Myocardial Biopsy Research Articles

Clinical Utilization of Multimodality Imaging for Myocarditis and Cardiac Sarcoidosis

Myocarditis is defined as inflammation of the myocardium according to clinical, histological, biochemical, immunohistochemical, or imaging findings. Inflammation can be categorized histologically by cell type or pattern, and many causes have been implicated, including infectious, most commonly viral, systemic autoimmune diseases, vaccine-associated processes, environmental factors, toxins, and hypersensitivity to drugs. Sarcoid myocarditis is increasingly recognized as an important cause of cardiomyopathy and has important diagnostic, prognostic, and therapeutic implications in patients with systemic sarcoidosis. The clinical presentation of myocarditis may include an asymptomatic, subacute, acute, fulminant, or chronic course and may have focal or diffuse involvement of the myocardium depending on the cause and time point of the disease. For most causes of myocarditis except sarcoidosis, myocardial biopsy is the gold standard but is limited due to risk, cost, availability, and variable sensitivity. Diagnostic criteria have been established for both myocarditis and cardiac sarcoidosis and include clinical and imaging findings particularly the use of cardiac magnetic resonance and positron emission tomography. Beyond diagnosis, imaging findings may also provide prognostic value. This case-based review focuses on the current state of multimodality imaging for the diagnosis and management of myocarditis and cardiac sarcoidosis, highlighting multimodality imaging approaches with practical clinical vignettes, with a discussion of knowledge gaps and future directions.

Morphology of the myocardium of the interventricular septum in children with hypertrophic cardiomyopathy

To carry out a comparative analysis of the morphology of the interventricular septum (IVS) myocardium in children with hypertrophic cardiomyopathy (HCM) and without cardiovascular pathology. A study of myocardial biopsies of the IVS in children with HCM (n=18, 1.2-17 years) and children without cardiovascular pathology (n=11, 1-16 years) was carried out. The volume of interstitial tissue in the IVS myocardium was determined, a morphometric study of the size of cardiomyocytes (CMCs), the myofibrillogenesis level and the ploidy of CMCs was carried out, the ultrastructure of the CMCs was studied, and the localization of the gap junction protein, connexin43 (Cx43), was revealed by immunohistochemistry. The proportion of interstitial tissue in the myocardium of children with HCM was 9-10% and did not differ from its proportion in the myocardium of children in the control group. The diameter of the CMCs of the IVS in children with HCM reached the limit of ontogenetic growth and exceeded the parameters of the control group (average 18.9±5.7 µm vs 9.3±4.4 µm). CMCs ploidy in children with HCM was 2 times higher than CMCs ploidy in control patients (5.3c vs 2.7c). In the myocardium of children with HCM, the assembly of myofibrils most actively occurred in small CMCs. At the ultrastructural level, signs of immaturity of the contractile apparatus and intercalated discs of the CMC in HCM were demonstrated. In the myocardium of children with HCM, Cx43-containing gap junctions were more often located on the lateral surfaces of the CMC than in the myocardium of the control group. In children with HCM, a morphological picture of an increase in the size of the CMCs and their ploidy during accelerated ontogenetic development was demonstrated in combination with ultrastructural signs of immaturity of the contractile apparatus and intercalated discs and the lack of growth of interstitial tissue of the IVS myocardium compared with patients in the control group.

Оценка функциональных свойств гибернирующего миокарда

Introduction.Currently, there are different approaches to assessing changes that occur in ischemic myocardium in patients with chronic coronary artery disease (CAD). Researchers argue about the timing and completeness of the restoration of myocardial dysfunction areas. We aimed to assess hibernating myocardium in the zones of hypokinesia in patients with CAD. Materials and methods. We performed a morphological and immunohistochemical study of left ventricular myocardial biopsies of 25 patients who underwent surgical reconstruction of the left ventricle with surgical revascularization. Results. Morphological and immunohistochemical studies revealed violated morphological structure of cardiomyocytes. It correlates with the accumulation of MMP9 in the cytoplasm of cardiomyocytes in the areas of affected myocardium in ischemia against the background of partial or complete destruction of CM basement membranes formed by type IV collagen. It also correlates with long-term consequences of treatment. Conclusion. As a result of the destructed structure of sarcomeres and cardiac basement membrane hibernating myocardium is unable to provide a contractile function in the future. Morphological examination showed that viable cells were likely to function only as a protective mechanism in early scar formation. Keywords: left ventricular remodeling, hibernating myocardium, basement membrane, cardiomyocytes, matrix metalloproteinase 9, type IV collagen

SARS-CoV-2-induced non-bacterial endomyocarditis with the development of acquired heart defects

Patients with damage of the mitral, aortic and tricuspid valves and systolic myocardial dysfunction associated with previous SARS-CoV-2 infection are described. The diagnosis of acquired defect was established in 4 patients based on medical history, electrocardiography, echocardiography, magnetic resonance imaging of the heart, endomyocardial or intraoperative myocardial biopsy, and in one case, autopsy. The study of the myocardium included H&E, Van Gieson staining, immunohistochemical (IHC) study with antibodies to CD3, CD20, CD45, CD68, to the nucleocapsid and Spike proteins of SARS-CoV-2. Previous valve diseases (prolapse, bicuspid aortic valve) served as a background for the development of the defect in 2 patients. In all cases, IHC studies revealed coronavirus proteins, lymphocytic endocarditis and myocarditis, moderate fibrosis, and signs of connective tissue disorganization. High titers of anticardiac antibodies indicated an autoimmune mechanism for carditis. No signs of infective endocarditis or thromboembolic complications were identified in any case. In patients with an unclear nature of valvular heart defects, a previous new coronavirus infection should be identified and taken into account as a possible etiological factor. The simultaneous development of lymphocytic myocarditis significantly increases the risk of surgical intervention on the valves and requires an integrated approach to treatment.

