Left Ventricular Endomyocardial Biopsy Research Articles

Fabry cardiomyopathy: myocardial fibrosis, inflammation and reduced mannose6phosphate receptors cause low accessibility to enzyme therapy

Abstract Background Clinical impact of enzyme replacement therapy (ERT) on advanced Fabry disease cardiomyopathy (FDCM) appears limited. Purpose Clarify the pathologic mechanisms responsible of ERT inefficacy in the advanced FDCM. Methods Ten male patients with advanced FDCM (echocardiographic maximal wall thickness 19.3 ± 2.1 mm) underwent left ventricular endomyocardial biopsy before and 4 hours after beta-agalsidase infusion. Comparative studies between pre and post infusion samples included: histology and electron microscopy; assessment of myocardial alpha-galactosidase A activity; immunohistochemistry for alpha-galactosidase A and semiquantitative evaluation (from 0 to 3) of its cardiomyocyte content; Ultrastructural immunogold analysis with anti-alpha-galactosidase A ab. Western Blot (WB) quantification of mannose-6-phosphate receptors (M6Pr). Controls were surgical left ventricular biopsies from patients with mitral stenosis. Results Histologic and Ultrastructural evaluation showed no removal of storage material while myocardial fibrosis was 9.8 ± 6.8 vs 3.8 ± 2.0 of controls and virus-negative lymphocytic inflammation was observed in 7 out of 10 patients. At Ultrastructural immunogold analysis, Myocardial alpha-galactosidase A activity increased in post infusion samples by overall 1.89-fold. Alpha-galactosidase A immunostaining in cardiomyocytes was absent at baseline in all patients and did not significantly improve in post-infusion samples. Immunogold particles increased by 1.33-fold remaining far from normal controls (86.9 ± 6.6). Protein analysis showed M6Pr in advanced FDCM to be 81% lower than in normal heart. Conclusions Our study shows a low accessibility to ERT of cardiomyocytes affected by advanced FDCM. It is sustained by myocardial fibrosis, inflammation and severe down-regulation of M6Pr. Figure Legend Histologic and ultrastructural and mannose6phosphate receptors characteristics of patients with severe Fabry Disease Cardiomyopathy. Panel A shows severe cellular glycolipid infiltration associated with diffuse interstitial fibrosis (Masson trichrome, 100x). Panel B reveals an overlapping lymphocytic CD45Ro+ myocardial inflammation with focal necrosis of adjacent cardiomyocytes. Insert(i), Ultrastructural detail showing vacuoles (black arrows) to consist of myelin bodies,( scale bar=3μm). Panel C (upper) Western blot analysis of all 10 patients of Mannose-6-phosphate Receptor, molecular weight 275 Kd. Alpha sarcomeric actin (43 kDa) was used as a loading control. (Panel C -lower) Panel D: Graphs document western blot of Mannose-6-phosphate Receptor, in all 10 patients with severe FDCM showing 3-fold lower of Mannose-6-phosphate Receptor values in patients versus normal heart (4.830 ± 1116,724 vs 14.737± 1145,386; p < 0.001).

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

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. 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 β-agalsidase in 7 cases. Both groups experienced symptom improvement except 1 patients treated with α-agalsidase and 1 treated with β-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. 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.

Interleukin 17A-correlated myocarditis in patients with psoriasis: cardiac recovery following secukinumab administration

