Differences Between Two Distinct Hypertrophic Cardiac Conditions: Fabry Disease versus Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) and Fabry disease (FD) are genetically inherited diseases with left ventricular hypertrophy (LVH) phenotype characteristics that cause adverse cardiac outcomes.

OBJECTIVES

To investigate the demographic, clinical, biochemical, electrocardiographic (ECG), and echocardiographic (ECHO) differences between HCM and FD.

METHODS

60 HCM and 40 FD patients were analyzed retrospectively as a subanalysis of the 'LVH-TR study' after excluding patients with atrial fibrillation, pace rhythm, bundle branch blocks, and second and third-degree atrioventricular (AV) blocks. The significance level was accepted as <0.05.

RESULTS

Male gender (p=0.048) and creatinine (p=0.010) are significantly higher in favor of FD; however, ST depression (p=0.028), QT duration (p=0.041), interventricular septum thickness (IVSd) (p=0.003), posterior wall thickness (PWd) (p=0.009), moderate-severe mitral regurgitation (MR) (p=0.013), and LV mass index (LVMI) (p=0.041) are significantly higher in favor of HCM in the univariate analyses. In multivariate analysis, statistical significance only continues in creatinine (p=0.018) and QT duration (0.045). FD was positively correlated with creatinine (rho=0.287, p=0.004) and HCM was positively correlated with PWd (rho=0.306, p=0.002), IVSd (rho=0.395, p<0.001), moderate-severe MR (rho=0.276, p<0.005), LVMI (rho=0.300, p=0.002), relative wall thickness (RWT) (rho=0.271, p=0.006), QT duration (rho=0.213, p=0.034) and ST depression (rho=0.222, p=0.026).

CONCLUSION

Specific biochemical, ECG, and ECHO characteristics can aid in the differentiation and early diagnosis of HCM and FD.

Left atrial remodeling in hypertrophic cardiomyopathy and Fabry disease: A CMR-based head-to-head comparison and outcome analysis

BACKGROUND

Hypertrophic cardiomyopathy (HCM) and Fabry disease cardiomyopathy (FD) are phenocopies, as they show left ventricular hypertrophy (LVH). The left atrium (LA) is emerging as a potential marker of disease severity in both cardiomyopathies. The present study compares HCM and FD cardiomyopathy with similar degree of LVH, exploring LA morpho-functional parameters and the correlates of clinical outcome.

METHODS

We performed a comprehensive CMR-based comparison between 30 HCM and 30 FD patients matched on age, sex, BSA, LV mass and major cardiovascular risk factors affecting LA remodeling (arterial hypertension and diabetes). 30 healthy controls were also included. CMR feature tracking (CMR-FT) analysis, T1 mapping and conventional parameters were evaluated. Patients also underwent transthoracic echocardiography for LV diastolic function assessment. Clinical events at follow-up were collected (atrial and ventricular events, bradyarrhythmia, heart failure (HF) hospitalization and death).

RESULTS

HCM patients showed greater LA remodeling compared to FD patients, namely higher LA end-systolic volume index (LAVi max), lower LA-ejection fraction (LA-EF) and worse reservoir (εs) and booster function (εa) (all p < 0.05). Accordingly, these parameters have demonstrated good potential for distinguishing between FD and HCM (AUC 0.68-0.73, all p < 0.05), with LAVi max being an independent predictor for HCM diagnosis (OR 1.07, 95%CI 1.011-1.132, p 0.02). Moreover, in HCM patients a significant association between εs and HF occurrence was observed at 2-year follow-up (OR 0.85, 95%CI 0.72-0.99, p 0.04).

CONCLUSIONS

In HCM, LA remodeling is greater than in FD cardiomyopathy with similar LVH, and reservoir strain is associated with HF at follow-up.

Impact of enzyme replacement therapy and migalastat on left atrial strain and cardiomyopathy in patients with Fabry disease

Aims

Cardiomyopathy in Fabry disease (FD) is a major determinant of morbidity and mortality. This study investigates the effects of FD-specific treatment using enzyme replacement therapy (ERT) and chaperone therapy on left atrial (LA) function using two-dimensional speckle tracking echocardiography (2DSTE).

