Multimodality Imaging in Cardiomyopathies with Hypertrophic Phenotypes

Hypertrophic Cardiomyopathy with Special Focus on Mavacamten and Its Future in Cardiology

Hypertrophic cardiomyopathy (HCM) is a heterogeneous group of heart muscle disorders that affects millions, with an incidence from 1 in 500 to 1 in 200. Factors such as genetics, age, gender, comorbidities, and environmental factors may contribute to the course of this disease. Diagnosis of HCM has improved significantly in the past few decades from simple echocardiographic evaluations to a more complex, multimodal approach embracing advanced imaging, genetic, and biomarker studies. This review focuses on Mavacamten, a selective allosteric inhibitor of cardiac myosin, as a pharmacological treatment for HCM. Patients with HCM experience pathological actomyosin interactions, leading to impaired relaxation and increased energy expenditure. Mavacamten decreases available myosin heads, reducing actomyosin cross-bridges during systole and diastole. By reducing the number of bridges left ventricular outflow tract pressure is normalized and cardiac cavities are filled. This mechanism enhances patient performance and alleviates symptoms such as chest pain and dyspnea. The results suggest the potential for Mavacamten to transform the treatment of obstructive hypertrophic cardiomyopathy. Studies to date have shown significant improvement in exercise capacity, symptom relief, and a reduction in the need for invasive procedures such as septal myectomy. Further studies are needed to confirm the clinical results.

Physical exercise in hypertensive heart disease: From the differential diagnosis to the complementary role of exercise

Arterial hypertension (AH) is one of the most common pathologic conditions and uncontrolled AH is a leading risk factor for cardiovascular disease and mortality. AH chronically causes myocardial and arterial remodelling with hemodynamic changes affecting the heart and other organs, with potentially irreversible consequences leading to poor outcomes. Therefore, a proper and early treatment of AH is crucial after the diagnosis. Beyond medical treatment, physical exercise also plays a therapeutic role in reducing blood pressure, given its potential effects on sympathetic tone, renin-angiotensin-aldosterone system, and endothelial function. International scientific societies recommend physical exercise among lifestyle modifications to treat AH in the first stages of the disease. Moreover, some studies have also shown its usefulness in addition to drugs to reduce blood pressure further. Therefore, an accurate, personalized exercise prescription is recommended to optimize the prevention and treatment of hypertension. On the other hand, uncontrolled AH in athletes requires proper risk stratification and careful evaluation to practice competitive sports safely. Moreover, the differential diagnosis between hypertensive heart disease and athlete's heart is sometimes challenging and requires a careful and comprehensive interpretation in order not to misinterpret the clinical findings. The present review aims to discuss the relationship between hypertensive heart disease and physical exercise, from diagnostic tools to prevention and treatment strategies.

Left ventricular hypertrophy: do not forget Fabry disease. Diagnostic work-up and differential diagnosis

BACKGROUND

Left ventricular (LV) hypertrophy is a common clinical finding. Differential diagnosis includes Fabry disease, a rare and progressive, but treatable storage disease caused by deficiency of α-galactosidase A. However, diagnosis of Fabry is often hampered by its clinical heterogeneity, LV hypertrophy phenocopies and unawareness of the clinician.

METHODS

This review summarises clinical data, family history, electrocardiogram (ECG) and imaging (echocardiogram and cardiovascular magnetic resonance (CMR)) characteristics to differentiate aetiologies of LV hypertrophy including clues for the diagnosis of Fabry.

RESULTS

LV hypertrophy is a consequence of pressure overload mostly, but differential diagnosis includes hypertrophic cardiomyopathy and infiltrative diseases. Clinical data, ECG, type and degree of LV hypertrophy, functional and tissue characteristics differ among aetiologies. LV hypertrophy in Fabry is progressive and mostly concentric but may copy any hypertrophic cardiomyopathy. Dependent on residual alfa-galactosidase A enzyme activity, degree of LV hypertrophy in Fabry may vary. Initially, low myocardial CMR T1-map values are calculated. At a later stage, midwall late gadolinium enhancement of the inferolateral LV wall may occur. Global longitudinal strain may be depressed in the inferolateral wall. Voltage criteria for LV hypertrophy and short PQ interval are common. Right ventricular (RV) hypertrophy is frequent. In addition, multisystemic symptoms including neuropathic pain, hypohidrosis, proteinuria, renal insufficiency and familial young stroke are pointing to Fabry.