Abstract Background Psoriasis (PS) is a common immune-mediated disease of the skin with possible extension to joints, aorta and eye. Myocardial inflammation has been rarely suggested. Purpose Report of PS-related myocarditis. Methods One hundred consecutive patients with PS were screened for cardiac involvement. Among them, five male patients (aged 56 ± 9.5 years) with moderate-severe form showed a dilated cardiomyopathy (LVEF &amp;lt;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 plays a major role in psoriasis pathogenesis; real-time PCR for cardiotropic viruses and Western blot analysis for myocardial expression of IL-17A. Patients’ sera were tested for anti-heart autoantibodies. Results An active lymphocytic myocarditis was revealed in all 5 patients, characterized by absence of viral genomes at PCR, positive anti-heart autoantibodies, overexpression of TLR-4 and enhancement of IL-17-A at western blot analysis showing a 2,48-fold increase in psoriatic myocarditis compared with no psoriatic myocarditis and a 6-fold increase compared to myocardial controls. Treatment included combination of prednisone (1 mg/Kg daily for 4 weeks, tapered to 0.33 mg/Kg) + azathioprine (2 mg/Kg, daily) in 3 pts or secukinumab (SK, 100 mg/monthly) in 2 pts for 6 months. LVEDD and LVEF improved in the first 3 pts (-14% and + 118%, respectively) while completely recovered (LVEF&amp;gt; 50%) in the last 2 pts on SK. Conclusion IL-17A-related myocarditis can occur in up-to 5% of patients with psoriasis. It manifests as a progressive dilated cardiomyopathy. It may completely recover following SK administration. Figure Legend Endomyocardial biopsy findings from pt 5 with PS-related myocarditis including histology (panel A). Immune-histochemistry for IL 17-A (panel B) and anti-heart abs (panels C, D). It shows an active lymphocytic myocarditis with overexpression of IL 17-A and positive anti-heart abs (panel C), cross-reacting with skeletal muscle (panel D).

Tachycardie ventriculaire récidivante révélant une sarcoïdose cardiaque

Sarcoidosis is an inflammatory disease whose diagnosis is suggested by clinical and paraclinical signs and confirmed by histological evidence showing granulomatosis without caseous necrosis. The clinical presentation is sometimes misleading and the diagnosis difficult to confirm. We report here the case of a young woman with cardiac sarcoidosis of difficult diagnosis, revealed by a myocardial infarction with normal coronary angiography and recurrent ventricular tachycardia. Multimodal imaging, combined with left ventricular endomyocardial biopsies guided by electrophysiological analysis and endocavitary mapping, finally confirmed the diagnosis, and allowed effective medical treatment.

Application of left ventricular endomyocardial biopsy in the diagnosis of mitochondrial cardiomyopathy: a case report

BackgroundThe clinical features of mitochondrial cardiomyopathy (MCM) are diverse. It can present as hypertrophic cardiomyopathy or dilated cardiomyopathy. The diagnosis of MCM is challenging and usually based on biopsy.Case presentationThe 30-year-old man was admitted to hospital due to dyspnea for 1 month and edema of both lower extremities for 1 week. Echocardiography suggested a whole heart enlargement, a whole heart diminished function. Renal impairment and diabetes were observed. Coronary angiography showed single-vessel disease (90% stenosis in the ostium of a small marginal branch). Left ventricular endomyocardial biopsy was performed.ConclusionMyocardial histopathology demonstrated a large number of abnormal mitochondrial accumulation, so the diagnosis was considered as mitochondrial cardiomyopathy.

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

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. 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. 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. The present study suggests a potential positive role of anti-GB3 antibodies as a marker of overlapping cardiac inflammation in patients with FDCM.

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.

P354 REMOVAL OF CARDIAC AL–AMYLOID LEADS TO CARDIOMYOCYTE POSITIVE REMODELING AND RESTRICTIVE PATTERN REVERSAL

Abstract Background Properly treated AL cardiac amyloidosis can have a long survival. However, the mechanism involved in arresting or reversing cardiomyopathy, such as toxic suppression of the light chain or removal of the amyloid substance, is still unclear. We describe the case of a patient with AL amyloidosis treated with chemotherapy in whom serial endomyocardial biopsies were performed at diagnosis and after 17 years. Clinical case A 71–year–old lady onset with a hypertrophic phenotype cardiomyopathy (maximum thickness LV 18.2 mm, diastolic dysfunction with E/A ratio 2.45. preserved contractility (EF 55%) and NYHA class 3) received a diagnosis in 2004 of AL amyloidosis and underwent several cycles of chemotherapy. At clinical onset, cardiac amyloidosis was documented by endomyocardial biopsy. After 17 years, in 2021, the patient was hospitalized for palpitations and chest pain and documented intermittent phases of atrial fibrillation. The patient was reevaluated with immunoelectrophoresis, echocardiogram, cardiac magnetic resonance, coronary angiography, and left ventricular endomyocardial biopsy. Serum monoclonal chain AL–K was reduced from initial 233 mg/L to 18.2 mg/L, vn&amp;lt;19.4 mg/L. The echocardiogram showed reduction of the heart walls with reduction of the thickness to 14 mm, with regression of the restrictive pattern (E/A ratio from 2.45 to 0.5). Serum NT–proBNP decreased from 3188 pg/mL to 480 pg/mL (n.v.&amp;lt;334 pg/mL). Cardiac MRI revealed normal myocardial wall thickness, with preserved systolic function, in the absence of the typical late gadolinium enhancement pattern. Histology and electron microscopy showed no more hypo/atrophic cardiomyocytes and the interstitium was almost completely devoid of amyloid fibrils, which were distant from the cardiac cell allowing an improvement in oxygenation and trophism. Conclusions Remission of monoclonal gammopathy is associated with a removal of cardiac amyloid deposits and with a regression of cardiac hypertrophy and restrictive pattern. Histologically, the degradation of amyloid fibrils determines a better trophism of cardiomyocytes.

