Cardiovascular magnetic resonance demonstration of the spectrum of morphological phenotypes and patterns of myocardial scarring in Anderson-Fabry disease

Constrained alternating minimization for parameter mapping (CAMP)

OBJECTIVE

To improve image quality in highly accelerated parameter mapping by incorporating a linear constraint that relates consecutive images.

APPROACH

In multi-echo T1 or T2 mapping, scan time is often shortened by acquiring undersampled but complementary measures of k-space at each TE or TI. However, residual undersampling artifacts from the individual images can then degrade the quality of the final parameter maps. In this work, a new reconstruction method, dubbed Constrained Alternating Minimization for Parameter mapping (CAMP), is introduced. This method simultaneously extracts T2 or T1* maps in addition to an image for each TE or TI from accelerated datasets, leveraging the constraints of the decay to improve the reconstructed image quality. The model enforces exponential decay through a linear constraint, resulting in a biconvex objective function that lends itself to alternating minimization. The method was tested in four in vivo volunteer experiments and validated in phantom studies and healthy subjects, using T2 and T1 mapping, with accelerations of up to 12.

MAIN RESULTS

CAMP is demonstrated for accelerated radial and Cartesian acquisitions in T2 and T1 mapping. The method is even applied to generate an entire T2 weighted image series from a single TSE dataset, despite the blockwise k-space sampling at each echo time. Experimental undersampled phantom and in vivo results processed with CAMP exhibit reduced artifacts without introducing bias.

SIGNIFICANCE

For a wide array of applications, CAMP linearizes the model cost function without sacrificing model accuracy so that the well-conditioned and highly efficient reconstruction algorithm improves the image quality of accelerated parameter maps.

The Diagnostic and Therapeutic Implications of Phenocopies and Mimics of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common myocardial disease defined by increased left ventricular wall thickness unexplained by loading conditions. HCM frequently is caused by pathogenic variants in sarcomeric protein genes, but several other syndromic, metabolic, infiltrative, and neuromuscular diseases can result in HCM phenocopies. This review summarizes the current understanding of these HCM mimics, highlighting their importance across the life course. The central role of a comprehensive, multiparametric diagnostic approach and the potential of precision medicine in tailoring treatment strategies are emphasized.

Arrhythmogenesis in Fabry Disease

PURPOSE OF REVIEW

Fabry Disease (FD) is a rare lysosomal storage disorder characterised by multiorgan accumulation of glycosphingolipid due to deficiency in the enzyme α-galactosidase A. Cardiac sphingolipid accumulation triggers various types of arrhythmias, predominantly ventricular arrhythmia, bradyarrhythmia, and atrial fibrillation. Arrhythmia is likely the primary contributor to FD mortality with sudden cardiac death, the most frequent cardiac mode of death. Traditionally FD was seen as a storage cardiomyopathy triggering left ventricular hypertrophy, diastolic dysfunction, and ultimately, systolic dysfunction in advanced disease. The purpose of this review is to outline the current evidence exploring novel mechanisms underlying the arrhythmia substrate.

RECENT FINDINGS

There is growing evidence that FD cardiomyopathy is a primary arrhythmic disease with each stage of cardiomyopathy (accumulation, hypertrophy, inflammation, and fibrosis) contributing to the arrhythmia substrate via various intracellular, extracellular, and environmental mechanisms. It is therefore important to understand how these mechanisms contribute to an individual's risk of arrhythmia in FD. In this review, we outline the epidemiology of arrhythmia, pathophysiology of arrhythmogenesis, risk stratification, and cardiac therapy in FD. We explore how advances in conventional cardiac investigations performed in FD patients including 12-lead electrocardiography, transthoracic echocardiography, and cardiac magnetic resonance imaging have enabled early detection of pro-arrhythmic substrate. This has allowed for appropriate risk stratification of FD patients. This paves the way for future work exploring the development of therapeutic initiatives and risk prediction models to reduce the burden of arrhythmia.

Clinical staging of Anderson-Fabry cardiomyopathy: An operative proposal

As a slowly progressive form of hypertrophic cardiomyopathy (HCM), Anderson-Fabry disease (FD) resembles the phenotype of the most common sarcomeric forms, although significant differences in presentation and long-term progression may help determine the correct diagnosis. A variety of electrocardiographic and imaging features of FD cardiomyopathy have been described at different times in the course of the disease, and considerable discrepancies remain regarding the assessment of disease severity by individual physicians. Therefore, we here propose a practical staging of FD cardiomyopathy, in hopes it may represent the standard for cardiac evaluation and facilitate communication between specialized FD centres and primary care physicians. We identified 4 main stages of FD cardiomyopathy of increasing severity, based on available evidence from clinical and imaging studies: non-hypertrophic, hypertrophic - pre-fibrotic, hypertrophic - fibrotic, and overt dysfunction. Each stage is described and discussed in detail, following the principle that speaking a common language is critical when managing such complex patients in a multi-disciplinary and sometimes multi-centre setting.

Anderson-Fabry Disease: Red Flags for Early Diagnosis of Cardiac Involvement

Anderson-Fabry disease (AFD) is a lysosome storage disorder resulting from an X-linked inheritance of a mutation in the galactosidase A (GLA) gene encoding for the enzyme alpha-galactosidase A (α-GAL A). This mutation results in a deficiency or absence of α-GAL A activity, with a progressive intracellular deposition of glycosphingolipids leading to organ dysfunction and failure. Cardiac damage starts early in life, often occurring sub-clinically before overt cardiac symptoms. Left ventricular hypertrophy represents a common cardiac manifestation, albeit conduction system impairment, arrhythmias, and valvular abnormalities may also characterize AFD. Even in consideration of pleiotropic manifestation, diagnosis is often challenging. Thus, knowledge of cardiac and extracardiac diagnostic "red flags" is needed to guide a timely diagnosis. Indeed, considering its systemic involvement, a multidisciplinary approach may be helpful in discerning AFD-related cardiac disease. Beyond clinical pearls, a practical approach to assist clinicians in diagnosing AFD includes optimal management of biochemical tests, genetic tests, and cardiac biopsy. We extensively reviewed the current literature on AFD cardiomyopathy, focusing on cardiac "red flags" that may represent key diagnostic tools to establish a timely diagnosis. Furthermore, clinical findings to identify patients at higher risk of sudden death are also highlighted.