CONCLUSIONS

LV hypertrophy should raise suspicion of Fabry disease, especially if LV hypertrophy is unexplained and/or associated with RV hypertrophy. In Fabry, LV hypertrophy may be heterogeneous and mimic any hypertrophic cardiomyopathy. ECG, multisystemic symptoms and imaging may provide clues for Fabry.

Advances in Multi-Modality Imaging in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by abnormal growth of the myocardium with myofilament disarray and myocardial hyper-contractility, leading to left ventricular hypertrophy and fibrosis. Where culprit genes are identified, they typically relate to cardiomyocyte sarcomere structure and function. Multi-modality imaging plays a crucial role in the diagnosis, monitoring, and risk stratification of HCM, as well as in screening those at risk. Following the recent publication of the first European Society of Cardiology (ESC) cardiomyopathy guidelines, we build on previous reviews and explore the roles of electrocardiography, echocardiography, cardiac magnetic resonance (CMR), cardiac computed tomography (CT), and nuclear imaging. We examine each modality's strengths along with their limitations in turn, and discuss how they can be used in isolation, or in combination, to facilitate a personalized approach to patient care, as well as providing key information and robust safety and efficacy evidence within new areas of research.

An Overview of Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) is a myocardial disorder that is characterised by structural and functional abnormalities of the heart muscle in the absence of hypertension, valvular heart disease, congenital heart defects, or coronary artery disease (CAD). After witnessing a particular form of cardiomyopathy in diabetic individuals, Rubler et al. came up with the moniker diabetic cardiomyopathy in 1972. Four stages of DCM are documented, and the American College of Cardiology/American Heart Association Stage and New York Heart Association Class for HF have some overlap. Diabetes is linked to several distinct forms of heart failure. Around 40% of people with heart failure with preserved ejection fraction (HFpEF) have diabetes, which is thought to be closely associated with the pathophysiology of HFpEF. Diabetes and HF are uniquely associated in a bidirectional manner. When compared to the general population without diabetes, those with diabetes have a risk of heart failure that is up to four times higher. A biomarker is a trait that is reliably measured and assessed as a predictor of healthy biological activities, pathological processes, or pharmacologic responses to a clinical treatment. Several biomarker values have been discovered to be greater in patients with diabetes than in control subjects among those who have recently developed heart failure. Myocardial fibrosis and hypertrophy are the primary characteristics of DCM, and structural alterations in the diabetic myocardium are often examined by non-invasive, reliable, and reproducible procedures. An invasive method called endomyocardial biopsy (EMB) is most often used to diagnose many cardiac illnesses.

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.

Advanced echocardiography techniques (AETs) to assess left atrial structure and function in individuals with resistant hypertension

AIMS

Resistant hypertension (RH) is a challenging phenotype within the hypertension (HTN) spectrum, requiring careful assessment and follow-up. Evaluation of left atrial function may be clinically informative, but is usually neglected. Advanced Echocardiography Techniques (AETs), such as Strain Analysis and three-dimensional echocardiography (3D ECHO) may be useful complementary tools to assess atrial function in patients with RH.

METHODS AND RESULTS

Ninety-six eligible adult patients were categorized into three groups: resistant hypertensive (RH), controlled hypertensive (CH), and normotensive (N), and underwent AETs to identify morphofunctional changes in the left atrium (LA) across different HTN phenotypes. The LA reservoir strain was significantly lower among RH than in N and CH patients (p < .001). Accordingly, LA conduit strain showed a gradient through the groups: higher among N, followed by CH and RH patients (p = .015). LA contraction strain was higher among CH than in N and RH patients (p = .02). Maximum indexed, pre-A, and minimum atrial volumes obtained by 3D ECHO showed differences between N and the others (p < .001), but not between CH and RH. N patients showed a higher fraction of passive emptying of the LA than the others (p = .02), with no difference between CH and RH. Total emptying of the LA only differed between N and RH patients, while active emptying of the LA showed no difference between the groups (p = .82).

