Prevalence and Clinical Significance of Intraventricular Conduction Disturbances in Hospitalized Children.

Introduction: Data on the prevalence and clinical significance of interventricular conduction disturbances (IVCDs) in children are scarce. While incomplete right bundle branch blocks (IRBBBs) seem to be the most frequent and benign findings, complete bundle blocks and fascicular blocks are often seen in children with congenital/acquired cardiac conditions. This study aims to delineate the prevalence and the diagnostic accuracy of IVCD in children admitted to a paediatric cardiology unit. Methods: Children admitted to the paediatric cardiology unit between January 2010 and December 2020 who had an ECG were included in the study. IVCDs were diagnosed according to standard criteria adjusted for age. Results: Three thousand nine hundred and ninety-three patients were enrolled. The median age was 3.1 years (IQR: 0.0-9.2 years), and 52.7% were males. IVCDs were present in 22.5% of the population: 17.4% of the population presented with IRBBBs, 4.8% with a complete right bundle branch block (CRBBB), 0.1% with a complete left bundle branch block (CLBBB), 0.2% with a left anterior fascicular block (LAFB) and 0.2% with a combination of CRBBB and LAFB. Also, 26% of children with congenital heart disease had an IVCD, and 18% of children with an IVCD had previous cardiac surgery. The overall sensitivity of IVCD in detecting a cardiac abnormality was 22.2%, with a specificity of 75.5%, a PPV of 83.1% and an NPV of 15.1%, but the values were higher for CLBBB and LAFB. Conclusions: IVCDs were present in one-fifth of children admitted to the cardiology unit. IRBBB was the most frequent disturbance, while CRBBB, CLBBB and fascicular blocks were much rarer, though they had a higher predictive value for cardiac abnormalities.

Impact of GLA Variant Classification on the Estimated Prevalence of Fabry Disease: A Systematic Review and Meta-Analysis of Screening Studies.

BACKGROUND: The diagnosis of Fabry disease (FD) has relevant implications related to the management. Thus, a clear assignment of GLA variant pathogenicity is crucial. This systematic review and meta-analysis aimed to investigate the prevalence of FD in high-risk populations and newborns and evaluate the impact of different GLA variant classifications on the estimated prevalence of FD. METHODS: We searched the EMBASE and PubMed databases on February 21, 2023. Observational studies evaluating the prevalence of FD and reporting the identified GLA variants were included. GLA variants were re-evaluated for their pathogenicity significance using the American College of Medical Genetics and Genomics criteria and the ClinVar database. The pooled prevalence of FD among different settings was calculated. The study was registered on PROSPERO (CRD42023401663) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. RESULTS: Of the 3941 studies identified, 110 met the inclusion criteria. The pooled prevalence of FD was significantly different according to the clinical setting and criteria used for the pathogenicity assessment. Using the American College of Medical Genetics and Genomics criteria, the pooled prevalence was 1.2% in patients with left ventricular hypertrophy/hypertrophic cardiomyopathy (26 studies; 10 080 patients screened), 0.3% in end-stage renal disease/chronic kidney disease (38 studies; 62 050 patients screened), 0.7% in stroke (25 studies; 15 295 patients screened), 0.7% in cardiac conduction disturbance requiring pacemaker (3 studies; 1033 patients screened), 1.0% in small-fiber neuropathy (3 studies; 904 patients screened), and 0.01% in newborns (15 studies; 11 108 793 newborns screened). The pooled prevalence was different if the GLA variants were assessed using the ClinVar database, and most patients with a discrepancy in the pathogenicity assignment carried 1 of the following variants: p.A143T, p.D313Y, and p.E66Q. CONCLUSIONS: This systematic review and meta-analysis describe the prevalence of FD among newborns and high-risk populations, highlighting the need for a periodic reassessment of the GLA variants in the context of recent clinical, biochemical, and histological data. REGISTRATION: URL: https://crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42023401663.

Targeted Therapies in Pediatric and Adult Patients With Hypertrophic Heart Disease: From Molecular Pathophysiology to Personalized Medicine.

