The role of genetic testing in Marfan syndrome

PURPOSE OF REVIEW

This review aims to delineate the genetic basis of Marfan syndrome (MFS) and underscore the pivotal role of genetic testing in the diagnosis, differential diagnosis, genotype-phenotype correlations, and overall disease management.

RECENT FINDINGS

The identification of pathogenic or likely pathogenic variants in the FBN1 gene, associated with specific clinical features such as aortic root dilatation or ectopia lentis, is a major diagnostic criterion for MFS. Understanding genotype-phenotype correlations is useful for determining the timing of follow-up, guiding prophylactic aortic root surgery, and providing more precise information to patients and their family members during genetic counseling. Genetic testing is also relevant in distinguishing MFS from other conditions that present with heritable thoracic aortic diseases, allowing for tailored and individualized management.

SUMMARY

Genetic testing is essential in different steps of the MFS patients' clinical pathway, starting from the phase of diagnosis to management and specific treatment.

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.

Unique Features of Cardiovascular Involvement and Progression in Children with Marfan Syndrome Justify Dedicated Multidisciplinary Care

Marfan syndrome (MIM: # 154700; MFS) is an autosomal dominant disease representing the most common form of heritable connective tissue disorder. The condition presents variable multiorgan expression, typically involving a triad of cardiovascular, eye, and skeletal manifestations. Other multisystemic features are often underdiagnosed. Moreover, the disease is characterized by age related penetrance. Diagnosis and management of MFS in the adult population are well-described in literature. Few studies are focused on MFS in the pediatric population, making the clinical approach (cardiac and multiorgan) to these cases challenging both in terms of diagnosis and serial follow-up. In this review, we provide an overview of MFS manifestations in children, with extensive revision of major organ involvement (cardiovascular ocular and skeletal). We attempt to shed light on minor aspects of MFS that can have a significant progressive impact on the health of affected children. MFS is an example of a syndrome where an early personalized approach to address a dynamic, genetically determined condition can make a difference in outcome. Applying an early multidisciplinary clinical approach to MFS cases can prevent acute and chronic complications, offer tailored management, and improve the quality of life of patients.

[Clinical and genetic manifestations of left ventricular non-compaction in children]

Left ventricular non-compaction (LVNC) is a myocardial disease characterized by a two-layered structure typically seen at the apical and lateral left portions of the ventricular myocardium, distal to the papillary muscles. While considered a rare disease, its prevalence in children is increasing due to the increased awareness of this condition and improved resolution of imaging techniques. The etiology is heterogeneous, ranging from inherited conditions to acquired diseases. Although many patients are asymptomatic, some patients may experience adverse events, including heart failure, arrhythmias, or thromboembolic events. Several echocardiographic or cardiac magnetic resonance imaging diagnostic criteria have been proposed for diagnosing LVNC. However, their application in children is significantly limited. This review aims to describe the clinical and genetic characteristics of children with LVNC and discuss the role of the proposed diagnostic criteria.

OCT angiography indices and the choroidal vascularity index in wild-type transthyretin (TTR) amyloidosis (ATTRwt)

Purpose

Retinal angiopathy represents a well-known ocular manifestation of hereditary transthyretin amyloidosis (ATTRv). Until recently, there have been no reports on retinal changes in ATTRwt. In this retrospective observational clinical study, we aimed to determine whether vessel density (VD) indices and the choroidal vascularity index (CVI) could offer insights into retinal and choroidal vascular changes among patients affected by ATTRwt.

Methods

Eighteen patients with a confirmed diagnosis of ATTRwt underwent structural optical coherence tomography (OCT) and OCT angiography (OCTA). We established a control group consisting of 16 healthy subjects for statistical comparisons. The 3D OCT and OCTA datasets were analyzed to assess retinal and choroidal thickness and VD. For measuring CVI, we obtained measurements for the total choroid area (TCA), luminal area (LA), and stromal area (SA).

Results

The mean VD exhibited a statistically significant reduction in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) among the ATTRwt group in comparison to the control group (p < 0.0001). Notably, ATTRwt patients displayed decreased choroidal thickness (p = 0.08). Additionally, the median CVI was lower in the ATTRwt group than in the control group (p = 0.04).

Conclusion

The indices from OCTA and CVI have the potential to serve as non-invasive biomarkers for the quantitative evaluation of retinal and choroidal vascular involvement in patients with ATTRwt.

Prediction of incident atrial fibrillation in hypertrophic cardiomyopathy

BACKGROUND AND AIM

Atrial fibrillation (AF) is the most common sustained arrhythmia in hypertrophic cardiomyopathy (HCM) with significant effects on outcome. We aim to compare the left atrial (LA) diameter measurement with HCM-AF Score in predicting atrial fibrillation (AF) development in HCM.

METHODS

From the regional cohort of the Campania Region, Italy, 519 HCM patients (38% women, age45 ± 17 years) without history of AF, were enrolled in the study. The primary clinical endpoint was the development of AF, defined as at least 1 episode documented by ECG.

RESULTS

During the follow-up (mean 8 ± 6, IQ range 2.5-11.2 years), 99 patients (19%) developed AF. Patients who developed AF were more symptomatic, had higher prevalence of ICD implantation, had larger LA diameter, greater left ventricular (LV) maximal wall thickness and LV outflow tract obstruction (p < 0.01). Both LA diameter and HCM-AF score were higher in patients who developed AF versus those who did not (LA diameter 49 ± 7 versus 43 ± 6 mm; HCM-AF score 22 ± 4 versus 19 ± 4; p < 0.0001); however, ROC curve analysis demonstrated that LA diameter had a significant greater area under the curve than HCM-AF Score (p < 0.0001). At 5 years follow-up, a LA diameter > 46 mm, showed a similar accuracy in predicting AF development of HCM-AF score ≥ 22, which identifies patients at high risk to develop AF.

CONCLUSION

Our analysis shows that LA diameter, a worldwide and simple echocardiographic measure, is capable alone to predict AF development in HCM patients.

Left Ventricular Non-Compaction in Children: Aetiology and Diagnostic Criteria

Left ventricular non-compaction (LVNC) is a heterogeneous myocardial disorder characterized by prominent trabeculae protruding into the left ventricular lumen and deep intertrabecular recesses. LVNC can manifest in isolation or alongside other heart muscle diseases. Its occurrence among children is rising due to advancements in imaging techniques. The origins of LVNC are diverse, involving both genetic and acquired forms. The clinical manifestation varies greatly, with some cases presenting no symptoms, while others typically manifesting with heart failure, systemic embolism, and arrhythmias. Diagnosis mainly relies on assessing heart structure using imaging tools like echocardiography and cardiac magnetic resonance. However, the absence of a universally agreed-upon standard and limitations in diagnostic criteria have led to ongoing debates in the scientific community regarding the most reliable methods. Further research is crucial to enhance the diagnosis of LVNC, particularly in early life stages.

An atypical Aymé-Gripp phenotype detected by exome sequencing

Aymé-Gripp Syndrome (AGS) is an ultra-rare syndrome characterized by peculiar facial traits combined with early bilateral cataracts, sensorineural hearing loss, and variable neurodevelopmental abnormalities. Only a few cases carrying a pathogenic variant in MAF have been described to date. A significant effort is then required to expand the genotypic and phenotypic spectrum of this condition. In this paper, we report the peculiar case of a 6-year-old girl carrying a de novo missense pathogenic variant in MAF, being the first case reported to show a milder phenotype with no cataracts and deafness displayed. Furthermore, we performed a systematic review of previously published cases, focusing on clinical manifestation and genotype.