136 A SHOCKING CASE OF MYOCARDITIS?

Abstract Background Cardiac involvement is common in systemic sclerosis (SSc), being a poor prognostic factor and the leading cause of mortality. Cardiac involvement ranges from a serendipitous diagnosis to relevant cardiac manifestations such as arrhythmias, pericardial effusion, myocardial dysfunction, and valvular diseases. Case report A 39-year-old female without remarkable medical history, on estroprogestinic therapy was admitted to our hospital in June 2020 after an out-of-hospital cardiovascular arrest due to ventricular fibrillation (VF). A coronary angiography ruled out coronary artery disease. Magnetic resonance imaging (MRI) showed a picture of acute myopericarditis characterized by late linear and nodular intramyocardial and subepicardial gadolinium enhancement of the septal and inferior segments of the left ventricle, with trivial oedema in the same location in turbo inversion recovery magnitude (TIRM) sequences. A subcutaneous-implantable cardiac defibrillator (S-ICD) was positioned for secondary prevention. At the 5 months ICD interrogation, 3 episodes of VF detected and treated by the device were documented. In December 2020 two more appropriate device interventions on polymorphic VT/VF occurred. A septal myocardial biopsy was then performed showing diffused replacement fibrosis in the absence of signs of acute inflammation or virus on the molecular investigation. In March 2021 the patient was referred to our institution after experiencing several ventricular arrhythmia episodes successfully treated by the ICD. A myocardial positron emission tomography (PET) scan documented the uptake of 18-fluorodeoxyglucose at middle and basal septum. A 'targeted' myocardial biopsy showed a substitutive fibroadiposis with sporadic inflammatory cells, in absence of cardiotropic viruses on the molecular investigation. We then initiated Anakinra, an anti-IL1 agent with an anti-inflammatory effect to prevent further development of "inflammation-driven fibrosis". Given the Raynaud's phenomenon reported by the patient, a capillaroscopy was performed, confirming isolated megacapillaries and apical haemorrhages, compatible with early pattern scleroderma. Immunologic examinations found homogeneous ANA 1:320 and anti-RNA polymerase III, while other autoantibodies, viral serologies and tubercular analysis were negative. In October 2021, the patient was readmitted to our hospital for recurrence of arrhythmic storm. A radiofrequency catheter-based ablation was performed. After a new episode of VT properly treated by the S-ICD in May 2022, the device was explanted, and a cardiac resynchronization therapy defibrillator was implanted. The genetic analysis identified a heterozygous deletion (c1262_1263del) of Lamin A (LMNA) classified as probably pathogenic in left ventricular arrhythmogenic cardiomyopathy or dilated cardiomyopathy. Conclusion A diagnosis of borderline myocarditis in anti-RNA-polymerase III+ systemic sclerosis with heterozygous deletion of LMNA was finally formulated, after having excluded pulmonary (PET, forced vital capacity, and CO lung diffusion in normal range), cutaneous, musculoskeletal and gastro-oesophageal involvement as well as a paraneoplastic nature (by total body PET) given the positivity for antiRNA-polymerase III.

470 MYOCARDIAL FIBROSIS IN ASYMPTOMATIC PATIENTS UNDERGOING SURGERY FOR MITRAL AND AORTIC VALVE REGURGITATION

Abstract Background Chronic heart valve regurgitation induces left ventricular (LV) volume overload, leading to the development of hypertrophy and progressive dilatation of the ventricle to maintain physiological cardiac output. In order to prevent potential irreversible LV structural changes, the identification of the best timing for treatment is pivotal. Objective To assess the presence and extent of fibrosis in myocardial tissue in asymptomatic patients with valvular heart disease (VHD) and preserved LV dimensions and function undergoing cardiac surgery. Methods Thirty-nine patients were enrolled. Sixteen patients were affected by aortic or mitral regurgitation: they were all asymptomatic, undergoing valve surgery according to VHD European Society of Cardiology guidelines. Twentythree patients with end-stage nonischemic dilated cardiomyopathy (DCM) and severe LV dysfunction undergoing cardiac surgery for implantation of a durable left ventricular assist device (LVAD) served as controls. During surgery, VHD patients underwent three myocardial biopsies at the level of the septum, the lateral wall and LV apex, while in LVAD patients the coring of the apex of the LV was used. For both groups, the tissue samples were analyzed on one section corresponding to the apical area. All slides were stained with hematoxylin and eosin and Masson's trichrome staining and further digitalized. The degree of fibrosis was then calculated as a percentage of the total area. Results Of 39 patients, 23 met the inclusion criteria: 12 had mitral or aortic insufficiency with a preserved ejection fraction and 11 had idiopathic dilated cardiomyopathy. Quantitative analysis of apical sections revealed a myocardial fibrosis amount of 10±6% in VHD patients, while in LVAD patients the mean apical myocardial fibrosis rate was 38±9%. In VHD patients, fibrosis was also present in the lateral wall (9±4%) and in the septum (9±6%). Conclusion Our case series study highlights the presence of tissue remodeling with fibrosis in asymptomatic patients with VHD and preserved LV function. According to our results, myocardial fibrosis is present at an early stage of the disease, well before developing detectable LV dysfunction and symptoms. Since the relationship between the progressive magnitude of myocardial fibrosis and potential prognostic implications are not yet defined, further studies on this topic are warranted.