Hypertrophic cardiomyopathy is a myocardial disease defined by an increased left ventricular wall thickness not solely explained by abnormal loading conditions. It is often genetically determined, with sarcomeric gene mutations accounting for around 50% of cases. Several conditions, including syndromic, metabolic, infiltrative, and neuromuscular diseases, may present with left ventricular hypertrophy, mimicking the hypertrophic cardiomyopathy phenotype but showing a different pathophysiology, clinical course, and outcome. Despite being rare, they are collectively responsible for a large proportion of patients presenting with hypertrophic heart disease, and their timely diagnosis can significantly impact patients' management. The understanding of disease pathophysiology has advanced over the last few years, and several therapeutic targets have been identified, leading to a new era of tailored treatments applying to different etiologies associated with left ventricular hypertrophy. This review aims to provide an overview of the existing and emerging therapies for the principal causes of hypertrophic heart disease, discussing the potential impact on patients' management and clinical outcome.

Prevalence and clinical significance of right ventricular pulmonary arterial uncoupling in cardiac amyloidosis.

BACKGROUND: This study aims to evaluate the prevalence and the clinical significance of the right ventricular pulmonary arterial (RV-PA) uncoupling in patients with cardiac amyloidosis (CA). METHODS: The study population consisted in 92 consecutive patients with CA (age 71.1 ± 12.2 years, 71% males; 47% with immunoglobulin light chain (AL), 53% with transthyretin [ATTR]). A pre-specified tricuspid anulus plane systolic excursion on pulmonary arterial systolic pressure (TAPSE/PASP) value <0.31 mm/mmHg was used to define RV-PA uncoupling and to dichotomize the study population. RESULTS: Thirty-two patients (35%) showed RV-PA uncoupling at baseline evaluation (15/44 [34%] AL and 17/48 [35%] ATTR). Patients with RV-PA uncoupling, in both AL and ATTR, showed worse NYHA functional class, lower systemic blood pressure, and more pronounced left ventricular and RV systolic dysfunction than those with RV-PA coupling. During a median follow-up of 8 months (IQR 4-13), 26 patients (28%) experienced cardiovascular death. Patients with RV-PA uncoupling showed lower survival at 12 months follow-up than those with RV-PA coupling (42.7% [95%CI 21.7-63.7%] vs. 87.3% [95%CI 78.3-96.3%], p-value<0.001). Multivariate analysis identified high-sensitivity troponin I values (HR 1.01 [95%CI 1.00-1.02] per 1 pg/mL increase; p-value 0.013) and TAPSE/PASP (HR 1.07 [95%CI 1.03-1.11] per 0.01 mm/mmHg decrease; p-value 0.002) as independent predictors of cardiovascular death. CONCLUSIONS: RV-PA uncoupling is common among patient with CA, and it is a marker of advanced disease and worse outcome. This study suggest that TAPSE/PASP ratio has the potential to improve risk stratification and guide management strategies in patients with CA of different etiology and advanced disease.

Clinical, Genetic, and Histological Characterization of Patients with Rare Neuromuscular and Mitochondrial Diseases Presenting with Different Cardiomyopathy Phenotypes.