A Novel Homozygous Loss-of-Function Variant in SPRED2 Causes Autosomal Recessive Noonan-like Syndrome

Noonan syndrome is an autosomal dominant developmental disorder characterized by peculiar facial dysmorphisms, short stature, congenital heart defects, and hypertrophic cardiomyopathy. In 2001, PTPN11 was identified as the first Noonan syndrome gene and is responsible for the majority of Noonan syndrome cases. Over the years, several other genes involved in Noonan syndrome (KRAS, SOS1, RAF1, MAP2K1, BRAF, NRAS, RIT1, and LZTR1) have been identified, acting at different levels of the RAS-mitogen-activated protein kinase pathway. Recently, SPRED2 was recognized as a novel Noonan syndrome gene with autosomal recessive inheritance, and only four families have been described to date. Here, we report the first Italian case, a one-year-old child with left ventricular hypertrophy, moderate pulmonary valve stenosis, and atrial septal defect, with a clinical suspicion of RASopathy supported by the presence of typical Noonan-like facial features and short stature. Exome sequencing identified a novel homozygous loss-of-function variant in the exon 3 of SPRED2 (NM_181784.3:c.325del; p.Arg109Glufs*7), likely causing nonsense-mediated decay. Our results and the presented clinical data may help us to further understand and dissect the genetic heterogeneity of Noonan syndrome.

Clinical manifestation of patients with Fabry disease and R356W GLA variant

BACKGROUND

The R356W GLA variant is an ultra-rare cause of Fabry disease (FD). The clinical manifestations of adult patients carrying this variant have never been reported. This study aims to describe the clinical phenotype of the R356W GLA variant.

METHODS

The cohort consisted of consecutive patients diagnosed with FD and carrying the R356W GLA variant. An observational, longitudinal, retrospective cohort study design was used. Clinical, laboratory, and imaging data have been collected from the baseline evaluation to the last clinical review.

RESULTS

Six families, including 36 patients with FD and the R356W GLA variant (age 41.1 ± 15.9 years, 67% females), were evaluated. Eleven patients (31%) showed left ventricular hypertrophy (LVH), and 6 (17%) had chronic kidney disease (CKD). Patients with LVH were older (53.4 ± 8.5 vs. 35.7 ± 15.5, p-value 0.001), showed a higher prevalence of CKD (45% vs. 4%, p-value 0.002), and worse structural and functional cardiac parameters at echocardiographic evaluation. During a median follow-up of 42 (IQR 21-98) months, one patient experienced advanced atrioventricular block requiring pacemaker implantation and one end-stage renal disease requiring dialysis. No patients experienced major adverse events.

CONCLUSION

This study suggests that the R356W GLA variant could be a late-onset FD-causing variant with incomplete penetrance and predominantly cardiac manifestations.

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.

Cardiovascular Involvement in Fabry's Disease: New Advances in Diagnostic Strategies, Outcome Prediction and Management

Cardiovascular involvement is common in Fabry's disease and is the leading cause of morbidity and mortality. The research is focused on identifying diagnostic clues suggestive of cardiovascular involvement in the preclinical stage of the disease through clinical and imaging markers. Different pathophysiologically driven therapies are currently or will soon be available for the treatment of Fabry's disease, with the most significant benefit observed in the early stages of the disease. Thus, early diagnosis and risk stratification for adverse outcomes are crucial to determine when to start an aetiological treatment. This review describes the cardiovascular involvement in Fabry's disease, focusing on the advances in diagnostic strategies, outcome prediction and disease management.

Natural History of Hypertrophic Cardiomyopathy in Noonan Syndrome With Multiple Lentigines

BACKGROUND

We aimed to examine clinical features and outcomes of consecutive molecularly characterized patients with Noonan syndrome with multiple lentigines and hypertrophic cardiomyopathy.

METHODS

A retrospective, longitudinal multicenter cohort of consecutive children and adults with a genetic diagnosis of Noonan syndrome with multiple lentigines and hypertrophic cardiomyopathy between 2002 and 2019 was assembled. We defined a priori 3 different patterns of left ventricular remodeling during follow-up: (1) an increase in ≥15% of the maximal left ventricular wall thickness (MLVWT), both in mm and z-score (progression); (2) a reduction ≥15% of the MLVWT, both in mm and z-score (absolute regression); (3) a reduction ≥15% of the MLVWT z-score with a stable MLVWT in mm (relative regression). The primary study end point was a composite of cardiovascular death, heart transplantation, and appropriate implantable cardioverter defibrillator-shock.

RESULTS

The cohort comprised 42 patients with Noonan syndrome with multiple lentigines and hypertrophic cardiomyopathy, with a median age at diagnosis of 3.5 (interquartile range, 0.2-12.3) years. Freedom from primary end point was 92.7% (95% CI, 84.7%-100%) 1 year after presentation and 80.9% (95% CI, 70.1%-90.7%) at 5 years. Patients with MLVWT z-score >13.7 showed reduced survival compared with those with <13.7. During a median follow-up of 3.7 years (interquartile range, 2.6-7.9), absolute regression was the most common type of left ventricular remodeling (n=9, 31%), followed by progression (n=6, 21%), and relative regression (n=6, 21%).

CONCLUSIONS

These findings provide insights into the natural history of left ventricular hypertrophy, and can help inform clinicians regarding risk stratification and clinical outcomes in patients with Noonan syndrome with multiple lentigines and hypertrophic cardiomyopathy.

A Novel Homozygous GPAA1 Variant in a Patient with a Glycosylphosphatidylinositol Biosynthesis Defect

Glycosylphosphatidylinositol biosynthesis defect 15 is a rare autosomal recessive disorder due to biallelic loss of function of GPAA1. At the moment, less than twenty patients have been reported, usually compound heterozygous for GPAA1 variants. The main clinical features are intellectual disability, hypotonia, seizures, and cerebellar atrophy. We describe a 4-year-old male with a novel, homozygous variant. The patient presents with typical features, such as developmental delay, hypotonia, seizures, and atypical features, such as macrocephaly, preauricular, and cheek appendages. When he was 15 months, the cerebellum was normal. When he was 33 months old, after the molecular diagnosis, magnetic resonance imaging was repeated, showing cerebellar atrophy. This case extends the clinical spectrum of the GPAA1-related disorder and helps to delineate phenotypic differences with defects of other subunits of the transamidase complex.

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.

Multimodality Imaging in Arrhythmogenic Left Ventricular Cardiomyopathy

The term arrhythmogenic cardiomyopathy (ACM) describes a large spectrum of myocardial diseases characterized by progressive fibrotic or fibrofatty replacement, which gives the substrate for the occurrence of ventricular tachyarrhythmias and the development of ventricular dysfunction. This condition may exclusively affect the left ventricle, leading to the introduction of the term arrhythmogenic left ventricular cardiomyopathy (ALVC). The clinical features of ALVC are progressive fibrotic replacement with the absence or mild dilation of the LV and the occurrence of ventricular arrhythmias within the left ventricle. In 2019, the diagnostic criteria for the diagnosis of ALVC, based on family history and clinical, electrocardiographic, and imaging features, have been proposed. However, since the significant clinical and imaging overlap with other cardiac diseases, genetic testing with the demonstration of a pathogenic variant in an ACM-related gene is required for diagnostic confirmation. In ALVC, the multimodality imaging approach comprises different imaging techniques, such as echocardiography, cardiac magnetic resonance, and cardiac nuclear imaging. It provides essential information for the diagnosis, differential diagnosis, sudden cardiac death risk stratification, and management purposes. This review aims to elucidate the current role of the different multimodality imaging techniques in patients with ALVC.