CONCLUSION

The left atrium may present early functional changes in response to HTN, which are detectable by AETs. AETs, especially S-LA, allowed to identify markers of atrial myocardial damage in both RH and CH patients.

Imaging cardiac hypertrophy in hypertrophic cardiomyopathy and its differential diagnosis

PURPOSE OF REVIEW

The aim of this study was to review imaging of myocardial hypertrophy in hypertrophic cardiomyopathy (HCM) and its phenocopies. The introduction of cardiac myosin inhibitors in HCM has emphasized the need for careful evaluation of the underlying cause of myocardial hypertrophy.

RECENT FINDINGS

Advances in imaging of myocardial hypertrophy have focused on improving precision, diagnosis, and predicting prognosis. From improved assessment of myocardial mass and function, to assessing myocardial fibrosis without the use of gadolinium, imaging continues to be the primary tool in understanding myocardial hypertrophy and its downstream effects. Advances in differentiating athlete's heart from HCM are noted, and the increasing rate of diagnosis in cardiac amyloidosis using noninvasive approaches is especially highlighted due to the implications on treatment approach. Finally, recent data on Fabry disease are shared as well as differentiating other phenocopies from HCM.

SUMMARY

Imaging hypertrophy in HCM and ruling out other phenocopies is central to the care of patients with HCM. This space will continue to rapidly evolve, as disease-modifying therapies are under investigation and being advanced to the clinic.

From the phenotype to precision medicine: an update on the cardiomyopathies diagnostic workflow

Cardiomyopathies are disease of the cardiac muscle largely due to genetic alterations of proteins with 'structural' or 'functional' roles within the cardiomyocyte, going from the regulation of contraction-relaxation, metabolic and energetic processes to ionic fluxes. Modifications occurring to these proteins are responsible, in the vast majority of cases, for the phenotypic manifestations of the disease, including hypertrophic, dilated, arrhythmogenic and restrictive cardiomyopathies. Secondary nonhereditary causes to be excluded include infections, toxicity from drugs or alcohol or medications, hormonal imbalance and so on. Obtaining a phenotypic definition and an etiological diagnosis is becoming increasingly relevant and feasible, thanks to the availability of new tailored treatments and the diagnostic advancements made particularly in the field of genetics. This is, for example, the case for transthyretin cardiac amyloidosis, Fabry disease or dilated cardiomyopathies due to laminopathies. For these diseases, specific medications have been developed, and a more tailored arrhythmic risk stratification guides the implantation of a defibrillator. In addition, new medications directly targeting the altered protein responsible for the phenotype are becoming available (including the myosin inhibitors mavacantem and aficamten, monoclonal antibodies against Ras-MAPK, genetic therapies for sarcoglycanopathies), thus making a precision medicine approach less unrealistic even in the field of cardiomyopathies. For these reasons, a contemporary approach to cardiomyopathies must consider diagnostic algorithms founded on the clinical suspicion of the disease and developed towards a more precise phenotypic definition and etiological diagnosis, based on a multidisciplinary methodology putting together specialists from different disciplines, facilities for advanced imaging testing and genetic and anatomopathological competencies.

Cardiomyopathy: A New Perspective from Diagnostic Strategy

Cardiomyopathy entails a broad group of diseases, acquired or genetic, which result in a similar phenotype [...].

Cardiac Multimodality Imaging in Hypertrophic Cardiomyopathy: What to Look for and When to Image

Hypertrophic cardiomyopathy (HCM), now recognized as a common cardiomyopathy of complex genomics and pathophysiology, is defined by the presence of left ventricular hypertrophy of various morphologies and severity, significant hemodynamic consequences, and diverse phenotypic, both structural and clinical, profiles. Advancements in cardiac multimodality imaging, including echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography, with and without angiography have greatly improved the diagnosis of HCM, and enable precise measurements of cardiac mass, volume, wall thickness, function, and physiology. Multimodality imaging provides comprehensive and complementary information and hasemerged as the bedrock for the diagnosis, clinical assessment, serial monitoring, and sudden cardiac death risk stratification of patients with HCM. This review highlights the role of cardiac multimodality imaging in the modern diagnosis and management of HCM.

