Acute myocarditis after COVID-19 vaccination with mRNA-1273 in a patient with former SARS-CoV-2 infection

COVID-19 vaccine-associated myocarditis: Analysis of the suspected cases reported to the EudraVigilance and a systematic review of the published literature

Background

Myocarditis secondary to Coronavirus Disease 2019 (COVID-19) vaccination has been reported in the literature.

Objective

This study aimed to characterize the reported cases of myocarditis after COVID-19 vaccination based on age, gender, doses, and vaccine type from published literature and the EudraVigilance database.

Methods

We performed an analysis in the EudraVigilance database (until December 18, 2021) and a systematic review of published literature for reported cases of suspected myocarditis and pericarditis (until 30th June 2022) after the COVID-19 vaccination.

Results

EudraVigilance database analysis revealed 16,514 reported cases of myocarditis or pericarditis due to the vaccination with COVID-19 vaccines. The cases of myo- or pericarditis were reported predominantly in the age group of 18-64 (n = 12,214), and in males with a male-to-female (M: F) ratio of 1.7:1. The mortality among myocarditis patients was low, with 128 deaths (2 cases per 10.000.000 administered doses) being reported. For the systematic review, 72 studies with 1026 cases of myocarditis due to the vaccination with COVID-19 vaccines were included. The analysis of published cases has revealed that the male gender was primarily affected with myocarditis post-COVID-vaccination. The median (IQR) age of the myocarditis cases was 24.6 [19.5-34.6] years, according to the systematic review of the literature. Myocarditis cases were most frequently published after the vaccination with m-RNA vaccines and after the second vaccination dose. The overall mortality of published cases was low (n = 5).

Conclusion

Myocarditis is a rare serious adverse event associated with a COVID-19 vaccination. With early recognition and management, the prognosis of COVID-19 vaccine-induced myocarditis is favorable.

Myocarditis post-SARS-CoV-2 vaccination: a systematic review

Variable clinical criteria taken by medical professionals across the world for myocarditis following coronavirus disease 2019 (COVID-19) vaccination along with wide variation in treatment necessitates understanding and reviewing the same. A systematic review was conducted to elucidate the clinical findings, laboratory parameters, treatment and outcomes of individuals with myocarditis after COVID-19 vaccination after registering with PROSPERO. Electronic databases including MEDLINE, EMBASE, PubMed, LitCovid, Scopus, ScienceDirect, Cochrane Library, Google Scholar and Web of Science were searched. A total of 85 articles encompassing 2184 patients were analysed. It was a predominantly male (73.4%) and young population (mean age: 25.5 ± 14.2 years) with most having taken an mRNA-based vaccine (99.4%). The mean duration from vaccination to symptom onset was 4.01 ± 6.99 days. Chest pain (90.1%), dyspnoea (25.7%) and fever (11.9%) were the most common symptoms. Only 2.3% had comorbidities. CRP was elevated in 83.3% and cardiac troponin in 97.6% patients. An abnormal ECG was reported in 979/1313 (74.6%) patients with ST-segment elevation being most common (34.9%). Echocardiographic data were available for 1243 patients (56.9%), of whom 288 (23.2%) had reduced left ventricular ejection fraction. Non-steroidal antiinflammatory drugs (76.5%), steroids (14.1%) followed by colchicine (7.3%) were used for treatment. Only 6 patients died among 1317 of whom data were available. Myocarditis following COVID-19 vaccination is often mild, seen more commonly in young healthy males and is followed by rapid recovery with conservative treatment. The emergence of this adverse event calls for harmonizing case definitions and definite treatment guidelines, which require wider research.

Myocardial Injury and Altered Gene Expression Associated With SARS-CoV-2 Infection or mRNA Vaccination

SARS CoV-2 enters host cells via its Spike protein moiety binding to the essential cardiac enzyme angiotensin-converting enzyme (ACE) 2, followed by internalization. COVID-19 mRNA vaccines are RNA sequences that are translated into Spike protein, which follows the same ACE2-binding route as the intact virion. In model systems, isolated Spike protein can produce cell damage and altered gene expression, and myocardial injury or myocarditis can occur during COVID-19 or after mRNA vaccination. We investigated 7 COVID-19 and 6 post-mRNA vaccination patients with myocardial injury and found nearly identical alterations in gene expression that would predispose to inflammation, coagulopathy, and myocardial dysfunction.

Cardiovascular complications of COVID-19 vaccines: A review of case-report and case-series studies

BACKGROUND

There are multiple reviews on cardiovascular aspects of COVID-19 disease on cardiovascular system in different population but there is lack of evidence about cardiovascular adverse effects of COVID vaccines.

OBJECTIVES

The purpose of this study was to compare the cardiac complications of COVID19 vaccines, based on vaccine type (mRNA, vector-based, and inactivated vaccines).