Cardiomyopathies are mostly determined by genetic mutations affecting either cardiac muscle cell structure or function. Nevertheless, cardiomyopathies may also be part of complex clinical phenotypes in the spectrum of neuromuscular (NMD) or mitochondrial diseases (MD). The aim of this study is to describe the clinical, molecular, and histological characteristics of a consecutive cohort of patients with cardiomyopathy associated with NMDs or MDs referred to a tertiary cardiomyopathy clinic. Consecutive patients with a definitive diagnosis of NMDs and MDs presenting with a cardiomyopathy phenotype were described. Seven patients were identified: two patients with ACAD9 deficiency (Patient 1 carried the c.1240C>T (p.Arg414Cys) homozygous variant in ACAD9; Patient 2 carried the c.1240C>T (p.Arg414Cys) and the c.1646G>A (p.Ar549Gln) variants in ACAD9); two patients with MYH7-related myopathy (Patient 3 carried the c.1325G>A (p.Arg442His) variant in MYH7; Patient 4 carried the c.1357C>T (p.Arg453Cys) variant in MYH7); one patient with desminopathy (Patient 5 carried the c.46C>T (p.Arg16Cys) variant in DES); two patients with mitochondrial myopathy (Patient 6 carried the m.3243A>G variant in MT-TL1; Patient 7 carried the c.253G>A (p.Gly85Arg) and the c.1055C>T (p.Thr352Met) variants in MTO1). All patients underwent a comprehensive cardiovascular and neuromuscular evaluation, including muscle biopsy and genetic testing. This study described the clinical phenotype of rare NMDs and MDs presenting as cardiomyopathies. A multidisciplinary evaluation, combined with genetic testing, plays a main role in the diagnosis of these rare diseases, and provides information about clinical expectations, and guides management.

Pathophysiology, Functional Assessment and Prognostic Implications of Nutritional Disorders in Systemic Amyloidosis.

Gastrointestinal involvement is a common clinical feature of patients with systemic amyloidosis. This condition is responsible for invalidating gastrointestinal symptoms, a significant macro and micronutrient deficit, and is a marker of disease severity. Gastrointestinal involvement should be actively sought in patients with systemic amyloidosis, while its diagnosis is challenging in patients with isolated gastrointestinal symptoms. The nutritional status in systemic amyloidosis plays an essential role in the clinical course and is considered a significant prognostic factor. However, the definition of nutritional status is still challenging due to the lack of internationally accepted thresholds for anthropometric and biochemical variables, especially in specific populations such as those with systemic amyloidosis. This review aims to elucidate the fundamental steps for nutritional assessment by using clinical and instrumental tools for better prognostic stratification and patient management regarding quality of life and outcomes.

Effect of Migalastat on cArdiac InvOlvement in FabRry DiseAse: MAIORA study.

BACKGROUND: A small but significant reduction in left ventricular (LV) mass after 18 months of migalastat treatment has been reported in Fabry disease (FD). This study aimed to assess the effect of migalastat on FD cardiac involvement, combining LV morphology and tissue characterisation by cardiac magnetic resonance (CMR) with cardiopulmonary exercise testing (CPET). METHODS: Sixteen treatment-naïve patients with FD (4 women, 46.4±16.2 years) with cardiac involvement (reduced T1 values on CMR and/or LV hypertrophy) underwent ECG, echocardiogram, troponin T and NT-proBNP (N-Terminal prohormone of Brain Natriuretic Peptide) assay, CMR with T1 mapping, and CPET before and after 18 months of migalastat. RESULTS: No change in LV mass was detected at 18 months compared to baseline (95.2 g/m2 (66.0-184.0) vs 99.0 g/m2 (69.0-121.0), p=0.55). Overall, there was an increase in septal T1 of borderline significance (870.0 ms (848-882) vs 860.0 ms (833.0-875.0), p=0.056). Functional capacity showed an increase in oxygen consumption (VO2) at anaerobic threshold (15.50 mL/kg/min (13.70-21.50) vs 14.50 mL/kg/min (11.70-18.95), p=0.02), and a trend towards an increase in percent predicted peak VO2 (72.0 (63.0-80.0) vs 69.0 (53.0-77.0), p=0.056) was observed. The subset of patients who showed an increase in T1 value and a reduction in LV mass (n=7, 1 female, age 40.5 (28.6-76.0)) was younger and at an earlier disease stage compared to the others, and also exhibited greater improvement in exercise tolerance. CONCLUSION: In treatment-naïve FD patients with cardiac involvement, 18-month treatment with migalastat stabilised LV mass and was associated with a trend towards an improvement in exercise tolerance. A tendency to T1 increase was detected by CMR. The subset of patients who had significant benefits from the treatment showed an earlier cardiac disease compared to the others. TRIAL REGISTRATION NUMBER: NCT03838237.

