Myocardial extracellular volume measurement using cardiac computed tomography.

Myocardial fibrosis is a common endpoint of many cardiac diseases and increasingly recognized as a predictor of heart failure, arrhythmia, and death. Recent studies have utilised cardiac computed tomography (CT) scans with delayed phase imaging to quantify diffuse fibrosis of the myocardium. CT extracellular volume (CT-ECV) measurement correlates well with CMR and histological myocardial fibrosis. Furthermore, CT-ECV predicts outcomes such as death, heart failure and arrhythmia in various disease states. This review summarizes the rationale and methodology behind CT-ECV measurement and provides a detailed summary of the current clinical evidence for the use of CT-ECV.

Atlas of Regional Left Ventricular Scar in Nonischemic Cardiomyopathies: Substrates and Etiologies.

Most acquired and inherited cardiomyopathies are characterized by regional left ventricular involvement and nonischemic myocardial scars, often with a disease-specific pattern. Irrespective of the etiology and pathophysiological mechanisms, myocardial disorders are invariably associated with cardiac fibrosis, which contributes to dysfunction and electrical instability. Accordingly, cardiac magnetic resonance plays a central role in the diagnostic work-up and prognostic risk stratification of cardiomyopathies, particularly with the increasing correlation between genetic background and specific disease phenotype. Starting from pattern and distribution of myocardial fibrosis at cardiac magnetic resonance, we provide a practical regional atlas of nonischemic myocardial scar to guide the diagnostic approach to nonischemic cardiomyopathies.

The effect of long-term tafamidis treatment on quality of life in people with transthyretin amyloid cardiomyopathy (ATTR-CM): A plain language summary.

WHAT IS THIS SUMMARY ABOUT?: This summary explains some results of a study called ATTR-ACT and its ongoing long-term extension study that were published in the European Journal of Heart Failure. The purpose of ATTR-ACT was to find out if a drug called tafamidis is an effective treatment for people with a heart condition called transthyretin amyloid cardiomyopathy (ATTR-CM). People took tafamidis or placebo for up to 2.5 years in ATTR-ACT (the initial study). A placebo looks like the study medicine but does not contain any active ingredients. After people completed the initial study, they could take part in the extension study. An extension study allows people to continue receiving treatment after the original clinical study ends and helps researchers understand how well a treatment works over a longer time period. This extension study allows people to receive tafamidis for up to an additional 5 years. People who took placebo in the initial study now receive tafamidis. People who took tafamidis in the initial study continue tafamidis treatment. Researchers looked at changes in peoples' ability to enjoy life ('quality of life') and heart failure symptoms since they started ATTR-ACT. Results are available for the first 2.5 years of the extension study. WHAT ARE THE KEY TAKEAWAYS?: During the initial study, there was less worsening of quality of life and heart failure symptoms in people who took tafamidis compared to people who took placebo. In the extension study, quality of life and heart failure symptoms were maintained or nearly maintained in people who took tafamidis in the initial study. In people who started tafamidis in the extension study, quality of life and heart failure symptoms continued to worsen, but the worsening slowed down. WHAT WERE THE MAIN CONCLUSIONS REPORTED BY THE RESEARCHERS?: Tafamidis slows the worsening of quality of life and heart failure symptoms in people with ATTR-CM. People with ATTR-CM should start treatment early to receive the most benefit.Clinical Trial Registration: NCT01994889 (ATTR-ACT) (ClinicalTrials.gov).

Exploring the role of exosomes in the pathogenesis and treatment of cardiomyopathies: A comprehensive literature review.