[Diagnosis of cardiovascular involvement in Fabry disease]

Fabry disease is a rare X-linked genetic disorder, caused by partial or total loss of function of the lysosomal enzyme α-galactosidase A that induces glycosphingolipid accumulation in various organs and tissues, modifying their structure and function. Cardiovascular involvement in classic and late onset forms has emerged to be a major determinant of prognosis. In recent years, a constant evolution in imaging techniques and their mindful application has led to interesting results in the diagnostic workup, progressively reducing time required to recognize early signs of this disease. Owing to the growing awareness for diagnostic screening and the efficacy of the many therapeutic options currently available, the clinical history of Fabry patients has changed during the last decades. Therefore, an early diagnosis of Fabry disease and especially of cardiac involvement is essential to promptly adopt an adequate therapy.

835 CARDIOMYOPATHIES: IS IT USEFUL TO ANALYZE MINOR GENES?

The diffusion of Next Generation Sequencing (NGS)-based approaches has allowed the identification of cardiomyopathies and channelopathies pathogenic mutations in more than 200 different genes. Since also genes considered uncommon for a clinical phenotype are now included in molecular testing, the detection rate of disease-causing variants is increased. Here, we report the prevalence of genetic variants detected in a cohort of 133 patients, among which 73 showed complex or borderline phenotypes or a positive family history for SCD. The analysis was conducted by analyzing an enlarged panel of 129 genes, including 60 main genes associated to the different genetic cardiomyopathies (HCM, DCM, ACM, LQTS, BrS) and 69 genes without a strong or definitive evidence of disease association according to the NIH-funded Clinical Genome Resource (ClinGen), here named “uncommon genes”.

We identified 82 variants, of which 50 (61%) were identified in uncommon genes. Among these, thirty-five (70%) were reported as variants of unknown significance (VUSs), thirteen (26%) as pathogenic (P) or likely pathogenic (LP) mutations and 2 (4%) as novel (likely) benign (B/LB) variants, according to the American College of Medical Genetics (ACMG) classification. Interestingly, about 85% of P/LP variants identified in uncommon genes were in patients showing complex/unclear/borderline phenotypes or a positive family history for SCD.

These data support the need for an extended genetic testing, including genes that are not usually explored due to a currently poor association with the clinical phenotype, particularly when phenotype is borderline, in order to increase the diagnostic sensitivity of inherited cardiomyopathies and channelopathies genetic testing.

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 <18 years) between 2013 and 2020, with LVEF <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 ± 8 years). The mean LVEF was 30.2 ± 10% before treatment and 43.7 ± 9.6% after treatment, at the maximum therapeutic dose (p < 0.0001). There was a positive relationship between HRR and increase in LVEF (R 2 = 0.06, p = 0.014). A HRR of >20% correlated with an improvement in LVEF >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 < 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.

HCM-AF South Italy score for prediction of new-onset atrial fibrillation in patients with hypertrophic cardiomyopathy: data from a derivation and validation italian cohorts

Background

Only one score for prediction of new-onset atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) has been developed in North America (HCM-AF North America score).

Purpose

To develop a new score (HCM-AF South Italy score) in an Italian derivation cohort and to test the new score with that from North America, in an Italian validation cohort.

Methods

A cohort of 228 patients with HCM and without history of AF, followed at referral center 1 for HCM, was used for model development. A cohort of 226 patients without history of AF, followed at referral center 2, was used for external validation. During follow-up (IQR 3–13 years, median 8 years), 59 (26%) patients developed new-onset AF. Data in the development cohort generated the HCM-AF South Italy score, a point score to predict AF probability: left atrial dimension &gt;49 mm (+5 points), age at clinical evaluation &lt;55 years (+2 points), the use of angiotensin-converting enzyme (ACE) or inhibitor or angiotensin receptor blocker (ARB) at initial evaluation (+2 points), low left ventricular (LV) ejection fraction (&lt;50%) (+2 points), LV outflow tract obstruction (LVOTO) &gt;25 mmHg (+2 points), NYHA class &gt;1 (+1 point).

Results

Patients from the validation cohort were older, had lower prevalence of HCM family history, lower systolic and diastolic blood pressure, taken fewer drugs like beta-blockers, ACE or ARB, calcium-channel blockers, and antiarrhythmic drugs and had lower LVOTO than patients from the derivation cohort, (overall p&lt;0.05). During follow-up (IQR 1–10 years, median 5 years), 25 (11%) patients developed AF. ROC curve analysis demonstrated that HCM-AF South Italy score was superior to HCM-AF North America score (Figure). A HCM- AF South Italy score &gt;4 identified patients at risk of AF with a sensitivity of 48%, specificity of 76%, PPV of 20% and NPV of 92%.

Conclusion

Although derived and tested in little and quite different populations, the performance of the HCM-AF South Italy score was superior to that of the score developed in North America.

Funding Acknowledgement

Type of funding sources: None.

Next-Generation Sequencing Gene Panels in Inheritable Cardiomyopathies and Channelopathies: Prevalence of Pathogenic Variants and Variants of Unknown Significance in Uncommon Genes

The diffusion of next-generation sequencing (NGS)-based approaches allows for the identification of pathogenic mutations of cardiomyopathies and channelopathies in more than 200 different genes. Since genes considered uncommon for a clinical phenotype are also now included in molecular testing, the detection rate of disease-causing variants has increased. Here, we report the prevalence of genetic variants detected by using a NGS custom panel in a cohort of 133 patients with inherited cardiomyopathies (n = 77) or channelopathies (n = 56). We identified 82 variants, of which 50 (61%) were identified in genes without a strong or definitive evidence of disease association according to the NIH-funded Clinical Genome Resource (ClinGen; "uncommon genes"). Among these, 35 (70%) were variants of unknown significance (VUSs), 13 (26%) were pathogenic (P) or likely pathogenic (LP) mutations, and 2 (4%) benign (B) or likely benign (LB) variants according to American College of Medical Genetics (ACMG) classifications. These data reinforce the need for the screening of uncommon genes in order to increase the diagnostic sensitivity of the genetic testing of inherited cardiomyopathies and channelopathies by allowing for the identification of mutations in genes that are not usually explored due to a currently poor association with the clinical phenotype.

Severe Lymphatic Disorder and Multifocal Atrial Tachycardia Treated with Trametinib in a Patient with Noonan Syndrome and SOS1 Mutation

Noonan syndrome (NS) is a multisystemic disorder caused by germline mutations in the Ras/MAPK cascade, causing a broad spectrum of phenotypical abnormalities, including abnormal facies, developmental delay, bleeding diathesis, congenital heart disease (mainly pulmonary stenosis and hypertrophic cardiomyopathy), lymphatic disorders, and uro-genital abnormalities. Multifocal atrial tachycardia has been associated with NS, where it may occur independently of hypertrophic cardiomyopathy. Trametinib, a highly selective MEK1/2 inhibitor currently approved for the treatment of cancer, has been shown to reverse left ventricular hypertrophy in two RIT1-mutated newborns with NS and severe hypertrophic cardiomyopathy. Severe lymphatic abnormalities may contribute to decreased pulmonary compliance in NS, and pulmonary lymphangiectasias should be included in the differential diagnosis of a newborn requiring prolonged oxygen administration. Herein we report the case of a pre-term newborn who was admitted to our unit for the occurrence of severe respiratory distress and subentrant MAT treated with trametinib.