An Overview of Molecular Mechanisms in Fabry Disease.

Fabry disease (FD) (OMIM #301500) is a rare genetic lysosomal storage disorder (LSD). LSDs are characterized by inappropriate lipid accumulation in lysosomes due to specific enzyme deficiencies. In FD, the defective enzyme is α-galactosidase A (α-Gal A), which is due to a mutation in the GLA gene on the X chromosome. The enzyme deficiency leads to a continuous deposition of neutral glycosphingolipids (globotriaosylceramide) in the lysosomes of numerous tissues and organs, including endothelial cells, smooth muscle cells, corneal epithelial cells, renal glomeruli and tubules, cardiac muscle and ganglion cells of the nervous system. This condition leads to progressive organ failure and premature death. The increasing understanding of FD, and LSD in general, has led in recent years to the introduction of enzyme replacement therapy (ERT), which aims to slow, if not halt, the progression of the metabolic disorder. In this review, we provide an overview of the main features of FD, focusing on its molecular mechanism and the role of biomarkers.

Medical treatment of patients with hypertrophic cardiomyopathy: An overview of current and emerging therapy.

Several treatments have demonstrated safety and effectiveness in the treatment of patients with hypertrophic cardiomyopathy; however, no drug has been shown to modify the natural history of the disease or to decrease maximal wall thickness. Improvement in our knowledge of the physiopathology of the disease has permitted the development of new therapeutical approaches, including sarcomere modulators and gene therapy. A sarcomere modulator - mavacamten - has been shown to improve exercise capacity, left ventricular outflow tract obstruction, New York Heart Association functional class and health status in a phase 3 trial. Gene therapy - although still far from human experimentation - also has promising characteristics that may radically revolutionize the treatment of hypertrophic cardiomyopathy in the future. This therapy is currently approved for the treatment of select haematological malignancies, inherited retinal dystrophy and spinal muscular atrophy, and could potentially correct the genetic alterations of the most frequent sarcomeric forms of hypertrophic cardiomyopathy. This review provides an overview of current conventional therapies for the management of patients with hypertrophic cardiomyopathy, discusses emerging therapeutic approaches and presents future perspectives.

Myocardial infarction with non-obstructive coronary arteries in hypertrophic cardiomyopathy vs Fabry disease.

BACKGROUND: Little is known about prevalence and predictors of myocardial infarction with non-obstructive coronary arteries (MINOCA) in Fabry disease (FD) and hypertrophic cardiomyopathy (HCM). We assessed and compared the prevalence and predictors of MINOCA in a large cohort of HCM and FD patients. METHODS: In this multicenter, retrospective study we enrolled 2870 adult patients with HCM and 267 with FD. The only exclusion criterion was documented obstructive coronary artery disease. MINOCA was defined according to guidelines. For each patient we collected clinical, ECG and echocardiographic data recorded at initial evaluation. RESULTS: Overall, 36 patients had MINOCA during a follow-up period of 4.5 ± 11.2 years. MINOCA occurred in 16 patients with HCM (0.5%) and 20 patients with FD (7.5%; p < 0.001). The difference between the 2 groups was highly significant, also after adjustment for the main clinical, ECG and echocardiographic variables (OR 6.12; 95%CI 2.80-13.3; p < 0.001). In the FD population MINOCA occurred in 17 out of 96 patients with left ventricle hypertrophy (LVH, 17.7%) and in 3 out of 171 patients without LVH (1.7%; OR 12.0; 95%CI 3.43-42.3; p < 0.001). At multivariable analysis, voltage criteria for LVH at ECG (OR 7.3; 95%CI 1.93-27.7; p = 0.003) and maximal LV wall thickness at echocardiography (OR 1.15; 95%CI 1.05-1.27; p = 0.002) maintained an independent association with MINOCA. No major significant differences were found in clinical, ECG and echocardiographic findings between HCM patients with or without MINOCA. CONCLUSIONS: MINOCA was rare in HCM patients, and 6-fold more frequent in FD patients. MINOCA may be considered a red flag for FD and aid in the differential diagnosis from HCM.