Exosomes, a subset of small extracellular vesicles that play a crucial role in intercellular communication, have garnered significant attention for their potential applications in the diagnosis and treatment of cardiomyopathies. Cardiomyopathies, which encompass a spectrum of heart muscle disorders, present complex challenges in diagnosis and management. Understanding the role of exosomes in the etiology of cardiomyopathies such as dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), arrhythmogenic cardiomyopathy (AC), and hypertrophic cardiomyopathy (HCM) may open new possibilities for therapeutic intervention and diagnosis. Exosomes have indeed demonstrated promise as diagnostic biomarkers, particularly in identifying cardiac conditions such as atrial fibrillation (AF) and in the timely classification of high-risk patients with different forms of cardiomyopathy. In DCM, exosomes have been implicated in mediating pathological responses in cardiomyocytes, potentially exacerbating disease progression. Moreover, in RCM, AC, and HCM, exosomes present significant potential as diagnostic biomarkers and therapeutic targets, offering insights into disease pathogenesis and potential avenues for intervention. Understanding the influence of exosomes on disease progression and identifying the specific molecular pathways involved in cardiomyopathy pathogenesis may significantly advance diagnostic and treatment strategies. While key findings highlight the multifaceted role of exosomes in cardiomyopathy, they also emphasize the need for further research to elucidate molecular mechanisms and translate findings into clinical practice. This review highlights the evolving landscape of exosome research in cardiomyopathies and underscores the importance of ongoing investigations to harness the full potential of exosomes in improving patient outcomes.

Identifying the Pathogenic Variants in Heart Genes in Vietnamese Sudden Unexplained Death Victims by Next-Generation Sequencing.

In forensics, one-third of sudden deaths remain unexplained after a forensic autopsy. A majority of these sudden unexplained deaths (SUDs) are considered to be caused by inherited cardiovascular diseases. In this study, we investigated 40 young SUD cases (<40 years), with non-diagnostic structural cardiac abnormalities, using Targeted NGS (next-generation sequencing) for 167 genes previously associated with inherited cardiomyopathies and channelopathies. Fifteen cases identified 17 variants on related genes including the following: AKAP9, CSRP3, GSN, HTRA1, KCNA5, LAMA4, MYBPC3, MYH6, MYLK, RYR2, SCN5A, SCN10A, SLC4A3, TNNI3, TNNI3K, and TNNT2. Of these, eight variants were novel, and nine variants were reported in the ClinVar database. Five were determined to be pathogenic and four were not evaluated. The novel and unevaluated variants were predicted by using in silico tools, which revealed that four novel variants (c.5187_5188dup, p.Arg1730llefsTer4 in the AKAP9 gene; c.1454A>T, p.Lys485Met in the MYH6 gene; c.2535+1G>A in the SLC4A3 gene; and c.10498G>T, p.Asp3500Tyr in the RYR2 gene) were pathogenic and three variants (c.292C>G, p.Arg98Gly in the TNNI3 gene; c.683C>A, p.Pro228His in the KCN5A gene; and c.2275G>A, p.Glu759Lys in the MYBPC3 gene) still need to be further verified experimentally. The results of our study contributed to the general understanding of the causes of SUDs. They provided a scientific basis for screening the risk of sudden death in family members of victims. They also suggested that the Targeted NGS method may be used to identify the pathogenic variants in SUD victims.

Catecholamine-Induced Cardiomyopathy Secondary to Pheochromocytoma Rescued With Percutaneous Left Ventricular Assist Device: Novel Application of the Impella CP in a Pediatric Patient.

Background: Catecholamine-induced cardiomyopathy is an uncommon complication of pheochromocytoma. Pheochromocytoma is a rare tumor that predominantly occurs in adults, making catecholamine-induced cardiomyopathy secondary to pheochromocytoma in children an exceedingly rare presentation. Treatment typically consists of medical management followed by surgical resection. Mechanical support, typically salvage therapy with extracorporeal membrane oxygenation, has been used in adult patients with cardiogenic shock and after cardiac arrest, but to our knowledge, the use of mechanical support has not been described in pediatric patients. Case Report: A 16-year-old female presented with cardiogenic shock resulting from catecholamine-induced cardiomyopathy secondary to pheochromocytoma. She was treated with a percutaneous left ventricular assist device to allow myocardial recovery while medical therapy was optimized. Given the early initiation, the patient's myocardial recovery was prompt, and only 3 days of device support were required. She was discharged in good condition and subsequently underwent uncomplicated laparoscopic resection of the tumor a few weeks later. Conclusion: In pediatric patients with catecholamine-induced cardiomyopathy secondary to pheochromocytoma, aggressive measures of support-including mechanical support and infrequently used options such as percutaneous left ventricular assist devices-should be considered early in treatment to maintain adequate cardiac output, avoid cardiac arrest, and allow for prompt myocardial recovery.