Fabry Disease: More than a Phenocopy of Hypertrophic Cardiomyopathy

Fabry disease (FD) is a genetic lysosomal storage disease with frequent cardiovascular involvement, whose presence is a major determinant of adverse clinical outcomes. As a potentially treatable cause of left ventricular hypertrophy (LVH) and heart failure with preserved ejection fraction, the early recognition of FD is crucial to initiate enzyme replacement therapy and improve long-term prognosis. Multimodality imaging plays a central role in the evaluation of patients with FD and helps in the differential diagnosis of other conditions presenting with LVH. In the present review, we explore the current applications of multimodality cardiac imaging, in particular echocardiography and cardiovascular magnetic resonance, in the diagnosis, prognostic assessment, and follow-up of patients with FD.

State-of-the-Art Imaging of Infiltrative Cardiomyopathies: A Scientific Statement From the American Heart Association

Infiltrative cardiomyopathies comprise a broad spectrum of inherited or acquired conditions caused by deposition of abnormal substances within the myocardium. Increased wall thickness, inflammation, microvascular dysfunction, and fibrosis are the common pathological processes that lead to abnormal myocardial filling, chamber dilation, and disruption of conduction system. Advanced disease presents as heart failure and cardiac arrhythmias conferring poor prognosis. Infiltrative cardiomyopathies are often diagnosed late or misclassified as other more common conditions, such as hypertrophic cardiomyopathy, hypertensive heart disease, ischemic or other forms of nonischemic cardiomyopathies. Accurate diagnosis is also critical because clinical features, testing methodologies, and approach to treatment vary significantly even within the different types of infiltrative cardiomyopathies on the basis of the type of substance deposited. Substantial advances in noninvasive cardiac imaging have enabled accurate and early diagnosis. thereby eliminating the need for endomyocardial biopsy in most cases. This scientific statement discusses the role of contemporary multimodality imaging of infiltrative cardiomyopathies, including echocardiography, nuclear and cardiac magnetic resonance imaging in the diagnosis, prognostication, and assessment of response to treatment.

Advanced CMR Techniques in Anderson-Fabry Disease: State of the Art

Anderson-Fabry disease (AFD) is a rare multisystem X-linked lysosomal storage disorder caused by α-galactosidase A enzyme deficiency. Long-term cardiac involvement in AFD results in left ventricular hypertrophy and myocardial fibrosis, inducing several complications, mainly arrhythmias, valvular dysfunction, and coronary artery disease. Cardiac magnetic resonance (CMR) represents the predominant noninvasive imaging modality for the assessment of cardiac involvement in the AFD, being able to comprehensively assess cardiac regional anatomy, ventricular function as well as to provide tissue characterization. This review aims to explore the role of the most advanced CMR techniques, such as myocardial strain, T1 and T2 mapping, perfusion and hybrid imaging, as diagnostic and prognostic biomarkers.

Cardiac Magnetic Resonance Imaging T1 and T2 Mapping in Systemic Lupus Erythematosus in Relation to Antimalarial Treatment

PURPOSE

Patients with systemic lupus erythematosus (SLE) are at risk of cardiac disease including antimalarial-induced cardiomyopathy (AMIC). The purpose of this study is to evaluate cardiac magnetic resonance imaging parametric mapping findings in SLE patients with AMIC and investigate the relationship of T1/T2 mapping to antimalarial (AM) treatment duration.

MATERIALS AND METHODS

All patients with SLE who had undergone cardiac magnetic resonance imaging with T1/T2 mapping for evaluation of suspected cardiac disease between 2018 and 2021 were evaluated and compared with healthy controls. To facilitate comparison between scanners, T1/T2 values were converted to a z -score using scanner-specific local reference values. Patients were classified into 3 groups: AMIC, myocarditis, and other (no AMIC or myocarditis).

RESULTS

Forty-five SLE patients (47±17 y, 80% female; 8 [18%] with AMIC and 7 [16%] with myocarditis) and 30 healthy controls (39±15 y, 60% female) were included. Patients with AMIC had higher T1 and T2 compared with controls ( z -score 1.1±1.3 vs. 0±0.6, P =0.01 and 1.7±1.1 vs. 0±1.0, P <0.01, respectively) and lower values compared with those with myocarditis (3.7±1.6, P <0.01 and 4.0±2.0, P <0.01, respectively). T1 correlated negatively with AM treatment duration in patients without AMIC or myocarditis ( r =-0.36, P =0.048) and positively in patients with AMIC ( r =0.92, P =0.001). AM treatment duration did not correlate significantly with T1 in patients with myocarditis or with T2 in any group.

CONCLUSIONS

The relationship between T1 and AM treatment duration differed between groups. Native T1 decreases with longer treatment in patients without AMIC or myocarditis, possibility due to glycosphingolipid accumulation. In patients with AMIC, increasing T1 with longer treatment could reflect fibrosis.

Clinical and CMR characteristics associated with cardiac events in patients with Fabry disease

BACKGROUND

The assessment of late gadolinium enhancement (LGE) and left ventricular hypertrophy (LVH) by cardiac magnetic resonance (CMR) as diagnostic and prognostic maker in Fabry disease is advancing. We aimed to investigate the impact of clinical characteristics and CMR findings on cardiac outcome in patients with FD.

METHODS

In this study 55 patients with genetically confirmed FD and available CMR imaging were included. The primary endpoint was defined as a composite of cardiac events including cardiac death, new occurrence of atrial fibrillation, heart failure, ventricular tachycardia and bradycardia requiring device insertion.

