Comparative analysis of right ventricular strain in Fabry cardiomyopathy and sarcomeric hypertrophic cardiomyopathy

Left atrial structural and functional remodelling in Fabry disease and cardiac amyloidosis: A comparative analysis

BACKGROUND

Fabry disease (FD) and transthyretin cardiac amyloidosis (TTR CA) are cardiomyopathies with hypertrophic phenotype that share several features, including left atrial (LA) enlargement and dysfunction, but direct comparative data are lacking. Aim of the present study was to perform a comparative analysis of LA remodelling between the two diseases.

METHODS AND RESULTS

In this prospective study, a total of 114 patients (31 FD and 83 TTR CA) were included; all of them had left ventricular hypertrophy (LVH), defined as left ventricular (LV) wall thickness ≥ 12 mm. Despite similar degree of LVH, patients with TTR CA showed worse LV systolic and diastolic function. LA maximal volume index was not significantly different between the two groups (p = 0.084), while patients with TTR CA showed larger LA minimal volume index (p = 0.001). Moreover, all phases of LA mechanics were more impaired in the TTR CA group vs FD (reservoir: 6.9[4.2-15.5] vs 19.0[15.5-29.5], p < 0.001). After excluding patients with atrial fibrillation (AF), these differences remained clearly significant. In multivariable regression analyses, LA reservoir strain showed an independent correlation with TTR CA, controlling for demographic characteristics, AF and LV systolic and diastolic performance (p ≤ 0.001), whereas LV global longitudinal strain did not. Finally, among echocardiographic parameters, LA function demonstrated the highest accuracy in discriminating the two diseases.

CONCLUSIONS

TTR CA is characterized by a more advanced LA structural and functional remodelling in comparison to patients with FD and similar degree of LVH. The association between TTR CA and LA dysfunction remains consistent after adjustment for potential confounders.

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.

Right heart and left atrial strain to differentiate cardiac amyloidosis and Fabry disease

Echocardiographic differentiation of cardiac amyloidosis (CA) and Fabry disease (FD) is often challenging using standard echocardiographic parameters. We retrospectively analyzed the diagnostic accuracy of right heart and left atrial strain parameters to discriminate CA from FD using receiver operating characteristic curve analyses and logistic regression models. A total of 47 FD and 88 CA patients with left ventricular wall thickening were analyzed. The comparison of both cardiomyopathies revealed significantly reduced global and free wall longitudinal right ventricular strain (RVS; global RVS: CA - 13 ± 4%, n = 67, vs. FD - 18 ± 4%, n = 39, p < 0.001) as well as right atrial strain (RAS; reservoir RAS: CA 12 ± 8%, n = 70, vs. FD 26 ± 9%, n = 40, p < 0.001) and left atrial strain (LAS) in CA patients. Individually, global RVS as well as phasic LAS and RAS showed the highest diagnostic accuracy to distinguish CA and FD. The best diagnostic accuracy was achieved by combining the age, basal RV diameter, global RVS, and reservoir and conduit RAS (area under the curve 0.96 [95% CI 0.90-1.00]). Differential echocardiographic diagnostic work-up of patients with suspected CA or FD can be improved by integrating structural and functional parameters of the right heart and the left atrium.Trial registration: DRKS00027403.

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.

Diagnosis and management of patients with left ventricular hypertrophy: Role of multimodality cardiac imaging. A scientific statement of the Heart Failure Association of the European Society of Cardiology

Left ventricular (LV) hypertrophy consists in an increased LV wall thickness. LV hypertrophy can be either secondary, in response to pressure or volume overload, or primary, i.e. not explained solely by abnormal loading conditions. Primary LV hypertrophy may be due to gene mutations or to the deposition or storage of abnormal substances in the extracellular spaces or within the cardiomyocytes (more appropriately defined as pseudohypertrophy). LV hypertrophy is often a precursor to subsequent development of heart failure. Cardiovascular imaging plays a key role in the assessment of LV hypertrophy. Echocardiography, the first-line imaging technique, allows a comprehensive assessment of LV systolic and diastolic function. Cardiovascular magnetic resonance provides added value as it measures accurately LV and right ventricular volumes and mass and characterizes myocardial tissue properties, which may provide important clues to the final diagnosis. Additionally, scintigraphy with bone tracers is included in the diagnostic algorithm of cardiac amyloidosis. Once the diagnosis is established, imaging findings may help predict future disease evolution and inform therapy and follow-up. This consensus document by the Heart Failure Association of the European Society of Cardiology provides an overview of the role of different cardiac imaging techniques for the differential diagnosis and management of patients with LV hypertrophy.