The Role of Cardiovascular Imaging in the Diagnosis of Athlete's Heart: Navigating the Shades of Grey.

Athlete's heart (AH) represents the heart's remarkable ability to adapt structurally and functionally to prolonged and intensive athletic training. Characterized by increased left ventricular (LV) wall thickness, enlarged cardiac chambers, and augmented cardiac mass, AH typically maintains or enhances systolic and diastolic functions. Despite the positive health implications, these adaptations can obscure the difference between benign physiological changes and early manifestations of cardiac pathologies such as dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), and arrhythmogenic cardiomyopathy (ACM). This article reviews the imaging characteristics of AH across various modalities, emphasizing echocardiography, cardiac magnetic resonance (CMR), and cardiac computed tomography as primary tools for evaluating cardiac function and distinguishing physiological adaptations from pathological conditions. The findings highlight the need for precise diagnostic criteria and advanced imaging techniques to ensure accurate differentiation, preventing misdiagnosis and its associated risks, such as sudden cardiac death (SCD). Understanding these adaptations and employing the appropriate imaging methods are crucial for athletes' effective management and health optimization.

Temporal trends in the prevalence, incidence, and mortality of cardiac amyloidosis in South Korea over 12 years.

Objectives: This study investigated the prevalence, incidence, and prognosis of cardiac amyloidosis (CA) in South Korea. Methods: This retrospective nationwide population-based study used the Health Insurance Review and Assessment Service databases between 2008 and 2020. All patients diagnosed with amyloidosis were included, and those with a diagnosis of heart failure or cardiomyopathy were classified as having CA. Both the special code for amyloidosis (V121), which enables coverage of medical expenses, and the corresponding International Classification of Diseases, 10th Revision codes for amyloidosis (E850-E854, E858, E859) were used to improve the reliability of amyloidosis diagnosis. Results: Among 2,239 patients with amyloidosis, 758 met the criteria for CA (mean age, 64.4±11.9 years; 59.1% male). The mean age of patients with CA increased from 59.5±14.7 years in 2009 to 68.1±13.9 years in 2020. The incidence and prevalence increased from 0.09 (95% confidence interval [CI], 0.06-0.12) to 0.22 (95% CI, 0.18-0.27) per 100,000 person-years and 0.20 (95% CI, 0.16-0.25) to 1.30 (95% CI, 0.12-0.42) per 100,000 persons, respectively (all p<0.001). Patients with light-chain CA showed similar trends. In-hospital mortality decreased from 17.3% (95% CI, 9.23%-29.6%) to 6.1% (95% CI, 4.21%-8.48%) between 2009 and 2020. While age-specific in-hospital mortality was significantly higher in patients aged ≥70 years (p=0.004), no significant age-specific difference in in-hospital mortality was observed in patients with CA aged <70 years (p=0.981). Conclusion: The prevalence and incidence of CA have increased in South Korea, predominantly affecting older individuals, particularly males. Notably, in-hospital mortality decreased significantly.

Prevalence of cardiomyopathy and cardiac mortality in a colony of non-purebred cats in New Zealand.