C64 UNMASKING THE PREVALENCE OF AMYLOID CARDIOMYOPATHY IN THE REAL WORLD: RESULTS FROM PHASE 2 OF AC–TIVE STUDY, AN ITALIAN NATIONWIDE SURVEY

Background

Clinicians need to identify patients with amyloid cardiomyopathy (AC) at an early stage, due to the availability of disease–modifying therapies. Some echocardiographic findings may rise the suspicion of AC, also in patients with mild or no symptoms, addressing second level diagnostic tests.

Aim

To investigate the prevalence of AC in consecutive patients ≥55 years undergoing clinically indicated, routine transthoracic echocardiogram in Italy and presenting echocardiographic signs suggestive of AC.

Methods

This is a prospective multicentric study conducted in Italy. It comprises two phases: 1) a recording phase consisting in a national survey on prevalence of possible echocardiographic red flags of AC in consecutive unselected patients ≥55 years undergoing routine echocardiogram (previously published) and 2) an AC diagnostic phase involving a diagnostic work–up for AC to investigate AC prevalence among patients with at least one echocardiographic red flag (herein presented). Patients that in Phase 1 presented an “AC suggestive” echocardiogram (i.e., at least one red flag of AC in hypertrophic, non–dilated left ventricles with preserved ejection fraction) underwent clinical evaluation, blood and urine tests and scintigraphy with bone tracer. Diagnosis of transthyretin related–AC (ATTR–AC) was made in presence of grade 2–3 Perugini uptake at scintigraphy and absence of monoclonal protein. The study was registered at ClinicalTrials.gov (#NCT04738266).

Results

Of the 5315 screened echocardiograms, 381 exams (7.2%) were classified as “AC suggestive” and proceeded to Phase 2. 217 patients completed Phase 2 investigations. Main reasons for the 164 non–entering patients into Phase 2 were death (n = 49) and refusal to participate (n = 66). A final diagnosis of AC was made in 62 patients with an estimated prevalence of 28,6% (95% CI: 22,5%–34,7%). ATTR–AC was diagnosed in 51 and AL–AC in 11 patients, ascertaining a prevalence of 23,5% (95% CI: 17,8%–29,2%) and 5,1% (95% CI: 2,2%–8,0%), respectively.

Conclusion

Among a cohort of consecutive unselected patients ≥55 years with echocardiographic findings suggestive of AC, the prevalence of AC ranged from 23% up to 35%. Although ATTR–AC was predominant, AL–AC was diagnosed in a significant number of cases. Echocardiography has a fundamental role in screening patients, raising the suspicion of disease and orienting diagnostic work–up for AC.

Unmasking the Prevalence of Amyloid Cardiomyopathy in the Real World: Results from Phase 2 of AC-TIVE Study, an Italian Nationwide Survey

AIM

To investigate the prevalence of amyloid cardiomyopathy (AC) and the diagnostic accuracy of echocardiographic red flags of AC among consecutive adult patients undergoing transthoracic echocardiogram for reason other than AC in 13 Italian institutions.

METHODS AND RESULTS

This is an Italian prospective multicentric study, involving a clinical and instrumental work-up to assess AC prevalence among patients ≥ 55 years old with an "AC suggestive" echocardiogram (i.e. at least one echocardiographic red flag of AC in hypertrophic, non-dilated left ventricles with preserved ejection fraction). The study was registered at ClinicalTrials.gov (#NCT04738266). 381 patients with an "AC suggestive" echocardiogram were identified among a cohort of 5315 screened subjects. 217 patients completed the investigations. A final diagnosis of AC was made in 62 patients with an estimated prevalence of 29% (95% CI: 23%-35%). Transthyretin-related AC (ATTR-AC) was diagnosed in 51 and light chain related AC (AL-AC) in 11 patients. Either apical sparing or a combination of ≥ 2 other echocardiographic red flags, excluding interatrial septum thickness, provided a diagnostic accuracy > 70%.

CONCLUSION

In a cohort of consecutive adults with echocardiographic findings suggestive of AC and preserved LVEF, the prevalence of AC (either ATTR or AL) was 29%. Easily available echocardiographic red flags, when combined together, demonstrated good diagnostic accuracy.

Association between common cardiovascular risk factors and clinical phenotype in patients with hypertrophic cardiomyopathy from the European Society of Cardiology (ESC) EurObservational Research Programme (EORP) Cardiomyopathy/Myocarditis registry

AIMS

The interaction between common cardiovascular risk factors (CVRF) and hypertrophic cardiomyopathy (HCM) is poorly studied. We sought to explore the relation between CVRF and the clinical characteristics of patients with HCM enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy registry.

METHODS AND RESULTS

1739 patients with HCM were studied. The relation between hypertension (HT), diabetes (DM), body mass index (BMI), and clinical traits was analysed. Analyses were stratified according to the presence or absence of a pathogenic variant in a sarcomere gene. The prevalence of HT, DM, and obesity (Ob) was 37, 10, and 21%, respectively. HT, DM, and Ob were associated with older age (P<0.001), less family history of HCM (HT and DM P<0.001), higher New York Heart Association (NYHA) class (P<0.001), atrial fibrillation (HT and DM P<0.001; Ob p = 0.03) and LV (left ventricular) diastolic dysfunction (HT and Ob P<0.001; DM P = 0.003). Stroke was more frequent in HT (P<0.001) and mutation-positive patients with DM (P = 0.02). HT and Ob were associated with higher provocable LV outflow tract gradients (HT P<0.001, Ob P = 0.036). LV hypertrophy was more severe in Ob (P = 0.018). HT and Ob were independently associated with NYHA class (OR 1.419, P = 0.017 and OR 1.584, P = 0.004, respectively). Other associations, including a higher proportion of females in HT and of systolic dysfunction in HT and Ob, were observed only in mutation-positive patients.

CONCLUSION

Common CVRF are associated with a more severe HCM phenotype, suggesting a proactive management of CVRF should be promoted. An interaction between genotype and CVRF was observed for some traits.

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.

Pathophysiological, haemodynamic and prognostic implications of left atrial dysfunction in cardiac amyloidosis and other cardiomyopathies with hypertrophic phenotype

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND & PURPOSE. Left atrial function (LAF) is a determinant of clinical status and outcome in many cardiac disorders, including cardiac amyloidosis (CA). Aim of this study is to explores the LAF in CA and other cardiomyopathies with hypertrophic phenotype, and its consequences on cardiovascular haemodynamics, right ventricular function and survival.

METHODS. We enrolled 50 patients with CA (26 AL and 24 wtATTR) and 75 with hypertrophic phenotype (LVH group) [25 hypertrophic cardiomyopathy (HCM) pts, 25 hypertensive pts (HypCM), and 25 pts with aortic stenosis (AS)]. LAF was analysed using the phasic method [LAEI as reservoir, LAPEF as conduit, LAAEF as active pump and TLAEF as total emptying function; see figure 1] by LA volumes determination.

