Endomyocardial biopsy: safety and prognostic utility in paediatric and adult myocarditis in the European Society of Cardiology EURObservational Research Programme Cardiomyopathy and Myocarditis Long-Term Registry.

BACKGROUND AND AIMS: Contemporary multicentre data on clinical and diagnostic spectrum and outcome in myocarditis are limited. Study aims were to describe baseline features, 1-year follow-up, and baseline predictors of outcome in clinically suspected or biopsy-proven myocarditis (2013 European Society of Cardiology criteria) in adult and paediatric patients from the EURObservational Research Programme Cardiomyopathy and Myocarditis Long-Term Registry. METHODS: Five hundred eighty-one (68.0% male) patients, 493 adults, median age 38 (27-52) years, and 88 children, aged 8 (3-13) years, were divided into 3 groups: Group 1 (n = 233), clinically suspected myocarditis with abnormal cardiac magnetic resonance; Group 2 (n = 222), biopsy-proven myocarditis; and Group 3 (n = 126) clinically suspected myocarditis with normal or inconclusive or no cardiac magnetic resonance. Baseline features were analysed overall, in adults vs. children, and among groups. One-year outcome events included death/heart transplantation, ventricular assist device (VAD) or implantable cardioverter defibrillator (ICD) implantation, and hospitalization for cardiac causes. RESULTS: Endomyocardial biopsy, mainly right ventricular, had a similarly low complication rate in children and adults (4.7% vs. 4.9%, P = NS), with no procedure-related death. A classical myocarditis pattern on cardiac magnetic resonance was found in 31.3% of children and in 57.9% of adults with biopsy-proven myocarditis (P < .001). At 1-year follow-up, 11/410 patients (2.7%) died, 7 (1.7%) received a heart transplant, 3 underwent VAD (0.7%), and 16 (3.9%) underwent ICD implantation. Independent predictors at diagnosis of death or heart transplantation or hospitalization or VAD implantation or ICD implantation at 1-year follow-up were lower left ventricular ejection fraction and the need for immunosuppressants for new myocarditis diagnosis refractory to non-aetiology-driven therapy. CONCLUSIONS: Endomyocardial biopsy was safe, and cardiac magnetic resonance using Lake Louise criteria was less sensitive, particularly in children. Virus-negative lymphocytic myocarditis was predominant both in children and adults, and use of immunosuppressive treatments was low. Lower left ventricular ejection fraction and the need for immunosuppressants at diagnosis were independent predictors of unfavourable outcome events at 1 year.

Long-Term Clinical-Pathologic Results of Enzyme Replacement Therapy in Prehypertrophic Fabry Disease Cardiomyopathy.

BACKGROUND: The limited ability of enzyme replacement therapy (ERT) in removing globotriaosylceramide from cardiomyocytes is recognized for advanced Fabry disease cardiomyopathy (FDCM). Prehypertrophic FDCM is believed to be cured or stabilized by ERT. However, no pathologic confirmation is available. We report here on the long-term clinical-pathologic impact of ERT on prehypertrophic FDCM. METHODS AND RESULTS: Fifteen patients with Fabry disease with left ventricular maximal wall thickness ≤10.5 mm at cardiac magnetic resonance required endomyocardial biopsy because of angina and ventricular arrhythmias. Endomyocardial biopsy showed coronary small-vessel disease in the angina cohort, and vacuoles in smooth muscle cells and cardiomyocytes ≈20% of the cell surface containing myelin bodies at electron microscopy. Patients received α-agalsidase in 8 cases, and ß-agalsidase in 7 cases. Both groups experienced symptom improvement except 1 patients treated with α-agalsidase and 1 treated with ß-agalsidase. After ERT administration ranging from 4 to 20 years, all patients had control cardiac magnetic resonance and left ventricular endomyocardial biopsy because of persistence of symptoms or patient inquiry on disease resolution. In 13 asymptomatic patients with FDCM, left ventricular maximal wall thickness and left ventricular mass, cardiomyocyte diameter, vacuole surface/cell surface ratio, and vessels remained unchanged or minimally increased (left ventricular mass increased by <2%) even after 20 years of observation, and storage material was still present at electron microscopy. In 2 symptomatic patients, FDCM progressed, with larger and more engulfed by globotriaosylceramide myocytes being associated with myocardial virus-negative lymphocytic inflammation. CONCLUSIONS: ERT stabilizes storage deposits and myocyte dimensions in 87% of patients with prehypertrophic FDCM. Globotriaosylceramide is never completely removed even after long-term treatment. Immune-mediated myocardial inflammation can overlap, limiting ERT activity.