73 WHICH IS THE CULPRIT OF THIS MYOCARDIAL INFILTRATION?

Abstract Introduction Myocardial infiltration by primary cardiac neoplasm is a rare condition and the pathological spectrum includes more widespread benign cell types, providing exceptional diagnostic and therapeutic challenges. Refractory heart failure, pericardial effusion and arrhythmias due to infiltrative mass are the most common clinical manifestations. Multimodality imaging, with echocardiography, computed tomography and magnetic resonance imaging, is essential to determine the characteristics of a cardiac tumor. Clinical case: A 35-year-old man without cardiovascular risk factors presented with two months of shortness of breath and weight loss. A previous history of acute myeloid leukemia undergoing allogenic bone marrow transplant was reported. Transthoracic echocardiography revealed an apical thrombus in left ventricle with inferior and septal hypokinesia conditioning mildly reduced ejection fraction, circumferential pericardial effusion without cardiac tamponade and abnormal right ventricular thickening (Figure 1). The cardiac magnetic resonance imaging confirmed diffuse thickening of the right ventricular free wall (maximum diameter 30 mm), suspected for myocardial infiltration, extending to the right atrium and left ventricle with an ischemic pattern of the inferior wall (Figure 2). No coronary artery disease was found by coronary angiography, but the right coronary artery was incorporated by the pathological tissue in chest computed tomography scan. Cardiac positron emission tomography demonstrated the presence of neoplastic tissue with increased metabolic activity, whose similar characteristics were also evident in the ascending aorta and aortic arch. Being the percutaneous endomyocardial biopsy inconclusive, a pericardiectomy was performed through a median sternotomy incision, showing widespread cardiac neoplastic infiltration. Histopathological analysis, done on samples taken by surgical myocardial biopsy, revealed tissue involvement by a rare and aggressive cardiac anaplastic large T-cell non-Hodgkin lymphoma (ALK -, Ki-67 90%). Few days after surgery, the patient developed a refractory cardiogenic shock and unluckily died before establishing an adequate therapy. Conclusion Primary cardiac lymphoma is very infrequent and the non-specificity of the symptoms makes the diagnosis extremely challenging and often limited to autopsy findings. Our case highlights the importance of an appropriate diagnostic algorithm that can allow an early diagnosis and an adequate therapy of this otherwise fatal pathology. In this condition surgical removal of the tumor in not indicated, being chemotherapy the only effective treatment. However, because of rarity, data are lacking to produce definitive regarding guidelines.

180 LONG TERM FOLLOW UP OF A NON-PROGRESSIVE LEFT MAIN CORONARY ARTERY FISTULA TO RIGHT ATRIUM

Abstract A 63 years old man, with multiple cardiovascular risk factor, presented at the emergency department with a transient ischemic attack during an hypertensive crisis. Electrocardiogram revealed a sinus rhythm and no sign of ischemia. No critical stenosis were detected at ultrasonography of the supra-aortic trunks. Brain CT showed an arachnoid cyst in right posterior cerebellar site. Transthoracic echocardiographic showed normal wall motion with a left ventricular ejection fraction of 66%. The transesophageal echocardiography, performed for searching possible emboligenic heart disease, revealed a fistulous aneurysmal formation arising from the left main coronary artery. Angio-CT confirmed a CAF between distal left main coronary artery and right atrium, with a retro-aortic serpiginous course and an ectasic vascular structure (above 8.35 mm), this pathological vessel also had an aneurismatic formation of maximum diameter of 1 cm. CT scan detected also a 50% soft eccentric plaque in mid circumflex coronary artery and a less than 50% soft eccentric plaque in the right coronary artery. An elective hospitalization was performed in order to better assess the CAF. Coronary angiography revealed no significant coronary atherosclerotic disease and confirmed the CAF with its convoluted course. No left to right shunt was found either in cardiac magnetic resonance (Qp/Qs close to 1) or in right heart catheterization. Maximal stress test with cycloergometer was negative for clinical and electrocardiographic inducible ischemia (120W). CAF is a rare vascular abnormality, occurring in only 0.002% of the general population. The majority of CAFs have a congenital origin, but occasionally they may be acquired after cardiac surgery or repeated myocardial biopsies in cardiac transplantation. The CAFs may increase in size over time, although this does not occur invariably, and complications include: myocardial ischemia (due to myocardial ‘steal’), thrombosis and embolism, heart failure, atrial fibrillation, rupture, endocarditis/endarteritis, arrhythmias and also spontaneous rupture of the CAF causing hemopericardium. Current treatment options for CAF include surgery or transcatheter closure. Considered the age of the patient, the absence of clinical symptoms and the absence of left to right shunt, a conservative strategy was chosen. The patient had strict follow up, with clinical and echocardiographic assessment every 6 months, and with annually CT scan and stress test. During these 9 years of follow up the CAF remained stable, and the patients clinically asymptomatic.