RESULTS. ATTR patients showed higher LA dimensions and impaired reservoir and total LA emptying function (TLAEF) compared to AL without differences LAF. Compared to the LVH group, CA patients showed higher LA dimension with impaired LAF in all phasic parameters, higher LV filling pressures and reduced biventricular function. We further divided CA and LVH patients into four subgroups based on the presence or absence of LA dysfunction (LADys+ for TLAEF values below the median: &lt;50.2%; range 9.3-70.9%]. Among the groups, patients with CA/LADys+ showed worst clinical status, higher pulmonary pressures (sPAP) and lower TAPSE and TAPSE/sPAP ratio values. After a median follow-up of 24 months, 19 patients died from cardiovascular (CV) causes (15 in CA/LADys+ group and 4 in LVH/LADys+). The overall survival free of CV death was  64% in CA/LADys+ and 85% in LVH/LADys+ (4/26) group [log-rank χ2 29.6; p &lt; 0.0001]. A sequential multivariate model was employed to assess whether LAF could predict CV deaths: TLAEF was entered together with established clinical and echocardiographic parameters (NYHA functional class, LAVI, E/Em, sPAP, TAPSE and TAPSE/sPAP ratio). At the final backward analysis, LAVI, TAPSE/sPAP and TLAEF were independent prognosticators of CV death.

CONCLUSIONS. LAF is significantly more impaired in CA than LVH group and is associated with worst clinical status, RV dysfunction and higher LV filling and pulmonary pressure. Moreover, LADys is a frequent feature of CA and significantly associated with higher CV mortality. We suggests that LADys in LVH group could results from chronic pressure overload due to LA"s exposure to high LV diastolic pressure (impaired LV compliance). In CA, LADys could also be determined by direct LA infiltration. The pathophysiological result is a progressive LA remodelling with increased LA pressure, consequent backward transmission to the pulmonary venous system and, ultimately, RV dysfunction. TLAEF is parameter of LAF that correlates with increased pulmonary vascular resistance (measured elsewhere with cardiac catheterisation) and RV dysfunction. In CA, it  seems  promising as marker of the haemodynamic consequences of LADys and CV mortality. Abstract Figure 1  Abstract Figure 2

Diagnostic and prognostic implications of myocardial work in cardiac amyloidosis and in genetic and non-genetic cardiomyopathies with hypertrophic phenotype

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND & PURPOSE. Cardiac amyloidosis (CA) is an infiltrative disorder characterized by left ventricular (LV) thickening with early systolic and diastolic dysfunction. Due to it poor prognosis, and the beneficial impact of novel treatments when started in early stages of disease, its forward detection is crucial. Aim of this study is comparing the diagnostic accuracy of classical and novel echocardiographic parameters in detecting CA among other forms of genetic and non-genetic cardiomyopathies with hypertrophic phenotype.

METHODS. We enrolled 50 pts with CA (26 AL and 24 wtATTR) and 75 phenocopies (LVH group) [25 hypertrophic cardiomyopathy (HCM) pts, 25 hypertensive (HypCM) pts, and 25 pts with non-severe aortic stenosis (AS)]. Standard and novel LV morpho-functional echo parameters [LV ejection fraction (LVEF), myocardial contraction fraction (MCF), global longitudinal strain (GLS), relative regional strain ratio (RRSR), ejection fraction on strain ratio (EFSR)], and novel Myocardial Work (MW) parameters [Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW), Global Work Efficiency (GWE)] were analyzed.

RESULTS. LV standard, novel and MW-derived systolic parameters were more impaired in CA compared to LVH group. At ROC curve analysis, GCW showed the best performance in discriminating CA from other forms of LVH (AUC 0.886; 95% CI: 0.819-0.954; P &lt; 0.0001), with a cut-off value &lt; 1473 mmHg% showing 90% of sensitivity and 82% of specificity). At linear regression analysis, GCW correlated with many echocardiographic parameters (IVSD, PWD, RWT ratio, LVMi, MCF, LVESV, LVEF, EFSR and RRSR). At multivariate analysis, PWD (P &lt; 0,029) and RWT ratio (p &lt; 0,014) were the only parameters associated with GCW. At 24 months follow-up, there were 15 deaths in CA and 4 in LVH group. At Kaplan-Meier analysis the overall survival free of cardiovascular death was reduced in the lowest GCW interquartile ranges (log-rank χ2 21.5; p &lt; 0.0001). At Cox hazard ratio analysis, GCW was the only prognostic parameter associated with cardiovascular mortality (β 1.006; 95% CI: 1.003-1.009; P &lt; 0.0001).

CONCLUSIONS. Despite CA and LVH patients shows a similar phenotype, the systolic function differs greatly. In the present study, the GCW showed the best ability in detecting CA among other forms of LVH. Its reduction in CA seems reflect the infiltrative burden and its consequences on myocardial deformation properties, while its reduction in LVH group has been attributed elsewhere to fibrotic derangement. GCW showed to be a promising novel diagnostic and prognostic factor in this setting. Abstract Figure 1  Abstract Table 1

Diagnostic and prognostic implications of right ventricular-arterial coupling in cardiac amyloidosis and in genetic and non-genetic cardiomyopathies with hypertrophic phenotype

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND & PURPOSE. Right ventricular (RV) dysfunction in cardiomyopathies is a consequence of chronic overload (i.e. aortic stenosis, AS) or direct involvement of systemic disorders (i.e. cardiac amyloidosis, CA). The Tricuspid Annular Plane Systolic Excursion/Systolic Pulmonary Artery Pressure (TAPSE/sPAP) ratio has been recently proposed as a surrogate of RV-arterial coupling (RVAC). This study aims to compare RVAC between CA subgroups and between CA and other forms of genetic and non-genetic cardiomyopathies with hypertrophic phenotype.

METHODS. We enrolled 50 patients with CA (26 AL and 24 wtATTR) and 75 cardiomyopathies with hypertrophy phenotype (LVH group) [25 pts with hypertrophic cardiomyopathy (HCM), 25 hypertensive pts(HypCM), and 25 pts with AS]. Besides routine echocardiographic measurements, we analysed right chambers dimensions and classical and novel parameters of RV function [TAPSE, TAPSE/sPAP, St wave, global (RVGLS) and free-wall (RVFWS) strain].

RESULTS. Compared to AL, the ATTR group showed higher right chambers dimensions, without differences in all RV systolic parameters. Compared to the LVH group, CA patients showed no differences in RV dimensions while RV systolic parameters,  including the TAPSE/sPAP ratio, were significantly reduced in the presence of significantly higher LV filling pressures.  At ROC curve analysis, TAPSE (AUC 0.877; 95% CI: 0.811-0.943; p &lt; 0,0001) and TAPSE/sPAP ratio (AUC 0.859; 95% CI: 0.783-0.935; p &lt; 0,0001) showed the best ability in discriminating CA among other forms of LVH (cut-off 20.5 mm for TAPSE with sensibility of 80.5% and specificity of 78.8%, respectively; cut-off 0.62 for TAPSE/sPAP ratio with  sensibility of 85.4% and specificity 81.8%). At 24 months follow-up, there were 15 deaths in CA (30%) and 4 in LVH group (5%). At Kaplan-Meier estimation, the TAPSE/sPAP ratio showed progressively a significantly reduced survival in the lowest interquartile ranges. Moreover, at multivariate analysis, TAPSE/sPAP was the only independent prognostic factor (β -5,644; 95% IC: 0,000-0,522; p &lt; 0,027).