AIMS: To evaluate the prevalence of subclinical cardiomyopathy and cardiac mortality in a research colony of non-purebred cats, established as a model of the wider cat population in New Zealand. METHODS: All apparently healthy, compliant, non-pregnant, non-neonatal cats in the colony at the Centre for Feline Nutrition (Massey University, Palmerston North, NZ) underwent physical examination and echocardiography using a 4.4-6.2-MHz probe by a board-certified veterinary cardiologist. Cardiac phenotype was classified following current guidelines. Hypertrophic cardiomyopathy (HCM) phenotype was defined as an end-diastolic left ventricular wall thickness ≥ 6 mm. Colony mortality data from February 2012 to February 2022 was reviewed to determine cardiac mortality. RESULTS: Cats (n = 132; 65 females and 67 males) included in the study had a median age of 4.1 (IQR 3.0-8.0) years. Thirty-two (24%) cats had a heart murmur, and three (2%) cats had an arrhythmia. Echocardiography revealed heart disease in 24 (18.2%) cats, including 23 with an HCM phenotype and one with a restrictive cardiomyopathy phenotype. Of the cats with the HCM phenotype, 3/23 had systemic hypertension or hyperthyroidism or both, and these cats were excluded from the final diagnosis of HCM (20/132; 15.2 (95% CI = 9.5-22.4)%).Between 2012 and 2022, 168 colony cats died, with 132 undergoing post-mortem examination. Heart disease was considered the cause of death in 7/132 (5.3%; 95% CI = 2.2-10.6%) cats; five had HCM, one a congenital heart defect, and one myocarditis. The overall prevalence of death related to HCM in the colony during this period was 3.8% (95% CI = 1.2-8.6%). Three cats with HCM and the cat with a congenital heart defect died unexpectedly without prior clinical signs, while congestive heart failure was observed prior to death in two cats with HCM and the cat with myocarditis. Additionally, 30/132 (22.7%) cats had cardiac abnormalities but died for non-cardiac reasons. CONCLUSIONS: Subclinical cardiomyopathy, specifically HCM, was common in cats in the colony. Given that the colony originated as a convenience selection of non-purebred cats in New Zealand, the true prevalence of HCM in the wider New Zealand population is likely to fall within the 95% CI (9.5-22%). The proportion of deaths of colony cats due to HCM was lower (3.8%) supporting the conclusion that subclinical cardiomyopathy may not progress to clinical disease causing death. CLINICAL RELEVANCE: Veterinarians should be aware of the high prevalence of subclinical HCM when treating cats. ABBREVIATIONS: CAM: Systolic anterior motion of the chordae tendineae; CFN: Centre for Feline Nutrition; HCM: Hypertrophic cardiomyopathy; LA/Ao: Left atrial to aortic ratio; LV FS: Left ventricular fractional shortening; LVIDd: Left ventricular internal diameters in end-diastole; LVIDs: Left ventricular internal diameter in end-systole; LVWT: Max Maximum left ventricular wall thickness; SAM: Systolic anterior motion of the mitral valve; 2D: Two-dimensional.

[Race against sudden death : the benefits of pre-participation cardiovascular screening]. / Course contre la mort subite : intérêt du dépistage cardiovasculaire avant une compétition sportive.

Sudden death (SD) in young, apparently healthy athletes under 35 is an underestimated public health problem in Belgium. This is dramatically illustrated by the case of a 28-year old ultra-trail runner who suffered cardiac arrest during training, revealing an unrecognized cardiomyopathy. This highlights the importance of pre-participation cardiovascular screening in identifying such hidden conditions. The variety of causes of SD, mainly of cardiac origin, underlines the complexity of screening and the need to tailor it to the specific risks of each individual. The central issue in screening is the relevance of the resting 12-lead electrocardiogram (ECG). While some countries have adopted it with positive results, others continue to debate its systematic inclusion. Sudden death affects not only professional athletes, but also amateurs, who are often less medically monitored. The aim of cardiovascular screening is twofold: to identify young people at risk, while not unnecessarily limiting access to sport for those with no cardiac pathology. The effectiveness of the ECG is well recognized, but the implementation of such systematic screening in Belgium must take into account certain practical aspects.