Multimodality Imaging in Cardiomyopathies with Hypertrophic Phenotypes.

Multimodality imaging is a comprehensive strategy to investigate left ventricular hypertrophy (LVH), providing morphologic, functional, and often clinical information to clinicians. Hypertrophic cardiomyopathy (HCM) is defined by an increased LV wall thickness not only explainable by abnormal loading conditions. In the context of HCM, multimodality imaging, by different imaging techniques, such as echocardiography, cardiac magnetic resonance, cardiac computer tomography, and cardiac nuclear imaging, provides essential information for diagnosis, sudden cardiac death stratification, and management. Furthermore, it is essential to uncover the specific cause of HCM, such as Fabry disease and cardiac amyloidosis, which can benefit of specific treatments. This review aims to elucidate the current role of multimodality imaging in adult patients with HCM.

Standard ECG for differential diagnosis between Anderson-Fabry disease and hypertrophic cardiomyopathy.

OBJECTIVES: To evaluate the role of the ECG in the differential diagnosis between Anderson-Fabry disease (AFD) and hypertrophic cardiomyopathy (HCM). METHODS: In this multicentre retrospective study, 111 AFD patients with left ventricular hypertrophy were compared with 111 patients with HCM, matched for sex, age and maximal wall thickness by propensity score. Independent ECG predictors of AFD were identified by multivariate analysis, and a multiparametric ECG score-based algorithm for differential diagnosis was developed. RESULTS: Short PR interval, prolonged QRS duration, right bundle branch block (RBBB), R in augmented vector left (aVL) ≥1.1 mV and inferior ST depression independently predicted AFD diagnosis. A point-by-point ECG score was then derived with the following diagnostic performances: c-statistic 0.80 (95% CI 0.74 to 0.86) for discrimination, the Hosmel-Lemeshow χ2 6.14 (p=0.189) for calibration, sensitivity 69%, specificity 84%, positive predictive value 82% and negative predictive value 72%. After bootstrap resampling, the mean optimism was 0.025, and the internal validated c-statistic for the score was 0.78. CONCLUSIONS: Standard ECG can help to differentiate AFD from HCM while investigating unexplained left ventricular hypertrophy. Short PR interval, prolonged QRS duration, RBBB, R in aVL ≥1.1 mV and inferior ST depression independently predicted AFD. Their systematic evaluation and the integration in a multiparametric ECG score can support AFD diagnosis.

Diagnosis and Management of Cardiovascular Involvement in Fabry Disease.

Fabry disease (FD, OMIM 301500) is an X-linked lysosomal storage disease caused by pathogenic variants in the GLA gene. Cardiac involvement is common in FD and is responsible for impaired quality of life and premature death. The classic cardiac involvement is a nonobstructive form of hypertrophic cardiomyopathy, usually manifesting as concentric left ventricular hypertrophy, with subsequent arrhythmogenic intramural fibrosis. Treatment of patients with FD should be directed to prevent the disease progression to irreversible organ damage and organ failure. The aim of this review is to describe the current state of knowledge regarding cardiovascular involvement in FD, focusing on clinical and instrumental features, cardiovascular management, and targeted therapy.

Cardiovascular Involvement in Transthyretin Cardiac Amyloidosis.

Transthyretin cardiac amyloidosis (ATTR-CA) is a systemic disorder resulting from the extracellular deposition of amyloid fibrils of misfolded transthyretin protein in the heart. ATTR-CA is a life-threatening disease, which can be caused by progressive deposition of wild type transthyretin (wtATTR) or by aggregation of an inherited mutated variant of transthyretin (mATTR). mATTR Is a rare condition transmitted in an autosomal dominant manner with incomplete penetrance, causing heterogenous phenotypes which can range from predominant neuropathic involvement, predominant cardiomyopathy, or mixed. Diagnosis of ATTR-CA is complex and requires integration of different imaging tools (echocardiography, bone scintigraphy, magnetic resonance) with genetics, clinical signs, laboratory tests, and histology. In recent years, new therapeutic agents have shown good efficacy and impact on survival and quality of life in this subset of patients, nevertheless patients affected by ATTR-CA may still carry an unfavorable prognosis, thus highlighting the need for new therapies. This review aims to assess cardiovascular involvement, diagnosis, and management of patients affected by ATTR-CA.