CONCLUSIONS. The RVAC is significantly impaired in CA compared to the LVH group but not between CA subgroups. Its reduction seems attributable to both increase LV filling pressure, due to the restrictive nature of the infiltrative cardiomyopathy, and reduced RV systolic function, due to either indirect RV chronic overload and direct myocardial infiltration. The TAPSE/sPAP ratio is a surrogate of RVAC and proved to be a novel echocardiographic parameter useful in both discriminating CA among genetic and non-genetic forms of LVH, and stratifying the prognosis. Abstract Table 1  Abstract Figure 1

A complex unit for a complex disease: the HCM-Family Unit

Hypertrophic cardiomyopathy (HCM) is a group of heterogeneous disorders that are most commonly passed on in a heritable manner. It is a relatively rare disease around the globe, but due to increased rates of consanguinity within the Kingdom of Saudi Arabia, we speculate a high incidence of undiagnosed cases. The aim of this paper is to elucidate a systematic approach in dealing with HCM patients and since HCM has variable presentation, we have summarized differentials for diagnosis and how different subtypes and genes can have an impact on the clinical picture, management and prognosis. Moreover, we propose a referral multi-disciplinary team HCM-Family Unit in Saudi Arabia and an integrated role in a network between King Faisal Hospital and Inherited and Rare Cardiovascular Disease Unit-Monaldi Hospital, Italy (among the 24 excellence centers of the European Reference Network (ERN) GUARD-Heart).   Graphical Abstract.

Natural history of left ventricular hypertrophy in infants of diabetic mothers

BACKGROUND

This study sought to describe the characteristics and the natural course of left ventricular hypertrophy (LVH) in a well-characterized consecutive cohort of infants of diabetic mothers (IDMs).

METHODS

Sixty consecutive IDMs with LVH have been retrospectively identified and enrolled in the study. All IDMs were evaluated at baseline and every 6 months until LV wall thickness regression, defined as the decrease of wall thickness measurement into the normal reference range for cardiac parameters (z-score > -2 and < 2). A comprehensive assessment was performed in those patients with diagnostic markers suggestive of a different cause and/or without significant reduction of the LVH during follow-up.

RESULTS

At 1-year follow-up, all IDMs showed a significant reduction of maximal wall thickness MWT (6.00 mm [IQR 5.00-712] vs. 5.50 mm [IQR 5.00-6.00], p-value <0.001; MWT-z-score: 4.86 [IQR 3.93-7.61] vs. 1.72 [IQR 1.08-2.85], p-value <0.001) compared to baseline, and all patients showed LV wall thickness regression or residual mild or moderate LVH (57%, 28%, and 12%, respectively), except 2 patients with persistent severe LVH, that after a comprehensive clinical-genetic assessment were diagnosed as Noonan syndrome with multiple lentigines. At multivariate analysis, MWT was negatively associated with LV wall thickness regression at 1-year follow-up (MWT-mm: OR 0.48[0.29-0.79], p-value = 0.004; MWT-z-score: OR 0.71[0.56-0.90], p-value = 0.004).

CONCLUSIONS

LVH in IDMs represents a benign condition with complete regression during the first years of life. In those patients without LV wall thickness regression, combined with clinical markers suggesting a specific disease, a complete work-up is required for a definite diagnosis.

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.

465 Unmasking the prevalence of cardiac amyloidosis in the real world: first insights from the phase 2 of active study, an Italian nationwide survey

Aims

Clinicians needs to identify patients with cardiac amyloidosis (CA) at an early stage, due to the availability of disease modifying therapies. Some echocardiographic findings may rise the suspicion of CA, also in patients with mild or no symptoms, addressing second level diagnostic tests. To investigate the prevalence of CA in consecutive patients ≥55 years undergoing clinically indicated, routine transthoracic echocardiogram (TTE) in Italy with echocardiographic signs suggestive of CA.

Methods and results

This is a prospective multicentric study conducted in Italy. It comprises two phases: 1) an observational phase consisting in a national survey on prevalence of possible echocardiographic red flags of CA in consecutive patients ≥55 years undergoing routine TTE (previously published) and 2) a CA diagnostic phase. Preliminary results of phase 2 are herein presented. Patients that in the phase 1 presented a CA-suggestive TTE (i.e. at least one red flag of CA in hypertrophic, non-dilated left ventricles) were re-evaluated for a cardiological visit. Those who consented to proceed in the study, underwent clinical evaluation, blood and urine tests and scintigraphy with bone tracer. Diagnosis of transthyretin related-CA (TTR-CA) was made in presence of Grades 2–3 Perugini uptake at scintigraphy and absence of monoclonal protein. The study was registered at ClinicalTrials.gov (#NCT04738266). Of the 5315 screened echocardiograms, 381 exams (7.2%) were classified as AC-suggestive. Two-hundred-twelve of the 381 patients with a CA-suggestive TTE underwent phase 2 study. Main reasons for the 169 non-entering patients into the phase 2 were death (n = 53) and refusal to participate (n = 85). Sixty-five of these 212 patients (31%; 17% considering also the 169 non-entering patients into the phase 2) had a diagnosis of CA. Finally, TTR-CA was diagnosed in 53 (25%) and AL-CA in 12 (5.7%) patients.

Conclusions

Among a cohort of consecutive unselected patients ≥55 years with echocardiographic findings suggestive of CA, the real prevalence of CA ranged from 17 up to 31%. Although TTR-CA was predominant, AL-CA was diagnosed in a significant amount of cases. TTE has a fundamental role in screening patients, raising the suspicion of CA and orienting diagnostic work-up for CA.

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

Aims

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 and results

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. Among the 152 patients included in the study, 50 (33%) were diagnosed as CA, 25 (16%) had severe aortic stenosis, 25 (16%) had hypertensive remodelling, 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.

577 Bisoprolol for the treatment of symptomatic patients with obstructive hypertrophic cardiomyopathy

Aims

To evaluate to role of bisoprolol to control symptoms and left ventricular outflow tract obstruction (LVOTO) in a consecutive cohort of adults with hypertrophic cardiomyopathy (HCM).

Methods and results

In this retrospective study, patients with HCM with an LVOT gradient ≥50mmHg after Valsalva manoeuvre and New York Heart Association (NYHA) class II-III symptoms were assigned to receive bisoprolol (starting at 1.25 mg daily). The initial dose was increased every two weeks to achieve the target in LVOT gradient &lt;30 mmHg or the maximum tolerated dose. The primary endpoint was the achievement of a LVOT gradient &lt;30 mmHg and ≥1 NYHA class improvement. The secondary endpoints were proportion of patients with LVOT gradient &lt;30 mmHg or &lt; 50 mmHg, proportion of patients with ≥1 NYHA class improvement, and change from baseline in LVOT gradient. Between December 2001 and December 2020, 92 patients were enrolled into the study. Sixteen (17%) patients on bisoprolol met the primary endpoint. Bisoprolol reduced the LVOT gradient to less than 30 mmHg in 33 (36%) patients, to less than 50 mmHg in 57 (62%), and improved NYHA class in 30 (33%). The mean reduction of LVOT gradient on bisoprolol was 28 (±14) mmHg and the percentage reduction was 42 (±21)%. In 35 (39%) patients, bisoprolol did not reduce the gradient to less than 50 mmHg requiring disopyramide and/or myectomy to achieve this goal.