48 A CASE OF RECURRENT VENTRICULAR TACHYCARDIA IN A PATIENT WITH GRANULOMATOSIS WITH POLYANGIITIS WITH A CHALLEGING IDENTIFICATION OF ARRHYTHMIC SUBSTRATE: THE ROLE OF MULTIMODALITY IMAGING

Abstract Background Granulomatosis with polyangiitis (GPA), previously known as Wegener's granulomatosis, is a pulmonary-renal syndrome affecting small and medium sized blood vessels. Cardiac involvement is rare and generally includes pericarditis, myocarditis and aortic valve disease. We report a case of recurrent sustained ventricular tachycardia (VTs) in a patient with GPA. Case summary A 67-year-old man with past medical history of GPA presented palpitations, chest pain and episodes of presyncope. Electrocardiographic tracing upon ED presentation showed sustained monomorphic VT (fig.1) associated with global hypokinesia of the left ventricle and moderately reduced ejection fraction at transthoracic echocardiography (TTE). As the patient was hemodynamically stable, prompt treatment with amiodarone was adopted with successful recovery of sinus rhythm. After a few hours, TTE was normal. However, as troponin I was markedly elevated, coronarography was performed and coronary disease was ruled out. Contrast-enhanced cardiac magnetic resonance imaging (ceCMR) revealed late gadolinium enhancement in basal anteroseptal mid wall, suggestive of myocardial scar tissue with non-ischemic pattern. No sustained ventricular arrhythmias were induced during electrophysiological study (EPS), even with an aggressive protocol (up to 4 extra stimuli and ventricular refractoriness) and electro-anatomical mapping of both ventricles failed to show any arrhythmic substrate. An implantable cardioverter defibrillator (ICD) was then implanted. After 4 months the patient was admitted for multiple episodes of sustained VT (with cycle length in the ICD monitoring window) refractory to drugs and three external defibrillations. Repeated EPS failed to induce sustained arrhythmias. High-density electroanatomical mapping of the right ventricle, however, showed fragmented potentials in the mid-posterior septal wall (fig. 2-3). After myocardial biopsy of the region of interest, radiofrequency catheter ablation of the area was performed with regression of the potentials. The results of endomyocardial biopsy demonstrated fibrosis. At 5 months of follow-up, the patient didn't relapse. Discussion Multimodality imaging is of paramount importance in identifying arrhythmogenic substrate and in characterizing the specific anatomical–functional components of VT circuits. In our patient high-density electroanatomical mapping was able to identify fragmented potentials and define the ablation target area, despite the mismatch with ceCMR.

Targeting cardiomyocyte ADAM10 ectodomain shedding promotes survival early after myocardial infarction.

After myocardial infarction the innate immune response is pivotal in clearing of tissue debris as well as scar formation, but exaggerated cytokine and chemokine secretion with subsequent leukocyte infiltration also leads to further tissue damage. Here, we address the value of targeting a previously unknown a disintegrin and metalloprotease 10 (ADAM10)/CX3CL1 axis in the regulation of neutrophil recruitment early after MI. We show that myocardial ADAM10 is distinctly upregulated in myocardial biopsies from patients with ischemia-driven cardiomyopathy. Intriguingly, upon MI in mice, pharmacological ADAM10 inhibition as well as genetic cardiomycyte-specific ADAM10 deletion improves survival with markedly enhanced heart function and reduced scar size. Mechanistically, abolished ADAM10-mediated CX3CL1 ectodomain shedding leads to diminished IL-1β-dependent inflammation, reduced neutrophil bone marrow egress as well as myocardial tissue infiltration. Thus, our data shows a conceptual insight into how acute MI induces chemotactic signaling via ectodomain shedding in cardiomyocytes.

A circular network of purine metabolism as coregulators of dilated cardiomyopathy

BackgroundThe crosstalk of purine biosynthesis and metabolism exists to balance the cell energy production, proliferation, survival and cytoplasmic environment stability, but disorganized mechanics of with respect to developing heart failure (HF) is currently unknown.MethodsWe conducted a multi-omics wide analysis, including microarray-based transcriptomes, and full spectrum metabolomics with respect to chronic HF. Based on expression profiling by array, we applied a bioinformatics platform of quantifiable metabolic pathway changes based on gene set enrichment analysis (GSEA), gene set variation analysis (GSVA), Shapley Additive Explanations (SHAP), and Xtreme Gradient Boosting (XGBoost) algorithms to comprehensively analyze the dynamic changes of metabolic pathways and circular network in the HF development. Additionally, left ventricular tissue from patients undergoing myocardial biopsy and transplantation were collected to perform the protein and full spectrum metabolic mass spectrometry.ResultsSystematic bioinformatics analysis showed the purine metabolism reprogramming was significantly detected in dilated cardiomyopathy. In addition, this result was also demonstrated in metabolomic mass spectrometry. And the differentially expressed metabolites analysis showing the guanine, urea, and xanthine were significantly detected. Hub markers, includes IMPDH1, ENTPD2, AK7, AK2, and CANT1, also significantly identified based on XGBoost, SHAP model and PPI network.ConclusionThe crosstalk in the reactions involved in purine metabolism may involving in DCM metabolism reprogramming, and as coregulators of development of HF, which may identify as potential therapeutic targets. And the markers of IMPDH1, ENTPD2, AK7, AK2, and CANT1, and metabolites involved in purine metabolism shown an important role.