The inflammatory spectrum of cardiomyopathies.

Infiltration of the myocardium with various cell types, cytokines and chemokines plays a crucial role in the pathogenesis of cardiomyopathies including inflammatory cardiomyopathies and myocarditis. A more comprehensive understanding of the precise immune mechanisms involved in acute and chronic myocarditis is essential to develop novel therapeutic approaches. This review offers a comprehensive overview of the current knowledge of the immune landscape in cardiomyopathies based on etiology. It identifies gaps in our knowledge about cardiac inflammation and emphasizes the need for new translational approaches to improve our understanding thus enabling development of novel early detection methods and more effective treatments.

Infertility in Fabry's Disease: role of hypoxia and inflammation in determining testicular damage.

Introduction: Fabry's disease (FD) is a genetic X-linked systemic and progressive rare disease characterized by the accumulation of globotriaosylceramide (GB3) into the lysosomes of many tissues. FD is due to loss-of-function mutations of α-galactosidase, a key-enzyme for lysosomal catabolism of glycosphingolipids, which accumulate as glycolipid bodies (GB). In homozygous males the progressive deposition of GB3 into the cells leads to clinical symptoms in CNS, skin, kidney, etc. In testis GB accumulation causes infertility and alterations of spermatogenesis. However, the precise damaging mechanism is still unknown. Our hypothesis is that GB accumulation reduces blood vessel lumen and increases the distance of vessels from both stromal cells and seminiferous parenchyma; this, in turn, impairs oxygen and nutrients diffusion leading to subcellular degradation of seminiferous epithelium and sterility. Methods: To test this hypothesis, we have studied a 42-year-old patient presenting a severe FD and infertility, with reduced number of spermatozoa, but preserved sexual activity. Testicular biopsies were analyzed by optical (OM) and transmission electron microscopy (TEM). Activation and cellular localization of HIF-1α and NFκB was analyzed by immunofluorescence (IF) and RT-PCR on homogeneous tissue fractions after laser capture microdissection (LCMD). Results: OM and TEM showed that GB were abundant in vessel wall cells and in interstitial cells. By contrast, GB were absent in seminiferous epithelium, Sertoli's and Leydig's cells. However, seminiferous tubular epithelium and Sertoli's cells showed reduced diameter, thickening of basement membrane and tunica propria, and swollen or degenerated spermatogonia. IF showed an accumulation of HIF-1α in stromal cells but not in seminiferous tubules. On the contrary, NFκB fluorescence was evident in tubules, but very low in interstitial cells. Finally, RT-PCR analysis on LCMD fractions showed the expression of pro-inflammatory genes connected to the HIF-1α/NFκB inflammatory-like pathway. Conclusion: Our study demonstrates that infertility in FD may be caused by reduced oxygen and nutrients due to GB accumulation in blood vessels cells. Reduced oxygen and nutrients alter HIF-1α/NFκB expression and localization while activating HIF-1α/NFκB driven-inflammation-like response damaging seminiferous tubular epithelium and Sertoli's cells.

Novel Genetic Microvascular Dysplasia Causing Hypoperfusion of Cardiac, Renal, and Cerebral Circulation.

