Acute Lymphocyte Myocarditis Associated with Influenza Vaccination

An elderly patient was admitted to our hospital for acute heart failure soon after receiving influenza vaccination. On admission, chest radiography revealed pulmonary edema. An electrocardiogram showed poor R progression, and echocardiography showed diffuse hypokinesis and myocardial edema. The serum troponin level was elevated. A histopathological evaluation indicated active myocarditis with lymphocyte-predominant infiltrates. A drug-induced lymphocyte stimulation test (DLST) was positive. The patient rapidly recovered from heart failure after treatment with conventional heart failure drugs, such as intravenous diuretics and vasodilators. These experimental data and the clinical course suggest that influenza vaccination was responsible for heart failure due to acute lymphocyte myocarditis.

Sinus Node Dysfunction Co-occurring with Immune Checkpoint Inhibitor-associated Myocarditis

Immune checkpoint inhibitor (ICI)-induced myocarditis is a potentially life-threatening adverse event. We herein report a rare case of sick sinus syndrome (SSS) co-occurring with ICI-associated myocarditis. A 71-year-old woman with lung cancer undergoing pembrolizumab monotherapy was admitted owing to a fever, worsening kidney function, and sinus bradycardia. She was diagnosed with multi-organ immune-related adverse events, including myocarditis. Pulse steroid therapy was initiated immediately under the support of a temporary pacemaker, which resulted in the resolution of SSS in a few days. Biopsy specimens of the endomyocardium showed active myocarditis. Thus, we should be aware that SSS can co-occur with ICI-induced myocarditis.

Cardiovascular symptom phenotypes of post-acute sequelae of SARS-CoV-2

Background

Acute COVID-19 infection has been shown to have significant effects on the cardiovascular system. Post-acute sequelae of SARS-CoV-2 (PASC) are being identified in patients; however, the cardiovascular effects are yet to be well-defined. The Post-COVID Cardiology Clinic at Washington University evaluates and treats patients with ongoing cardiovascular PASC.

Objectives

This investigation aims to describe the phenotypes of cardiovascular symptoms of PASC in patients presenting to the Post-COVID Cardiology Clinic, including their demographics, symptoms, and the clinical phenotypes observed.

Methods

This was a retrospective analysis of symptoms, clinical findings, and test results from the first 100 consecutive adult patients who presented to the Post-COVID Cardiology Clinic at Washington University in St. Louis, between September 2020 to May 2021 with cardiovascular symptoms following COVID-19 infection.

Results

The population (n = 100) had a mean age of 46.3 years and was 81% female. Most patients had mild acute illness, with only 23% of patients requiring hospitalization during acute COVID-19 infection. The most commonly reported PASC symptoms were chest pain (66%), palpitations (59%), and dyspnea on exertion (56%). Of those presenting with these symptoms, 74/98 patients (75.5%) were found to have a significant blood pressure elevation, considerable sinus tachycardia burden, reduced global longitudinal strain, increased indexed left-ventricular end-diastolic volume (LVEDVi) by echocardiogram, and/or cMRI findings consistent with possible active or healing myocarditis.

Conclusions

Our findings highlight clinical phenotypes of the cardiovascular manifestations of PASC. Further studies are needed to evaluate the pathophysiology, treatment options and long-term outcomes for these patients.

Clinical variants of myocardial involvement in COVID-19-positive patients: a cumulative experience of 2020

Myocardial injury, diagnosed by troponin elevation, is common in COVID-19 patients, but cardiac involvement with clinical manifestations occurs less frequently. We analyzed the literature on COVID-19 (2020) and systematically reviewed the cases where individual patient data were presented. We searched PubMed and Google Scholar for "COVID," "COVID-19," and "coronavirus" in combination with "myocarditis," "heart failure," "takotsubo," "cardiomyopathy," and "cardiogenic shock." We identified 90 cases of COVID-19 with myocardial involvement, mean age 52.9 ± 18.3 years, 54.5% males. Of them, 55 survived (61.1%), 20 died (22.2%), and in 15 (16.7%) the outcome was unknown at the time of publication. Among patients with known outcome, mortality was 26%. The nadir LVEF was 31.7 ± 13.1% and recovered to 50.1 ± 16.0%. Pericardial effusion was a common finding, reported in 21 (23.3%) of patients, including moderate size effusion in 8.9% and large in 7.8%. The effusion caused tamponade in 11 (12.2%) of patients. Out of 83 patients who experienced a decrease in LVEF, 30 could be classified as takotsubo syndrome. The takotsubo patients were older than those with myocarditis, and with relatively high proportion of males. About one third of the cases was complicated by cardiogenic shock. Myocardial involvement in COVID-19 patients most often presents as a new, rapid decrease in LVEF, although normal LVEF or takotsubo-like wall motion pattern does not rule out myocarditis. Moderate and large pericardial effusion is common, and cardiac tamponade occurs in 12.2% of patients. Cardiogenic shock develops in one third of the patients. Mortality appears to be high at 26%.