Conclusions

Treatment with bisoprolol was well-tolerated and effective in relieving obstruction and improving symptoms in a significant proportion of patients with symptomatic obstructive HCM.

Clinical presentation and long-term outcomes of infantile hypertrophic cardiomyopathy: a European multicentre study

AIMS

Children presenting with hypertrophic cardiomyopathy (HCM) in infancy are reported to have a poor prognosis, but this heterogeneous group has not been systematically characterized. This study aimed to describe the aetiology, phenotype, and outcomes of infantile HCM in a well-characterized multicentre European cohort.

METHODS AND RESULTS

Of 301 children diagnosed with infantile HCM between 1987 and 2019 presenting to 17 European centres [male n = 187 (62.1%)], underlying aetiology was non-syndromic (n = 138, 45.6%), RASopathy (n = 101, 33.6%), or inborn error of metabolism (IEM) (n = 49, 16.3%). The most common reasons for presentation were symptoms (n = 77, 29.3%), which were more prevalent in those with syndromic disease (n = 62, 61.4%, P < 0.001), and an isolated murmur (n = 75, 28.5%). One hundred and sixty-one (53.5%) had one or more co-morbidities. Genetic testing was performed in 163 (54.2%) patients, with a disease-causing variant identified in 115 (70.6%). Over median follow-up of 4.1 years, 50 (16.6%) underwent one or more surgical interventions; 15 (5.0%) had an arrhythmic event (6 in the first year of life); and 48 (15.9%) died, with an overall 5 year survival of 85%. Predictors of all-cause mortality were an underlying diagnosis of IEM [hazard ratio (HR) 4.4, P = 0.070], cardiac symptoms (HR 3.2, P = 0.005), and impaired left ventricular systolic function (HR 3.0, P = 0.028).

CONCLUSIONS

This large, multicentre study of infantile HCM describes a complex cohort of patients with a diverse phenotypic spectrum and clinical course. Although overall outcomes were poor, this was largely related to underlying aetiology emphasizing the importance of comprehensive aetiological investigations, including genetic testing, in infantile HCM.

Imaging the "Hot Phase" of a Familiar Left-Dominant Arrhythmogenic Cardiomyopathy

We describe the case of a young man with an initial diagnosis of acute myocarditis that was finally recognized as a familial left-dominant arrhythmogenic cardiomyopathy. The diagnostic process was also based on demonstration, serial cardiac magnetic resonance imaging, and typical patterns of myocardial damage, including features of the disease’s inflammatory “hot phase”.

Multidisciplinary In-Depth Investigation in a Young Athlete Suffering from Syncope Caused by Myocardial Bridge

Laboratory medicine, along with genetic investigations in sports medicine, is taking on an increasingly important role in monitoring athletes’ health conditions. Acute or intense exercise can result in metabolic imbalances, muscle injuries or reveal cardiovascular disorders. This study aimed to monitor the health status of a basketball player with an integrated approach, including biochemical and genetic investigations and advanced imaging techniques, to shed light on the causes of recurrent syncope he experienced during exercise. Biochemical analyses showed that the athlete had abnormal iron, ferritin and bilirubin levels. Coronary Computed Tomographic Angiography highlighted the presence of an intramyocardial bridge, suggesting this may be the cause of the observed syncopes. The athlete was excluded from competitive activity. In order to understand if this cardiac malformation could be caused by an inherited genetic condition, both array-CGH and whole exome sequencing were performed. Array-CGH showed two intronic deletions involving MACROD2 and COMMD10 genes, which could be related to a congenital heart defect; whole exome sequencing highlighted the genotype compatible with Gilbert syndrome. However, no clear pathogenic mutations related to the patient’s cardiological phenotype were detected, even after applying machine learning methods. This case report highlights the importance and the need to provide exhaustive personalized diagnostic work up for the athletes in order to cover the cause of their malaise and for safeguarding their health. This multidisciplinary approach can be useful to create ad personam training and treatments, thus avoiding the appearance of diseases and injuries which, if underestimated, can become irreversible disorders and sometimes can result in the death of the athlete.

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).

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.

Clinical Manifestations of 22q11.2 Deletion Syndrome

DiGeorge syndrome (DGS), also known as "22q11.2 deletion syndrome" (22q11DS) (MIM # 192430 # 188400), is a genetic disorder caused by hemizygous microdeletion of the long arm of chromosome 22. In the last decades, the introduction of fluorescence in situ hybridization assays, and in selected cases the use of multiplex ligation-dependent probe amplification, has allowed the detection of chromosomal microdeletions that could not be previously identified using standard karyotype analysis. The aim of this review is to address cardiovascular and systemic involvement in children with DGS, provide genotype-phenotype correlations, and discuss their medical management and therapeutic options.

The Risk of Sudden Unexpected Cardiac Death in Children: Epidemiology, Clinical Causes, and Prevention

"Sudden unexplained death (SUD) is a tragic event for both the family and community, particularly when it occurs in young individuals. Sudden cardiac death (SCD) represents the leading form of SUD and is defined as an unexpected event without an obvious extracardiac cause, occurring within 1 hour after the onset of symptoms. In children, the main causes of SCD are inherited cardiac disorders, whereas coronary artery diseases (congenital or acquired), congenital heart diseases, and myocarditis are rare. The present review examines the current state of knowledge regarding SCD in children, discussing the epidemiology, clinical causes, and prevention strategies."

Diagnosis and Management of Cardiovascular Involvement in Friedreich Ataxia

Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by a homozygous GAA triplet repeat expansion in the frataxin gene. Cardiac involvement, usually manifesting as hypertrophic cardiomyopathy, can range from asymptomatic cases to severe cardiomyopathy with progressive deterioration of the left ventricular ejection fraction and chronic heart failure. The management of cardiac involvement is directed to prevent disease progression and cardiovascular complications. However, direct-disease therapies are not currently available for FRDA. The present review aims to describe the current state of knowledge regarding cardiovascular involvement of FRDA, focusing on clinical-instrumental features and management of cardiac manifestation.

Myocardial performance is impaired in cardiac amyloidosis: role of myocardial work-derived parameter in differential diagnosis with phenocopies and prognostic implications

Background

Cardiac amyloidosis (CA) is an infiltrative disorder characterized by left ventricular (LV) thickening and dysfunction. Due to it poor prognosis its early detection and differential diagnosis among other forms of cardiomyopathies is fundamental.

Purpose

This study aimed to compare the diagnostic accuracy of LV classical and and novel echocardiographic parameters in differentiating CA from other forms of genetic and non-genetic cardiomyopathies with hypertrophic phenotype.

Methods

We included 50 patients with CA (26 pts with AL and 24 pts with wild type ATTR form) and 75 patients with LV hypertrophy (LVH) [25 patients with hypertrophic cardiomyopathy (HCM), 25 with hypertensive cardiomyopathy (HypCM), and 25 with aortic stenosis (AS)]. Besides routine echocardiographic measurements, we analysed standard and novel echo parameters implied in LV assessment [LV ejection fraction (LVEF), myocardial contraction fraction (MCF), global longitudinal strain (GLS), relative regional strain ratio (RRSR), ejection fraction on strain ratio (EFSR)], included novel Myocardial Work (MW) parameters [Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW), Global Work Efficiency (GWE)].