La mort subite (MS) chez les jeunes sportifs de moins de 35 ans, en bonne santé apparente, est une problématique de santé publique sous-estimée en Belgique. Cette réalité est dramatiquement illustrée par le cas d'un ultra-traileur de 28 ans, victime d'un arrêt cardiaque lors d'un entraînement, révélant une cardiomyopathie méconnue. Cela met en lumière l'importance d'un dépistage cardiovasculaire pré-participatif pour identifier de telles affections cachées. La variété des causes de MS, principalement d'origine cardiaque, souligne la complexité du dépistage et la nécessité de l'adapter en fonction des risques spécifiques à chaque individu. La question centrale du dépistage est la pertinence de l'électrocardiogramme (ECG) à 12 dérivations de repos. Tandis que certains pays l'ont adopté avec des résultats positifs, d'autres continuent de débattre sur son inclusion systématique. La MS n'affecte pas que les athlètes professionnels, mais aussi les amateurs, souvent moins suivis sur le plan médical. L'objectif du dépistage cardiovasculaire est double : identifier les jeunes à risque, tout en ne limitant pas inutilement l'accès au sport pour ceux dépourvus de pathologie cardiaque. L'efficacité de l'ECG est reconnue, mais la mise en œuvre d'un tel dépistage systématique en Belgique doit tenir compte de certains aspects pratiques.

Unveiling the Spectrum of Minor Genes in Cardiomyopathies: A Narrative Review.

Hereditary cardiomyopathies (CMPs), including arrhythmogenic cardiomyopathy (ACM), dilated cardiomyopathy (DCM), and hypertrophic cardiomyopathy (HCM), represent a group of heart disorders that significantly contribute to cardiovascular morbidity and mortality and are often driven by genetic factors. Recent advances in next-generation sequencing (NGS) technology have enabled the identification of rare variants in both well-established and minor genes associated with CMPs. Nowadays, a set of core genes is included in diagnostic panels for ACM, DCM, and HCM. On the other hand, despite their lesser-known status, variants in the minor genes may contribute to disease mechanisms and influence prognosis. This review evaluates the current evidence supporting the involvement of the minor genes in CMPs, considering their potential pathogenicity and clinical significance. A comprehensive analysis of databases, such as ClinGen, ClinVar, and GeneReviews, along with recent literature and diagnostic guidelines provides a thorough overview of the genetic landscape of minor genes in CMPs and offers guidance in clinical practice, evaluating each case individually based on the clinical referral, and insights for future research. Given the increasing knowledge on these less understood genetic factors, future studies are essential to clearly assess their roles, ultimately leading to improved diagnostic precision and therapeutic strategies in hereditary CMPs.

First report of the clinical characteristics and outcomes of cardiac amyloidosis in Saudi Arabia.

AIMS: Cardiac amyloidosis (CA) is a potentially fatal multisystemic disease that remains significantly underdiagnosed, particularly in the Middle East. This study aims to evaluate the prevalence and clinical characteristics of CA in a high-risk population at a tertiary centre in Saudi Arabia. METHODS: This cross-sectional, retrospective, single-centre study was conducted at a tertiary hospital in Riyadh, Saudi Arabia. We reviewed the medical records of heart failure patients seen between August 2018 and July 2022 who exhibited red flags for CA and subsequently underwent CA screening. Red flags that prompted the workup included at least two of the following factors: the presence of unilateral or bilateral carpal tunnel syndrome, a family history of transthyretin amyloid (ATTR) amyloidosis and specific electrocardiographic features (relative/absolute low QRS voltage, pseudoinfarct pattern and atrioventricular/interventricular conduction abnormalities). Echocardiographic red flags included mainly increased wall thickness (≥12 mm), significant diastolic dysfunction, reduced left ventricular (LV) longitudinal function, right ventricular (RV) dysfunction and elevated right atrial (RA)/pulmonary artery (PA) pressure. Cardiac magnetic resonance (CMR) red flags included aspects similar to those in an echocardiogram as well as a subendocardial or transmural late gadolinium enhancement (LGE) pattern. These patients were assessed for CA through technetium-99m pyrophosphate ([99mTc]Tc-PYP) bone scintigraphy, serum and urine protein electrophoresis with immunofixation and a serum-free light chain assay. RESULTS: A total of 177 patients were screened, of which 21.0 (11.9%) patients were diagnosed with transthyretin amyloid CA (ATTR-CA) and 13 (7.3%) patients were diagnosed with light chain CA (AL-CA). Compared with patients with negative/equivocal [99mTc]Tc-PYP scans (grades 0-1), patients with positive [99mTc]Tc-PYP scans (grades 2-3) were older (78.0 vs. 68.0 years, P < 0.001), had higher levels of troponin (P = 0.003) and N-terminal pro-brain natriuretic peptide (NT-proBNP) (P < 0.001), had a higher LV mass index (P < 0.001), displayed a more depressed global longitudinal strain (GLS) (P < 0.001) with a greater prevalence of a relative apical sparing pattern (P < 0.001) and demonstrated a higher incidence of first-degree atrioventricular block (P = 0.008) and low voltage patterns on electrocardiography (P < 0.001). Patients with ATTR-CA and AL-CA were more likely to have a subendocardial or transmural LGE pattern on CMR (P < 0.001) and had a significantly lower overall survival (P < 0.001) when compared with other heart failure aetiologies. CONCLUSIONS: This is the first study to describe the clinical characteristics and outcomes of CA in the Middle East and Saudi Arabia. The prevalence of CA among screened heart failure patients here aligns with major international studies, suggesting significant underdiagnosis in the region. Therefore, larger multicentric studies and regional screening programmes are urgently needed to accurately characterize the epidemiology and outcomes of CA in the Middle East.