Coronavirus disease 2019 and the cardiologist

PURPOSE OF REVIEW

There continues to be extensive clinical and epidemiological data to suggest that coronavirus disease 2019 (COVID-19) infection is associated with numerous different types of cardiac involvement.

RECENT FINDINGS

Myocardial injury has been reported in over 25% of patients hospitalized due to COVID-19 infection and is not only associated with a worse prognosis but with higher mortality, approaching 40%. Currently proposed mechanisms of myocardial injury include direct viral infection, cytokine storm, endothelial inflammation, demand ischemia, interferon-mediated response and stress cardiomyopathy. COVID-19 infection is associated with new-onset arrhythmias and heart failure regardless of history of previous cardiovascular disease. Echocardiographic findings can be useful to predict mortality in COVID-19 patients and cardiac MRI is an effective tool to both assess COVID-19 induced myocarditis and to follow-up on cardiac complications of COVID-19 long-term. Although there is an association between COVID-19 vaccination and myocarditis, pericarditis or arrhythmias, the risk appears lower when compared to risk attributable to the natural infection.

SUMMARY

Patients with cardiovascular disease are not only more likely to suffer from severe COVID-19 infection but are at increased risk for further complications and higher mortality. Further data compilation on current and emerging treatments of COVID-19 will have additional impact on cardiovascular morbidity and mortality of COVID-19 infection.

Incidence of acute myocarditis and pericarditis during the coronavirus disease 2019 pandemic: comparison with the prepandemic period

BACKGROUND

Myocarditis and pericarditis have been proposed to account for a proportion of cardiac injury during SARS-CoV-2 infection. The impact of COVID-19 the pandemic on the incidence of this acute inflammatory cardiac disease was not systematically evaluated.

AIM

To examine the incidence and prevalence of inflammatory heart disorders prior to and during the COVID-19 pandemic.

METHODS

We compared the incidence and prevalence of acute inflammatory heart diseases (myocarditis, pericarditis) in the provinces of Pisa, Lucca and Livorno in two time intervals: prior to (PRECOVID, from 1 June 2018 to 31 May 2019) and during the COVID-19 pandemic (COVID, from 1 June 2020 to May 2021).

RESULTS

Overall 259 cases of inflammatory heart disease (myocarditis and/or pericarditis) occurred in the areas of interest. The annual incidence was of 11.3 cases per 100 000 inhabitants. Particularly, 138 cases occurred in the pre-COVID, and 121 in the COVID period. The annual incidence of inflammatory heart disease was not significantly different (12.1/100 000 in PRECOVID vs 10.3/100 000 in COVID, P = 0.22). The annual incidence of myocarditis was significantly higher in PRECOVID than in COVID, respectively 8.1/100 000/year vs. 5.9/100 000/year (P = 0.047) consisting of a net reduction of 27% of cases. Particularly the incidence of myocarditis was significantly lower in COVID than in PRECOVID in the class of age 18-24

[2022 Update on myocarditis and pericarditis following COVID-19 vaccination. Expert Opinion of the Italian Society of Cardiology]

Vaccine-associated myocarditis and pericarditis usually develop within 14 days of COVID-19 vaccination, are exceptionally rare, manifest with mild clinical pictures and are commonly characterized by a favorable evolution. Young men inoculated with two doses of an mRNA vaccine are the subgroup at higher risk. Recent epidemiological studies evaluated the incidence and risk of vaccine-associated myocarditis and pericarditis among men and women, in different ranges of age and specific types of vaccines. Long-term population analyses demonstrated that the cardiovascular risk conferred by COVID-19 extends beyond the acute phase, representing the rationale for implementing prevention strategies for SARS-CoV-2 infection, monitoring specific populations at higher risk and pursuing the completion of the vaccination campaign. This document provides an update on the most recent scientific evidence and critical interpretation of available data in constant evolution towards personalized strategies of immunization.