RESULTS

During a median follow-up of 4.9 years (IQR 3.7-5.9), 9 patients (16.3%) reached the primary cardiac end point. The global amount of LGE was associated with an increased risk for primary endpoint in the univariate analysis (HR 1.4 per 10% increase in LGE, p = 0.002). However maximal wall thickness (MWT) was the sole independent predictor of the primary endpoint in a stepwise logistic regression model (HR 9.8 per mm increase in MWT, p < 0.0001). Kaplan-Meier analysis revealed significant difference in event free survival rate between patients with and without LVH (Long-rank p = 0.006) and in patients with and without LGE (Long-rank p < 0.001). Patients without LVH and LGE were free of adverse cardiac events.

CONCLUSION

LVH and LGE detected by CMR were associated with adverse cardiac events in FD. In particular maximal wall thickness can be useful in cardiac risk stratification of FD patients.

Treatment of Fabry Disease: Established and Emerging Therapies

Fabry disease (FD) is a rare, X-linked inherited disorder of glycosphingolipid metabolism. It leads to the progressive accumulation of globotriaosylceramide within lysosomes due to a deficiency of α-galactosidase A enzyme. It involves multiple organs, predominantly the renal, cardiac, and cerebrovascular systems. Early diagnosis and treatment are critical to prevent progression to irreversible tissue damage and organ failure, and to halt life-threatening complications that can significantly reduce life expectancy. This review will focus on the established and emerging treatment options for FD.

Cardiac MRI in Fabry disease

Fabry disease is a rare, progressive X-linked inherited disorder of glycosphingolipid metabolism due to a deficiency of α-galactosidase A enzyme. It leads to the accumulation of globotriaosylceramide within lysosomes of multiple organs, predominantly the vascular, renal, cardiac, and nervous systems. Fabry cardiomyopathy is characterized by increased left ventricular wall thickness/mass, functional abnormalities, valvular heart disease, arrhythmias, and heart failure. Early diagnosis and treatment are critical to avoid cardiac or renal complications that can significantly reduce life expectancy in untreated FD. This review will focus on the role of cardiovascular magnetic resonance imaging in the diagnosis, clinical decision-making, and monitoring of treatment efficacy.

Quantitative MRI in cardiometabolic disease: From conventional cardiac and liver tissue mapping techniques to multi-parametric approaches

Cardiometabolic disease refers to the spectrum of chronic conditions that include diabetes, hypertension, atheromatosis, non-alcoholic fatty liver disease, and their long-term impact on cardiovascular health. Histological studies have confirmed several modifications at the tissue level in cardiometabolic disease. Recently, quantitative MR methods have enabled non-invasive myocardial and liver tissue characterization. MR relaxation mapping techniques such as T₁, T_1ρ, T₂ and T₂* provide a pixel-by-pixel representation of the corresponding tissue specific relaxation times, which have been shown to correlate with fibrosis, altered tissue perfusion, oedema and iron levels. Proton density fat fraction mapping approaches allow measurement of lipid tissue in the organ of interest. Several studies have demonstrated their utility as early diagnostic biomarkers and their potential to bear prognostic implications. Conventionally, the quantification of these parameters by MRI relies on the acquisition of sequential scans, encoding and mapping only one parameter per scan. However, this methodology is time inefficient and suffers from the confounding effects of the relaxation parameters in each single map, limiting wider clinical and research applications. To address these limitations, several novel approaches have been proposed that encode multiple tissue parameters simultaneously, providing co-registered multiparametric information of the tissues of interest. This review aims to describe the multi-faceted myocardial and hepatic tissue alterations in cardiometabolic disease and to motivate the application of relaxometry and proton-density cardiac and liver tissue mapping techniques. Current approaches in myocardial and liver tissue characterization as well as latest technical developments in multiparametric quantitative MRI are included. Limitations and challenges of these novel approaches, and recommendations to facilitate clinical validation are also discussed.

Cardiac Magnetic Resonance in Fabry Disease: Morphological, Functional, and Tissue Features

Fabry disease (FD) is an X-linked inheritable storage disease caused by a deficiency of alpha-galactosidase causing lysosomal overload of sphingolipids. FD cardiomyopathy is characterized by left ventricular (LV) hypertrophy and should be considered in differential diagnosis with all the other causes of LV hypertrophy. An early diagnosis of FD is very important because the enzyme replacement therapy (ERT) may change the fate of patients by blocking both cardiac and systemic involvement and improving prognosis. Diagnosis may be relatively easy in young patients with the typical signs and symptoms of FD, but in male patients with late onset of disease and in females, diagnosis may be very challenging. Morphological and functional aspects are not specific to FD, which cannot be diagnosed or excluded by echocardiography. Cardiac magnetic resonance (CMR) with tissue characterization capability is an accurate technique for the differential diagnosis of LV hypertrophy. The finding of decreased myocardial T1 value in LV hypertrophy is specific to FD. Late gadolinium enhancement (LGE) is found in the late stage of the disease, but it is useful to predict the cardiac response to ERT and to stratify the prognosis.

Value of Electrocardiography to Distinguish Fabry Disease from Sarcomeric Hypertrophic Cardiomyopathy

Fabry disease (FD) is a rare genetic disorder that leads to left ventricular hypertrophy (LVH), frequently misdiagnosed as hypertrophic cardiomyopathy (HCM). We sought to assess the value of electrocardiography for distinguishing FD from HCM. We retrospectively reviewed and compared standard electrocardiograms and echocardiograms from 26 patients with FD and LVH and 33 sarcomeric patients with HCM, matched for gender, age, and degree of LVH. The mean age of patients with FD was 46 years (interquartile range) (28 to 53) and of HCM 50 (30 to 61) years (p = 0.27). Of them, 16 (61%) and 25 (76%) were male, respectively (p = 0.26). Indexed left ventricular mass was 166 g/m² in FD versus 181 g/m² in HCM (p = 0.88). All patients with FD and 30 (91%) with HCM were in sinus rhythm (p = 0.25). A higher prevalence of right bundle branch block (RBBB) was observed in FD (27%) versus HCM (6%) (p = 0.03). The PR interval was shorter in FD, 140 ms (120-160) versus 160 ms (140 to 180) (p = 0.004). P-wave duration was longer in patients with FD, 100 ms (80 to 120) versus 80 ms (80 to 100) (p = 0.01). The PQ interval (PR interval minus P-wave duration) was shorter in patients with FD, 40 ms (20 to 45) versus 80 ms (40 to 80) (p = 0.001). There were no differences regarding P-wave amplitude, QRS complex duration, corrected QT length, conduction or repolarization abnormalities, Sokolow-Lyon index, and Cornell index. After multivariate adjustments for RBBB, PR interval, P-wave duration, and PQ interval, a PQ interval ≤40 ms and RBBB were significantly associated with FD. In conclusion, there are electrocardiogram characteristics, such as the presence of RBBB or a PQ interval ≤40 ms, that may be helpful for screening and reducing the delay in FD diagnosis.