Methods and results

In this prospective observational single-center study, 20 FD patients [10 (50%) females] treated with migalastat, 48 FD patients [24 (50%) females] treated with ERT (agalsidase-alfa and agalsidase-beta), and 30 untreated FD patients (all females) as controls were analyzed. The mean follow-up time ranged from 26 to 81 months. 2DSTE was performed for left ventricle strain, right ventricle strain, and LA strain (LAS). FD-specific treated patients presented with increased left ventricular mass index (LVMi) and higher frequency of left ventricular hypertrophy at baseline, whereas untreated control patients showed normal baseline values. FD-specific treated (including migalastat and ERT) patients showed stabilization of LAS over time (p > 0.05). LVMi was also stable in treated FD patients during observation (p > 0.05).

Conclusion

In patients with FD, treated with either ERT or chaperone therapy, LAS values measured by echocardiographic speckle tracking were stable over time, pointing toward disease stabilization.

Cardiac "hypertrophy" phenotyping: differentiating aetiologies with increased left ventricular wall thickness on echocardiography

Aims

Differentiating phenotypes of cardiac "hypertrophy" characterised by increased wall thickness on echocardiography is essential for management and prognostication. Transthoracic echocardiography is the most commonly used screening test for this purpose. We sought to identify echocardiographic markers that distinguish infiltrative and storage disorders that present with increased left ventricular (LV) wall thickness, namely, cardiac amyloidosis (CA) and Anderson-Fabry disease (AFD), from hypertensive heart disease (HHT).

Methods

Patients were retrospectively recruited from Westmead Hospital, Sydney, and Princess Alexandra Hospital, Brisbane. LV structural, systolic, and diastolic function parameters, as well as global (LVGLS) and segmental longitudinal strains, were assessed. Previously reported echocardiographic parameters including relative apical sparing ratio (RAS), LV ejection fraction-to-strain ratio (EFSR), mass-to-strain ratio (MSR) and amyloidosis index (AMYLI) score (relative wall thickness × E/e') were evaluated.

Results

A total of 209 patients {120 CA [58 transthyretin amyloidosis (ATTR) and 62 light-chain (AL) amyloidosis], 31 AFD and 58 HHT patients; mean age 64.1 ± 13.7 years, 75% male} comprised the study cohort. Echocardiographic measurements differed across the three groups, The LV mass index was higher in both CA {median 126.6 [interquartile range (IQR) 106.4-157.9 g/m²]} and AFD [median 134 (IQR 108.8-152.2 g/m²)] vs. HHT [median 92.7 (IQR 79.6-102.3 g/m²), p < 0.05]. LVGLS was lowest in CA [median 12.29 (IQR 10.33-15.56%)] followed by AFD [median 16.92 (IQR 14.14-18.78%)] then HHT [median 18.56 (IQR 17.51-19.97%), p < 0.05]. Diastolic function measurements including average e' and E/e' were most impaired in CA and least impaired in AFD. Indexed left atrial volume was highest in CA. EFSR and MSR differentiated secondary (CA + AFD) from HHT [receiver operating curve-area under the curve (ROC-AUC) of 0.80 and 0.91, respectively]. RAS and AMYLI score differentiated CA from AFD (ROC-AUC of 0.79 and 0.80, respectively). A linear discriminant analysis with stepwise variable selection using linear combinations of LV mass index, average e', LVGLS and basal strain correctly classified 79% of all cases.

Conclusion

Simple echocardiographic parameters differentiate between different "hypertrophic" cardiac phenotypes. These have potential utility as a screening tool to guide further confirmatory testing.

Incidence of stroke in patients with hypertrophic cardiomyopathy in stable sinus rhythm during long-term monitoring

INTRODUCTION

Patients with hypertrophic cardiomyopathy (HCM) are at increased risk of stroke, but the incidence and factors associated with cardioembolic events in HCM patients without atrial fibrillation (AF) remain unresolved. We determined the incidence of stroke in patients in sinus rhythm (SR) monitored with a cardiac implantable electronic device (CIED).

METHODS

All consecutive patients diagnosed with HCM and referred to CIED implantation with >16 years at diagnosis and ≥ 1 year follow-up post CIED implantation were retrospectively reviewed. Severe LA dilatation was defined as ≥48 mm. Patients were stratified by rhythm as: Pre-existing AF (AF present prior to CIED); De novo AF (AF present after CIED implantation); SR: no episodes of AF.