[Incidental Diagnosis of Giant Cell Myocarditis at Open Heart Surgery:Report of Case]

Giant cell myocarditis (GCM) is one of the rare diseases that cause fatal heart failure and suspected to be associated with autoimmune disorder. There are few reports that the patients of GCM live long because of their progressive heart failure. We report a rare case of patient who was suspected two long hospitalizations due to heart failure in her childhood and peripartum period, and incidentally diagnosed with GCM by myocardial biopsy performed at the aortic valve replacement and mitral annuloplasty for severe aortic valve regurgitation and moderate mitral regurgitation.

Simultaneous Occurrence of Immune-Mediated Thrombocytopenia and Myocarditis After mRNA-1273 COVID-19 Vaccination: A Case Report

With the global spread of severe acute respiratory syndrome coronavirus 2, several vaccines were developed; messenger RNA (mRNA) vaccines have recently been widely used worldwide. However, the incidence of myocarditis following mRNA vaccination is increasing; although the cause of myocarditis has not yet been clearly identified, it is presumed to be caused by a problem in the innate immune system. Immune-mediated thrombocytopenia (ITP) after vaccination is rare but has been reported and is also assumed to occur by the same mechanism. We report the first case of simultaneous myocarditis and ITP after mRNA vaccination. A 38-year-old woman presented with chest pain, mild dyspnea, and sweating after vaccination with mRNA-1273 vaccine (Moderna) 4 days prior to admission. Upon admission to the emergency department, cardiac enzymes were elevated; blood test performed 5 months ago showed normal platelet count, but severe thrombocytopenia was observed upon admission. After administration of intravenous immunoglobulin, the platelet count improved; subsequently, myocarditis was observed on endomyocardial biopsy. Thus, myocarditis and ITP were judged to have occurred simultaneously due to the expression of the innate immune system markers after mRNA vaccination. The patient was discharged on day 6 of admission.

COVID-19 Myocarditis: Prognostic Role of Bedside Speckle-Tracking Echocardiography and Association with Total Scar Burden

SARS-CoV2 infection, responsible for the COVID-19 disease, can determine cardiac as well as respiratory injury. In COVID patients, viral myocarditis can represent an important cause of myocardial damage. Clinical presentation of myocarditis is heterogeneous. Furthermore, the full diagnostic algorithm can be hindered by logistical difficulties related to the transportation of COVID-19 patients in a critical condition to the radiology department. Our aim was to study longitudinal systolic cardiac function in patients with COVID-19-related myocarditis with echocardiography and to compare these findings with cardiac magnetic resonance (CMR) results. Patients with confirmed acute myocarditis and age- and gender-matched healthy controls were enrolled. Both patients with COVID-19-related myocarditis and healthy controls underwent standard transthoracic echocardiography and speckle-tracking analysis at the moment of admission and after 6 months of follow-up. The data of 55 patients with myocarditis (mean age 46.4 ± 15.3, 70% males) and 55 healthy subjects were analyzed. The myocarditis group showed a significantly reduced global longitudinal strain (GLS) and sub-epicardial strain, compared to the control (p < 0.001). We found a positive correlation (r = 0.65, p < 0.0001) between total scar burden (TSB) on CMR and LV GLS. After 6 months of follow-up, GLS showed marked improvements in myocarditis patients on optimal medical therapy (p < 0.01). Furthermore, we showed a strong association between baseline GLS, left ventricular ejection fraction (LVEF) and TSB with LVEF at 6 months of follow-up. After a multivariable linear regression analysis, baseline GLS, LVEF and TSB were independent predictors of a functional outcome at follow-up (p < 0.0001). Cardiac function and myocardial longitudinal deformation, assessed by echocardiography, are associated with TSB at CMR and have a predictive value of functional recovery in the follow-up.