Rare Metabolic and Endocrine Diseases with Cardiovascular Involvement: Insights from Cardiovascular Magnetic Resonance - A Review

The identification of rare diseases with cardiovascular involvement poses significant diagnostic challenges due to the rarity of the diseases, but also due to the lack of knowledge and expertise. Most of them remain underrecognized and undiagnosed, leading to clinical mismanagement and affecting the patients' prognosis, as these diseases are per definition life-threatening or chronic debilitating. This article reviews the cardiovascular involvement of the most well-known rare metabolic and endocrine diseases and their diagnostic approach through the lens of cardiovascular magnetic resonance (CMR) imaging and its prognostic role, highlighting its fundamental value compared to other imaging modalities.

Cardiac MRI of Hereditary Cardiomyopathy

Hereditary cardiomyopathy comprises a heterogeneous group of diseases of the cardiac muscle that are characterized by the presence of genetic mutations. Cardiac MRI is central to evaluation of patients with cardiomyopathy owing to its ability to allow evaluation of many different tissue properties in a single examination. For example, cine MRI is the standard of care for assessment of myocardial structure and function. It clearly shows regions of asymmetric wall thickening that are typical of hypertrophic cardiomyopathy and allows it to be differentiated from other hereditary disorders such as Fabry disease or transthyretin cardiac amyloidosis that produce concentric hypertrophy. Late gadolinium enhancement provides a different tissue property and allows these latter two causes of concentric hypertrophy to be distinguished on the basis of their enhancement appearances (Fabry disease shows midwall basal inferolateral enhancement, and amyloidosis shows global subendocardial enhancement). Native T1 mapping may similarly allow differentiation between Fabry disease and amyloidosis without the use of contrast material. T2*-weighted MRI is important in the detection and quantification of iron overload cardiomyopathy. Other hereditary entities for which comprehensive MRI has proven essential include Danon disease, familial dilated cardiomyopathy, hereditary muscular dystrophy, arrhythmogenic right ventricular cardiomyopathy, and ventricular noncompaction. As a result of the diagnostic power of cardiac MRI, cardiac MRI examinations are being requested with increasing frequency, not only in academic centers but also in community practices. The genetic background, pathophysiologic characteristics, and clinical presentation of patients with hereditary cardiomyopathy are described; the characteristic cardiac MRI features of hereditary cardiomyopathy are discussed; and the role of MRI in risk stratification, treatment, and prognostication in patients with cardiomyopathy is reviewed. ^©RSNA, 2022 Online supplemental material is available for this article.

Expert opinion on the recognition, diagnosis and management of children and adults with Fabry disease: a multidisciplinary Turkey perspective

This consensus statement by a panel of Fabry experts aimed to identify areas of consensus on conceptual, clinical and therapeutic aspects of Fabry disease (FD) and to provide guidance to healthcare providers on best practice in the management of pediatric and adult patients with FD. This consensus statement indicated the clinical heterogeneity of FD as well as a large number of pathogenic variants in the GLA gene, emphasizing a need for an individualized approach to patient care. The experts reached consensus on the critical role of a high index of suspicion in symptomatic patients and screening of certain at-risk groups to reveal timely and accurate diagnosis of FD along with an increased awareness of the treating physician about the different kinds of pathogenic variants and their clinical implications. The experts emphasized the crucial role of timely recognition of FD with minimal delay from symptom onset to definite diagnosis in better management of FD patients, given the likelihood of changing the disease's natural history, improving the patients' quality of life and the prognosis after enzyme replacement therapy (ERT) administered through a coordinated, multidisciplinary care approach. In this regard, this consensus document is expected to increase awareness among physicians about unique characteristics of FD to assist clinicians in recognizing FD with a well-established clinical suspicion consistent with pathogenic variants and gender-based heterogeneous clinical manifestations of FD and in translating this information into their clinical practice for best practice in the management of patients with FD.

Multimodality Cardiac Imaging in Cardiomyopathies: From Diagnosis to Prognosis

Cardiomyopathies are a group of structural and/or functional myocardial disorders which encompasses hypertrophic, dilated, arrhythmogenic, restrictive, and other cardiomyopathies. Multimodality cardiac imaging techniques are the cornerstone of cardiomyopathy diagnosis; transthoracic echocardiography should be the first-line imaging modality due to its availability, and diagnosis should be confirmed by cardiovascular magnetic resonance, which will provide more accurate morphologic and functional information, as well as extensive tissue characterization. Multimodality cardiac imaging techniques are also essential in assessing the prognosis of patients with cardiomyopathies; left ventricular ejection fraction and late gadolinium enhancement are two of the main variables used for risk stratification, and they are incorporated into clinical practice guidelines. Finally, periodic testing with cardiac imaging techniques should also be performed due to the evolving and progressive natural history of most cardiomyopathies.

Looking for the Right Diagnosis? Cardiovascular Magnetic Resonance Imaging Can Help Differentiate Cardiomyopathies

Differentiating cardiomyopathies is a common clinical quandary in cardiology. Getting the right diagnosis is important for guiding patient management and providing prognosis. Incorrect or uncertain diagnoses can lead to further unnecessary investigations and/or treatment decisions applied inappropriately, which can have consequences for both the patient and health care costs. Cardiovascular magnetic resonance (CMR) imaging offers strength here due to its precision and breadth in assessing cardiac function and tissue characterisation. This review aims to raise awareness among cardiologists and physicians of the important insights provided by CMR-insights that can improve diagnosis and guide management, as well as aid in risk stratification, in different cardiomyopathies.