Results

Patients in CA group showed a smallest LV cavity size, higher LV mass and, consequently, a more pronounced concentric hypertrophy compared to LVH group. All LV systolic parameters where more impaired in CA than in LVH group. At ROC curve analysis, among all others, GCW showed the best performance in discriminating CA from LVH (AUC 0.886; 95% CI: 0.819–0.954; P&lt;0,0001), with a cut-off value &lt;1473 mmHg% showing good sensitivity and specificity (90% and 82%, respectively). At linear regression analysis GCW correlated with IVSD (P&lt;0,0001), PWD (p&lt;0,0001), RWT ratio (p&lt;0,0001), LVMi (p&lt;0,0001), MCF (P&lt;0,0001), LVESV (p&lt;0,002), LVEF (P&lt;0,0001), EFSR (p&lt;0,0001) and RRSR (p&lt;0,0001). At multivariate analysis, PWD (P&lt;0,029) and RWT ratio (p&lt;0,014) were the only parameters associated. At 24 months follow-up there were 15 deaths in the CA group and 4 in LVH group. At Kaplan-Meier analysis the overall survival free of cardiovascular death was reduced in the lowest GCW interquartile ranges (log-rank χ2 21,5; p&lt;0,0001). At Cox hazard ratio analysis GCW (β 1,233; 95% CI: 1,201–1,246; P&lt;0,0001) was the only prognostic parameter associated with cardiovascular mortality.

Discussion

Although CA and and LVH have with similar phenotype, they differ greatly in terms of systolic function. The MW, estimated by non-invasive pressure-strain loops, is a novel method for a load-independent LV systolic function assessment. In the present study the GCW showed the best ability in detecting CA in comparison to other parameters usually implied in clinical practice.

Conclusion

Myocardial performance is significantly reduced in CA compared to other forms of LVH. GCW showed to be a promising novel diagnostic and prognostic factor in this setting.

Funding Acknowledgement

Type of funding sources: None. Table 1Figure 1

Natural history of left ventricular hypertrophy in infants of diabetic mothers

Background

Left ventricular hypertrophy (LVH) in infants of diabetic mothers (IDMs) has been generally considered a benign condition, which usually regresses as the stimulus for the insulin production disappears, resulting in normalized left ventricular wall thickness in the 6 months of life. However, these conclusions have been based on small, mostly outdated cohort studies. Indeed, it has been recently shown that increased left ventricular mass persists in late infancy (6 to 12 months), long after the intrauterine exposure has been removed, suggesting that other factors may potentially contribute.

Purpose

This study sought to describe the characteristics and the natural course of LVH in a well-characterized consecutive cohort of IDMs.

Methods

Sixty consecutive IDMs with LVH have been retrospectively identified and enrolled in the study. All IDMs were evaluated at baseline and every 6 months until LV wall thickness regression, defined as the decrease of wall thickness measurement into the normal reference range for cardiac parameters (z-score &gt;−2 and &lt;2). A comprehensive assessment was performed in those patients with diagnostic markers suggestive of a different cause and/or without significant reduction of the LVH during follow-up.

Results

At 1-year follow-up, all IDMs showed a significant reduction of maximal wall thickness (MWT) (MWT-mm: 6.67±2.37 vs. 5.83±1.70, p-value&lt;0.001; MWT-z-score: 6.67±4.71 vs. 2.39±2.55, p-value&lt;0.001) and left ventricular outflow tract (LVOT) gradient (15.35±15.58 vs. 11.22±8.14, p-value&lt;0.004), compared to baseline, and all patients showed LV wall thickness regression or residual mild or moderate LVH (57%, 28%, and 12%, respectively) (Figure 1), except 2 patients with persistent severe LVH, that after a comprehensive clinical-genetic assessment were diagnosed as Noonan syndrome with multiple lentigines.

At multivariate analysis, MWT was significantly associated with LV wall thickness regression at 1-year follow-up (MWT-mm: OR 0.48 [0.29–0.79], p-value=0.004; MWT-z-score: OR 0.71 [0.56–0.90], p-value=0.004) in an inversely proportional fashion.

Overall, 59%, 72% and 79% of IDMs with LVH showed a complete LV wall thickness regression at 1-year, 2-year and 3-year follow-up, respectively (Figure 2). Excluding the two patients with a different cause of LVH, all IDMs showed a LV wall thickness regression in the first 6 years of life.

Conclusions

LVH in IDMs represents a benign condition with complete regression during the first years of life. In those patients without LV wall thickness regression, combined with clinical markers suggesting a specific disease, a complete work-up is required for a definite diagnosis.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Left atrial function is impaired in cardiac amyloidosis and other cardiomyopathies with hypertrophic phenotype: haemodynamic correlations, pathophysiological consequences and prognostic implications

Background

Left atrial function (LAF) is emerging as a novel determinant of clinical status and outcome in cardiomyopathies. However, few studies compare LAF between CA subgroups and between CA and other hypertrophic cardiomyopathies.

Purpose

This study explores the LAF in cardiomyopathies with hypertrophic phenotype and between CA subgroups and its consequences on clinical status, haemodynamic consequences and survival.

Methods

We enrolled 50 patients with CA (26 with AL and 24 with wild type ATTR form), 75 patients with LV hypertrophy (LVH) [25 with hypertrophic cardiomyopathy (HCM), 25 with hypertensive cardiomyopathy (HypCM), and 25 with aortic stenosis (AS)]. Besides routine echocardiographic measurements, we analysed LAF using the phasic method (LAEI as reservoi, LAPEF as conduit, LAAEF as pump and TLAEF as total emptying LA function).

Results

The ATTR showed higher atrial dimensions with a significant reduction in the reservoir and total LA emptying function compared to the AL group (see Table 1). Instead, compared to the LVH group, CA patients showed higher atrial dimension with all LAF phasic parameters reduced, higher LV filling pressures and reduced biventricular function. Then, we further divided the CA and LVH group into subgroups based on the presence or absence of LA dysfunction (LADys+) defined as TLAEF values below the median [TLAEF &lt;50,2%; range 9,3–70,9%]. Patients in CA/LADys+ group showed the worst NYHA class, higher sPAP and lower values of TAPSE and TAPSE/sPAP ratio (see Figure 2). After a follow-up of 24 months, 19 patients died from cardiovascular causes [0/8 in CA/LADys-, 15/42 in CA/LADys+, 0/60 in LVH/LADys- and 4/26 in LVH/LADys+ group; (log-rank χ2 29,6; p&lt;0,0001)]. To predict whether LAF could predict cardiovascular deaths sequential multivariate model was employed, and TLAEF was entered together with established clinical and echocardiographic parameters (NYHA class, LAVI, E/Em, sPAP, TAPSE and TAPSE/sPAP ratio). At the final backward analysis, LAVI, TAPSE/sPAP and TLAEF were the independent prognosticators for adverse events.

Discussion

The LAF is significantly impaired in CA and associated with worst clinical status, higher incidence of RV dysfunction and higher LV filling and pulmonary pressure. Moreover, LADys is significant associated with higher cardiovascular mortality. LADys results from chronic pressure overload due to LA's exposition to the higher LV diastolic pressure due to impaired LV compliance, and from direct infiltration in CA The result is a progressive LA remodelling with an increased LA pressure and consequenT backward transmission to the pulmonary venous system and to RV.

Conclusions

The TLAEF is a novel parameter of LAF that correlates with increased pulmonary vascular resistance and RV dysfunction. It seems a promising novel prognosticator and amarker of the haemodynamic consequences of LADys.

Funding Acknowledgement

Type of funding sources: None. Table 1Figure 1