BACKGROUND: Microvascular disorders represent an uncommon site of tissue hypo-perfusion and damage. Various genetic and acquired causes can be involved. A 65-year-old man was admitted because of refractory angina, which he had had since the age of 30 years, micro-hematuria, and recurrent transitory ischemic attacks from the age of 64. METHODS: Hematochemical studies, ECG, Holter monitoring, 2D-echo, cardiac magnetic resonance (CMR), CTA of cerebral vessels, endomyocardial coronary angiography, and kidney biopsy processes were undertaken. Gene mutation analysis was conducted using next-generation sequencing, which included more than 5000 genes associated with inherited diseases. RESULTS: Hematochemical findings were unremarkable. The ECG, Holter, 2D-echo, and CTA of brain vessels were normal. Cerebral magnetic resonance showed the presence of multiple small foci of ischemia. Coronary and ventricular angiography showed normal arteries with remarkably slow flow and multiple biventricular micro-aneurysms. At the endomyocardial biopsy, five of seven arterioles presented severe lumen obstruction due to hypertrophy and disarray of the muscular coat. Similarly, obstructed pre-glomerular arteries with glomerular sclerosis were seen at the renal biopsy. Genetics identified mutations in the ABCC6, MMP2, and XYLT1 genes, which play pivotal roles in the extracellular matrix. CONCLUSION: This study described a new genetic microvascular obstructive disease causing progressive hypo-perfusion of the human brain, heart, and kidney.

Hypertrophic obstructive cardiomyopathy caused by Fabry disease: implications for surgical myectomy.

Hypertrophic obstructive cardiomyopathy can be the phenotype of storage disorders as Fabry disease cardiomyopathy. In this instance, its recognition through GLA gene analysis and preventive administration of enzyme replacement therapy may reduce heart failure risk of surgical septal myectomy (SSM). A 59-year-old man was referred for SSM as dyspnoea and low threshold muscle fatigue associated to severe left ventricular outflow obstruction (gradient of 100 mmHg) due to both interventricular septal hypertrophy and mitral leaflet systolic anterior motion were not controlled by metoprolol 100 mg bid. Electrocardiogram showed sinus rhythm and a complete left bundle branch block. Cardiac magnetic resonance imaging showed a preserved left ventricular (LV) contractility (ejection fraction 70%) but failed to reveal reduced T1 mapping and fibrosis of postero-lateral LV wall suggesting Fabry disease cardiomyopathy. Cardiac catheterization and coronary angiography documented increased LV end-diastolic pressure but normal coronary arteries. SSM was followed by acute renal and heart failure with left ventricular ejection fraction declining to 35%. Histology of SSM showed regularly arranged severely enlarged cardiomyocytes containing extensive vacuoles that were intensely positive to immunofluorescence with anti-Gb3 antibodies and appeared at electron microscopy to consist of myelin bodies suggesting the diagnosis of FD. This entity was confirmed by low blood levels of alpha-galactosidase A (0.8 nmol/mL/h; NV > 1), high values of Lyso-Gb3 (5.85 nmol/L; NV < 2.3), and the presence of the pathogenic mutation c.644A>G in the exon 5 of GLA gene. This study emphasizes the importance of a genetic screening for FD before SSM be considered for hypertrophic obstructive cardiomyopathy.

Interleukin-17A-Correlated Myocarditis in Patients with Psoriasis: Cardiac Recovery following Secukinumab Administration.