Left ventricular global longitudinal strain in low cardiac risk outpatients who recently recovered from coronavirus disease 2019

The cardiac sequelae of coronavirus disease 2019 (COVID-19), a worldwide global pandemic, are still uncertain, particularly in the asymptomatic, low cardiac risk outpatient population. This study aims to evaluate the asymptomatic, low cardiac risk out-patient population who recently recovered from COVID-19, using 2-D left ventricular-global longitudinal strain (LV-GLS) proven to be capable of detecting subclinical myocardial injury. Out of 305 COVID-19 positive patients, 70 asymptomatic out-patients were determined as the study group and 70 age and sex-matched healthy adults as the control group. The echocardiographic examination was performed with the Philips IE33 system, and LV-GLS was measured using commercially available software QLAB 9 (cardiac motion quantification; Philips Medical Systems). The absolute value of LV-GLS ≤ 18 did deem to be impaired LV-GLS. The absolute value of LV-GLS was statistically significantly lower in the COVID-19 group than in healthy controls (19.17 ± 2.65 vs. 20.07 ± 2.19, p = 0.03). The correlation between having recovered from COVID-19 and impaired LV-GLS (≤18) did detect with the Pearson correlation test (p = 0.02). Having recovered from COVID-19 was found as a predictor for detecting impaired LV-GLS (≤18) in the multivariable logistic regression analysis (odds ratio, 0.133 (0.038-0.461); 95% CI, p = 0.001). This study suggests that COVID-19 may cause subclinical LV dysfunction detected by LV-GLS during early recovery even in a population of patients at low cardiac risk, asymptomatic, and recovered with home quarantine. The study findings indicate that the long-term cardiovascular follow-up of these patients may be more important than thought.

Anderson-fabry disease: role of traditional and new cardiac MRI techniques

Anderson-Fabry (FD) disease is a rare X-linked disorder caused by different mutations in the Galactosidase α (GLA) gene, which leads to α-galactosidase A enzyme deficiency and the storage of glycosphingolipids in different kinds of organs, included the heart. This results in myocardial inflammation and left ventricular hypertrophy (LVH) and fibrosis. Echocardiography and cardiac magnetic resonance (C-MRI), in particular with new techniques, such as mapping analysis, late gadolinium enhancement (LGE) assessment and strain imaging, are important tools that allow a correct diagnosis, discriminating FD from other hypertrophic heart conditions. C-MRI is able to detect tissue alterations in the early stages of the disease, when an appropriate treatment could be more effective, and it has a fundamental role in monitoring therapy.

Cardiac Imaging in Anderson-Fabry Disease: Past, Present and Future

Anderson-Fabrydisease is an X-linked lysosomal storage disorder caused by a deficiency in the lysosomal enzyme α-galactosidase A. This results in pathological accumulation of glycosphingolipids in several tissues and multi-organ progressive dysfunction. The typical clinical phenotype of Anderson-Fabry cardiomyopathy is progressive hypertrophic cardiomyopathy associated with rhythm and conduction disturbances. Cardiac imaging plays a key role in the evaluation and management of Anderson-Fabry disease patients. The present review highlights the value and perspectives of standard and advanced cardiovascular imaging in Anderson-Fabry disease.

Fabry Disease and the Heart: A Comprehensive Review

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations of the GLA gene that result in a deficiency of the enzymatic activity of α-galactosidase A and consequent accumulation of glycosphingolipids in body fluids and lysosomes of the cells throughout the body. GB3 accumulation occurs in virtually all cardiac cells (cardiomyocytes, conduction system cells, fibroblasts, and endothelial and smooth muscle vascular cells), ultimately leading to ventricular hypertrophy and fibrosis, heart failure, valve disease, angina, dysrhythmias, cardiac conduction abnormalities, and sudden death. Despite available therapies and supportive treatment, cardiac involvement carries a major prognostic impact, representing the main cause of death in FD. In the last years, knowledge has substantially evolved on the pathophysiological mechanisms leading to cardiac damage, the natural history of cardiac manifestations, the late-onset phenotypes with predominant cardiac involvement, the early markers of cardiac damage, the role of multimodality cardiac imaging on the diagnosis, management and follow-up of Fabry patients, and the cardiac efficacy of available therapies. Herein, we provide a comprehensive and integrated review on the cardiac involvement of FD, at the pathophysiological, anatomopathological, laboratory, imaging, and clinical levels, as well as on the diagnosis and management of cardiac manifestations, their supportive treatment, and the cardiac efficacy of specific therapies, such as enzyme replacement therapy and migalastat.

Hybrid positron emission tomography-magnetic resonance imaging for assessing different stages of cardiac impairment in patients with Anderson-Fabry disease: AFFINITY study group

AIMS

Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder associated with multi-organ dysfunction. While native myocardial T1 mapping by magnetic resonance (MR) allow non-invasive measurement of myocyte sphingolipid accumulation, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and MR are able to identify different pathological patterns of disease progression. We investigated the relationship between T1 mapping and 18F-FDG uptake by hybrid PET-MR cardiac imaging in AFD female patients.

METHODS AND RESULTS

Twenty AFD females without cardiac symptoms underwent cardiac PET-MR using 18F-FDG for glucose uptake. In all patients and in seven age- and sex-matched control subjects, T1 mapping was performed using native T1 Modified Look-Locker Inversion-recovery prototype sequences. 18F-FDG myocardial uptake was quantified by measuring the coefficient of variation (COV) of the standardized uptake value using a 17-segment model. T1 values of AFD patients were lower compared with control subjects (1236 ± 49 ms vs. 1334 ± 27 ms, P < 0.0001). Focal 18F-FDG uptake with COV >0.17 was detected in seven patients. COV was 0.32 ± 0.1 in patients with focal 18F-FDG uptake and 0.12 ± 0.04 in those without (P < 0.001). Patients with COV >0.17 had higher T1 values of lateral segments of the mid ventricular wall, compared with those with COV ≤0.17 (1216 ± 22 ms vs. 1160 ± 59 ms, P < 0.05).