A Case of Heart Transplantation for Fulminant Myocarditis After ChAdOx1 nCoV-19 Vaccination

Vaccines have become the mainstay of management against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (coronavirus disease 2019; COVID-19) in the absence of effective antiviral therapy. Various adverse effects of COVID-19 vaccination have been reported, including cardiovascular complications such as myocarditis or pericarditis. Herein, we describe clinical records of a 63-year woman with fulminant myocarditis following ChAdOx1 nCoV-19 vaccination that was salvaged by heart transplantation. She complained chest pain, nausea, vomiting, and fever after the second vaccination. After the heart transplantation, the patient died due to necrotizing pneumonia on the 54th day of onset. Fulminant myocarditis is very rare after ChAdOx1 nCoV-19 vaccination but can be fatal.

Seronegative immune-mediated necrotising myopathy complicated by fulminant myocarditis resulting in cardiogenic shock and cardiac arrest

A woman in her late 30s recently diagnosed with viral myopericarditis presented with 1 month of worsening fatigue, diffuse myalgias and chest pain radiating to her back. While undergoing work-up for chest wall myositis, she rapidly decompensated, developing heart failure and acute hypoxaemic respiratory failure. Her clinical course was complicated by cardiac arrest and severe cardiogenic shock requiring intra-aortic balloon pump support.

Managing myocarditis in a patient with newly diagnosed dermatomyositis

A woman in her 20s presented with chest pain, dyspnoea, arthralgia, muscle weakness and skin discolouration. She was diagnosed with dermatomyositis. During her admission, she developed pleuritic chest pain and shortness of breath accompanied by a significant troponin I rise. Her echocardiogram showed a hyperdynamic left ventricle with a trivial pericardial effusion; there were no regional wall motion abnormalities. Gadolinium-diethylenetriaminepantaacetic-enhanced cardiac MRI showed extensive myocarditis. She was started on corticosteroids and azathioprine which led to an improvement of symptoms and biochemical markers.

Pericarditis and myocarditis after COVID-19 mRNA vaccination in a nationwide setting

INTRODUCTION

Despite reports suggesting an association between COVID-19 mRNA vaccination and pericarditis and myocarditis, detailed nationwide population-based data are sparsely available. We describe the incidence of pericarditis and myocarditis by age categories and sex after COVID-19 mRNA vaccination from a nationwide mass vaccination programme in Singapore.

METHODS

The incidence of adjudicated cases of pericarditis and myocarditis following COVID-19 mRNA vaccination that were reported to the vaccine safety committee between January to July 2021 was compared with the background incidence of myocarditis in Singapore.

RESULTS

As of end July 2021, a total of 34 cases were reported (9 pericarditis only, 14 myocarditis only, and 11 concomitant pericarditis and myocarditis) with 7,183,889 doses of COVID-19 mRNA vaccine administered. Of the 9 cases of pericarditis only, all were male except one. The highest incidence of pericarditis was in males aged 12-19 years with an incidence of 1.11 cases per 100,000 doses. Of the 25 cases of myocarditis, 80% (20 cases) were male and the median age was 23 years (range 12-55 years) with 16 cases after the second dose. A higher-than-expected number of cases were seen in males aged 12-19 and 20-29 years, with incidence rates of 3.72 and 0.98 case per 100,000 doses, respectively.

CONCLUSION

Data from the national registry in Singapore indicate an increased incidence of pericarditis and myocarditis in younger men after COVID-19 mRNA vaccination.

Pediatric Myopericarditis Presenting to the Emergency Department as Chest Pain: A Comparative Study With Myocarditis

METHODS

A database query was performed and identified patients over a 9-year period, and clinical data, laboratory data, and cardiac studies were extracted and analyzed from the electronic health record.

RESULTS

A total of 36 patients were identified with the discharge diagnosis of myopericarditis and 22 with myocarditis. The median age for myopericarditis patients was 16.2 years, and 97% were male. The median initial troponin was 7.1 ng/mL, the peak was at 16.6 ng/mL, and 58% had ST changes on electrocardiogram. The median length of stay for myopericarditis patients was 1.7 days, and 50% were discharged home on nonsteroidal anti-inflammatory medication. Compared with myocarditis, myopericarditis patients were older, had a higher incidence of chest pain, and were less likely to have fever, vomiting, abdominal pain, upper respiratory infection symptoms, chest radiograph abnormalities, or T-wave inversion (P < 0.05). Myopericarditis patients also had lower Pediatric Risk of Mortality version 3 scores, B-type natriuretic peptide levels, and higher left ventricular ejection fractions on admission (67% vs 41%; P < 0.05). A classification model incorporating initial left ventricular ejection fraction, B-type natriuretic peptide, electrocardiogram, and chest radiograph findings distinguished myopericarditis from myocarditis with correct classification in 95% of patients.