The Changing Complementary Role of Multimodality Imaging in Clinical Cardiology

Over the past two decades, major technological developments and progress have been reached for all imaging modalities applied to clinical cardiology, from echocardiography to magnetic resonance, computed tomography, nuclear imaging, etc [...].

Alginate-Derivative Encapsulated Carbon Coated Manganese-Ferrite Nanodots for Multimodal Medical Imaging

Carbon-decorated ferrite nanodots (MNF@Cs) have been enhanced with superparamagnetism and higher fluorescence quantum yield by encapsulation with an alginate derivative to create a cost-effective and less toxic multimodal contrast agent for replacing the conventional heavy metal Gd-containing contrast agent used in MR imaging. The novel surface-engineered particles (MNF@C-OSAs), devoid of labels, can simultaneously provide both longitudinal and transverse relaxation-based magnetic resonance imaging (MRI) and fluorescence emission. According to the findings of in vitro studies, the calculated molar relaxivities and the molar radiant efficiencies are indicative of the multimodal efficacy of MNF@C-OSA as compared with MNF@C particles and conventional contrast agents used in medical imaging. MNF@C-OSAs were shown to be significantly biocompatible and negligibly toxic when assessed against A549 cells and zebrafish embryos, indicating their potential for use as theranostic agents.

An Overview of Molecular Mechanisms in Fabry Disease

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

Papillary and Trabecular Muscles Have Substantial Impact on Quantification of Left Ventricle in Patients with Hypertrophic Obstructive Cardiomyopathy

Patients with obstructive hypertrophic cardiomyopathy (HOCM) have large papillary and trabecular muscles (PTMs), which are myocardial tissue. PTMs are usually excluded from the myocardium and included in the left ventricular (LV) cavity when determining LV mass (LVM) and volumes using cardiac magnetic resonance (CMR). This conventional method may result in large distortion of LVM and other indices. We investigated 74 patients with HOCM undergoing CMR imaging. LV short-axis cine images were obtained. LV contours were drawn using two different methods: (1) the conventional method, where PTMs were included in the LV cavity; and (2) the mask method, which includes the TPMs in the LV myocardium. The LV end-diastolic volume (LV-EDV), LV end-systolic volume (LV-ESV), LV ejection fraction (LVEF), and the LVM were then calculated. Fasting NT-proBNP and CK-MB levels were measured with ELISA. In patients with HOCM, mass of PTMs (MOPTM) was 47.9 ± 18.7 g, which represented 26.9% of total LVM. Inclusion of PTMs with the mask method resulted in significantly greater LVM and LVM index (both p < 0.0001) in comparison with those measured with the conventional method. In addition, the mask method produced a significant decrease in LV-EDV and LV-ESV. LVEF was significantly increased with the mask method (64.3 ± 7.9% vs. 77.2 ± 7.1%, p < 0.0001). MOPTM was positively correlated with BMI, septal wall thickness, LVM, LV-EDV, and LV-ESV. LVEF was inversely correlated with MOPTM. In addition, MOPTM correlated positively with NT-proBNP (r = 0.265, p = 0.039) and CK-MB (r = 0.356, p = 0.002). In conclusion, inclusion of PTMs in the myocardium has a substantial impact on quantification of the LVM, LV-EDV, LV-ESV, and LVEF in patients with HOCM. The effects of the PTMs in women was greater than that in men. Furthermore, the MOPTM was positively associated with NT-proBNP and CK-MB. The PTMs might be included in the myocardium when measuring the LV volumes and mass of patients with HOCM. At present, the clinical and prognostic meaning and relevance of the PTMs is not clear and should be further studied.

Special Issue "Multimodality Imaging in Cardiomyopathies"

Multimodality imaging has a crucial role in the identification and management of patients with suspected cardiomyopathies [...].

