordance with recent human findings. Our results are relevant in view of using KO mouse models for efficiently testing the efficacy of new therapies on distinct cardiovascular aspects of LSDs.

Enzyme Replacement Therapy Decreases Left Ventricular Mass Index in Patients with Hunter Syndrome?

Although enzyme replacement therapy (ERT) has shown benefit in improving cardiac systolic function in a murine model of cardiomyopathy associated with Hunter syndrome, few studies have analyzed its effect in humans. We evaluated the effect of ERT on patients with Hunter syndrome-related cardiomyopathy. We performed a retrospective analysis of serial transthoracic echocardiograms performed before and over the first 5 years after treatment initiation, in 14 patients with Hunter syndrome. An important cardiac remodeling occurred in all patients in this study. There was a significant reduction in left ventricular mass index from 70.88 to 26.75 g/m^2.7 (p = 0.003), with a trend towards a decrease in relative wall thickness from 0.515 at baseline to 0.370 after 5 years of enzyme therapy (p = 0.140). No differences were observed in aortic root diameter, left atrial diameter, left ventricular diastolic and systolic diameters, left ventricular ejection fraction, or myocardial performance index. Our findings demonstrate that ERT contributes to reducing left ventricular mass index in patients with Hunter syndrome.

Cardiac Evaluation using Two-Dimensional Speckle-Tracking Echocardiography and Conventional Echocardiography in Taiwanese Patients with Mucopolysaccharidoses

Background: Mucopolysaccharidoses (MPSs) are a group of rare inherited metabolic disorders that can damage various organs, including the heart. Cardiac abnormalities have been observed in patients with all MPS types, with the most documented abnormalities being cardiac valvular regurgitation and stenosis, valvular thickening, and hypertrophic cardiomyopathy. Methods: Cardiac features of 53 Taiwanese patients with MPS (31 men and 22 women; age range 1.1–34.9 years; seven with MPS I, 16 with MPS II, nine with MPS III, 14 with MPS IVA, and seven with MPS VI) were evaluated using two-dimensional speckle-tracking echocardiography and conventional echocardiography. Results: The mean z scores of the global longitudinal strain (GLS), left ventricular mass index (LVMI), interventricular septum diameter in diastole (IVSd), left ventricular posterior wall diameter in diastole (LVPWd), and aortic diameter of the 53 patients with MPS were 1.71, 0.35, 1.66, 1.03, and 3.15, respectively. Furthermore, z scores >2 were identified in 45%, 13%, 40%, 13%, and 70% of the GLS, LVMI, IVSd, LVPWd, and aortic diameter, respectively. The most severe GLS was observed in those with MPS VI, followed by in those with MPS II and MPS I. The GLS z score was positively correlated with the LVMI z score (p < 0.01). Moreover, diastolic dysfunction (reversed ratio between early and late (atrial) ventricular filling velocity (E/A ratio < 1)) was identified in 12 patients (23%). Ejection and shortening fractions were abnormal in four (8%) and seven (13%) patients, respectively. Mitral regurgitation (MR) (92%) was the most common valvular heart disease, followed by aortic regurgitation (AR) (57%), mitral stenosis (MS) (21%), and aortic stenosis (AS) (15%). The z scores of the GLS and LVMI and severity scores of the MS, MR, AS, and AR were all positively correlated with increasing age (p < 0.05). Twenty patients (38%) had a left ventricular remodeling pattern. Conclusions: The most significant left ventricular myocardial deformation, hypertrophy and valvular heart disease were observed in the patients with MPS VI, II, and I, followed by those with MPS IV; in contrast, patients with MPS III had the mildest manifestations. Cardiac abnormalities in patients with MPS worsened with increasing age in accordance with the progressive nature of this disease.

Left ventricular assessment in patients with mucopolysaccharidosis using conventional echocardiography and myocardial deformation by two-dimensional speckle-tracking method

OBJECTIVE

Mucopolysaccharidosis is a rare genetic disease characterized by the intralysosomal deposition of glycosaminoglycans. Cardiovascular impairment is a common feature. Cardiac signs and symptoms are underestimated due to the disease involvement in other organs. Enzyme replacement therapy can be used in mucopolysaccharidosis I, II, IV, and VI. Thus, the knowledge about the use of new echocardiography tools is relevant to improve the care of this population. This study aimed to describe left ventricular function assessment by conventional echocardiography and left ventricular global longitudinal strain analysis and compare the alterations in patients receiving enzyme replacement therapy and who had different ages at the start of therapy.