CONCLUSION

In females with AFD, focal 18F-FDG uptake with a trend towards a pseudo-normalization of abnormal T1 mapping values, may represent an intermediate stage before the development of myocardial fibrosis. These findings suggest a potential relationship between progressive myocyte sphingolipid accumulation and inflammation.

Different Phenotypes of Anderson-Fabry Disease Identified with Cardiac Magnetic Resonance Imaging in a Family with the Same Late-Onset Mutation

Case series

Patients: Male, 60-year-old • Male, 58-year-old • Female, 28-year-old

Final Diagnosis: Late-onset Anderson Fabry disease

Symptoms: Left ventricular hypertrophy

Medication: —

Clinical Procedure: Cardiac magnetic resonance imaging

Specialty: Cardiology

Cardiovascular Magnetic Resonance of Myocardial Fibrosis, Edema, and Infiltrates in Heart Failure

Cardiac magnetic resonance (CMR) imaging is a unique imaging modality, which provides accurate noninvasive tissue characterization. Various CMR sequences can be utilized to identify and quantify patterns of myocardial edema, fibrosis, and infiltrates, which are important determinants for diagnosis and prognostication of heart failure. This article describes available methods of tissue characterization imaging applied in CMR. The presence and patterns of abnormal tissue characterization are related to common etiologies of heart failure and the techniques employed to demonstrate this. CMR provides the opportunity to identify the etiology of heart failure based on the recognition of different patterns of myocardial abnormalities.

Role of CMR Mapping Techniques in Cardiac Hypertrophic Phenotype

Non-ischemic cardiomyopathies represent a heterogeneous group of myocardial diseases potentially leading to heart failure, life-threatening arrhythmias, and eventually death. Myocardial dysfunction is associated with different underlying pathological processes, ultimately inducing changes in morphological appearance. Thus, classification based on presenting morphological phenotypes has been proposed, i.e., dilated, hypertrophic, restrictive, and right ventricular cardiomyopathies. In light of the key diagnostic and prognostic role of morphological and functional features, cardiovascular imaging has emerged as key element in the clinical workflow of suspected cardiomyopathies, and above all, cardiovascular magnetic resonance (CMR) represents the ideal technique to be used: thanks to its physical principles, besides optimal spatial and temporal resolutions, incomparable contrast resolution allows to assess myocardial tissue abnormalities in detail. Traditionally, weighted images and late enhancement images after gadolinium-based contrast agent administration have been used to perform tissue characterization, but in the last decade quantitative assessment of pre-contrast longitudinal relaxation time (native T1), post-contrast longitudinal relaxation time (post-contrast T1) and transversal relaxation time (T2), all displayed with dedicated pixel-wise color-coded maps (mapping), has contributed to give precious knowledge insight, with positive influence of diagnostic accuracy and prognosis assessment, mostly in the setting of the hypertrophic phenotype. This review aims to describe the available evidence of the role of mapping techniques in the assessment of hypertrophic phenotype, and to suggest their integration in the routine CMR evaluation of newly diagnosed cardiomyopathies with increased wall thickness.

Prominent Longitudinal Strain Reduction of Basal Left Ventricular Segments in Patients With Coronavirus Disease-19

BACKGROUND

Coronavirus disease-19 (COVID-19) has been associated with overt and subclinical myocardial dysfunction. We observed a recurring pattern of reduced basal left ventricular (LV) longitudinal strain on speckle-tracking echocardiography in hospitalized patients with COVID-19 and subsequently aimed to identify characteristics of affected patients. We hypothesized that patients with COVID-19 with reduced basal LV strain would demonstrate elevated cardiac biomarkers.

METHODS AND RESULT

Eighty-one consecutive patients with COVID-19 underwent speckle-tracking echocardiography. Those with poor quality speckle-tracking echocardiography (n = 2) or a known LV ejection fraction of <50% (n = 4) were excluded. Patients with an absolute value basal longitudinal strain of <13.9% (2 standard deviations below normal) were designated as cases (n = 39); those with a basal longitudinal strain of ≥13.9% were designated as controls (n = 36). Demographics and clinical variables were compared. Of 75 included patients (mean age 62 ± 14 years, 41% women), 52% had reduced basal strain. Cases had higher body mass index (median 34.1; interquartile range 26.5-37.9 kg/m² vs median 26.9, interquartile range, 24.8-30.0 kg/m², P = .009), and greater proportions of Black (74% vs 36%, P = .0009), hypertensive (79% vs 56%, P = .026), and diabetic patients (44% vs 19%, P = .025) compared with controls. Troponin and N-terminal pro-brain natriuretic peptide levels trended higher in cases, but were not significantly different.

CONCLUSIONS

Reduced basal LV strain is common in patients with COVID-19. Patients with hypertension, diabetes, obesity, and Black race were more likely to have reduced basal strain. Further investigation into the significance of this strain pattern is warranted.

Clinical Significance of Papillary Muscles on Left Ventricular Mass Quantification Using Cardiac Magnetic Resonance Imaging: Reproducibility and Prognostic Value in Fabry Disease

PURPOSE

Accurate and reproducible assessment of left ventricular mass (LVM) is important in Fabry disease. However, it is unclear whether papillary muscles should be included in LVM assessed by cardiac magnetic resonance imaging (MRI). The purpose of this study was to evaluate the reproducibility and predictive value of LVM in patients with Fabry disease using different analysis approaches.

MATERIALS AND METHODS

A total of 92 patients (44±15 y, 61 women) with confirmed Fabry disease who had undergone cardiac MRI at a single tertiary referral hospital were included in this retrospective study. LVM was assessed at end-diastole using 2 analysis approaches, including and excluding papillary muscles. Adverse cardiac events were assessed as a composite end point, defined as ventricular tachycardia, bradycardia requiring device implantation, severe heart failure, and cardiac death. Statistical analysis included Cox proportional hazard models, Akaike information criterion, intraclass correlation coefficients, and Bland-Altman analysis.