Thoracic Aortic Dilation: Implications for Physical Activity and Sport Participation

Thoracic aortic dilatation is a progressive condition that results from aging and many pathological conditions (i.e., connective tissue, inflammatory, shear stress disorders, severe valvular heart disease) that induce degenerative changes in the elastic properties, leading to the loss of elasticity and compliance of the aortic wall. Mild aortic root enlargement may be also observed in athletes and is considered as a normal adaptation to regular exercise training. On the other hand, high-intensity physical activity in individuals with a particular genetic substrate, such as those carrying gene variants associated with Marfan syndrome or other inherited aortopathies, can favor an excessive aortic enlargement and trigger an acute aortic dissection. The evaluation of the aortic valve and aortic root diameters, as well as the detection of a disease-causing mutation for inherited aortic disease, should be followed by a tailored decision about sport eligibility. In addition, the risk of aortic complications associated with sport in patients with genetic aortic disease is poorly characterized and is often difficult to stratify for each individual athlete. This review aims to describe the relationship between regular physical activity and aortic dilation, focusing on patients with bicuspid aortic valve and inherited aortic disease, and discuss the implications in terms of aortic disease progression and sport participation.

Usefulness of Longitudinal Strain Adjusted to Regional Thickness in Hypertrophic Cardiomyopathy

Background. We assessed the usefulness of a longitudinal strain adjusted to regional thickness in hypertrophic cardiomyopathy (HCM). Indeed, with conventional software, the width of the region of interest (ROI) is the same over the entire myocardial wall, wherein the software analyzes only partially the left ventricular (LV) hypertrophic segments. Methods. We included 110 patients: 55 patients with HCM (HCM group) and 55 healthy subjects (age- and sex-matched control group). The global longitudinal strain (GLS) and regional strain for each of the 17 segments was calculated with standard software (for two groups) and with software adjusted to the myocardial wall thickness (for the HCM group). Results. GLS was significantly decreased in the HCM group compared to the control group (−15.1 ± 4.8% versus −20.5 ± 4.3%, p < 0.0001). In the HCM group, GLS (standard method versus adjusted to thickness) measurements were not significantly different (p = 0.34). Interestingly, the regional strain adjusted to thickness was significantly lower than the standard strain in the hypertrophic segments, especially in the basal inferoseptal segment (p = 0.0002), median inferoseptal segment (p < 0.001) and median anteroseptal segment (p = 0.02). The strain adjusted to thickness was still significantly lower in the most hypertrophic segments (≥20 mm) (−3.7 ± 3%, versus −5.9 ± 4.4%, p = 0.049 in the basal inferoseptal segment and −5.7 ± 3.5% versus −8.3 ± 4.5%, p = 0.0007 in the median inferoseptal segment). In the segments with significant myocardial fibrosis, the longitudinal strain adjusted to thickness was significantly lower than the conventional strain (−8.3 ± 3.3% versus −11.4 ± 4.5%, p = 0.002). The analysis of the strain adjusted to thickness had a better feasibility (97.5% versus 99%, p = 0.01). Conclusions. The analysis of a longitudinal strain adjusted to regional thickness is feasible in HCM and allows a better evaluation of myocardial deformation, especially in the most LV hypertrophic segments.

Diagnosis and Management of Rare Cardiomyopathies in Adult and Paediatric Patients. A Position Paper of the Italian Society of Cardiology (SIC) and Italian Society of Paediatric Cardiology (SICP)

Cardiomyopathies (CMPs) are myocardial diseases in which the heart muscle is structurally and functionally abnormal in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to cause the observed myocardial abnormality. Thought for a long time to be rare diseases, it is now clear that most of the CMPs can be easily observed in clinical practice. However, there is a group of specific heart muscle diseases that are rare in nature whose clinical/echocardiographic phenotypes resemble those of the four classical morphological subgroups of hypertrophic, dilated, restrictive, arrhythmogenic CMPs. These rare CMPs, often but not solely diagnosed in infants and paediatric patients, should be more properly labelled as specific CMPs. Emerging consensus exists that these conditions require tailored investigation and management. Indeed, an appropriate understanding of these conditions is mandatory for early treatment and counselling. At present, however, the multisystemic and heterogeneous presentation of these entities is a challenge for clinicians, and time delay in diagnosis is a significant concern. The aim of this paper is to define practical recommendations for diagnosis and management of the rare CMPs in paediatric or adult age. A modified Delphi method was adopted to grade the recommendations proposed by each member of the writing committee.