(1) Background: Psoriasis (PS) is a common immune-mediated disease of the skin with possible extension to joints, aorta and eye. Myocardial inflammation has rarely been suggested. (2) Aims: Report of PS-related myocarditis. (3) Methods and Results: One hundred consecutive patients with PS were screened for cardiac involvement. Among them, five male patients (aged 56 ± 9.5 years) with a moderate-severe form of PS showed dilated cardiomyopathy (LVEF < 35%) with normal coronary arteries and valves. They underwent a left-ventricular endomyocardial biopsy for evaluation of myocardial substrate. Endomyocardial samples were processed for histology and immunohistochemistry, including myocardial expression of Toll-Like Receptor 4 (TLR4) and interleukin-17A (IL-17A), which play a major role in PS pathogenesis. Real-time PCRs were carried out for cardiotropic viruses, and Western blot analysis was conducted for myocardial expression of IL-17A. Patients' sera were tested for anti-heart autoantibodies. Active lymphocytic myocarditis was revealed in all five patients, characterized by an absence of viral genomes with PCR, positive anti-heart autoantibodies, overexpression of TLR-4 and enhancement of IL-17-A during western blot analysis, showing a 2.48-fold increase in psoriatic myocarditis compared with no psoriatic myocarditis and a six-fold increase compared to myocardial controls. Treatment included combination of prednisone (1 mg/kg daily for 4 weeks, tapered to 0.33 mg/kg) and azathioprine (2 mg/kg, daily) in 3 pts or secukinumab (SK, 150 mg/weekly for 4 weeks followed by 150 mg/monthly) in 2 pts for 6 months. LVEDD and LVEF improved in the first 3 pts (-14% and + 118%, respectively), while they completely recovered (LVEF > 50%) in the last 2 pts on SK. (4) Conclusions: IL-17A-related myocarditis can occur in up to 5% of patients with PS. It manifests as progressive dilated cardiomyopathy. It may completely recover following SK administration.

Circulating Anti-GB3 Antibody as a Biomarker of Myocardial Inflammation in Patients with Fabry Disease Cardiomyopathy.

BACKGROUND: Fabry disease cardiomyopathy (FDCM) has manifested some resistance to enzyme replacement therapy (ERT), particularly in its advanced phase. Recently, myocardial inflammation of autoimmune origin has been demonstrated in FDCM. AIMS: The objective of this study was the assessment of circulating anti-globotriaosylceramide (GB3) antibodies as potential biomarkers of myocardial inflammation in FDCM, defined by the additional presence of ≥CD3+ 7 T lymphocytes/low-power field associated with focal necrosis of adjacent myocytes. Its sensitivity was based on the evidence of overlapping myocarditis at left ventricular endomyocardial biopsy. METHODS AND RESULTS: From January 1996 to December 2021, 85 patients received a histological diagnosis of FDCM in our department and 48 (56.5%) of them had an overlapping myocardial inflammation with negative PCR for common cardiotropic viruses, positive antiheart, and antimyosin abs. The presence of anti-GB3 antibodies was evaluated with an in-house ELISA assay (BioGeM scarl Medical Investigational Research, MIR-Ariano Irpino, Italy), along with antiheart and antimyosin abs, in the FDCM patients and compared with control healthy individuals. The correlation between levels of circulating anti-GB3 autoantibody myocardial inflammation and FDCM severity was assessed. Anti-Gb3 antibodies were above the positivity cut-off in 87.5% of FDCM subjects with myocarditis (42 out of 48), while 81.1% of FDCM patients without myocarditis were identified as negative for Gb3 antibodies. Positive anti-Gb3 abs correlated with positive antiheart and antimyosin abs. CONCLUSIONS: The present study suggests a potential positive role of anti-GB3 antibodies as a marker of overlapping cardiac inflammation in patients with FDCM.

Infiltration of Conduction Tissue Is a Major Cause of Electrical Instability in Cardiac Amyloidosis.