Left ventricular thrombus in patient with nonischemic cardiomyopathy: A case report.

Left ventricular thrombus (LVT) is a severe consequence that typically follows acute myocardial infarction (MI) and can occur in nonischemic cardiomyopathies. In patients who have experienced an ST-segment elevation acute myocardial infarction (STEMI), LVT is seen up to 15% of the time; for patients without an ischemic cardiomyopathy, it is only 2% to 36% of the time. According to Virchow's triad, the cornerstone of LVT formation includes endothelial injury, blood stasis, and hypercoagulability. However, LVT increases morbidity and mortality in patients with both ischemic and nonischemic cardiomyopathies by increasing the risk of stroke or systemic embolism. Studies on nonischemic etiology are limited, and the majority of LVT case series concentrate on ischemic cardiomyopathies. We present this case with the nonischemic cardiomyopathies caused by LVT. Specifically, the patient underwent coronary artery assessment using photon-counting computed tomography, which is among the most advanced systems worldwide.

Genetic testing for inherited arrhythmia syndromes and cardiomyopathies: results of the European Heart Rhythm Association survey.

AIMS: Indications and clinical impact of genetic testing for cardiac diseases have increased significantly over the past years. The aim of this physician-based European Heart Rhythm Association (EHRA) survey was to assess current clinical practice and access to genetic testing for cardiac diseases across European Society of Cardiology countries and to evaluate adherence to the 2022 EHRA/HRS/APHRS/LAHRS Expert Consensus Statement on genetic testing. METHODS AND RESULTS: An online questionnaire composed of 28 questions was submitted to the EHRA Research Network and European Reference Network GUARD-Heart healthcare partners and promoted via dedicated social media channels. There were 357 respondents from 69 countries, 40% working in a hospital setting with a cardiac genetic service and/or a dedicated clinic focusing on inherited cardiac diseases and 27% with an onsite genetic laboratory. No genetic testing or low annual rate (<10/year) was declared by 39% of respondents. The majority of respondents (78%) declared issues or limitations to genetic testing access in their clinical practice. The main reasons for not providing or limited access to genetic testing were no availability of dedicated unit or genetic laboratory (35%) or reimbursement issues (25%). The most frequently reported indication for genetic testing was diagnostic purpose (55%). Most respondents (92%) declared offering genetic testing preceded by genetic counselling and 42% regular multidisciplinary evaluations for patients with cardiac genetic diseases. The perceived value of genetic testing in the diagnostic, prognostic, and therapeutic assessment was variable (67, 39, and 29%, respectively) and primarily based on the specific inherited disease. The majority of respondents recommended cascade genetic testing for the first-degree family members in case of pathogenic/likely pathogenic variant in the proband. CONCLUSION: This survey highlights a significant heterogeneity of genetic testing access and provision and issues attributable to the availability of dedicated unit/genetic laboratory and reimbursement. However, adequate adherence to indications in the current recommendations for genetic testing in patients with cardiac diseases was observed.