Right Ventricular Myocardial Involvement in Anderson-Fabry Disease at Diagnosis: Evaluation with Three-Dimensional Strain Imaging

Background: Right ventricular (RV) involvement in Anderson-Fabry disease (AFD) is well known in the advanced stages of the disease RV hypertrophies, but little is known about the early involvement. The aim of our study was to assess RV function in AFD patients at diagnosis. Methods: A total of 23 AFD patients and 15 controls comparable for age and sex were recruited. A complete 2D standard echo with 3D volumetric and strain analysis of RV was performed. Results: Two patient populations, comparable for clinical baseline characteristics were considered. RV free wall thickness was significantly increased in the AFD group. No significant differences in standard RV indices (TAPSE, transverse diameter, tissue Doppler velocities of the lateral tricuspid annulus) were found. A 3D volumetric analysis showed reduced RV ejection fraction and lower values of longitudinal septal, free wall and global longitudinal strain (GLS) in AFD patients. RV free wall thickness significantly correlated with both free wall RV LS and RV GLS. In multiple linear regression analysis, RV free wall thickness was independently associated with RV GLS even after correction for age and heart rate. Conclusions: In AFD patients, 3D echocardiography allows for the identification of early subclinical functional impairment of RV. RV dysfunction is independently associated with RV hypertrophy.

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.

Right ventricular strain in Fabry disease: Prognostic implications

INTRODUCTION

Left ventricular (LV) hypertrophy is the main feature of cardiac involvement in Anderson-Fabry disease (FD), but the right ventricle (RV) is also frequently affected. Previous studies failed to demonstrate an independent association between conventional parameters of RV performance and outcomes in FD. Nevertheless, if RV free wall strain (RV-FWS), assessed by 2D speckle tracking analysis, may provide a better prognostication is currently unknown.

METHODS

We retrospectively evaluated the association between RV-FWS and the occurrence of cardiovascular events in a cohort of 56 patients with FD. The study endpoint comprises cardiovascular mortality, severe heart failure symptoms, new-onset atrial fibrillation and major arrhythmias requiring device implantation.

RESULTS

Reduced RV-FWS, defined by values lower than 23%, was found in 25 (45%) patients. During a median follow-up of 47 months, 16 (29%) patients met the study endpoint. A ROC-curve analysis confirmed the threshold of reduced RV-FWS (<23%) as the best cut-off for predicting cardiovascular events, but with a lower power compared to left-sided parameters. On univariable Cox regression analysis, RV-FWS, expressed as continuous variable, was significantly associated with the study endpoint (HR: 0.795, 95% CI: 0.710-0.889, p < 0.001). However, RV-FWS did not retain a significant association with outcomes, after adjustment for LV global longitudinal strain or indexed left atrial volume (p = 0.340 and p = 0.289 respectively).

CONCLUSIONS

RV-FWS was not independently associated with the occurrence of cardiovascular events in FD, confirming previous observations that prognosis is mainly driven by the severity of LV cardiomyopathy.

Multimodality Imaging in Sarcomeric Hypertrophic Cardiomyopathy: Get It Right…on Time

Hypertrophic cardiomyopathy (HCM) follows highly variable paradigms and disease-specific patterns of progression towards heart failure, arrhythmias and sudden cardiac death. Therefore, a generalized standard approach, shared with other cardiomyopathies, can be misleading in this setting. A multimodality imaging approach facilitates differential diagnosis of phenocopies and improves clinical and therapeutic management of the disease. However, only a profound knowledge of the progression patterns, including clinical features and imaging data, enables an appropriate use of all these resources in clinical practice. Combinations of various imaging tools and novel techniques of artificial intelligence have a potentially relevant role in diagnosis, clinical management and definition of prognosis. Nonetheless, several barriers persist such as unclear appropriate timing of imaging or universal standardization of measures and normal reference limits. This review provides an overview of the current knowledge on multimodality imaging and potentialities of novel tools, including artificial intelligence, in the management of patients with sarcomeric HCM, highlighting the importance of specific "red alerts" to understand the phenotype-genotype linkage.