METHOD

Outpatient-based descriptive study. The patients were submitted to conventional echocardiography and left ventricular global longitudinal strain measurement.

RESULTS

Sixteen patients were evaluated; median age of 14.2 years (SD=5.2 years). Left ventricular hypertrophy was found in nine patients (56.2%). All patients had preserved left ventricular systolic function (Simpson and Teichholz). Nine (56.2%) patients showed alterations in left ventricular global longitudinal strain. The study showed a positive association between left ventricular hypertrophy and alteration in the left ventricular global longitudinal strain, and late start of enzyme replacement therapy and alteration in the left ventricular global longitudinal strain.

CONCLUSION

Echocardiographic alterations in patients with mucopolysaccharidosis were frequently observed, especially alterations in the left ventricular geometry and subclinical dysfunction. Patients who had a late enzyme replacement therapy start showed an association with worse left ventricular global longitudinal strain values, reinforcing the need for early diagnosis and treatment. The use of new echocardiographic tools may improve the follow-up of these patients.

Early diagnosis and management of cardiac manifestations in mucopolysaccharidoses: a practical guide for paediatric and adult cardiologists

Mucopolysaccharidoses (MPS) are a group of hereditary disorders caused by lysosomal storage of glycosaminoglycans (GAGs) and characterized by a wide variability of phenotypes from severe fetal-neonatal forms to attenuated diseases diagnosed in adult individuals. The clinical picture generally worsens with age due to progressive storage involving mucosal tissue, upper airways and lungs, bones and joints, central and peripheral nervous system, heart, liver, eye, and ear. Cardiac storage of GAGs involves valves, heart muscle, and vessels (particularly the coronary arteries), and can be specific in relation to different MPS types and enzyme defects. MPS I, II, and VI are those with the most severe cardiac involvement. The cardiologist is a key figure in MPS, and their role is expanding from cardiac-specific management to early diagnosis when the mild disease phenotypes have not yet been recognized by other specialists. Familial and personal history, electrocardiography, imaging, and laboratory findings represent important steps in the clinical investigation of these patients. New treatments have led to an increased need for cardiologists to be on the lookout for MPS patients since they can significantly improve the lives of people with MPS if they suspect the diagnosis and refer them for enzyme replacement therapy or bone marrow transplantation.

Natural history of echocardiographic abnormalities in mucopolysaccharidosis III

BACKGROUND

Mucopolysaccharidosis (MPS) type III, Sanfilippo Syndrome, is an autosomal recessive lysosomal storage disorder. MPS I and II patients often develop cardiac involvement leading to early mortality, however there are limited data in MPS III. The objective of this study is to describe cardiac abnormalities in a large group of MPS III patients followed in a longitudinal natural history study designed to determine outcome measures for gene transfer trials.

METHODS

A single center study of MPS III patients who were enrolled in the Nationwide Children's Hospital natural history study in 2014. Two cardiologists reviewed all patient echocardiograms for anatomic, valvular, and functional abnormalities. Valve abnormalities were defined as abnormal morphology, trivial mitral regurgitation (MR) with abnormal morphology or at least mild MR, and any aortic regurgitation (AR). Abnormal left ventricular (LV) function was defined as ejection fraction < 50%. Group comparisons were assessed using two-sample t-tests or Wilcoxon rank sum tests for continuous variables and chi-square or Fisher's exact tests for categorical variables.

RESULTS

Twenty-five patients, 15 Type A and 10 Type B MPS III, underwent 45 echocardiograms. Fifteen patients (60%) demonstrated an abnormal echocardiographic finding with age at first abnormal echocardiogram within the study being 6.8 ± 2.8 years. Left-sided valve abnormalities were common over time: 7 mitral valve thickening, 2 mitral valve prolapse, 16 MR (8 mild, 8 trivial), 3 aortic valve thickening, and 9 AR (7 mild, 2 trivial). Two patients had asymmetric LV septal hypertrophy. No valvular stenosis or ventricular function abnormalities were noted. Incidental findings included: mild aortic root dilation (2), bicommissural aortic valve (1), and mild tricuspid regurgitation (3).

CONCLUSIONS

Individuals with Sanfilippo A and B demonstrate a natural history of cardiac involvement with valvular abnormalities most common. In short-term follow up, patients demonstrated only mild progression of abnormalities, none requiring intervention. Valvular disease prevalence is similar to MPS I and II, but appears less severe. These findings raise no specific concerns for gene transfer trials in patients in this age range.