RESULTS

Of 1651 patients, 185 (11.2%) implanted with a CIED were included (57% men, age: 54 ± 17 years). Baseline, pre-existing AF was present in 73 (39%) patients. Ischemic stroke was reported in 19 (10.3%, 1.78%/year) patients and was similar across the three groups (2.3%/year vs 1.1%/year vs 0.6%/year in patients in SR vs pre-existing AF vs de novo AF, respectively, p = 0.235). In SR patients, a LAD≥48 mm posed the greatest risk of stroke (Hazard Ratio: 10.03,95% Confidence-Interval 2.79-16.01). At Cox multivariable analysis, after adjustment for oral anticoagulation, LA was independently associated with stroke while rhythm was not.

CONCLUSIONS

in HCM patients with CIED long-term monitoring and no prior history of AF, stroke rates were similar in those with de novo AF or stable SR. Severe LA dilatation was a powerful risk factor, irrespective of AF.

Anderson-Fabry disease cardiomyopathy: an update on epidemiology, diagnostic approach, management and monitoring strategies

Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by deficient activity of the enzyme alpha-galactosidase. While AFD is recognized as a progressive multi-system disorder, infiltrative cardiomyopathy causing a number of cardiovascular manifestations is recognized as an important complication of this disease. AFD affects both men and women, although the clinical presentation typically varies by sex, with men presenting at a younger age with more neurologic and renal phenotype and women developing a later onset variant with more cardiovascular manifestations. AFD is an important cause of increased myocardial wall thickness, and advances in imaging, in particular cardiac magnetic resonance imaging and T1 mapping techniques, have improved the ability to identify this disease non-invasively. Diagnosis is confirmed by the presence of low alpha-galactosidase activity and identification of a mutation in the GLA gene. Enzyme replacement therapy remains the mainstay of disease modifying therapy, with two formulations currently approved. In addition, newer treatments such as oral chaperone therapy are now available for select patients, with a number of other investigational therapies in development. The availability of these therapies has significantly improved outcomes for AFD patients. Improved survival and the availability of multiple agents has presented new clinical dilemmas regarding disease monitoring and surveillance using clinical, imaging and laboratory biomarkers, in addition to improved approaches to managing cardiovascular risk factors and AFD complications. This review will provide an update on clinical recognition and diagnostic approaches including differentiation from other causes of increased ventricular wall thickness, in addition to modern strategies for management and follow-up.

Cardiac Magnetic Resonance in HCM Phenocopies: From Diagnosis to Risk Stratification and Therapeutic Management

Hypertrophic cardiomyopathy (HCM) is a genetic heart disease characterized by the thickening of the heart muscle, which can lead to symptoms such as chest pain, shortness of breath, and an increased risk of sudden cardiac death. However, not all patients with HCM have the same underlying genetic mutations, and some have conditions that resemble HCM but have different genetic or pathophysiological mechanisms, referred to as phenocopies. Cardiac magnetic resonance (CMR) imaging has emerged as a powerful tool for the non-invasive assessment of HCM and its phenocopies. CMR can accurately quantify the extent and distribution of hypertrophy, assess the presence and severity of myocardial fibrosis, and detect associated abnormalities. In the context of phenocopies, CMR can aid in the differentiation between HCM and other diseases that present with HCM-like features, such as cardiac amyloidosis (CA), Anderson-Fabry disease (AFD), and mitochondrial cardiomyopathies. CMR can provide important diagnostic and prognostic information that can guide clinical decision-making and management strategies. This review aims to describe the available evidence of the role of CMR in the assessment of hypertrophic phenotype and its diagnostic and prognostic implications.

Comparison of classical Fabry and its p.D313Y and p.A143T variants by cardiac T1 mapping, LGE and feature tracking myocardial strain