Whole-Heart Histological and Electroanatomic Assessment of Postinfarction Cardiac Magnetic Resonance Imaging Scar and Conducting Channels.

BACKGROUND: Cardiac magnetic resonance imaging (CMR)-defined ventricular scar and anatomic conduction channels (CMR-CCs) offer promise in delineating ventricular tachycardia substrate. No studies have validated channels with coregistered histology, nor have they ascertained the histological characteristics of deceleration zones (DZs) within these channels. We aimed to validate CMR scar and CMR-CCs with whole-heart histology and electroanatomic mapping in a postinfarction model. METHODS: Five sheep underwent anteroseptal infarction. CMR (116±20 days post infarct) was postprocessed using ADAS-3D, varying pixel intensity thresholds (5545, 6040, 6535, and 7030). DZs were identified by electroanatomic mapping (129±12 days post infarct). Explanted hearts were sectioned and stained with Picrosirius red, and whole-heart histopathologic shells were generated. Scar topography as well as percentage fibrosis, adiposity, and remaining viable myocardium within 3 mm histological biopsies and within CMR-CCs were determined. RESULTS: Using the standard 6040 thresholding, CMR had 83.8% accuracy for identifying histological scar in the endocardium (κ, 0.666) and 61.4% in the epicardium (κ, 0.276). Thirty-seven CMR-CCs were identified by varying thresholding; 23 (62%) were unique. DZs colocalized to 19 of 23 (83%) CMR-CCs. Twenty (87%) CMR-CCs were histologically confirmed. Within-channel histological fibrosis did not differ by the presence of DZs (P=0.242). Within-channel histological adiposity was significantly higher at sites with versus without DZs (24.1% versus 8.3%; P<0.001). CONCLUSIONS: Postprocessed CMR-derived scars and channels were validated by histology and electroanatomic mapping. Regions of CMR-CCs at sites of DZs had higher adiposity but similar fibrosis than regions without DZs, suggesting that lipomatous metaplasia may contribute to arrhythmogenicity of postinfarction scar.

Contemporary Multimodality Imaging for Diagnosis and Management of Fabry Cardiomyopathy.

Fabry disease (FD) is an X-linked lysosomal storage disorder which leads to the accumulation of globotriaosylceramide (Gb3) in various organs, including the heart. FD can be subdivided into classic disease resulting from negligible residual enzyme activity and a milder, atypical phenotype with later onset and less severe clinical presentation. The use of multimodality cardiac imaging including echocardiography, cardiac magnetic resonance and nuclear imaging is important for the diagnostic and prognostic evaluation in these patients. There are gaps in the literature regarding the comprehensive description of cardiac findings of FD and its evaluation by multimodality imaging. In this review, we describe the contemporary practices and roles of multimodality cardiac imaging in individuals affected with Fabry disease.

Myocardial hypertrophy: the differentiation of uremic, hypertensive, and hypertrophic cardiomyopathies by cardiac MRI.

OBJECTIVES: To apply cardiac magnetic resonance imaging (CMR) for detailed myocardial characterization in uremic cardiomyopathy (UC), hypertensive cardiomyopathy (HTN), and hypertrophic cardiomyopathy (HCM) aiming to enrich the understanding of UC's etiology and further support the development of therapeutic strategies. METHODS: A total of 152 patients (age: 49.2 ± 9.9 years; 65.8% male) underwent routine CMR from June 2016 to March 2023. Retrospectively, 53 patients with UC, 39 patients with HTN, 30 patients with HCM, and 30 healthy controls were included. Functional analysis, feature tracking of the left ventricle and left atrium, and myocardial T1, T2, and T2* mapping were performed. Statistical analysis included Pearson correlation and ROC analysis to define correlations and discriminators between groups. RESULTS: UC patients demonstrated significantly higher native T1 (p < 0.001 for all) and T2 (p < 0.002 for all) values compared with the other three groups. UC patients revealed higher left atrial reservoir strain rate (p < 0.001 for all) and left atrial conduit strain rate (p < 0.001 for all) absolute values as compared with HTN and HCM patients. A significant correlation between T1 and T2 values in UC patients (r = 0.511, p < 0.001) was found. The combination of T1 values and strain parameters was the best discriminator between UC and HTN patients (AUC = 0.872, 95% CI: 0.801-0.943) and between UC and HCM patients (AUC = 0.840, 95% CI: 0.746-0.934). CONCLUSION: UC reveals distinguishing tissue characteristics as evidenced by T1 and T2 mapping, as well as distinguishing functional strain parameters as compared with other hypertrophic phenotypes such as HTN and HCM. CRITICAL RELEVANCE STATEMENT: The use of CMR imaging in UC patients offers incremental information to elucidate its complex etiology, contributing to ongoing discourse on effective treatment pathways. KEY POINTS: This study investigated uremic, hypertensive, and hypertrophic cardiomyopathies using cardiac MRI. UC patients have higher T1 and T2 values and better preserved cardiac function. Combined strain and T1 values distinguish UC from other cardiomyopathies.