CONCLUSIONS

Myopericarditis is a relatively common cause of chest pain for patients admitted to the pediatric intensive care unit, presents differently than true myocarditis, and carries a good prognosis.

Inpatient Characteristics, Complications, and Outcomes of Patients with Cardiac Sarcoidosis: A Study from The National Inpatient Sample

Although seen in ∼5% of sarcoidosis patients, cardiac sarcoidosis (CS) accounts for nearly 25% of disease-related deaths. This study aimed to describe characteristics and outcomes among CS patients. Patients diagnosed with CS in 2016-2017 in the US National Inpatient Sample Database were evaluated to study patient characteristics, reasons ascribed to admission, in-hospital outcomes, and complications. A total of 2420 patients (median age 56 years) were included in the analysis. Most admissions occurred due to ventricular tachycardia (12.8%), followed by myocarditis (9.9%) with a mean length of stay of 7±7 days. The overall incidence of in-hospital mortality was 2.5%.

Myocarditis in systemic immune-mediated diseases: Prevalence, characteristics and prognosis. A systematic review

Many systemic immune-mediated diseases (SIDs) may involve the heart and present as myocarditis with different histopathological pictures, i.e. lymphocytic, eosinophilic, granulomatous, and clinical features, ranging from a completely asymptomatic patient to life-threatening cardiogenic shock or arrhythmias. Myocarditis can be part of some SIDs, such as sarcoidosis, systemic lupus erythematosus, systemic sclerosis, antiphospholipid syndrome, dermato-polymyositis, eosinophilic granulomatosis with polyangiitis and other vasculitis syndromes, but also of some organ-based immune-mediated diseases with systemic expression, such as chronic inflammatory bowel diseases. The aim of this review is to describe the prevalence, main clinical characteristics and prognosis of myocarditis associated with SIDs.

Viral Myocarditis Mimicking ST-Segment Elevation Myocardial Infarction Complicated by Thrombocytopenia and Vasculitic Peripheral Neuropathy

Symptomatic myocarditis is classically featured by a flu-like prodrome, dyspnea on exertion, palpitations, substernal chest pain, and abnormal electrocardiogram (ECG). The clinical diagnosis has often been challenging due to its similarities to acute coronary syndrome. Our case involved a patient who presented with claudication of bilateral lower extremity and ST-segment elevation myocardial infarction (STEMI) in the inferior leads. On cardiac catheterization, nonobstructed coronary arteries with left ventricular ejection fraction (LVEF) of 30% were demonstrated. His clinical presentation was consistent with suspected myocarditis, and he improved with immunosuppression. In addition, his thrombocytopenia and severe symptoms of peripheral neuropathy responded to both immunotherapy and anticoagulation. This case highlights the interplay between history taking, physical examination, and multimodal diagnostic imaging.

Acute Myocarditis with Severe Fever and Thrombocytopenia Syndrome

A 67-year-old man, hospitalized with fever and pancytopenia, experienced cardiogenic shock on the 3rd day of hospitalization. He complained of chest pain and exhibited cardiac dysfunction, upregulated serum troponin levels, and an ST elevation on electrocardiogram. Severe fever with thrombocytopenia syndrome (SFTS) was suspected based on the symptom course after a tick bite and was definitively diagnosed using the serum polymerase chain reaction (PCR) test. An endomyocardial biopsy performed in the convalescent phase revealed a sign of myocardial inflammation with increases in CD3- and CD68-positive cells. We herein report the first case of acute myocarditis complicated with SFTS.

Myocarditis as a manifestation of the disease COVID-19 and after vaccination against this disease

Although the involvement of the heart muscle in the coronavirus disease 2019 (COVID-19) is relatively common (5-10%), myocarditis is a complication with a much lower incidence, depending, however, on the diagnostic methods used. The pathophysiological mechanisms have been described, but there are significant gaps in current knowledge. Myocarditis in connection with vaccination against the disease COVID-19 is a separate nosological unit. Even here, the pathophysiological processes are not explored in detail. The incidence of this complication is estimated in the low tens per million vaccinated.