Cardiac manifestation of classical Fabry disease (cFD) varies with sex and presence of left ventricular hypertrophy. p.D313Y/p.A143T variants (vFD) represent milder late-onset phenotypes, however, data on vFD are scarce. Patients with FD (cFD = 37;vFD = 14) and 14 healthy controls underwent 1.5 T CMR including Cine, LGE, native T1 mapping(nT1) and myocardial strain(CMR-FT). CMR-FT was assessed using ventricular longitudinal, circumferential, radial (LV-GLS/RV-GLS, LV-GCS/LV-GRS), and atrial longitudinal strain (LA/RA_Total, LA/RA_Conduit, LA/RA_Booster). In cFD reduced myocardial strain (LV-GLS: -20 ± 4 vs. -24 ± 3%,p = 0.007; LV-GCS: -20 ± 4 vs. -26 ± 4%,p = 0.002, LA _Total -GLS: 29 ± 10 vs. 37 ± 6%,p = 0.007; LA _Conduit -GLS: 15 ± 10 vs. 23 ± 5%,p = 0.003) and nT1 values (951 ± 51 ms vs. 1036 ± 20 ms, p < 0.001) were observed compared to controls. In vFD findings were comparable to controls. LV-GCS provided the closest Area under the curve (AUC) to nT1 (0.84 vs. 0.92, p > 0.05) for discrimination of cFD versus controls. Significantly lower LV-GLS/LV-GCS was found in male compared to female cFD (-19 ± 4 vs. -22 ± 4%, p = 0.03). In six non-hypertrophied female cFD with normal nT1 LA_Total -GLS was the only discriminating parameter with an accuracy of 86%. LV-GLS, LV-GCS and LA_Total -GLS can detect impaired cardiac mechanics of cFD besides nT1. LA_Total -GLS might identify non-hypertrophied female cFD. Variants p.D313Y/p.A143T did not reveal cardiac involvement by multiparametric CMR.

Echocardiographic evaluation of hypertrophic cardiomyopathy: A review of up-to-date knowledge and practical tips

Hypertrophic cardiomyopathy (HCM) is the most frequent cardiac disease with genetic substrate, affecting about .2%-.5% of the population. The proper diagnosis is important for optimal management and follow-up. Echocardiography plays an essential role in the assessment of patients with HCM including diagnosis, screening, management formulation, prognosis, and follow up. It also helps to differentiate HCM from other diseases. The advancement of software and probe technology added many echo modalities and techniques that helped in refining the diagnostic and assessing the prognosis of patients with HCM. In this review, we briefly summarize how to integrate the different echocardiographic modalities to obtain comprehensive assessment supported by an updated knowledge of the latest guidelines and recently published articles. Many practical tips and tricks are included in this review to improve the diagnostic accuracy of echocardiography and minimize errors during interpretation.

Diagnostic value of left atrial strain in pediatric hypertrophic cardiomyopathy with normal maximum left atrial volume index: preliminary cardiac magnetic resonance study

BACKGROUND

The maximum left atrial volume index is the most widely used metric for assessing the left atrium in hypertrophic cardiomyopathy; however, it may be normal in the early phases of the disease.

OBJECTIVE

To assess whether pediatric hypertrophic cardiomyopathy patients with normal maximum left atrial volume index have impaired atrial functions on cardiac magnetic resonance imaging (MRI).

MATERIALS AND METHOD

A total of 26 pediatric hypertrophic cardiomyopathy patients and 24 age-matched children, as controls, were enrolled in the study. The left atrial reservoir, conduit and booster strain were calculated from two orthogonal planes and the left atrial volumes were calculated using the biplanar method. The extent of left ventricular late gadolinium enhancement (LGE-%) was calculated using the thresholding method. The left ventricular early diastolic longitudinal strain rate was calculated to assess diastolic dysfunction.

RESULTS

The maximum left atrial volume index of the children with hypertrophic cardiomyopathy and the controls were not significantly different (P>0.05). Most of the left atrial functional indices were worse in children with hypertrophic cardiomyopathy (P<0.05), yet no difference was observed between the left atrial booster strains of the two groups (P>0.05). The left atrial conduit strain showed moderate to good negative correlations with left ventricular LGE-% and diastolic dysfunction.

CONCLUSION

Left atrial conduit and reservoir strains are impaired in pediatric hypertrophic cardiomyopathy patients with normal maximum left atrial volumetric indices. Most left atrial strain parameters are closely linked to left ventricular LGE-% and diastolic dysfunction. Left atrial strain analysis may reveal subtle functional changes in the atrium before the increase in the maximum volume index.

Left atrial myocardial dysfunction in patients with primary aldosteronism as assessed by speckle-tracking echocardiography

BACKGROUND

We investigated the left atrial myocardial deformation in patients with primary aldosteronism using the speckle-tracking echocardiographic (STE) strain imaging technique.