RESULTS

Left ventricular end-diastolic volume, end-systolic volume, ejection fraction, and LVM all differed significantly between analysis approaches. LVM was significantly higher when papillary muscles were included versus excluded (157±71 vs. 141±62 g, P<0.001). Mean papillary mass was 16±11 g, accounting for 10%±3% of total LVM. LVM with pap illary muscles excluded had slightly better predictive value for the composite end point compared with LVM with papillary muscles included based on the model goodness-of-fit (Akaike information criterion 140 vs. 142). Interobserver agreement was slightly better for LVM with papillary muscles excluded compared with included (intraclass correlation coefficient 0.993 [95% confidence interval: 0.985, 0.996] vs. 0.989 [95% confidence interval: 0.975, 0.995]) with less bias and narrower limits of agreement.

CONCLUSIONS

Inclusion or exclusion of papillary muscles has a significant effect on LVM quantified by cardiac MRI, and therefore, a standardized analysis approach should be used for follow-up. Exclusion of papillary muscles from LVM is a reasonable approach in patients with Fabry disease given slightly better predictive value and reproducibility.

An expert consensus document on the management of cardiovascular manifestations of Fabry disease

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by pathogenic variants in the α-galactosidase A (GLA) gene that leads to reduced or undetectable α-galactosidase A enzyme activity and progressive accumulation of globotriaosylceramide and its deacylated form globotriaosylsphingosine in cells throughout the body. FD can be multisystemic with neurological, renal, cutaneous and cardiac involvement or be limited to the heart. Cardiac involvement is characterized by progressive cardiac hypertrophy, fibrosis, arrhythmias, heart failure and sudden cardiac death. The cardiac management of FD requires specific measures including enzyme replacement therapy or small pharmacological chaperones in patients carrying amenable pathogenic GLA gene variants and more general management of cardiac symptoms and complications. In this paper, we summarize current knowledge of FD-related heart disease and expert consensus recommendations for its management.

Increased Spread of Native T1 Values Assessed With MRI as a Marker of Cardiac Involvement in Fabry Disease

OBJECTIVE. Cardiac involvement is the leading cause of mortality in Fabry disease. Noninvasive markers of cardiac involvement are needed to identify patients at high risk. The purpose of this study was to evaluate the diagnostic potential of segmental native T1 spread as an imaging biomarker in Fabry disease. SUBJECTS AND METHODS. In this prospective study, 43 patients with confirmed Fabry disease (mean ± SD age, 46±14 years; 70% women) and 17 healthy control subjects (mean ± SD age, 44 ±13 years; 53% women) underwent 3-T cardiac MRI including modified Look-Locker inversion recovery T1 mapping. Segmental native T1 spread was calculated as the difference between maximum and minimum segmental native T1 values, expressed as an absolute value and as a relative percentage of global native T1. RESULTS. Absolute and relative segmental native T1 spreads were significantly higher in patients with Fabry disease than in healthy control subjects (absolute median, 115 vs 98 ms [p = 0.004]; relative median, 9.9% vs 8.0% [p < 0.001]) and correlated positively with quantitative late gadolinium enhancement (absolute, r = 0.434, p < 0.001; relative, r = 0.436, p < 0.001), indexed left ventricular mass (absolute, r = 0.316, p = 0.01; relative, r = 0.347, p = 0.007), and global longitudinal strain (absolute, r = 0.289, p = 0.03; relative, r = 0.277, p = 0.03). Relative segmental native T1 spread differentiated patients with Fabry disease from healthy control subjects (odds ratio, 1.44 [95% CI, 1.10-1.89]; p = 0.009). Interob-server agreement was excellent for both absolute (intraclass correlation coefficient, 0.932) and relative (intraclass correlation coefficient, 0.926) segmental native T1 spread. CONCLUSION. Increased native T1 spread is a reproducible imaging biomarker of cardiac involvement in Fabry disease and may be particularly useful in the evaluation of patients who cannot undergo late gadolinium enhancement imaging.

Predictors of Fabry disease in patients with hypertrophic cardiomyopathy: How to guide the diagnostic strategy?

BACKGROUND

Fabry disease (FD) is a treatable cause of hypertrophic cardiomyopathy (HCM). We aimed to determine the independent predictors of FD and to define a clinically useful strategy to discriminate FD among HCM.

METHODS

Multicenter study including 780 patients with the ESC definition of HCM. FD screening was performed by enzymatic assay in males and genetic testing in females. Multivariate regression analysis identified independent predictors of FD in HCM. A discriminant function analysis defined a score based on the weighted combination of these predictors.

RESULTS

FD was found in 37 of 780 patients with HCM (4.7%): 31 with p.F113L mutation due to a founder effect; and 6 with other variants (p.C94S; p.M96V; p.G183V; p.E203X; p.M290I; p.R356Q/p.G360R). FD prevalence in HCM adjusted for the founder effect was 0.9%. Symmetric HCM (OR 3.464, CI95% 1.151-10.430), basal inferolateral late gadolinium enhancement (LGE) (OR 10.677, CI95% 3.633-31.380), bifascicular block (OR 10.909, CI95% 2.377-50.059) and ST-segment depression (OR 4.401, CI95% 1.431-13.533) were independent predictors of FD in HCM. The score ID FABRY-HCM [-0.729 + (2.781xBifascicular block) + (0.590xST depression) + (0.831xSymmetric HCM) + (2.130xbasal inferolateral LGE)] had a negative predictive value of 95.8% for FD, with a cut-off of 1.0, meaning that, in the absence of both bifascicular block and basal inferolateral LGE, FD is a less probable cause of HCM, being more appropriate to perform HCM gene panel than targeted FD screening.

CONCLUSION

FD prevalence in HCM was 0.9%. Bifascicular block and basal inferolateral LGE were the most powerful predictors of FD in HCM. In their absence, HCM gene panel is the most appropriate step in etiological study of HCM.

Left Ventricular Mass and Wall Thickness Measurements Using Echocardiography and Cardiac MRI in Patients with Fabry Disease: Clinical Significance of Discrepant Findings

Purpose

To compare transthoracic echocardiography (TTE) and cardiac MRI measurements of left ventricular mass (LVM) and maximum wall thickness (MWT) in patients with Fabry disease and evaluate the clinical significance of discrepancies between modalities.