C61 RAREFACTION OF MYOCARDIAL LYMPHATIC VESSELS IN PATIENTS WITH CARDIAC AMYLOIDOSIS

Abstract Introduction In cardiac amyloidosis (CA), amyloid fibers accumulate in the extracellular spaces of the heart, causing a compression and obliteration of lymphatic vessels, and possibly their disappearance. As lympathic drainage removes proteins from the interstitial spaces, including amyloid precursors, an impairment of lympathic vessels could exacerbate amyloid accumulation, triggering a vicious circle. Methods Lymphatic vessels were visualized by immunohistochemistry using a monoclonal antibody against podoplanin (D2–40, a marker of lymphatic endothelial cells) and the immunopreroxidase technique. We investigated 3 groups of cases: 1) as a reference standard, endomyocardial specimens from the left ventricular (LV) endomyocardium of 10 heart valve donors, deceased for trauma and/or cerebral hemorrhage, with no evidence of cardiac disease on gross and microscopic examination; 2) 15 consecutive LV endomyocardial biopsies (EMBs) from patients with CA, where cardiac amyloid was detected and typed by Congo red staining, immunohistochemistry and proteomics, and 3) 13 surgical endomyocardial biopsies from patients with septal LV hypertrophy, undergoing aortic valve surgery and with CA excluded by histology. Results In donor hearts (n=10), lymphatic vessels were mostly distributed in the subendocardial and subepicardial layers, with some intra–myocardial lymphatic vessels near larger blood vessels. We then examined 15 patients with CA (amyloid transthyretin [ATTR]–CA, n=10; amyloid light–chain [AL]–CA, n=5; 50% men, median age 75 years [interquartile range 71–78]), and 13 patients with CA excluded (55% men, median age 68 years [59–71]). The density of lymphatic vessels in patients with CA was 0.52 vessels/mm2 (0–3.32), vs. 10.90 vessels/mm2 (3.10–26.25) in those without CA (p=0.001). No significant differences were found in LV mass index (p=0.170) or LV ejection fraction (p=0.262). Three patients with ATTR–CA and 2 patients with AL–CA showed no lymphatic vessels on EMB. The density of lymphatic vessels did not differ significantly in patients with ATTR– or AL–CA. Conclusions Patients with CA have significantly decreased endo–myocardial lymphatic vessels as compared to patients without CA, despite no significant difference in the degree of LV wall thickening or LV ejection fraction. These results support the hypothesis that the lymphatic drainage is deranged in patients with CA, possibly promoting further amyloid deposition.

Aortic valve calcification and myocardial fibrosis determine outcome following transcatheter aortic valve replacement.