METHODS

A systematic search was performed covering PubMed for English case-reports and case-series studies, and finally 100 studies were included.

RESULTS

Myocarditis (with overall rate around 1.62%) was shown to be the most common post-COVID19 immunization cardiac event. More than 90% of post-COVID19 vaccination myocarditis occurred after receiving mRNA vaccines (Moderna & Pfizer-BioNTech), but the report of this event was less in the case of vector-based vaccinations and/or inactivated vaccines. Myocarditis was reported more commonly in men and following the second dose of the immunization. Takotsubo cardiomyopathy (TTC) was reported after mRNA (more commonly) and vector-based vaccinations, with no case report after inactivated vaccines. When mRNA and vector-based vaccinations were used instead of inactivated vaccines, a greater frequency of vaccine-induced thrombotic thrombocytopenia (VITT) and pulmonary emboli (PE) was reported. Myocardial infarction/cardiac arrest was recorded in those beyond the age of 75 years.

CONCLUSION

The personal and public health benefits of COVID-19 vaccination much outweigh the minor cardiac risks. Reporting bias, regarding more available mRNA vaccines in developed countries, may conflict these results.

To Vaccinate or Not to Vaccinate-Reasons of Willingness and Reluctance of Students against SARS-CoV-2 Vaccination-An International Experience

Despite the vaccine against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) being reported to be safe and effective, the unwillingness to vaccinate and doubts are still common. The aim of this international study was to assess the major reasons for the unwillingness to vaccinate in a group of students from Poland (n = 1202), Bangladesh (n = 1586), India (n = 484), Mexico (n = 234), Egypt (n = 566), Philippines (n = 2076), Pakistan (n = 506), Vietnam (n = 98) and China (n = 503). We conducted an online cross-sectional study that aimed to assess (1) the percentage of vaccinated and unvaccinated students and (2) the reasons associated with willingness/unwillingness to the vaccine. The study included 7255 respondents from 9 countries with a mean age of 21.85 ± 3.66 years. Only 22.11% (n = 1604) of students were vaccinated. However, the majority (69.25%, n = 5025) expressed a willingness to be vaccinated. More willing to vaccinate were students in informal relationships who worked mentally, used psychological/psychiatric services before the pandemic, and studied medicine. There are cultural differences regarding the reasons associated with the unwillingness to vaccinate, but some 'universal' might be distinguished that apply to the whole group.

Cardiac MRI Findings in COVID-19 Vaccine-Related Myocarditis: A Pooled Analysis of 468 Patients

Understanding the pattern and severity of myocarditis caused by the coronavirus disease 2019 (COVID-19) vaccine is imperative for improving the care of the patients, and cardiac evaluation by MRI plays a key role in this regard. Our systematic review and meta-analysis aimed to summarize cardiac MRI findings in COVID-19 vaccine-related myocarditis. We performed a comprehensive systematic review of literature in PubMed, Scopus, and Google Scholar databases using key terms covering COVID-19 vaccine, myocarditis, and cardiac MRI. Individual-level patient data (IPD) and aggregated-level data (AD) studies were pooled through a two-stage analysis method. For this purpose, all IPD were first gathered into a single data set and reduced to AD, and then this AD (from IPD studies) was pooled with existing AD (from the AD studies) using fixed/random effect models. I² was used to assess the degree of heterogeneity, and the prespecified level of statistical significance (P value for heterogeneity) was <0.1. Based on meta-analysis of 102 studies (n = 468 patients), 79% (95% confidence interval [CI]: 54%-97%) of patients fulfilled Lake Louise criteria (LLC) for diagnosis of myocarditis. Cardiac MRI abnormalities included elevated T2 in 72% (95% CI: 50%-90%), myocardial late gadolinium enhancement (LGE) in 93% (95% CI: 83%-99%; nearly all with a subepicardial and/or midwall pattern), impaired left ventricular ejection fraction (LVEF) (<50%) in 4% (95% CI: 1.0%-9.0%). Moreover, elevated T1 and extracellular volume fraction (ECV) (>30), reported only by some IPD studies, were detected in 74.5% (76/102) and 32% (16/50) of patients, respectively. In conclusion, our findings may suggest that over two-thirds of patients with clinically suspected myocarditis following COVID-19 vaccination meet the LLC. COVID-19 vaccine-associated myocarditis may show a similar pattern compared to other acute myocarditis entities. Notably, preserved LVEF is probably a common finding in these patients. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 3.