The Role of New Imaging Technologies in the Diagnosis of Cardiac Amyloidosis.

Cardiac amyloidosis is an infiltrative disorder caused by transthyretin or immunoglobulin free light-chain deposition, which determines clinical disease with similar phenotype but different time course, prognosis and therapy. Multimodality imaging is the cornerstone for disease diagnosis and management. Multimodality imaging has revolutionized the approach to the disease favoring its awareness and simplifying its diagnosis, especially in ATTR cardiac amyloidosis. This describes the different imaging tools, from the traditional to the more novel ones, and highlights the different approach in each different setting (prognosis, subtyping, prognosis, monitoring disease progression, and response to therapy).

Global Left Ventricular Myocardial Work Efficiency in Heart Failure Patients with Cardiac Amyloidosis: Pathophysiological Implications and Role in Differential Diagnosis.

INTRODUCTION: Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy and a common cause of heart failure with preserved and mid-range ejection fraction (HFpEF and HFmrEF). Left ventricular (LV) systolic assessment is pivotal in differential diagnostic and prognostic stratification in CA. However, nondeformation and deformation-based parameters classically implied had many limitations. Myocardial work (MW) has been recently introduced for the evaluation of myocardial performance, in a load-independent fashion, in patients with cardiomyopathies. AIMS: This study aimed to evaluate MW parameters in LV performance assessment in CA and their possible role in differential diagnosis between AL and ATTR forms, compared with other echocardiographic parameters, also exploring the possible association between MW parameters and blood biomarkers. MATERIALS AND METHODS: The study population consisted of 25 patients with CA (10 with AL amyloidosis and 15 with wild-type ATTR [ATTRwt] form) and HFpEF or HFmrHF, enrolled between March 2018 and December 2019, undergoing a comprehensive clinical, biochemical, and imaging evaluation. Ten healthy individuals were studied as controls. ATTR patients had a noninvasive diagnosis of wtATTR-CA (positive 99mTc-hydroxy methylene-diphosphonate scintigraphy with a negative hematological screening), while AL patients underwent endomyocardial biopsy. All patients underwent standard transthoracic echocardiography. MW and related indices were estimated using a vendor-specific module. RESULTS: Compared to the ATTRwt group, patients in the AL group showed a more pronounced myocardial performance impairment assessed by Global Word Efficiency (GWE: 83.5% ± 6.3% vs. 88.2% ± 3.6%; P = 0.026). In multiple linear regression analysis, cardiac troponin I (Β = -0.55; P < 0.0001), global longitudinal strain (Β =0.35; P < 0.008), and regional relative strain ratio (Β = -0.30; P < 0.016) were significant predictors of GWE reduction in CA patients. At receiver operating characteristics curve analysis, among all other deformation-based and nondeformation-based echocardiographic parameters, GWE showed the highest area under the curve (AUC) (AUC 0.74; 95% CI: 0.55-0.96; P < 0.04). The optimal cutoff was determined by sensitivity/specificity analysis: a GWE < 86.5% identified patients with AL amyloidosis with a sensitivity and specificity, respectively, of 80.0% and 66.7%. CONCLUSIONS: The results of our pivotal study seem to highlight the importance of new deformation parameters to study myocardial performance in patients with CA, and to differentiate between AL CA and ATTR CA.

External validation of the increased wall thickness score for the diagnosis of cardiac amyloidosis.

