Hypersensitivity myocarditis and the pathogenetic conundrum of COVID 19 Vaccine Related Myocarditis

"When," "Where," and "How" of SARS-CoV-2 Infection Affects the Human Cardiovascular System: A Narrative Review

Coronavirus disease 2019 (COVID-19) is caused by the novel severe acute respiratory coronavirus-2 (SARS-CoV-2). Several explanations for the development of cardiovascular complications during and after acute COVID-19 infection have been hypothesized. The COVID-19 pandemic, caused by SARS-CoV-2, has emerged as one of the deadliest pandemics in modern history. The myocardial injury in COVID-19 patients has been associated with coronary spasm, microthrombi formation, plaque rupture, hypoxic injury, or cytokine storm, which have the same pathophysiology as the three clinical variants of Kounis syndrome. The angiotensin-converting enzyme 2 (ACE2), reninaldosterone system (RAAS), and kinin-kallikrein system are the main proposed mechanisms contributing to cardiovascular complications with the COVID-19 infection. ACE receptors can be found in the heart, blood vessels, endothelium, lungs, intestines, testes, neurons, and other human body parts. SARS-CoV-2 directly invades the endothelial cells with ACE2 receptors and constitutes the main pathway through which the virus enters the endothelial cells. This causes angiotensin II accumulation downregulation of the ACE2 receptors, resulting in prothrombotic effects, such as hemostatic imbalance via activation of the coagulation cascade, impaired fibrinolysis, thrombin generation, vasoconstriction, endothelial and platelet activation, and pro-inflammatory cytokine release. The KKS system typically causes vasodilation and regulates tissue repair, inflammation, cell proliferation, and platelet aggregation, but SARS-CoV-2 infection impairs such counterbalancing effects. This cascade results in cardiac arrhythmias, cardiac arrest, cardiomyopathy, cytokine storm, heart failure, ischemic myocardial injuries, microvascular disease, Kounis syndrome, prolonged COVID, myocardial fibrosis, myocarditis, new-onset hypertension, pericarditis, postural orthostatic tachycardia syndrome, pulmonary hypertension, stroke, Takotsubo syndrome, venous thromboembolism, and thrombocytopenia. In this narrative review, we describe and elucidate when, where, and how COVID-19 affects the human cardiovascular system in various parts of the human body that are vulnerable in every patient category, including children and athletes.

Uneventful COVID-19 Infection and Vaccination in a Cohort of Patients with Prior Myocarditis

Myocarditis has in rare cases been associated with COVID-19 infection and has emerged as a possible rare side effect of vaccination with anti-COVID-19 messenger RNA vaccines. However, little is known about possible COVID-19 infection- and/or vaccination-related myocarditis relapse in patients with previous clinically suspected or biopsy-proven myocarditis. Myocarditis may relapse, particularly in females with immune-mediated/autoimmune features and a predisposing immunogenetic background. We aimed to assess the prevalence of myocarditis relapse during the COVID-19 outbreak and following COVID-19 vaccination in a cohort of patients with prior myocarditis. We included in the analysis myocarditis patients on active follow-up, for whom COVID-19 infection and vaccination statuses were known, and collected data on clinical, laboratory and echocardiographic findings, and myocarditis relapse. We enrolled 409 patients, of whom 114 (28%) reported COVID-19 infection and 347 (85%) completed the vaccination scheme. Only one patient, having COVID-19 infection before the vaccination campaign started, was admitted to hospital because of pneumonia; the remaining patients had an uneventful COVID-19 infection course, with only mild symptoms. No myocarditis relapse was recorded following COVID-19 infection or vaccination. Moreover, the frequency of new myocarditis cases following the COVID-19 outbreak was not different compared to the three-year period preceding the COVID-19 era. In conclusion, in our cohort of patients with prior myocarditis, both COVID-19 infection and vaccination were uneventful.

Update on Myocarditis: From Etiology and Clinical Picture to Modern Diagnostics and Methods of Treatment

