Clinical and Histopathological Characteristics of Patients With Myocarditis After mRNA COVID-19 Vaccination.

Background: The effects of myocarditis after mRNA COVID-19 vaccination (mCV) on myocardial tissue, and the association between cardiomyocyte injury and clinical presentation, are not fully understood.

Methods And Results: We retrospectively registered patients clinically diagnosed with myocarditis after the first or second mCV who underwent endomyocardial biopsy or autopsy from 42 participating centers in Japan. We investigated the histological features and their association with clinical presentation based on cardiomyocyte injury.

Myocardial T-Lymphocytes as a Prognostic Risk-Stratifying Marker of Dilated Cardiomyopathy - Results of the Multicenter Registry to Investigate Inflammatory Cell Infiltration in Dilated Cardiomyopathy in Tissues of Endomyocardial Biopsy (INDICATE Study).

Background: Dilated cardiomyopathy (DCM) associated with inflammation is diagnosed by endomyocardial biopsy; patients with this have a poorer prognosis than patients without inflammation. To date, standard diagnostic criteria have not been established.

Methods and results: This study analyzed clinical records and endomyocardial biopsy samples of 261 patients with DCM (201 males, median left ventricular ejection fraction; 28%) from 8 institutions in a multicenter retrospective study.

Case Report: Acute Eosinophilic Myocarditis With a Low-Flow Heart Failure With Preserved Ejection Fraction Phenotype.

Eosinophilic myocarditis is a rare subtype of myocarditis characterized by myocardial eosinophilic infiltration, and it is potentially fatal if left untreated. Although endomyocardial biopsy (EMB) is a cornerstone for the histological diagnosis of acute eosinophilic myocarditis (AEM), as it is an invasive procedure and has a low diagnostic accuracy, the diagnosis of AEM with hemodynamic instability remains challenging. We describe a case of AEM presenting as low-flow heart failure with preserved ejection fraction (HFpEF), with rapid progression to cardiogenic shock.

Serum tenascin-C predicts resistance to steroid combination therapy in high-risk Kawasaki disease: a multicenter prospective cohort study.

Background: Tenascin-C (TN-C) is an extracellular matrix glycoprotein related to tissue inflammation. Our previous retrospective study conducted in 2016 revealed that the serum tenascin-C level was higher in patients with Kawasaki disease (KD) who were resistant to intravenous immunoglobulin (IVIG) and developed coronary artery lesions (CALs). The present study is a prospective cohort study to assess if the serum level of tenascin-C could be used as a novel biomarker to predict the risk of resistance to initial treatment for high-risk patients.

A New Mouse Model of Chronic Myocarditis Induced by Recombinant Bacille Calmette-Guèrin Expressing a T-Cell Epitope of Cardiac Myosin Heavy Chain-α.

Dilated cardiomyopathy (DCM) is a potentially lethal disorder characterized by progressive impairment of cardiac function. Chronic myocarditis has long been hypothesized to be one of the causes of DCM. However, owing to the lack of suitable animal models of chronic myocarditis, its pathophysiology remains unclear.

Radionuclide Imaging of Cardiac Amyloidosis and Sarcoidosis: Roles and Characteristics of Various Tracers.

Amyloidosis and sarcoidosis are systemic diseases that affect multiple organ systems. Accurate diagnosis of cardiac amyloidosis and sarcoidosis is particularly important because cardiac involvement can be fatal. Amyloidosis is characterized by the deposition of amyloid fibrils, and cardiac amyloidosis is classified into amyloid immunoglobulin light chain (AL) and amyloid transthyretin (ATTR) types.

Myocardial Native T Predicts Load-Independent Left Ventricular Chamber Stiffness In Patients With HFpEF.

Objectives: This study sought to evaluate the potential of cardiac magnetic resonance T mapping to detect load-independent left ventricular (LV) chamber stiffness by histological confirmation.

Background: Accurate noninvasive diagnosis of LV diastolic dysfunction in heart failure with preserved ejection fraction (HFpEF) remains challenging.

Methods: Nineteen HFpEF patients (14 female, 65 ± 16 years of age) without primary cardiomyopathy were prospectively enrolled.

Correction to: Performance of Tc-aprotinin scintigraphy for diagnosing light chain (AL) cardiac amyloidosis confirmed by endomyocardial biopsy.

This prospective study was conducted according to the principles outlined within the Declaration of Helsinki, and approved by the Ethics Review Board of National Center for Global Health and Medicine (NCGM-G-00839-01, NCGM-G-00839-02).

Postconditioning Accelerates Myocardial Inflammatory Resolution Demonstrated by C-Methionine Imaging and Attenuates Ventricular Remodeling After Ischemia and Reperfusion.

Background: Methionine uptake after myocardial infarction has been proven to reflect myocardial inflammation. The effect of postconditioning on the post-infarction inflammatory process, however, remains to be elucidated.

Methods and results: In control (n=22) and postconditioning rats (n=23), the left coronary artery was occluded for 30 min, followed by reperfusion for 1, 3, 7, and 14 days.

Performance of Tc-aprotinin scintigraphy for diagnosing light chain (AL) cardiac amyloidosis confirmed by endomyocardial biopsy.

Background: Light chain (AL) cardiac amyloidosis is associated with a poor prognosis. Diagnosing at an early stage is critical for treatment and the management of cardiac complication.

Purpose: We aimed to evaluate the diagnostic performance of Tc-aprotinin images in patients with AL cardiac amyloidosis.

Hereditary cardiac amyloidosis associated with Pro24Ser transthyretin mutation: a case report.