There is evidence to suggest that the subtype of aortic stenosis (AS), the degree of myocardial fibrosis (MF), and level of aortic valve calcification (AVC) are associated with adverse cardiac outcome in AS. Because little is known about their respective contribution, we sought to investigate their relative importance and interplay as well as their association with adverse cardiac events following transcatheter aortic valve replacement (TAVR). One hundred consecutive patients with severe AS and indication for TAVR were prospectively enrolled between January 2017 and October 2018. Patients underwent transthoracic echocardiography, multidetector computed tomography, and left ventricular endomyocardial biopsies at the time of TAVR. The final study cohort consisted of 92 patients with a completed study protocol, 39 (42.4%) of whom showed a normal ejection fraction (EF) high-gradient (NEFHG) AS, 13 (14.1%) a low EF high-gradient (LEFHG) AS, 25 (27.2%) a low EF low-gradient (LEFLG) AS, and 15 (16.3%) a paradoxical low-flow, low-gradient (PLFLG) AS. The high-gradient phenotypes (NEFHG and LEFHG) showed the largest amount of AVC (807±421 and 813±281mm3 , respectively) as compared with the low-gradient phenotypes (LEFLG and PLFLG; 503±326 and 555±594mm3 , respectively, P<0.05). Conversely, MF was most prevalent in low-output phenotypes (LEFLG>LEFHG>PLFLG>NEFHG, P<0.05). This was paralleled by a greater cardiovascular (CV) mortality within 600days after TAVR (LEFLG 28%>PLFLG 26.7%>LEFHG 15.4%>NEFHG 2.5%; P=0.023). In patients with a high MF burden, a higher AVC was associated with a lower mortality following TAVR (P=0.045, hazard ratio 0.261, 95% confidence interval 0.07-0.97). MF is associated with adverse CV outcome following TAVR, which is most prevalent in low EF situations. In the presence of large MF burden, patients with large AVC have better outcome following TAVR. Conversely, worse outcome in large MF and relatively little AVC may be explained by a relative prominence of an underlying cardiomyopathy. The better survival rates in large AVC patients following TAVR indicate TAVR induced relief of severe AS-associated pressure overload with subsequently improved outcome.

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

The pathology of conduction tissue (CT) and relative arrhythmias in living subjects with cardiac amyloid have never been reported. To report CT pathology and its arrhythmic correlations in human cardiac amyloidosis. 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. 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.

Abstract 10450: Interleukin-17A-Correlated Myocarditis in Patients With Psoriasis

Background. Psoriasis is a common immune-mediated disease of the skin with possible extension to joints, aorta and eye. Myocardial inflammation has been rarely suggested. However, its incidence and pathologic mechanism have not been elucidated so far. Methods. One hundred consecutive patients (62M/38F, mean age 55 ± 13.7 years) with psoriasis were screened for cardiac involvement. Among them, five male patients (mean age 56 ± 9.5 years) showed a dilated cardiomyopathy (LVEF &lt; 40%) with normal coronary arteries and valves, and 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 plays a major role in psoriasis pathogenesis. Real-time PCR for cardiotropic viruses and Western blot analysis for myocardial expression of IL-17A were also performed. As controls for IL-17A expression, myocardial samples from 10 male patients with inflammatory cardiomyopathy and no psoriasis were included. Patients’ sera were tested for anti-heart autoantibodies. Results. An active lymphocytic myocarditis was revealed in all 5 patients, characterized by absence of viral genomes at PCR, positive anti-heart autoantibodies, overexpression of TLR-4 and of IL-17A at both immunohistochemistry (Figure 1A vs 1B) and Western blot analysis (mean value 44 ± 6.7 vs 12 ± 61.9 in patients with no-psoriatic myocarditis and 4± 1.5 in normal controls; Figure 1C). Conclusion. Interleukin-17A-related myocarditis can occur in up-to 5% of patients with psoriasis. It manifests as a progressive dilated cardiomyopathy that can potentially benefit from immunosuppression or monoclonal antibodies as the skin disease.

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.