BACKGROUND: The pathology of conduction tissue (CT) and relative arrhythmias in living subjects with cardiac amyloid have never been reported. AIMS: To report CT pathology and its arrhythmic correlations in human cardiac amyloidosis. METHODS AND RESULTS: In 17 out of 45 cardiac amyloid patients, a left ventricular endomyocardial biopsy included conduction tissue sections. It was identified by Aschoff-Monckeberg histologic criteria and positive immunostaining for HCN4. The degree of conduction tissue infiltration was defined as mild when ≤30%, moderate when 30-70% and severe when >70% cell area was replaced. Conduction tissue infiltration was correlated with ventricular arrhythmias, maximal wall thickness and type of amyloid protein. Mild involvement was observed in five cases, moderate in three and severe in nine. Involvement was associated with a parallel infiltration of conduction tissue artery. Conduction infiltration correlated with the severity of arrhythmias (Spearman rho = 0.8, p < 0.001). In particular, major ventricular tachyarrhythmias requiring pharmacologic treatment or ICD implantation occurred in seven patients with severe, one patient with moderate and none with mild conduction tissue infiltration. Pacemaker implantation was required in three patients, with complete conduction section replacement. No significant correlation was observed between the degree of conduction infiltration and age, cardiac wall thickness or type of amyloid protein. CONCLUSIONS: Amyloid-associated cardiac arrhythmias correlate with the extent of conduction tissue infiltration. Its involvement is independent from type and severity of amyloidosis, suggesting a variable affinity of amyloid protein to conduction tissue.

Myocarditis following COVID-19 vaccine: incidence, presentation, diagnosis, pathophysiology, therapy, and outcomes put into perspective. A clinical consensus document supported by the Heart Failure Association of the European Society of Cardiology (ESC) and the ESC Working Group on Myocardial and Pericardial Diseases.

Over 10 million doses of COVID-19 vaccines based on RNA technology, viral vectors, recombinant protein, and inactivated virus have been administered worldwide. Although generally very safe, post-vaccine myocarditis can result from adaptive humoral and cellular, cardiac-specific inflammation within days and weeks of vaccination. Rates of vaccine-associated myocarditis vary by age and sex with the highest rates in males between 12 and 39 years. The clinical course is generally mild with rare cases of left ventricular dysfunction, heart failure and arrhythmias. Mild cases are likely underdiagnosed as cardiac magnetic resonance imaging (CMR) is not commonly performed even in suspected cases and not at all in asymptomatic and mildly symptomatic patients. Hospitalization of symptomatic patients with electrocardiographic changes and increased plasma troponin levels is considered necessary in the acute phase to monitor for arrhythmias and potential decline in left ventricular function. In addition to evaluation for symptoms, electrocardiographic changes and elevated troponin levels, CMR is the best non-invasive diagnostic tool with endomyocardial biopsy being restricted to severe cases with heart failure and/or arrhythmias. The management beyond guideline-directed treatment of heart failure and arrhythmias includes non-specific measures to control pain. Anti-inflammatory drugs such as non-steroidal anti-inflammatory drugs, and corticosteroids have been used in more severe cases, with only anecdotal evidence for their effectiveness. In all age groups studied, the overall risks of SARS-CoV-2 infection-related hospitalization and death are hugely greater than the risks from post-vaccine myocarditis. This consensus statement serves as a practical resource for physicians in their clinical practice, to understand, diagnose, and manage affected patients. Furthermore, it is intended to stimulate research in this area.

Removal of cardiac AL amyloid with positive remodelling of cardiomyocytes and of restrictive cardiomyopathy.

Herein, we describe histological mobilization of light chain cardiac amyloid documented by sequential left ventricular endomyocardial biopsies. These findings were associated with positive remodelling of cardiomyocytes and of restrictive cardiomyopathy resulting from 14 courses of chemotherapy over 17 years of time. Histological and ultrastructural findings of light chain cardiac amyloid removal led to increase in cardiomyocyte dimension and electrocardiogram voltages, reduction of biventricular wall thickness with improvement of left ventricular diastolic function, and NYHA class shifting from III to I.

Downregulation of Mannose-6-Phosphate Receptors in Fabry Disease Cardiomyopathy: A Potential Target for Enzyme Therapy Enhancement.