Background: Transthyretin amyloidosis is a systemic disorder caused by extracellular deposition of insoluble amyloid fibrils in peripheral and autonomic nerves, heart, kidney, gastrointestinal tract, and other organs. Hereditary transthyretin amyloidosis is an autosomal dominant disease. More than 120 mutations have been reported in the transthyretin gene with considerable phenotypic heterogeneity and geographic diversity.

Successful Inflammation Imaging of Non-Human Primate Hearts Using an Antibody Specific for Tenascin-C.

Inflammation after myocardial infarction (MI) may be a major factor influencing ventricular remodeling, leading to congestive heart failure and arrhythmia. Therefore, inflammation in the heart needs to be monitored. Tenascin-C (TNC) is an extracellular matrix molecule not normally expressed, but it is strongly upregulated when associated with active inflammation.

A case of biopsy-proven eosinophilic myocarditis related to tetanus toxoid immunization.

Vaccine-associated myocarditis is an extremely rare, yet potentially lethal disease, which requires early diagnosis and prompt treatment. However, its pathogenesis remains elusive. We report the first case of biopsy-proven eosinophilic myocarditis related to tetanus toxoid immunization, with unique histopathologic findings, characterized by perivascular eosinophilic infiltrates with myocyte necrosis and abundant interstitial lymphocytic infiltrates with myocyte necrosis, separately.

Tenascin-C accelerates adverse ventricular remodelling after myocardial infarction by modulating macrophage polarization.

Aims: Tenascin-C (TN-C) is an extracellular matrix protein undetected in the normal adult heart, but expressed in several heart diseases associated with inflammation. We previously reported that serum TN-C levels of myocardial infarction (MI) patients were elevated during the acute stage, and that patients with high peak TN-C levels were at high risk of left ventricular (LV) remodelling and poor outcome, suggesting that TN-C could play a significant role in the progression of ventricular remodelling. However, the detailed molecular mechanisms associated with this process remain unknown.

A multicenter trial of extracorporeal cardiac shock wave therapy for refractory angina pectoris: report of the highly advanced medical treatment in Japan.

We have previously demonstrated that cardiac shock wave therapy (CSWT) effectively improves myocardial ischemia through coronary neovascularization both in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris (AP). In this study, we further addressed the efficacy and safety of CSWT in a single-arm multicenter study approved as a highly advanced medical treatment by the Japanese Ministry of Health, Labour and Welfare. Fifty patients with refractory AP [mean age 70.

A case of cardiac sarcoidosis mimicking cardiac amyloidosis on cardiovascular magnetic resonance.

A 52-year-old male visited our hospital with abnormal electrocardiogram and exertional fatigue. The electrocardiogram showed first-degree atrioventricular block, complete right bundle branch block, and inverted T waves in Leads II, III, aVF, V3, and V4. Echocardiography showed biventricular wall thickening involving granular sparkling of the interventricular septum.

Steroid pulse therapy was effective for cardiac sarcoidosis with ventricular tachycardia and systolic dysfunction.

A 32-year-old man presented with palpitation. He was diagnosed with pulmonary sarcoidosis by lung biopsy. The electrocardiogram showed first-degree atrioventricular block and complete right bundle branch block (CRBBB).

Serum Tenascin-C as a Novel Predictor for Risk of Coronary Artery Lesion and Resistance to Intravenous Immunoglobulin in Kawasaki Disease - A Multicenter Retrospective Study.

Background: Tenascin-C (TN-C) is an extracellular matrix glycoprotein that is heavily upregulated at sites of inflammation. We conducted a retrospective study to assess the utility of TN-C as a novel biomarker to predict the risk of developing coronary artery lesions (CAL) and resistance to intravenous immunoglobulin (IVIG) in patients with Kawasaki disease (KD).Methods and Results:We collected blood samples of 111 KD patients (IVIG-responder: 89, IVIG-resistant: 22; CAL: 8) and 23 healthy controls, and measured the serum levels of TN-C.

Cardiac sarcoidosis, the complete atrioventricular block of which was completely recovered by intravenous steroid pulse therapy.

Atrioventricular block (AVB) in individuals with cardiac sarcoidosis (CS) is one of the major complications caused by inflammation of the conducting system of the heart, as a sign of worse prognosis. We report the case of a 53-year-old Japanese woman whose electrocardiogram showed complete AVB by the clinical diagnosis of CS. We administered intravenous methylpredonisolone (1 g/day) for 3 days.

Tenascin-C may accelerate cardiac fibrosis by activating macrophages via the integrin αVβ3/nuclear factor-κB/interleukin-6 axis.

Tenascin-C (TN-C) is an extracellular matrix protein not detected in normal adult heart, but expressed in several heart diseases closely associated with inflammation. Accumulating data suggest that TN-C may play a significant role in progression of ventricular remodeling. In this study, we aimed to elucidate the role of TN-C in hypertensive cardiac fibrosis and underlying molecular mechanisms.

Effect of postconditioning on dynamic expression of tenascin-C and left ventricular remodeling after myocardial ischemia and reperfusion.

Background: Tenascin-C (TNC), an extracellular matrix glycoprotein, is expressed transiently in distinct areas in association with active tissue remodeling. This study aimed to explore how ischemic postconditioning (PC) affects myocardial expression of TNC and ventricular remodeling using (125)I-labeled anti-TNC antibody ((125)I-TNC-Ab) in a rat model of ischemia and reperfusion.

Methods: In control rats (n = 27), the left coronary artery (LCA) was occluded for 30 min followed by reperfusion for 1, 3, 7, and 14 days.