METHODS

Our study included 107 primary aldosteronism patients [52 aldosterone-producing adenoma (APA) and 55 idiopathic hyperaldosteronism (IHA)] and 50 primary hypertensive patients. We performed conventional echocardiography to measure left atrial volume and ejection fraction, and STE to estimate left atrial myocardial deformation including peak velocity, strain and strain rate and calculate the ratio of E/e' to left atrial strain during left ventricular systole as the left atrial stiffness index.

RESULTS

Patients with APA, compared with those with IHA and primary hypertension had a significantly (P < 0.001) lower serum potassium concentration and higher 24-h urinary aldosterone excretion and plasma aldosterone-to-renin ratio. Patients with APA had a significantly (P < 0.01) larger maximal, precontraction, and minimal left atrial volumes and lower total, active and passive left atrial emptying fractions than those with IHA and primary hypertension. Among the three groups, patients with APA showed lowest left atrial velocity, strain, and strain rate during ventricular systole, early diastole and late diastole (P < 0.05) and highest left atrial stiffness index (P < 0.001). In unadjusted analysis, the left atrial strain, strain rate and stiffness index were significantly (P < 0.05) associated with plasma aldosterone concentration and urinary aldosterone excretion. After adjustment for various confounding factors, these associations remained statistically significant for urinary aldosterone excretion (P < 0.05) but not plasma aldosterone concentration (P ≥ 0.05).

CONCLUSION

Patients with primary aldosteronism, especially APA, had impaired left atrial deformation mechanics and increased left atrial stiffness, providing a promising insight into early detection of subclinical left atrial dysfunction by strain echocardiography.

The Role of Cardiac Imaging in the Diagnosis and Management of Anderson-Fabry Disease

Anderson-Fabry disease (AFD) is a rare X-linked inherited metabolic disorder which results in a deficiency or absence of the enzyme α-galactosidase A, leading to the accumulation of glycosphingolipids in various cells and organs including the heart. Cardiac involvement is common and results in increased myocardial inflammation, left ventricular hypertrophy (LVH), and myocardial fibrosis. Echocardiography and cardiovascular magnetic resonance (CMR) offer distinctive and often complementary use to assist in the diagnosis and monitoring pharmacologic therapy in AFD, including detection of the AFD cardiac phenotype, differentiation from other forms of LVH, and patient selection for therapeutic intervention. Advanced cardiac imaging holds promise in subclinical detection of AFD-related abnormalities as well as disease staging and prognostication.

Echocardiography in Infiltrative Cardiomyopathy

Left ventricular (LV) wall thickening can occur due to both physiological and pathological processes. Some LV wall thickening is caused by infiltrative cardiac deposition diseases - rare disorders from both inherited and acquired conditions, with varying systemic manifestations. They portend a poor prognosis and are generally not reversible except in rare circumstances when early diagnosis and treatment may alter the outcome (e.g., Fabry disease). Cardiac involvement is variable and depends on the degree of infiltration and type of infiltrate. These changes often lead to the development of abnormalities in both the relaxation and contractile function of the heart ultimately resulting in heart failure. Echocardiography is generally the first investigation of choice as it is easily available and gives valuable information about the thickness of the ventricular walls as well as systolic and diastolic function. It is also able to identify unique, characteristic features of the disease as well as detecting any haemodynamic sequelae. This review looks at the role of echocardiography in the diagnosis and prognosis of infiltrative cardiac deposition diseases.

Anderson-Fabry disease in heart failure

Anderson-Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the GLA gene that result in deficiency of the enzyme alpha-galactosidase A. The worldwide incidence of Fabry's disease is reported to be in the range of 1 in 40,000-117,000, although this value may be a significant underestimate given under recognition of symptoms and delayed or missed diagnosis. Deficiency in alpha-galactosidase A causes an accumulation of neutral glycosphingolipids such as globotriaosylceramide (Gb3) in lysosomes within various tissues including the vascular endothelium, kidneys, heart, eyes, skin and nervous system. Gb3 accumulation induces pathology via the release of pro-inflammatory cytokines, growth-promoting factors and by oxidative stress, resulting in myocardial extracellular matrix remodelling, left ventricular hypertrophy (LVH), vascular dysfunction and interstitial fibrosis. Cardiac involvement manifesting as ventricular hypertrophy, systolic and diastolic dysfunction, valvular abnormalities and conduction tissue disease is common in AFD and is associated with considerable cardiovascular morbidity and mortality from heart failure, sudden cardiac death and stroke-related death.