Background: The efficacy of enzyme replacement therapy (ERT) in mobilizing globotryaosylceramide (GB-3) from Fabry cardiomyocytes is limited. The mechanism involved is still obscure. Methods: Assessment of M6Pr, M6Pr-mRNA, and Ubiquitin has been obtained by Western blot analysis and real-time PCR of frozen endomyocardial biopsy samples, from 17 pts with FD, various degree of left ventricular hypertrophy, and maximal wall thickening (MWT) from 11.5 and 20 mm. The diagnosis and severity of FDCM followed definitions of GLA mutation, α-galactosidase A enzyme activity, cardiac magnetic resonance, and left ventricular endomyocardial biopsy with the quantification of myocyte hypertrophy and the extent of Gb-3 accumulation. All patients have received alpha or beta agalsidase for ≥3 years without a reduction in LV mass nor an increase in T1 mapping at CMR. Controls were surgical biopsies from 15 patients undergoing mitral valve replacement. Results: Protein analysis showed mean M6Pr in FDCM to be 5.4-fold lower than in a normal heart (4289 ± 6595 vs. 23,581 ± 4074, p = 0.0996) (p < 0.001): specifically, 9-fold lower in males, p = 0.009, (p < 0.001) and 3-fold lower in females, p = 0.5799, (p < 0.001) showing, at histology, a mosaic of normal and diseased cells. M6Pr-mRNA expression was normal, while ubiquitin showed an increase of 4.6 fold vs. controls (13,284 ± 1723 vs. 2870 ± 690, p = 0.001) suggesting that ubiquitin-dependent post-translational degradation is likely responsible for the reduction of M6Pr in FDCM. Conclusion: M6Pr expression is remarkably reduced in FDCM as a likely result of post-translational degradation. This may explain the reduced efficacy of ERT and be a therapeutic target for the enhancement of ERT activity.

Immunosuppressive therapy in virus-negative inflammatory cardiomyopathy: 20-year follow-up of the TIMIC trial.

AIMS: Long-term results of the Tailored IMmunosuppression in virus-negative Inflammatory Cardiomyopathy (TIMIC) trial protocol have been evaluated. METHODS AND RESULTS: Eighty-five patients with endomyocardial biopsy-proven virus-negative chronic inflammatory cardiomyopathy were enrolled in the randomized, double-blind, placebo-controlled TIMIC trial and received prednisone and azathioprine (n = 43) vs. placebo (n = 42) for 6 months. Immunosuppressive treatment promoted an improvement in cardiac function in 88% of the cases compared with none of the patients in the placebo group, which were switched to a 6-month immunosuppressive therapy at the end of the 6-month study period. Long-term (up to 20 years) clinical outcomes of the whole cohort of 85 patients originally enrolled in the TIMIC trial (Group A) were compared with those of a 1:2 propensity score-matched control cohort of patients untreated with the TIMIC protocol (Group B) and followed for a comparable period of time. The primary outcome was a composite of cardiovascular death and heart transplantation. At long-term follow-up, the risk of cardiovascular death [hazard ratio (HR) 6.77; 95% confidence interval (CI) 2.36-19.45] and heart transplantation (HR 7.92; 95% CI 1.80-34.88) was significantly higher in Group B patients. Group A showed a persistent improvement in the left ventricular ejection fraction compared with Group B (HR 7.24; 95% CI 3.05-17.18). A higher number of Group B patients underwent implantable cardioverter defibrillator implantation. The incidence of recurrent myocarditis was similar between groups, and patients with evidence of a recurrent cardiac inflammatory process promptly responded to a TIMIC protocol application. CONCLUSION: Virus-negative inflammatory cardiomyopathy benefits from immunosuppressive therapy even after long-term follow-up. Recurrence appears to respond to a new TIMIC protocol application.

Hypersensitivity Myocarditis after COVID-19 mRNA Vaccination.