INTRODUCTION: This study aimed to validate the increased wall thickness (IWT) score, a multiparametric echocardiographic score to facilitate diagnosis of cardiac amyloidosis (CA), in an independent population of patients with increased LV wall thickness suspicious for CA. METHODS: Between January 2019 and December 2020, 152 consecutive patients with increased LV wall thickness suspicious for CA were included. For all patient, the multiparametric echocardiographic score (IWT score) was calculated. To validate the diagnostic accuracy of an IWT score ≥ 8 to predict the diagnosis of CA, sensibility (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and predictive accuracy (PA) were calculated. RESULTS: Among the 152 patients included in the study, 50 (33%) were diagnosed as CA, 25 (16%) had severe aortic stenosis, 25 (16%) had hypertensive remodeling, and 52 (34%) had hypertrophic cardiomyopathy. Among the 50 and 102 patients with and without CA, 19 (38%) and 1 (1%) showed an IWT score ≥ 8, respectively. Overall, the diagnostic accuracy of an IWT score ≥ 8 for the diagnosis of CA in our population was the following: Se 38% (95%CI 25-53%); Sp 99% (95%CI 95-100%); PPV 95% (95%CI 72-99%); NPV 77% (95%CI 73-80%); PA 79% (95%CI 72-85%). CONCLUSIONS: This study reports the first external validation of the IWT score for the diagnosis of CA in patients with increased LV wall thickness. A score ≥ 8 showed a high Sp, PPV and PA, suggesting that the IWT score can be used to identify CA patients in those with increased LV wall thickness.

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.

Clinical significance of family history and bicuspid aortic valve in children and young adult patients with Marfan syndrome.

BACKGROUND: Marfan syndrome is an autosomal dominant disorder of the connective tissue, whose cardinal features affect eyes, musculoskeletal, and cardiovascular system. Despite prevalence and natural history of cardiovascular manifestation are well known in adults, little is known about children and young adult patients. The aim of this study was to describe a well-characterised cohort of consecutive children and young patients with marfan syndrome, looking at the impact of family history and presence of bicuspid aortic valve on disease severity. METHODS: A total of 30 consecutive children and young patients with Marfan syndrome were evaluated. All patients underwent a comprehensive clinical-instrumental-genetic evaluation. Particular attention was posed to identify differences in prevalence of cardiovascular abnormalities between patients with and without family history of Marfan syndrome or bicuspid aortic valve. RESULTS: Of these 30 patients, family history of Marfan syndrome and bicuspid aortic valve were present in 76 and 13%, respectively. Compared to patients with family history of Marfan syndrome, those without showed higher prevalence of aortic sinus dilation (87 versus 32%, p-value = 0.009), greater aortic sinus diameters (4.2 ± 2.1 versus 1.9 ± 1.1 z score, p-value = 0.002), and higher rate of aortic surgery during follow-up (37 versus 0%, p-value = 0.002). Compared to patients with tricuspid aortic valve, those with bicuspid aortic valve were younger (3.2 ± 4.3 versus 10.7 ± 6.8 years old, p-value = 0.043), showed greater aortic sinus diameters (4.2 ± 0.9 versus 2.2 ± 1.6 z score, p-value = 0.033), and underwent more frequently aortic root replacement (50 versus 4%, p-value = 0.004). CONCLUSIONS: In our cohort of patients with Marfan syndrome, the absence of family history and the presence of bicuspid aortic valve were associated to severe aortic phenotype and worse prognosis.

Diagnostic Clues for the Diagnosis of Nonsarcomeric Hypertrophic Cardiomyopathy (Phenocopies): Amyloidosis, Fabry Disease, and Mitochondrial Disease.

Hypertrophic cardiomyopathy (HCM) is the most common known inherited heart disorder, with a prevalence of 1:500 of the adult population. Etiology of HCM can be heterogeneous, with sarcomeric gene disease as the leading cause in up to 60% of the patients, and with a number of possible different diseases (phenocopies) in about 10%-15% of the patients. Early diagnosis of storage and infiltrative disorders, particularly those with specific treatments (i.e., Fabry disease and/or amyloidosis), means early management and treatment, with a significant impact on patients prognosis. Here, we report on four different cases of HCM, highlighting difficulties to make differential diagnosis of different forms of cardiomyopathies, and their potential impact on the management.