Magnetic resonance mapping for the assessment of cardiomyopathies and myocardial disease.

In recent years, the use of cardiac magnetic resonance (CMR) has grown exponentially in clinical practice. The keys for this success are represented by the possibility of tissue characterization, cardiac volumes and myocardial perfusion assessment, biventricular function evaluation, with no use of ionizing radiations and with an extremely interesting profile of reproducibility. The use of late gadolinium enhancement (LGE) nearly compares a non-invasive biopsy for cardiac fibrosis quantification. LGE, however, is partly unable to detect diffuse myocardial disease. These limits are overcome by new acquisition techniques, mainly T1 and T2 mapping, which allow the diagnosis and characterization of various cardiomyopathies, both ischemic and non-ischemic, such as amyloidosis (high T1), Fabry's disease (low T1), hemochromatosis (low T1), dilated and hypertrophic cardiomyopathy and myocarditis. In this review we detail and summarize principal evidence on the use of T1 and T2 mapping for the study and clinical management of cardiomyopathies.

Lysozyme 1 Inflamed CCR2+ Macrophages Promote Obesity-Induced Cardiac Dysfunction.

BACKGROUND: Macrophages are key players in obesity-associated cardiovascular diseases, which are marked by inflammatory and immune alterations. However, the pathophysiological mechanisms underlying macrophage's role in obesity-induced cardiac inflammation are incompletely understood. Our study aimed to identify the key macrophage population involved in obesity-induced cardiac dysfunction and investigate the molecular mechanism that contributes to the inflammatory response. METHODS: In this study, we used single-cell RNA-sequencing analysis of Cd45+CD11b+F4/80+ cardiac macrophages to explore the heterogeneity of cardiac macrophages. The CCR2+ (C-C chemokine receptor 2) macrophages were specifically removed by a dual recombinase approach, and the macrophage CCR2 was deleted to investigate their functions. We also performed cleavage under target and tagmentation analysis, chromatin immunoprecipitation-polymerase chain reaction, luciferase assay, and macrophage-specific lentivirus transfection to define the impact of lysozyme C in macrophages on obesity-induced inflammation. RESULTS: We find that the Ccr2 cluster undergoes a functional transition from homeostatic maintenance to proinflammation. Our data highlight specific changes in macrophage behavior during cardiac dysfunction under metabolic challenge. Consistently, inducible ablation of CCR2+CX3CR1+ macrophages or selective deletion of macrophage CCR2 prevents obesity-induced cardiac dysfunction. At the mechanistic level, we demonstrate that the obesity-induced functional shift of CCR2-expressing macrophages is mediated by the CCR2/activating transcription factor 3/lysozyme 1/NF-κB (nuclear factor kappa B) signaling. Finally, we uncover a noncanonical role for lysozyme 1 as a transcription activator, binding to the RelA promoter, driving NF-κB signaling, and strongly promoting inflammation and cardiac dysfunction in obesity. CONCLUSIONS: Our findings suggest that lysozyme 1 may represent a potential target for the diagnosis of obesity-induced inflammation and the treatment of obesity-induced heart disease.