Direct proteomic and high-resolution microscopy biopsy analysis identifies distinct ventricular fates in severe aortic stenosis

The incidence of aortic valve stenosis (AS), the most common reason for aortic valve replacement (AVR), increases with population ageing. While untreated AS is associated with high mortality, different hemodynamic subtypes range from normal left-ventricular function to severe heart failure. However, the molecular nature underlying four different AS subclasses, suggesting vastly different myocardial fates, is unknown. Here, we used direct proteomic analysis of small left-ventricular biopsies to identify unique protein expression profiles and subtype-specific AS mechanisms. Left-ventricular endomyocardial biopsies were harvested from patients during transcatheter AVR, and inclusion criteria were based on echocardiographic diagnosis of severe AS and guideline-defined AS-subtype classification: 1) normal ejection fraction (EF)/high-gradient; 2) low EF/high-gradient; 3) low EF/low-gradient; and 4) paradoxical low-flow/low-gradient AS. Samples from non-failing donor hearts served as control. We analyzed 25 individual left-ventricular biopsies by data-independent acquisition mass spectrometry (DIA-MS), and 26 biopsies by histomorphology and cardiomyocytes by STimulated Emission Depletion (STED) superresolution microscopy. Notably, DIA-MS reliably detected 2273 proteins throughout each individual left-ventricular biopsy, of which 160 proteins showed significant abundance changes between AS-subtype and non-failing samples including the cardiac ryanodine receptor (RyR2). Hierarchical clustering segregated unique proteotypes that identified three hemodynamic AS-subtypes. Additionally, distinct proteotypes were linked with AS-subtype specific differences in cardiomyocyte hypertrophy. Furthermore, superresolution microscopy of immunolabeled biopsy sections showed subcellular RyR2-cluster fragmentation and disruption of the functionally important association with transverse tubules, which occurred specifically in patients with systolic dysfunction and may hence contribute to depressed left-ventricular function in AS.

Safety and usefulness of left ventricular endomyocardial biopsy in new- onset acute heart failure requiring mechanical support by an Impella® device

BackgroundIn patients with de novo acute heart failure (AHF) requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO), endomyocardial biopsy (EMB) has been recently shown to be feasible and a helpful method to clarify differential diagnoses, including acute myocarditis. This study aimed to evaluate the feasibility and safety of EMB in patients with a left ventricular (LV) implanted Impella® device. Methods and resultsThis retrospective, single-center study involves 22 cardiogenic shock patients [SCAI shock stage: C (91%)] requiring mechanical circulatory support (MCS) either by Impella® axial pumps [20 patients (91%)] alone or in combination with VA-ECMO [2 patients (9%)] between December 2017 and January 2022. Coronary artery disease (CAD) or severe valvular heart disease were excluded. The study's primary endpoint was to verify the safety of EMB during MCS. Furthermore, histopathological analysis of the EMB samples was described. 30 LV-EMB procedures were performed. No major complications were reported (death, sustained ventricular tachycardia, need for cardiopulmonary resuscitation, cardiac tamponade, stroke, major bleeding). In 14 patients (64%), EMB-derived histology/immunohistology led to the definitive diagnosis of acute myocarditis. ConclusionsEMB can be safely performed in patients suffering from cardiogenic shock requiring an Impella®-based MCS without the risk of major complications. In about 50% of the patients, relevant inflammatory heart disease could be detected, which required a change in treatment decisions.

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.

Impact of Autophagy on Prognosis of Patients With Dilated Cardiomyopathy

BackgroundAutophagy is a cellular process that degrades a cell’s own cytoplasmic components for energy provision and to maintain a proper intracellular environment. Left ventricular reverse remodeling (LVRR) promises a better prognosis for patients with dilated cardiomyopathy (DCM). ObjectivesThe authors tested the hypothesis that autophagy is involved in LVRR and has prognostic value in the human failing heart. MethodsUsing left ventricular endomyocardial biopsy specimens from 42 patients with DCM (21 LVRR-positive and 21 LVRR-negative) and 7 patients with normal cardiac function (control), the authors performed immunohistochemistry and immunofluorescent labeling of LC3 and cathepsin D and electron microscopic observation in addition to general morphometry under light microscopy. ResultsThe clinical characteristics of LVRR-positive patients were similar to those of the LVRR-negative patients, except for pulmonary artery pressure and left atrial dimension. Morphometry under light microscopy did not differ among specimens from DCM patients, regardless of their LVRR status. Electron microscopy revealed that autophagic vacuoles (autophagosomes and autolysosomes) and lysosomes were abundant within cardiomyocytes from DCM patients. Moreover, cardiomyocytes from LVRR-positive patients contained significantly more autophagic vacuoles with higher autolysosome ratios and cathepsin D expression levels than cardiomyocytes from LVRR-negative patients. Logistic regression analysis adjusted for age showed that increases in autophagic vacuole number and cathepsin D expression were predictive of LVRR. DCM patients who achieved LVRR experienced fewer cardiovascular events during the follow-up period. ConclusionsThe authors show that autophagy is a useful marker predictive of LVRR in DCM patients. This provides novel pathologic insight into a strategy for treating the failing DCM heart.