Although the frequency of myocarditis in the general population is very difficult to accurately determine due to the large number of asymptomatic cases, the incidence of this disease is increasing significantly due to better defined criteria for diagnosis and the development of modern diagnostic methods. The multitude of different etiological factors, the diversity of the clinical picture, and the variability of the diagnostic findings make this disease often demanding both for the selection of the diagnostic modality and for the proper therapeutic approach. The previously known most common viral etiology of this disease is today overshadowed by new findings based on immune-mediated processes, associated with diseases that in their natural course can lead to myocardial involvement, as well as the iatrogenic cause of myocarditis, which is due to use of immune checkpoint inhibitors in the treatment of cancer patients. Suspecting that a patient with polymorphic and non-specific clinical signs and symptoms, such as changes in ECG and echocardiography readings, has myocarditis is the starting point in the diagnostic algorithm. Cardio magnetic resonance imaging is non-invasive and is the gold standard for diagnosis and clinical follow-up of these patients. Endomyocardial biopsy as an invasive method is the diagnostic choice in life-threatening cases with suspicion of fulminant myocarditis where the diagnosis has not yet established or there is no adequate response to the applied therapeutic regimen. The treatment of myocarditis is increasingly demanding and includes conservative methods of treating heart failure, immunomodulatory and immunospressive therapy, methods of mechanical circulatory support, and heart transplantation. The goal of developing new diagnostic and therapeutic methods is to reduce mortality from this complex disease, which is still high.

Covid- 19 Vaccine-induced Myocarditis

Myocarditis and pericarditis are rare adverse reactions, more commonly seen in young males after receiving the second dose of an mRNA vaccine. However, the benefits of vaccination heavily outweigh the risk of these side effects. In addition, vaccination boosters are effective against the newest, more infective variants. Therefore we expect more vaccines to be administered in the following years. The objective of this study is to review the current understanding of the mechanism, diagnosis, and treatment of myocarditis and pericarditis. Proposed mechanisms include molecular mimicry against the S protein and hypersensitivity reactions with mRNA vaccines and platelet aggregation and thrombus formation in cardiac blood vessels with adenoviral vaccines. Diagnosis of myocarditis is based on clinical findings, cardiac enzymes, ECG, MRI, and echocardiographic findings. Management includes NSAIDs and cardiovascular support in selected cases with ventricular dysfunction. Most patients have a mild presentation with preservation of cardiac function and recover entirely within seven days; the average hospital stay is three days. Long-term complications are infrequent.

Characteristics of Electrocardiogram Findings in Fulminant Myocarditis

Fulminant myocarditis (FM) is an acute and severe form of myocarditis with rapid progression and poor clinical outcomes in the absence of acute or chronic coronary artery disease. Electrocardiogram (ECG) abnormalities can provide preliminary clues for diagnosis; however, there is a lack of systemic descriptions on ECG changes in FM populations. Thus, a retrospective analysis of 150 consecutive FM patients and 300 healthy controls was performed to determine the characteristic ECG findings in FM. All patients included had markedly abnormal ECG findings. Specifically, 83 (55.33%) patients had significantly lower voltage with remarkably decreased QRS amplitudes in all leads compared with healthy controls (p < 0.01), and 77 (51.33%) patients had a variety of arrhythmias with lethality ventricular tachycardia/ventricular fibrillation in 21 (14.00%) patients and third-degree atrioventricular block in 21 (14.00%) patients, whereas sinus tachycardia was only found in 43 (28.67%) patients with the median heart rate (HR; 88.00 bpm, IQR: 76.00-113.50) higher than that of controls (73.00 bpm, IQR: 68.00-80.00) (p = 0.000). Conduction and repolarization abnormalities were common in patients. A longer QTc interval (452.00 ms, IQR: 419.00-489.50) and QRS duration (94.00 ms, IQR: 84.00-119.00) were observed in patients compared to controls (QTc interval = 399.00 ms, IQR: 386.00-414.00; QRS duration = 90.00 ms, IQR: 86.00-98.00) (p < 0.05). Additionally, HR > 86.50 bpm, QTc > 431.50 ms, and RV5 + SV1 < 1.715 mV can be used to predict FM. Thus, marked and severe ECG abnormalities provide preliminary clues for the diagnosis of FM.

Delayed presentation of biopsy-proven eosinophilic myocarditis following COVID-19 mRNA vaccine

Myopericarditis associated with COVID-19 mRNA vaccines has been recognized as an uncommon adverse reaction, especially among young, healthy adult males. Eosinophilic myocarditis is a rare form of inflammation reflecting a hypersensitivity reaction following an inciting event commonly caused by drugs including vaccines. Eosinophilic myocarditis, a subtype of myocarditis, is characterized by eosinophilic myocardial infiltrates. It is usually accompanied by systemic eosinophilia in the form of a drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and is rarely associated with myocyte fibrosis and/or necrosis. In this report, we present a case of biopsy-proven eosinophilic myocarditis in a 24-year-old male patient, likely secondary to COVID-19 mRNA vaccination. To our knowledge, this is the first report to describe delayed eosinophilic myocarditis following the COVID-19 mRNA vaccine. Clinicians should be aware of possible delayed presentation to avoid associated morbidity.

