Incidental histological diagnosis of acute rheumatic myocarditis: case report and review of the literature

A study protocol to characterise pathophysiological and molecular markers of rheumatic heart disease and degenerative aortic stenosis using multiparametric cardiovascular imaging and multiomics techniques

INTRODUCTION

Rheumatic heart disease (RHD), degenerative aortic stenosis (AS), and congenital valve diseases are prevalent in sub-Saharan Africa. Many knowledge gaps remain in understanding disease mechanisms, stratifying phenotypes, and prognostication. Therefore, we aimed to characterise patients through clinical profiling, imaging, histology, and molecular biomarkers to improve our understanding of the pathophysiology, diagnosis, and prognosis of RHD and AS.

METHODS

In this cross-sectional, case-controlled study, we plan to recruit RHD and AS patients and compare them to matched controls. Living participants will undergo clinical assessment, echocardiography, CMR and blood sampling for circulatory biomarker analyses. Tissue samples will be obtained from patients undergoing valve replacement, while healthy tissues will be obtained from cadavers. Immunohistology, proteomics, metabolomics, and transcriptome analyses will be used to analyse circulatory- and tissue-specific biomarkers. Univariate and multivariate statistical analyses will be used for hypothesis testing and identification of important biomarkers. In summary, this study aims to delineate the pathophysiology of RHD and degenerative AS using multiparametric CMR imaging. In addition to discover novel biomarkers and explore the pathomechanisms associated with RHD and AS through high-throughput profiling of the tissue and blood proteome and metabolome and provide a proof of concept of the suitability of using cadaveric tissues as controls for cardiovascular disease studies.

Fatal Myocarditis following COVID-19 mRNA Immunization: A Case Report and Differential Diagnosis Review

Carditis in childhood is a rare disease with several etiologies. We report a case of infant death due to pericarditis and myocarditis after the mRNA vaccine against COVID-19 (COVIDmRNAV). A 7-year-old male child received the first dose of the COVIDmRNAV and presented with monoarthritis and a fever non-responsive to oral antibiotics. The laboratory investigation showed signs of infection (leukocytosis, high levels of c-reactive protein). His condition rapidly deteriorated, and the patient died. The autopsy identified pericardial fibrin deposits, hemorrhagic areas in the myocardium, and normal valves. A diffuse intermyocardial inflammatory infiltrate composed of T CD8+ lymphocytes and histiocytes was identified. An antistreptolysin O (ASO) dosage showed high titers. The presence of arthritis, elevated ASO, and carditis fulfills the criteria for rheumatic fever. However, valve disease and Aschoff's nodules, present in 90% of rheumatic carditis cases, were absent in this case. The temporal correlation with mRNA vaccination prompted its inclusion as one of the etiologies. In cases of myocardial damage related to COVID-19mRNAV, it appears to be related to the expression of exosomes and lipid nanoparticles, leading to a cytokine storm. The potential effects of the COVID-19mRNAV must be considered in the pathogenesis of this disease, whether as an etiology or a contributing factor to a previously initiated myocardial injury.

Incidental Diagnosis of Rheumatic Myocarditis during Cardiac Surgery-Impact on Late Prognosis

Rheumatic fever (RF) and rheumatic heart disease (RHD) are still highly prevalent, particularly in low- and middle-income countries. RHD is a neglected and underdiagnosed disease for which no specific laboratory diagnostic test is completely reliable. This is a retrospective observational study, which included 118 patients with RHD who underwent cardiac surgery from 1985 to 2018. The aim of this investigation was to evaluate the clinical, epidemiological, echocardiographic and pathological characteristics in two cohorts of RHD patients: one cohort with Aschoff bodies present in their pathological results and the other without such histopathological characteristics. No conventional clinical and laboratory tests for RHD myocarditis were able to identify active carditis during the preoperative phase of valve repair or replacement. Patients who had Aschoff bodies in their pathological results were younger (median age of 13 years (11-24 years) vs. 27 years (17-37 years), p = 0.001) and had higher rate of late mortality (22.9% vs. 5.4%, p = 0.043). In conclusion, the presence of Aschoff bodies in pathological findings may predict increased long-term mortality, emphasizing the importance of comprehensive pathology analysis for suspected myocarditis during heart surgery.

Chronic rheumatic heart disease with recrudescence of acute rheumatic fever on histology: a case report

Background

Rheumatic heart disease (RHD) is endemic in sub-Saharan Africa where it is the leading cause of cardiovascular mortality in the young. Rheumatic heart disease results from recurrent episodes of acute rheumatic fever (ARF), which are often difficult to diagnose clinically. Acute rheumatic fever may be diagnosed based on the revised Jones Criteria 2015 for the diagnosis of ARF. Histologically, acute rheumatic valvulitis manifests with active inflammation characterized by lymphocytic infiltration, Aschoff bodies, and Anitschkow cells. Chronic rheumatic valvulitis is associated with neovascularization, and/or dystrophic calcification. The combination of histological features of both ARF and chronic RHD is a rare finding.

Case summary

Here we report on a case of a 59-year-old woman with mixed aortic and mitral valve disease of probable rheumatic aetiology (elevated C-reactive protein and prolonged PR interval) and with histological evidence of lymphocytic infiltration, Aschoff bodies, and fibrinoid necrosis admixed with features of chronic RHD.

Discussion

Cases of chronic RHD admixed with ARF are very rare; however, they should be considered in regions with a high prevalence of RHDs.

Focused Cardiac Ultrasound Examination as a Tool for Diagnosis of Infective Endocarditis and Myocarditis in Dogs and Cats

Symptoms of infective endocarditis (IE) and myocarditis are usually nonspecific and include fever, apathy, and loss of appetite. This condition can lead to severe heart failure with ascites or/and fluid in the thoracic cavity or/and in the pericardial sac. We describe infective endocarditis and myocarditis in 3 dogs and 4 cats. In all animals, the initial diagnosis was performed on the basis of a focused cardiac ultrasound examination performed by a general practitioner after a training in this technique. The initial findings were confirmed by a board-certified specialist in veterinary cardiology. Post mortem positive microbiological results from valves were obtained in 4 of 7 patients. Methicillin-resistant Staphylococcus aureus was confirmed in 2 cases and Staphylococcus epidermidis was confirmed in 2 cases, one of which included Enterococcus sp. coinfection. Histopathological examination confirmed initial diagnosis in 5 of 7 animals. In the remaining 2 patients, the time elapsed from the onset of clinical symptoms to death was about 1 month and no active inflammation but massive fibrosis was found microscopically. This is, to our best knowledge, the first report of IE and myocarditis diagnosed in small animals using focused cardiac ultrasound examination. Therefore, we conclude that common usage of this technique by trained general veterinarians may increase the rate of diagnosed patients with these conditions.