Aortic valve calcification and endomyocardial fibrosis determine adverse outcomes following transcatheter aortic valve replacement

Abstract Funding Acknowledgements Type of funding sources: None. Aims There is evidence to suggest that subtype of aortic stenosis (AS), degree of myocardial fibrosis (MF) and level of aortic valve calcification (AVC) are associated with adverse cardiac outcome in AS. Since little is known about their respective contribution, we sought to investigate their relative importance and interplay as well as association with adverse cardiac events. Methods 100 consecutive patients with severe AS and indication for transfemoral transcatheter aortic valve replacement (TAVR) were prospectively enrolled between January 2017 and October 2018. Patients underwent transthoracic echocardiography, multi detector computed tomography (MDCT) and left ventricular endomyocardial biopsy at the time of TAVR. Results The final study cohort consisted of 92 patients with completed study protocol comprising of 39 (42.4 %) normal ejection fraction high gradient (NEFHG), 13 (14.1 %) low EF high gradient (LEFHG), 25 (27.2 %) low EF (flow) low gradient (LEFLG) and 15 (16.3 %) paradoxical low flow low gradient (PLFLG) AS. The high gradient phenotypes (NEFHG and LEFHG) showed the largest amount of AVC (807 ± 421; 813 ± 281 mm³ respectively) as compared to the low gradient phenotypes (LEFLG and PLFLG; 503 ± 326; 555 ± 594 mm³ respectively, p &amp;lt; 0.05). Conversely, MF was most prevalent in low output phenotypes (LEFLG &amp;gt; LEFHG &amp;gt; PLFLG &amp;gt; HEFHG, p &amp;lt; 0.05). This was paralleled by larger cardiovascular mortality within 600 days post TAVR (LEFLG n = 7 &amp;gt; PLFLG n = 4 &amp;gt; LEFHG n = 2 &amp;gt; NEFHG n = 1). In Patients with high MF burden a higher AVC was associated with a lower mortality (p = 0.045, HR = 0.261, 95%CI 0.07-0.97). Within LEFLG AS, patients with larger AVC (&amp;gt;476.8 mm³) had larger MF (40.2%) and higher cardiovascular mortality (n = 5) as compared to patients with lower AVC (£476.8 mm³, 17.1% MF, p = 0.027, cardiovascular mortality n = 2). Conclusion MF is associated with adverse cardiovascular outcome following TAVR which is most prevalent in low ejection fraction situations. In the presence of large MF burden patients with large AVC have better outcome following TAVR. Conversely worse outcome in large MF and relatively little AVC may be explained by a relative prominence of an underlying cardiomyopathy while better survival rates in large AVC patients may indicate severe AS associated pressure overload relief and subsequently improved survival following TAVR.

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.

Is This the Prime Time for Transradial Access Left Ventricular Endomyocardial Biopsy?

Left ventricular endomyocardial biopsy (EMB) is an essential tool in the management of myocarditis and is conventionally performed via transfemoral access (TFA). Transradial access EMB (TRA-EMB) is a novel alternative and the authors sought to determine its safety and feasibility by conducting a systematic review of the literature. Medline was searched in 2020, and cohort demographics, procedural details and complications were extracted from selected studies. Four observational studies with a combined total of 496 procedures were included. TRA-EMB was most frequently performed with a sheathless MP1 guide catheter via the right radial artery. The most common complication was pericardial effusion (up to 11% in one study), but pericardial drainage for tamponade was rare (one reported case). Death and mitral valve damage have not been reported. TRA-EMB was successful in obtaining samples in 99% of reported procedures. The authors concluded that TRA-EMB is a safe and feasible alternative to TFA-EMB and the most common complication is uncomplicated pericardial effusion.