Evaluation of Autoantibody Binding to Cardiac Tissue in Multisystem Inflammatory Syndrome in Children and COVID-19 Vaccination-Induced Myocarditis

Importance

Cardiac dysfunction and myocarditis have emerged as serious complications of multisystem inflammatory syndrome in children (MIS-C) and vaccines against SARS-CoV-2. Understanding the role of autoantibodies in these conditions is essential for guiding MIS-C management and vaccination strategies in children.

Objective

To investigate the presence of anticardiac autoantibodies in MIS-C or COVID-19 vaccine-induced myocarditis.

Design, Setting, and Participants

This diagnostic study included children with acute MIS-C or acute vaccine myocarditis, adults with myocarditis or inflammatory cardiomyopathy, healthy children prior to the COVID-19 pandemic, and healthy COVID-19 vaccinated adults. Participants were recruited into research studies in the US, United Kingdom, and Austria starting January 2021. Immunoglobulin G (IgG), IgM, and IgA anticardiac autoantibodies were identified with immunofluorescence staining of left ventricular myocardial tissue from 2 human donors treated with sera from patients and controls. Secondary antibodies were fluorescein isothiocyanate-conjugated antihuman IgG, IgM, and IgA. Images were taken for detection of specific IgG, IgM, and IgA deposits and measurement of fluorescein isothiocyanate fluorescence intensity. Data were analyzed through March 10, 2023.

Main Outcomes and Measures

IgG, IgM and IgA antibody binding to cardiac tissue.

Results

By cohort, there were a total of 10 children with MIS-C (median [IQR] age, 10 [13-14] years; 6 male), 10 with vaccine myocarditis (median age, 15 [14-16] years; 10 male), 8 adults with myocarditis or inflammatory cardiomyopathy (median age, 55 [46-63] years; 6 male), 10 healthy pediatric controls (median age, 8 [13-14] years; 5 male), and 10 healthy vaccinated adults (all older than 21 years, 5 male). No antibody binding above background was observed in human cardiac tissue treated with sera from pediatric patients with MIS-C or vaccine myocarditis. One of the 8 adult patients with myocarditis or cardiomyopathy had positive IgG staining with raised fluorescence intensity (median [IQR] intensity, 11 060 [10 223-11 858] AU). There were no significant differences in median fluorescence intensity in all other patient cohorts compared with controls for IgG (MIS-C, 6033 [5834-6756] AU; vaccine myocarditis, 6392 [5710-6836] AU; adult myocarditis or inflammatory cardiomyopathy, 5688 [5277-5990] AU; healthy pediatric controls, 6235 [5924-6708] AU; healthy vaccinated adults, 7000 [6423-7739] AU), IgM (MIS-C, 3354 [3110-4043] AU; vaccine myocarditis, 3843 [3288-4748] AU; healthy pediatric controls, 3436 [3313-4237] AU; healthy vaccinated adults, 3543 [2997-4607] AU) and IgA (MIS-C, 3559 [2788-4466] AU; vaccine myocarditis, 4389 [2393-4780] AU; healthy pediatric controls, 3436 [2425-4077] AU; healthy vaccinated adults, 4561 [3164-6309] AU).

Conclusions and Relevance

This etiological diagnostic study found no evidence of antibodies from MIS-C and COVID-19 vaccine myocarditis serum binding cardiac tissue, suggesting that the cardiac pathology in both conditions is unlikely to be driven by direct anticardiac antibody-mediated mechanisms.

Current evidence of COVID-19 vaccination-related cardiovascular events

Currently, the world is recovering from the shock of the coronavirus disease 2019 (COVID-19) pandemic; however, this situation is still fragile. Health authorities recommend administering COVID-19 vaccines as the safest and most reliable tool for eliminating COVID-19. Subsequent to the extensive administration of the COVID-19 vaccines, a series of cardiovascular adverse effects have been reported. This comprehensive review aimed to provide an update on the etiology, pathophysiology, clinical features, and management of the cardiovascular adverse events associated with COVID-19 vaccines, including myocarditis, pericarditis, thrombosis with thrombocytopenia syndrome, myocardial infarction, cardiac arrhythmias, hypertension, and stress-induced cardiomyopathy. The benefits of COVID-19 vaccination far outweigh the reported adverse events. It would be clinically important to provide diagnostic scoring systems to differentiate COVID-19-related cardiovascular adverse events from other causes and develop therapeutic approaches for their management. Further evaluation of cardiovascular adverse events of the COVID-19 vaccines is crucial for implementing vaccination programs and developing safer and more reliable vaccines.