Abstract 14605: Deleterious Effects of Type 2 Diabetes on the Myocardium of Patients With Aortic Stenosis

Introduction: Type 2 diabetes (T2D) may induce myocardial alterations and is associated with an increased risk of heart failure. T2D is often associated to LV pressure overload, as encountered in aortic stenosis (AS). Hypothesis: We hypothesized that T2D has deleterious effects on LV remodelling and function in patients with severe AS and we explored some underlying mechanisms. Methods: Non diabetic and T2D patients with severe AS, referred for aortic valve replacement, were included. Patients with atrial fibrillation, LV ejection fraction (LVEF) <50%, significant coronaropathy or other valvulopathy were excluded. Before surgery, patients underwent blood tests and a complete echocardiography. During surgery, a LV myocardium biopsy was obtained for histological analysis. Results: We included 82 patients, including 33 T2D. Hypertension and dyslipidaemia were more frequent in T2D patients. Severity of the AS was similar between the two groups. Echocardiography revealed that T2D was associated with a more pronounced LV hypertrophy (mass LV 3D/hight 2.7 ; p=0.03) and systolic dysfunction (Global Longitudinal Strain (GLS) 15±3 vs 18±2 %; p<0.01). In addition, LV ventricular filling pressure was more often increased in T2D patients (50% of T2D vs 26% of non-diabetics; p=0.03). Circulating levels of leptin and endothelin 1 were significantly higher in T2D. Interestingly leptin level correlates with diastolic function (left atrial strain; r=-0.25, p=0.01) and Endothelin 1 with LV mass (r=0.27, p<0.001) and GLS. Histologic analysis revealed an enhanced cardiomyocyte hypertrophy in T2D biopsies but similar degrees of fibrosis. Proximity ligation assay displayed a significant decreased proximity between the IP3-receptor and the mitochondrial porin VDAC in T2D hearts suggesting a reduced reticulum-mitochondria Ca 2+ transfer. Conclusions: T2D is associated with an increased LV remodelling and dysfunction in patients with a severe AS as well as an increased circulating level of leptin and endothelin-1. Our results also suggest a potential role of reticulum-mitochondria Ca 2+ uncoupling.

Biochemical and biophysical properties of an unreported T96R mutation causing transthyretin cardiac amyloidosis

Objectives We presented an unreported T96R mutation induced transthyretin cardiac amyloidosis (ATTR). The biochemical and biophysical properties were explored to support its pathogenicity. Background Understanding the biochemical and biophysical nature of genetically mutated transthyretin (TTR) proteins is key to provide precise medical cares for ATTR patients. Results Genetic testing showed heterozygosity for the T96R pathogenic variant c.347C > G (ATTR p.T116R) after myocardial biopsy confirmed amyloid deposition. Biochemical characterizations revealed slight perturbation of its thermodynamic stability (Cm=3.7 M for T96R, 3.4 M for WT and 2.3 M for L55P (commonly studied TTR mutant)) and kinetic stability (t1/2=39.8 h for T96R, 42 h for WT and 4.4 h in L55P). Crosslinking experiment demonstrated heterozygous subunit exchange between wild-type and TTR T96R protein destabilized the tetramer. Inhibitory effect of tafamidis and diflunisal on TTR T96R fibril formation was slightly less effective compared to WT and L55P. Conclusions A novel T96R mutation was identified for TTR protein. Biochemical and biophysical analyses revealed slightly destabilized kinetic stability. T96R mutation destabilized heterozygous protein but not proteolytic degradation, explaining its pathogenicity. Inhibitory effect of small molecule drugs on T96R mutation was different, suggesting personalized treatment may be required.

Calcineurin-NFAT dynamics correspond to cardiac remodeling during aortic banding and debanding, mimicking aortic valve replacement.

Aortic valve stenosis (AS) is a major health problem. Extensive myocardial remodeling increases operative risk and might lead to incomplete reverse remodeling with persistent symptoms after aortic valve replacement (AVR); this makes the optimal timing of AVR a clinical challenge. The pathogenesis behind incomplete reverse remodeling is unclear. Central among signaling pathways in the remodeling heart is the pro-hypertrophic Ca2+-activated calcineurin and its downstream nuclear factor of activated T-cell (NFATc1-c4) transcription factors. We investigated calcineurin-NFATc dynamics in patient and mouse hearts during remodeling and reverse remodeling. Myocardial biopsies were obtained from AS patients during AVR and left ventricles harvested from mice subjected to aortic banding (AB) and debanding (DB). The transcript and protein of the NFATc-responsive gene regulator of calcineurin 1-4 (RCAN1-4) and luciferase activity in NFAT-luciferase mice were used as read-outs for calcineurin-NFATc activity. Calcineurin-NFATc activation was sustained through AB 24 h to 18 weeks and elevated in AS patients. All four NFATc isoforms were elevated in AS, while NFATc4 was persistently elevated during chronic remodeling after AB in mice. NFAT activation remained reversible when 1week's AB was followed by 1week's DB and accompanied functional improvement. However, when DB for 1week followed AB for 4weeks, NFAT activation was not reversed. In conclusion, calcineurin-NFAT dynamics correspond with cardiac remodeling and reverse remodeling during experimental AB and DB. Our data suggest that calcineurin-NFATc attenuation is important for reverse remodeling and outcomes after AVR for AS.

Bioinformatics Analysis of Common Differential Genes of Viral Myocarditis and Dilated Cardiomyopathy: Screening for Potential Pharmacological Compounds.