BACKGROUND: Myocarditis, even in a severe and lethal form, may occur after COVID-19 mRNA (BNT162b2) vaccination. However, its pathway, morphomolecular characterization and treatment are still unknown. METHODS: Routine hematochemical screening, ECG, Holter monitoring, 2D echocardiogram cardiac magnetic resonance (CMR) and invasive cardiac studies (cardiac catheterization, selective coronary angiography, left ventriculography and left ventricular endomyocardial biopsy) are reported from three patients (39F-pt1, 78M-pt2, 52M-pt3) with severe compromise of conduction tissue (junctional rhythm and syncope, pt1) or cardiac function compromise (LVEF ≤ 35%, pt2 and pt3) after COVID-19 mRNA (BNT162b2). RESULTS: Hematochemical data and coronary angiography were normal in the patients studied. Histology showed in all three patients extensive myocardial infiltration of degranulated eosinophils and elevation of serum cationic protein directly responsible for cardiomyocyte damage. These findings demonstrate myocarditis hypersensitivity to some component of the vaccine (spike protein?) acting as a hapten to some macromolecules of cardiomyocytes. Steroid administration (prednisone, 1 mg/kg die for 3 days, followed by 0.33 mg/kg for 4 weeks) was followed by complete recovery of cardiac contractility in pt2 and pt3. CONCLUSIONS: Eosinophilic myocarditis is a possible adverse reaction to the mRNA COVID-19 vaccine. Its pathway is mediated by release of cationic protein and responds to short courses of steroid administration.

Myocardial Aldosterone Receptor and Aquaporin 1 Up-Regulation Is Associated with Cardiomyocyte Remodeling in Human Heart Failure.

BACKGROUND: Abnormal aldosterone signaling is a recognized source of cardiovascular damage. Its influence on cardiomyocyte structure, function, and hormonal receptors when associated with heart failure is still unreported. METHODS: Twenty-six consecutive patients with heart failure (LVEF < 40%) and normal coronaries and valves underwent left ventricular endomyocardial biopsy (EMB) for evaluation of myocardial substrate. Biopsy samples were processed for histology, electron microscopy, immunohistochemistry, and Western blot analysis of myocardial aldosterone receptor and aquaporin-1 correlated with plasma aldosterone (AD) and renin activity (PRA). Eight patients with virus-negative inflammatory cardiomyopathy (ICM) had a control EMB after 6 months of immunosuppressive therapy and recovery of cardiac function with re-evaluation of cardiomyocyte structure and receptor expression. RESULTS: EMB in addition to the diagnosis of myocarditis (15 cases), dilated cardiomyopathy CM (6), alcohol CM (2), and diabetic CM (3) showed vacuolar degeneration and cloudy swelling of cardiomyocytes corresponding at electron microscopy to ions and water accumulation into cytosol, membrane-bound vesicles, nucleus, and other organelles, and was associated with an increased AD, PRA, and myocardial expression of aldosterone receptor (2.6 fold) and aquaporin 1 (2.7 fold). In the 8 patients recovered from ICM, cardiomyocyte diameter reduced with disappearance of intracellular vacuoles and normalization of cytosol, nucleus, and cell organelles' electron-density, along with down-regulation of aldosterone receptor and aquaporin-1. CONCLUSION: Human heart failure is associated with overexpression of myocardial aldosterone receptor and aquaporin-1. These molecular changes are paralleled by intracellular water overloading and cardiomyocyte swelling and dysfunction. Cardiac recovery is accompanied by down-regulation of hormonal receptors and normalization of cell structure and composition.

Pemphigus-associated cardiomyopathy: report of autoimmune myocarditis and review of literature.