Allergic Reactions to COVID-19 Vaccination in High-Risk Allergic Patients: The Experience of Trieste University Hospital (North-Eastern Italy)

Background. Allergic patients may develop reactions following COVID-19 vaccination more frequently than non-allergic individuals. The aim of our study was to assess the risk of reactions in high-risk allergic patients vaccinated for COVID-19 at the University Health Agency Giuliano-Isontina (ASUGI) of Trieste (northeastern Italy). Methods. Patients were considered at high risk for allergic reactions in case of: prior anaphylactic reaction to any drug/vaccine; multiple drug allergy; intolerance to polyethylene glycol (PEG) or polysorbate 80 (PS80) containing drugs; and mast cell disorders. High-risk allergic patients were immunized in hospital by a dedicated allergy team supported by resuscitation staff. Patients were interviewed over the phone one month after vaccination to complete a structured questionnaire investigating signs and symptoms developed after immunization. Results. From March 2021 to February 2022, 269 patients with a history of severe allergic reactions were assessed, of whom 208 (77.3%) eventually received COVID-19 vaccination, 50 (18.6%) refused to be immunized, 10 (3.7%) were deferred for medical reasons and one was declared exempted due to testing positive for PS80. Mild reactions (urticaria, angioedema, rhinitis, erythema) to COVID-19 vaccines were reported by 30.3% of patients, 8.7% within 4 h and 21.6% > 4 h after immunization. No anaphylactic events were observed. Although they were 80 times (3.8%) more prevalent than in COVID-19 vaccinees from the general population (0.047%), vaccine allergic reactions in high-risk patients were mainly mild and late, more likely affecting women (OR = 3.05; 95% CI 1.22−7.65). Conclusions. High-risk allergic patients with urticaria and angioedema may experience mild flare-ups of mast cell activation-like symptoms following COVID-19 vaccination, supporting antihistamine premedication before vaccination and to be continued for one week afterwards.

Myocarditis Following COVID-19 Vaccination: Cardiac Imaging Findings in 118 Studies

We reviewed the reported imaging findings of myocarditis in the literature following COVID-19 vaccination on cardiac imaging by a literature search in online databases, including Scopus, Medline (PubMed), Web of Science, Embase (Elsevier), and Google Scholar. In total, 532 cases of myocarditis after COVID-19 vaccination were reported (462, 86.8% men and 70, 13.2% women, age range 12 to 80) with the following distribution: Pfizer-BioNTech: 367 (69%), Moderna: 137 (25.8%), AstraZeneca: 12 (2.3%), Janssen/Johnson & Johnson: 6 (1.1%), COVAXIN: 1 (0.1%), and unknown mRNA vaccine: 9 (1.7%). The distribution of patients receiving vaccine dosage was investigated. On cardiac MR Imaging, late intravenous gadolinium enhancement (LGE) was observed mainly in the epicardial/subepicardial segments (90.8%, 318 of 350 enhancing segments), with the dominance of inferolateral segment and inferior walls. Pericardial effusion was reported in 13.1% of cases. The vast majority of patients (94%, 500 of 532) were discharged from the hospital except for 4 (0.7%) cases. Post-COVID-19 myocarditis was most commonly reported in symptomatic men after the second or third dose, with CMRI findings including LGE in 90.8% of inferior and inferolateral epicardial/subepicardial segments. Most cases were self-limited.

Immune Response in Regard to Hypersensitivity Reactions after COVID-19 Vaccination

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), is a member of the genus Betacoronavirus. This virus was first detected in December 2019, and the situation quickly escalated to cause a global pandemic within a few months. COVID-19 had caused more than 5.5 million deaths as of January 2022. Hence, the urgency of effective vaccination contributed to the fastest rate of vaccine development seen to date (i.e., within 1.5 years). Despite reports of good vaccine efficacy without severe systemic reactions at the clinical trial stage, hypersensitivity reactions have been reported following worldwide vaccination campaigns. We provide a brief review regarding the structure of SARS-CoV-2. We also review the most acceptable types of vaccines in terms of safety profiles, namely the BNT162b2, mRNA-1273, and AZD1222 vaccines. This review aims to facilitate an understanding of the possible immune mechanisms regarding COVID-19-vaccination-related hypersensitivity reactions, such as thrombosis and thrombocytopenia, cutaneous adverse reactions, myocarditis, and perimyocarditis.