(1) Background: The mechanism of viral myocarditis (VMC) progression to dilated cardiomyopathy (DCM) remains unclear. The aim of this study was to identify key genes in the progression of VMC to DCM, so as to find potential therapeutic drugs and provide insights for future research. (2) Methods: Differential expression analysis of GSE4172 and GSE17800 from the Gene Expression Omnibus (GEO) database was performed using GEO2R, which contained genome-wide analysis of myocardial biopsies from VMC and DCM, respectively. We used the Venn diagram analysis to screen the common differentially expressed genes (DEGs). GO functional enrichment analysis and KEGG pathway analysis were also performed. Then we conducted protein–protein interaction (PPI) networks using STRING and identified hub genes using Cytoscape. Finally, we used cMAP to screen out candidate compounds targeting these hub genes; (3) Results: In total, 2143 DEGs for VMC and 1365 DEGs for DCM were found. Then a total of 191 common DEGs were identified. Biological processes and pathway involved in these genes mainly include GABA−gated chloride ion channel activity and Rap1 signaling pathway. A total of 14 hub genes were identified. PPI network showed these hubs mainly enriched in regulation of WNT signaling pathway and GABA-gated chloride ion channel activity. Subgroup analysis of Severe VMC cohort revealed 10 hub genes which mainly clustered in GABA channel activity, extracellular matrix remodeling and sarcomere dysfunction. Using cMAP, we obtained top 10 potential medications, but only amlodipine is currently viable; (4) Conclusions: Our study finds the hub genes and reveals the important role of GABA-gated chloride ion channel, Rap1 signaling pathway, WNT signaling pathway, extracellular matrix remodeling and sarcomere dysfunction in the progression from VMC to DCM. Amlodipine is a potential viable drug in preventing the progression of VMC to DCM.

Diving in the big blue: Atypical Mott cells in rapidly fatal primary amyloidosis.

A 75-year-old man with no previous medical history presented at the emergency unit with asthenia, anorexia, weight loss, and progressively increasing dyspnea revealing acute heart failure (N-terminal pro b-type natriuretic peptide:16 667 ng/L; troponemia: 47 ng/L). Echocardiography showed a granular appearance of the myocardium and interventricular septal hypertrophy, suggestive of amyloidosis. Chemistry disclosed high levels of immunoglobulin kappa light chains at 1240 mg/L (lambda light chains 14 mg/L; κ/λ ratio 86) and a detectable but unquantifiable IgA κ peak. Myocardial biopsies pathology showed an endocardium thickened by fibrosis. Within the myocardium, the presence of interstitial fibrillary deposits stained by Congo red and birefringent in polarized light confirmed the diagnosis of cardiac amyloid light-chain (AL) amyloidosis. The search for other organ damage disclosed vegetative involvement with orthostatic hypotension, icteric cholestasis (bilirubin 51.8 mg/L), undocumented digestive involvement (diarrhea with evocative endoscopic lesions), and glomerulonephritis (urinary proteinuria 4 g/24 h with 3 g/24 h albumin and 1 g/24 h immunoglobulin light chains). A bone marrow aspirate displayed 17% of plasma cells. Interestingly, a particular pattern of huge atypical Mott cells was identified (Figure 1A,B). The latter had so many cytoplasmic inclusions that the cytoplasm, and the nucleus could not be discriminated. These atypical cells are however plasma cells with an endoplasmic reticulum loaded with immunoglobulins and should be integrated as such in cell counts. Classical plasma cells and typical Mott cells with a few Russel bodies were also present (Figure 1C) indicating a continuum in the shape of the diseased plasma cells. Treatment with cyclophosphamide–bortezomib–dexamethasone-daratumumab was initiated in emergency. Unfortunately, the patient died 3 days later, of multiple organ failure. No additional septic or toxic causes could be identified. Mott cells are activated plasma cells containing intracytoplasmic inclusions with a “bunch of grapes” appearance. These inclusions, called Russell bodies, are dilated cisternae of the endoplasmic reticulum containing condensed immunoglobulins. They were identified in 1901 by the surgeon F.W Mott in the brains of monkeys with trypanosomiasis. Mott cells have been described in various pathological conditions: reactive plasmacytosis, monoclonal gammopathies, high grade B-cell lymphomas, Wiskott-Aldrich syndrome, and von Recklinghausen neurofibromatosis. AL amyloidosis is caused by clonal expansion of plasma cells producing misfolded immunoglobulin light chains responsible for the deposition of insoluble fibrillar proteins in many organs. Those most frequently affected are the kidneys, heart, liver, and peripheral nervous system. AL amyloidosis is a rare disease, and its diagnosis is often delayed. Although associated with a poor prognosis, AL amyloidosis presents a heterogeneous clinical expression and evolution. To our knowledge, the presence of Mott cells has rarely been described in this pathology. KR, ME, and BLC wrote the manuscript. KR, ME, and BLC performed biological analyses. CS treated the patient. All authors critically reviewed the manuscript. The authors have no conflict of interest to disclose. The authors received no specific funding for this work. The research was conducted in accordance with the principles embodied in the Declaration of Helsinki and in accordance with local statutory requirements.