Targeting Mediators of Inflammation in Heart Failure: A Short Synthesis of Experimental and Clinical Results

Inflammation has emerged as an important contributor to heart failure (HF) development and progression. Current research data highlight the diversity of immune cells, proteins, and signaling pathways involved in the pathogenesis and perpetuation of heart failure. Chronic inflammation is a major cardiovascular risk factor. Proinflammatory signaling molecules in HF initiate vicious cycles altering mitochondrial function and perturbing calcium homeostasis, therefore affecting myocardial contractility. Specific anti-inflammatory treatment represents a novel approach to prevent and slow HF progression. This review provides an update on the putative roles of inflammatory mediators involved in heart failure (tumor necrosis factor-alpha; interleukin 1, 6, 17, 18, 33) and currently available biological and non-biological therapy options targeting the aforementioned mediators and signaling pathways. We also highlight new treatment approaches based on the latest clinical and experimental research.

Left Heart Decompression on Veno-Arterial Extracorporeal Membrane Oxygenation in Children With Dilated Cardiomyopathy and Myocarditis: An Extracorporeal Life Support Organization Registry Review

OBJECTIVES

To describe the association between left heart decompression on veno-arterial extracorporeal membrane oxygenation and survival in patients with myocarditis and dilated cardiomyopathy. The secondary outcome is to study association of left heart decompression with survival in children with myocarditis compared with those with dilated cardiomyopathy.

DESIGN

Retrospective study of a multicenter registry database.

SETTING

Data reported to Extracorporeal Life Support Organization from international extracorporeal membrane oxygenation centers.

PATIENTS

Patients less than or equal to 18 years old with a diagnosis of myocarditis or dilated cardiomyopathy receiving extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 1,438 pediatric extracorporeal membrane oxygenation runs were identified. Thirty-seven percent of the patients had myocarditis (n = 532), whereas the rest had dilated cardiomyopathy. Survival to hospital discharge was 63%. Median extracorporeal membrane oxygenation duration was 148 hours with interquartile range (84-248 hr). Nineteen percent of patients (n = 274) had left heart decompression. Multivariable analysis revealed using left heart decompression (adjusted odds ratio, 1.42; 95% CI, 1.06-1.89; p = 0.02), e-cardiopulmonary resuscitation (adjusted odds ratio, 0.63; 95% CI, 0.51-0.79; p < 0.001), higher pH (adjusted odds ratio, 3.69; 95% CI, 1.80-7.53; p < 0.001), and diagnosis of myocarditis (adjusted odds ratio, 1.69; 95% CI, 1.35-2.08; p < 0.001) were associated with greater odds of survival. In the multivariable analysis for patients with dilated cardiomyopathy, left heart decompression failed to reveal a significant association with survival (20% among survivors vs 17% among nonsurvivors, 95% CI, -2.2% to 8.0%). Meanwhile in patients with myocarditis, the multivariable analysis failed to exclude the possibility that left heart decompression was associated with up to a three-fold greater odds of survival (adjusted odds ratio, 1.77; 95% CI, 0.99-.15).

CONCLUSIONS

Retrospective review of the Extracorporeal Life Support Organization registry revealed an association between left heart decompression and greater odds of survival in children with myocarditis and dilated cardiomyopathy on extracorporeal membrane oxygenation. When comparing patients with dilated cardiomyopathy against those with myocarditis, we could not exclude a three-fold greater odds of survival associated with the use of left heart decompression. This finding warrants further prospective evaluation.

Myocarditis-induced Sudden Death after BNT162b2 mRNA COVID-19 Vaccination in Korea: Case Report Focusing on Histopathological Findings

We present autopsy findings of a 22-year-old man who developed chest pain 5 days after the first dose of the BNT162b2 mRNA vaccine and died 7 hours later. Histological examination of the heart revealed isolated atrial myocarditis, with neutrophil and histiocyte predominance. Immunohistochemical C4d staining revealed scattered single-cell necrosis of myocytes which was not accompanied by inflammatory infiltrates. Extensive contraction band necrosis was observed in the atria and ventricles. There was no evidence of microthrombosis or infection in the heart and other organs. The primary cause of death was determined to be myocarditis, causally-associated with the BNT162b2 vaccine.