Materials and Methods

Seventy-eight patients with Fabry disease (mean age, 46 years ± 14 [standard deviation]; 63% female) who underwent TTE and cardiac MRI within a 6-month interval between 2008 and 2018 were included in this retrospective cohort study. The clinical significance of measurement discrepancies was evaluated with respect to diagnosis of left ventricular hypertrophy (LVH), eligibility for disease-specific therapy, and prognosis. Statistical analysis included paired-sample t test, Cox proportional hazard models, Akaike information criterion (AIC), and intraclass correlation coefficients.

Results

LVM indexed to body surface area (LVMI) and MWT were significantly higher at TTE compared with MRI (105 g/m² ± 48 vs 78 g/m² ± 36, P < .001 and 14 mm ± 4 vs 13 mm ± 5, P = .008, respectively). LVH classification was discordant between modalities in 23 patients (29%) (P < .001). Eligibility for disease-specific therapy based on MWT was discordant between modalities in 20 patients (26%) (P < .001). LVMI assessed with MRI was a better predictor of the combined endpoint compared with LVMI assessed with TTE (AIC, 127 vs 131). Interobserver agreement for LVMI and MWT was higher for MRI (intraclass correlation coefficient, 0.951 and 0.912, respectively) compared with TTE (intraclass correlation coefficient, 0.940 and 0.871; respectively).

Conclusion

TTE overestimates LVM and MWT and has lower reproducibility compared with cardiac MRI in Fabry disease. Measurement discrepancies between modalities are clinically significant with respect to diagnosis of LVH, prognosis, and treatment decisions.© RSNA, 2020.

The use of cardiovascular magnetic resonance for the assessment of left ventricular hypertrophy

Cardiovascular magnetic resonance (CMR) is a powerful tool to assess and diagnose the cause of left ventricular hypertrophy (LVH). This review provides an overview of the typical CMR findings in the various causes of LVH, focusing mainly on late gadolinium enhancement (LGE) imaging. It will also cover the more novel techniques of T1 mapping, extracellular volume (ECV) fraction estimation and diffusion tensor imaging (DTI) and their role in the imaging assessment of LVH.

Late-Onset Fabry Disease Presenting With Ventricular Tachycardia Originating From Typical Inferolateral Scar

Late-onset cardiac Fabry disease is not uncommon among patients with unexplained left ventricular hypertrophy. Despite a less severe phenotype, life-threatening complications are possible in late-onset cardiac Fabry and may be the first presentation of the disease. Classical imaging features support the diagnosis; however, the presence of less common findings, such as ischemic features, should not lead to overlooking the diagnosis. Indeed, the coexistence of Fabry and ischemic heart disease is possible, even in the absence of obstructive coronary artery disease. Therefore, a high level of suspicion should be maintained, even in the presence of atypical presentations.

Characterization of Fabry Disease cardiac involvement according to longitudinal strain, cardiometabolic exercise test, and T1 mapping

In Anderson-Fabry disease (FD), we sought to evaluate relation between left ventricular (LV) hypertrophy, longitudinal strain (LS), myocardial T1 mapping and cardiopulmonary exercise parameters, and their prognostic value in term of cardiovascular outcomes. In this prospective, observational, monocentric study called "FABRY-Image", we evaluated consecutive adult FD patients by echocardiography, cardiac magnetic resonance, and cardiopulmonary exercise testing. We investigated regional LS, the relations between LV hypertrophy, LS, T1 mapping, and VO2 peak and VE/VCO2, and the prediction of cardiovascular events during follow-up. From 2016 to 2019, we included 35 FD patients (44 ± 17 years, 40% male), that were compared with 20 controls. In FD patients, global, basal and mid-LV LS, as well as mean T1 were significantly altered compared to controls (p < 0.05) with relative apical LS sparing. LV wall thickness was particularly related to mean of basal LS (r =  - 0.73), to T1 (r =  - 0.48), and to VE/VCO2 (r = 0.45). Mean of basal LS was well related to myocardial T1 (r = 0.59). A good relation was observed between VO2 peak and global LS (r = 0.39) while VE/VCO2 slope was more related to maximal LV wall thickness (r = 0.45), and T1 (r =  - 0.61). During a median follow-up of 2.4 years, 6/31 patients presented de novo atrial fibrillation or stroke. In Cox univariate analyses, LV wall thickness, basal LS, T1 value, and VE/VCO2 were significantly predictive of occurrence of de novo atrial fibrillation or stroke (p < 0.05). Our study shows an apical LS sparing in FD patients as observed in amyloidosis, and a close relation between LV hypertrophy, LS, T1 mapping, and VE/VCO2 which are all associated to the occurrence of de novo atrial fibrillation or TIA/stroke during follow-up. These results need to be confirmed by future multicentric studies.

Genetic Testing for Diagnosis of Hypertrophic Cardiomyopathy Mimics

Background

Genetic testing is helpful for diagnosis of hypertrophic cardiomyopathy (HCM) mimics. Little data are available regarding the yield of such testing and its clinical impact.

Methods

The HCM genetic database at our center was used for identification of patients who underwent HCM-directed genetic testing including at least 1 gene associated with an HCM mimic ( GLA , TTR , PRKAG2 , LAMP2 , PTPN11 , RAF1 , and DES ). Charts were retrospectively reviewed and genetic and clinical data extracted.

Results

There were 1731 unrelated HCM patients who underwent genetic testing for at least 1 gene related to an HCM mimic. In 1.45% of cases, a pathogenic or likely pathogenic variant in one of these genes was identified. This included a yield of 1% for Fabry disease, 0.3% for familial amyloidosis, 0.15% for PRKAG2 -related cardiomyopathy, and 1 patient with Noonan syndrome. In the majority of patients, diagnosis of the HCM mimic based on clinical findings alone would have been challenging. Accurate diagnosis of an HCM mimic led to change in management (eg, enzyme replacement therapy) or family screening in all cases.

Conclusions

Genetic testing is helpful in the diagnosis of HCM mimics in patients with no or few extracardiac manifestations. Adding these genes to all HCM genetic panels should be considered.

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.