Association between global longitudinal strain and myocardial fibrosis biomarkers in patients with end-stage chronic kidney disease

Abstract Introduction Myocardial fibrosis represents a landmark characteristic of uremic cardiomyopathy, leading to a high burden of arrhythmias, diastolic dysfunction (DD) and ultimately heart failure in this population. Collagen-derived biomarkers (Procollagen type I carboxy-terminal propeptide (PICP), Procollagen type III N-terminal peptide (P3NP)) and Galectin-3 (Gal-3) are associated with the extent of myocardial fibrosis on myocardial biopsy. Global longitudinal strain (GLS) as assessed by two-dimensional speckle tracking echocardiography (2D-STE) has been shown to detect subclinical myocardial dysfunction in various populations. The correlation between GLS and the serum level of these biomarkers has not been studied so far. Purpose The aim of this study was to evaluate the association between the left ventricular GLS measured by 2D-STE and the serum level of three biomarkers (PICP, P3NP, Gal-3) known to be associated with the presence of myocardial fibrosis, in patients with end-stage renal disease (ESRD), not on dialysis. Methods We conducted a cross-sectional study that included 135 patients with an eGFR (CKD-EPI) <15 ml/min/1.73 m2, stable, asymptomatic, not on dialysis. We performed a complete transthoracic echocardiography with 2D-STE and determined serum levels of PICP, P3NP and Gal-3 by ELISA. Patients in atrial fibrillation, with a permanent pacemaker or with a poor acoustic window were excluded. Results The mean age was 59.2±15.5 (median 61 years), 44% of the patients were males, 33% were diabetic, 11% had a history of myocardial infarction and 14% were smokers. The average volumetric ejection fraction (EF) was 54.4±9.8% (median 55%), with only 6.3% of the patients having an EF <40%. The majority of the patients (86.6%) had at least grade I DD, with only 5.3% having a restrictive pattern (grade III DD). The mean GLS was −16.8% ± 0.1 (median −17%). The average serum levels of PICP, P3NP and Gal-3 were 440.2±139.6, 244.9±380.1 and 10.8±6.7, respectively. After regression analysis, GLS was correlated with PICP, P3NP and Gal-3 levels (p=0.005, r=0.88; p=0.001, r=0.75; and p=0.006, r=0.81 respectively). Additionally, GLS was inversely correlated with the severity of DD (p=0.0001, r=0.84). In multiple regression analysis of a model consisting of GLS, PICP, P3NP and Gal-3, the serum level of PICP counted for 34% of the variance of GLS (R2=0.559, p=0.002, F=32.39). Conclusions In conclusion, this study proves that although stable and asymptomatic, patients with ESRD have lower values of GLS, a high proportion of DD and higher values of PICP, P3NP and Gal-3, when compared with the general population, in spite of a normal EF. Our study is the first to demonstrate that these biomarkers correlated with GLS in patients with ESRD, suggesting that GLS could represent an important tool for estimating the amount of fibrosis and risk stratification in this population. Funding Acknowledgement Type of funding sources: None.

Histology-verified myocardial fibrosis and quantification in severe AS patients: correlation with non-invasive LV myocardial tissue assessment

Abstract Background Myocardial fibrosis (MF) is a common finding and a potential adverse prognostic marker in several cardiac diseases, including in severe aortic stenosis (AS). While histological analysis obtained through endomyocardial biopsy remains the gold-standard for MF assessment, non-invasive cardiac imaging may offer surrogate biomarkers for fibrosis. We tried to assess the correlation between MF quantification at histopathology and cardiac magnetic resonance (CMR)-derived tissue characterization data in patients with severe AS. Methodology Single-center prospective cohort enrolling 71 patients with severe symptomatic high-gradient AS undergoing surgical aortic valve replacement (SAVR) (mean age 71±9 years; 49% male, mean valvular transaortic gradient 60±20 mmHg; mean left ventricle [LV] ejection fraction 58±9%). Those with past history of myocardial infarction or cardiomyopathy were excluded. All patients underwent pre-operative CMR study with LV tissue characterization and quantification. Normal T1 mapping value was defined as >1021ms as per center protocol. Myocardial tissue was obtained during SAVR either through myocardial biopsy at basal LV septum or harvested from surgical myectomy specimens. Masson's trichrome stain was used for collagen/fibrosis assessment. Automatic quantification was obtained at QuPathTM digital pathology software after applying a dedicated artificial intelligence algorithm on ultra-high-resolution digital slide scanning images. Results Histology-confirmed MF was observed in all patients (median percentage of fibrotic myocardial tissue 15% [IQR 9–22%]). Median global T1 mapping and extracellular volume (ECV) percentage was 1048ms (IQR 1027–1078) and 24% (IQR 20–30%), respectively. Late gadolinium enhancement (LGE) with a non-ischemic pattern was present in 42 patients (59%) with a median LGE mass of 5.8g [IQR 1.0–10.2]; median percentage of 3.7% [IQR 0.6–10.4]. While neither T1 mapping (global or basal LV septum), ECV nor LGE had any significant correlation with histology-confirmed MF (Figure 1) the vast majority had significantly elevated global and basal LV septum T1 mapping – 81% and 92%, respectively. Conclusion In this single-center prospective study, microscopic MF was present in all patients with severe symptomatic high-gradient AS, was accompanied by elevated T1 mapping values but no correlation was found between myocardial fibrosis at histopathology analysis and CMR-derived LV tissue characterization parameters. This may not only stem from sampling (single point biopsy vs. whole myocardial tissue assessment) but also from distinct evaluation of different types of fibrosis by different methods. Funding Acknowledgement Type of funding sources: None.

Relative apical sparing in severe aortic stenosis: does it mean concomitant amyloid cardiomyopathy?