Autoimmune and autoinflammatory conditions after COVID-19 vaccination. New case reports and updated literature review

Autoimmunity linked to COVID-19 immunization has been recorded throughout the pandemic. Herein we present six new patients who experienced relapses of previous autoimmune disease (AD) or developed a new autoimmune or autoinflammatory condition following vaccination. In addition, we documented additional cases through a systematic review of the literature up to August 1st, 2022, in which 464 studies (928 cases) were included. The majority of patients (53.6%) were women, with a median age of 48 years (IQR: 34 to 66). The median period between immunization and the start of symptoms was eight days (IQR: 3 to 14). New-onset conditions were observed in 81.5% (n: 756) of the cases. The most common diseases associated with new-onset events following vaccination were immune thrombocytopenia, myocarditis, and Guillain-Barré syndrome. In contrast, immune thrombocytopenia, psoriasis, IgA nephropathy, and systemic lupus erythematosus were the most common illnesses associated with relapsing episodes (18.5%, n: 172). The first dosage was linked with new-onset events (69.8% vs. 59.3%, P = 0.0100), whereas the second dose was related to relapsing disease (29.5% vs. 59.3%, P = 0.0159). New-onset conditions and relapsing diseases were more common in women (51.5% and 62.9%, respectively; P = 0.0081). The groups were evenly balanced in age. No deaths were recorded after the disease relapsed, while 4.7% of patients with new-onset conditions died (P = 0.0013). In conclusion, there may be an association between COVID-19 vaccination and autoimmune and inflammatory diseases. Some ADs seem to be more common than others. Vaccines and SARS-CoV-2 may induce autoimmunity through similar mechanisms. Large, well-controlled studies are warranted to validate this relationship and assess additional variables such as genetic and other environmental factors.

Acute Polyserositis with Cardiac Tamponade and Bilateral Refractory Pleural Effusion after ChAdOx1 nCoV-19 Vaccination

The association of SARS-CoV-2 messenger ribonucleic acid vaccines with pericarditis in young adults has been reported. However, data regarding other types of vaccines are extremely limited. We presented a 94-year-old man with rapidly progressive dyspnea and fatigue six days after his first ChAdOx1 nCoV-19 vaccination. Impending cardiac tamponade and bilateral pleural effusion were found. Hence, massive yellowish pericardial and pleural effusion were drained. However, the pleural effusion persisted and pigtail catheters were inserted bilaterally. After serial studies including surgical pleural biopsy, acute polyserositis (pericarditis and pleurisy) was diagnosed. Anti-inflammatory treatment with colchicine and prednisolone was administered. All effusions resolved accordingly. This rare case sheds light on the presentation of ChAdOx1 nCoV-19 vaccine-related acute polyserositis. In conclusion, awareness of this potential adverse event may facilitate the diagnosis for unexplained pericardial or pleural effusion after vaccination.

Clinical Characteristics of Patients with Myocarditis following COVID-19 mRNA Vaccination: A Systematic Review and Meta-Analysis

COVID-19 mRNA vaccinations have recently been implicated in causing myocarditis. Therefore, the primary aim of this systematic review and meta-analysis was to investigate the clinical characteristics of patients with myocarditis following mRNA vaccination. The secondary aims were to report common imaging and laboratory findings, as well as treatment regimes, in these patients. A literature search was performed from December 2019 to June 2022. Eligible studies reported patients older than 18 years vaccinated with mRNA, a diagnosis of myocarditis, and subsequent outcomes. Pooled mean or proportion were analyzed using a random-effects model. Seventy-five unique studies (patient n = 188, 89.4% male, mean age 18–67 years) were included. Eighty-six patients had Moderna vaccines while one hundred and two patients had Pfizer-BioNTech vaccines. The most common presenting symptoms were chest pain (34.5%), fever (17.1%), myalgia (12.4%), and chills (12.1%). The most common radiologic findings were ST-related changes on an electrocardiogram (58.7%) and hypokinesia on cardiac magnetic resonance imaging or echocardiography (50.7%). Laboratory findings included elevated Troponin I levels (81.7%) and elevated C-reactive protein (71.5%). Seven patients were admitted to the intensive care unit. The most common treatment modality was non-steroid anti-inflammatory drugs (36.6%) followed by colchicine (28.5%). This meta-analysis presents novel evidence to suggest possible myocarditis post mRNA vaccination in certain individuals, especially young male patients. Clinical practice must therefore take appropriate pre-cautionary measures when administrating COVID-19 mRNA vaccinations.

Fulminant Myocarditis 24 Days after Coronavirus Disease Messenger Ribonucleic Acid Vaccination

A 60-year-old Japanese woman was hospitalized for cardiogenic shock 24 days after receiving the second dose of the coronavirus disease 2019 BNT162b2 vaccine. Impella CP left ventricular assist device implantation and venoarterial peripheral extracorporeal membranous oxygenation were immediately initiated along with inotropic support and steroid pulse therapy, as an endomyocardial biopsy specimen showed myocarditis. Three weeks later, her cardiac function had recovered, and she was discharged. An immune response associated with the presence of spike protein in cardiac myocytes may be related to myocarditis in the present case because of positive immunostaining for severe acute respiratory syndrome coronavirus 2 spike protein and C4d in the myocardium.