Pemphigus is a rare disease characterized by bullous lesions of the skin and mucous membranes. The aetiology is autoimmune and related to the formation of IgG autoantibodies against desmogleins, which are structural proteins of desmosomes that ensure the stability of contacts between cells. Cardiac involvement in patients with pemphigus is poorly documented. We report the data in the literature on this topic and a case of pemphigus-associated autoimmune myocarditis with damage of intercalated disc responding to immunosuppressive therapy. The occurrence of cardiomyopathy with left ventricular dysfunction in patients affected by pemphigus should be appropriately screened with endomyocardial biopsy as it could be the myocardial extension of a potentially reversible autoimmune disorder.

False-positive bone scintigraphy denoting transthyretin amyloid in elderly hypertrophic cardiomyopathy.

A positive nuclear scintigraphy with hydroxy bisphosphonate bone tracer (99mTc-HPD) is believed to have high sensitivity (>99%) and specificity (91%) for the diagnosis of transthyretin amyloid cardiomyopathy. We report the case of an 85-year-old man with increased thickness of ventricular walls and a positive bone scintigraphy, who was unexpectedly found to have sarcomeric hypertrophic cardiomyopathy at left ventricular endomyocardial biopsy. Congo Red staining, immunohistochemistry, and transmission electronmicroscopy on six left ventricular samples scored negative for amyloidosis but were suggestive for sarcomeric hypertrophic cardiomyopathy. Genetic study did not show TTR and most commonly involved sarcomeric genes mutations. In hypertrophic cardiomyopathy focal cell necrosis related to demand/supply oxygen mismatch, small vessels disease or inflammation could be responsible of a false-positive bone scintigraphy signal for transthyretin amyloidosis. Because of this, especially in view of a possible specific treatment, endomyocardial biopsy is highly recommended for the correct diagnosis of cardiomyopathies with hypertrophic phenotype.

Hypertrophy of unaffected cardiomyocytes correlates with severity of cardiomyopathy in female patients with Fabry disease.

AIM: To investigate the contribution of unaffected cardiomyocytes in Fabry disease cardiomyopathy. FINDINGS: Left ventricular (LV) endomyocardial biopsies from twenty-four females (mean age 53 ± 11 ys) with Fabry disease cardiomyopathy were studied. Diagnosis of FD was based on the presence of pathogenic GLA mutation, Patients were divided in four groups according with LV maximal wall thickness (MWT): group 1 MWT ≤ 10.5 mm, group 2 MWT 10.5-15 mm, group 3 MWT 16-20 mm, group 4 MWT > 20 mm. At histology mosaic of affected and unaffected cardiomyocytes was documented. Unaffected myocytes' size ranged from normal to severe hypertrophy. Hypertrophy of unaffected cardiomyocytes correlated with severity of MWT (p < 0.0001, Sperman r 0,95). Hypertrophy of unaffected myocytes appear to concur to progression and severity of FDCM. It is likely a paracrine role from neighboring affected myocytes.

Novel dilated cardiomyopathy associated to Calreticulin and Myo7A gene mutation in Usher syndrome.

We report a novel cardiomyopathy associated to Usher syndrome and related to combined mutation of MYO7A and Calreticulin genes. A 37-year-old man with deafness and vision impairment because of retinitis pigmentosa since childhood and a MYO7A gene mutation suggesting Usher syndrome, developed a dilated cardiomyopathy with ventricular tachyarrhythmias and recurrent syncope. At magnetic resonance cardiomyopathy was characterized by left ventricular dilatation with hypo-contractility and mitral prolapse with valve regurgitation. At left ventricular endomyocardial biopsy, it was documented cardiomyocyte disconnection because of cytoskeletal disorganization of cell-to-cell contacts, including intercalated discs, and mitochondrial damage and dysfunction with significant reduction of adenosine triphosphate production in patient cultured fibroblasts. At an extensive analysis by next-generation-sequencing of 4183 genes potentially related to the cardiomyopathy a pathogenic mutation of calreticulin was found. The cardiomyopathy appeared to be functionally and electrically stabilized by a combination therapy including carvedilol and amiodarone at a follow-up of 18 months.