Abstract Background Relative apical sparing (RAS) of left ventricular (LV) longitudinal strain (LS) is a red flag marker for the suspicion of amyloid cardiomyopathy. However, it has also been described in patients with severe aortic stenosis (AS). Aim To assess the prevalence of RAS in patients with severe symptomatic AS referred for surgical aortic valve replacement (AVR), to evaluate its clinical significance and assess its presence after surgery. Methods We prospectively studied 135 consecutive patients (age: 73 y [IQR 68–77 y], 49% men) with severe symptomatic AS – mean transaortic pressure gradient (AVmean): 60.9±17.7 mmHg; mean aortic valve area: 0.7±0.2 cm2, referred for surgical AVR with no previous history of ischemic cardiomyopathy or other. Beyond 12 lead-ECG and transthoracic echocardiography (TTE), all patients underwent cardiac magnetic resonance (CMR) before surgery. RAS was defined by the ratio >1 of average LS at apical segments/sum of the average basal and mid LS at speckle tracking analysis. AVR with septal myocardial biopsy, for investigational purposes, was performed in 80 patients. AS severity indexes, LV remodeling and tissue characterization parameters were compared in both groups of patients, with and without RAS. LS deformation pattern was reassessed at 3–6 months after AVR. Results RAS was present in 24 patients (18%). In the whole cohort there were neither pseudoinfarct pattern or low voltage ECG criteria, nor infiltration suspicion from CMR (native T1 value 1053 ms [IQR 1025–1071 ms] for institutional reference values: 972–1070 ms; ECV 24% [IQR 21–27%]). None of the patients had amyloid deposition at histopathology. Overall, mean CMR LV ejection fraction (LVEF) was 59.6±10.5% and 98 patients (74%) had non-ischemic delayed enhancement, with a median fibrosis fraction of 4.1% [IQR 1.6–7.8%]. RAS cohort had a significantly higher AVmean gradient, relative wall thickness, maximum septal thickness, peak systolic dispersion, with lower global LS at TTE, as well as higher LV mass and lower LVEF at CMR. RAS group has also higher NT-proBNP ambulatory values (Table 1). Follow-up evaluation after AVR revealed RAS disappearance in 19 patients (79.2%). Conclusions RAS occurs in almost one-fifth of the patients in this cohort despite the absence of signs of myocardial infiltration. This deformation pattern elapses with worse indexes of LV remodeling consistent with a more advanced stage of the disease, being reversible after AVR, which stands for the absence of concomitant myocardial infiltration. Funding Acknowledgement Type of funding sources: None.

Myocardial ischaemia in cardiac amyloidosis: a change of perspective

Abstract Introduction Cardiac involvement is the main driver of clinical outcomes in systemic amyloidosis; however many clinical observations are not explained by the concept of replacement of the interstitium by amyloid material. Preliminary studies support the hypothesis that myocardial ischaemia contributes to cellular damage. Purpose This study assesses the presence and mechanisms of myocardial ischaemia using cardiovascular magnetic resonance (CMR) with multiparametric mapping and histopathological assessment. Methods Ninety-two patients with cardiac amyloidosis (CA) (AL = 41, ATTR = 51) and 97 without CA (3-vessel coronary disease (3VD) = 47, unobstructed coronary arteries = 26, healthy volunteers (HV) = 24) underwent quantitative stress perfusion CMR with myocardial blood flow (MBF) mapping. Twenty-six myocardial biopsies and 3 explanted hearts with CA were analysed histopathologically. Results Stress MBF was severely reduced in patients with CA with lower values than patients with 3VD, unobstructed coronary arteries and HV (CA = 1.03±0.51 ml/min/g, 3VD = 1.35±0.50 ml/min/g, Unobstructed coronaries = 2.92±0.52 ml/min/g, HV = 3.14±0.69 ml/min/g; CA vs 3VD p=0.008, CA vs Unobstructed coronaries p<0.001, CA vs HV p<0.001). After adjustment for intracellular volume the MBF in patients with CA remained significantly lower than in HV (stress MBF/ICV: AL = 2.24±1.12, ATTR = 2.22±0.93, HV = 4.38±1.06; AL vs. ATTR p=1.000, AL vs HV p<0.001, ATTR vs. HV p<0.001). Myocardial perfusion reserve (MPR) was severely reduced in CA patients, compared to HV and patients with unobstructed coronary arteries, with the degree of reduction being comparable only to patients with 3VD (CA = 1.55±0.60, 3VD = 1.54±0.51, unobstructed coronaries = 2.78±0.70, HV = 4.08±0.86; CA vs 3VD p=1.000, CA vs unobstructed coronary arteries p<0.001, CA vs. HV p<0.001). Myocardial perfusion abnormalities correlated with amyloid burden, systolic and diastolic function, structural parameters and blood biomarkers (p<0.05). Biopsies demonstrated diffuse hypoxia with abnormal VEGF staining in cardiomyocytes and endothelial cells. Amyloid infiltration in intramural arteries was associated with severe lumen reduction in 20% of vessels, and severe reduction in capillary density. Conclusion CA is associated with severe myocardial ischaemia demonstrable by histology and CMR stress perfusion mapping. Histological evaluation indicates a complex pathophysiology, where systolic and diastolic dysfunction, amyloid infiltration of the epicardial arteries and disruption and rarefaction of the capillaries play a role in contributing to myocardial ischaemia. Funding Acknowledgement Type of funding sources: None.