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.

Diagnostics of messenger ribonucleic acid (mRNA) severe acute respiratory syndrome-corona virus‑2 (SARS-CoV‑2) vaccination-associated myocarditis—A systematic review

Background

Objective

Methods

Results

Conclusion

Supplementary Information

Myocarditis Following COVID-19 Vaccination: A Systematic Review of Case Reports

Introduction: COVID-19, the infectious disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), often presents with a spectrum of symptoms at varying levels of severity, ranging from asymptomatic patients to those with fatal complications, such as myocarditis. With increased availability of COVID-19 vaccines, the awareness of possible side effects has expanded as reports surface. This study reviewed cases of myocarditis following COVID-19 vaccination and with existing literature on COVID-19 infection-induced myocarditis to compare clinical courses and analyze possible mechanisms of action. Methods: A systematic review of literature was conducted to identify published case reports (as of February 3, 2022) pertaining to the development of myocarditis following COVID-19 vaccination with either Pfizer or Moderna for an in-depth analysis. Additional subgroup analyses were conducted based on age, past medical history, vaccine manufacturer, and dose number. Results: There were 53 eligible case reports that were included in this study. Patients were mostly male with a median age of 24 years, and the most reported symptom upon presentation was chest pain. Seventy percent of the cases involved the Pfizer vaccine with a majority of myocarditis developing subsequent to second dose. Resolution of symptoms was achieved in all but one patient. Clinical severity, as measured primarily by left ventricular ejection fraction, appeared to be worse among adult patients than pediatric, as well as for patients with comorbidities. Conclusion: This study revealed an observable association between COVID-19 vaccines and myocarditis. However, the clinical course and prognosis seem favorable and less prevalent than those conferred from natural infection.

Myocarditis after COVID-19 mRNA vaccination: A systematic review of case reports and case series

Background

The coronavirus disease of 2019 (COVID‐19) is a global pandemic with over 266 million cases and 5 million deaths worldwide. Anti‐COVID‐19 vaccinations have had exceptional success in subduing the incidence, prevalence, and disease severity of COVID‐19, but rare cases of myocarditis have been reported after COVID‐19 vaccinations.

Hypothesis

Myocarditis occurring after COVID‐19 mRNA vaccinations have distinguishable clinical characteristics. They usually have a favorable prognosis.

Methods

We performed a systematic literature search on PUBMED and MEDLINE database from inception to December 5, 2021. Studies were analyzed based on predetermined eligibility criteria.

Results

A total of 57 studies containing 275 cases of COVID‐19 vaccine‐associated myocarditis were catalogued. Mean age was 26.7 years and male to female ratio was 14:1. For 86.9% of patients, myocarditis occurred after the second dose. Average time to onset and length of hospitalization were 3.7 and 3.9 days, respectively. Prognosis was largely benign, but there was a 1.1% reported mortality. Chest pain (95.2%), elevation of troponin (100%), and ST elevation on electrocardiography (68.5%) were common. Nonsteroidal anti‐inflammatory drugs (81.4%) were the most used medication, followed by colchicine (33.1%).

Conclusions

Patients with COVID‐19 vaccine‐associated myocarditis are usually younger males presenting with chest pain 3–4 days after receiving their second dose of COVID vaccine. Diagnosis is made by exclusion of all other etiologies. Given significant population benefit from COVID‐19 vaccination, physicians should continue to encourage vaccination while remaining vigilant of the very rare occurrence of myocarditis following COVID‐19 vaccination.

Case Report: Importance of MRI Examination in the Diagnosis and Evaluation of COVID-19 mRNA Vaccination Induced Myocarditis: Our Experience and Literature Review

Acute myocarditis is a rare but serious complication associated with mRNA-based coronavirus disease 2019 (COVID-19) vaccination. In this article, four COVID-19 mRNA vaccination induced myocarditis cases managed at our tertiary Medical Center have been discussed. Three patients had typical myocarditis. One patient suffered from atrioventricular block and heart failure, which required more intensive treatment, but eventually improved. Additionally, a review of cardiac magnetic resonance imaging (MRI) features related to the diagnosis of myocarditis showed that COVID-19 mRNA vaccine-associated myocarditis tend to have more late-gadolinium enhancement (LGE) accumulation in the inferior lateral wall direction. According to a report by the U.S. Centers for Disease Control and Prevention (CDC), the diagnosis of COVID-19 mRNA vaccine-associated myocarditis is based on clinical symptoms, altered myocardial enzymes, cardiac MRI finding, or histopathology. Cardiac MRI is relatively less invasive than myocardial biopsy and plays an important role in the diagnosis of myocarditis. This review may aid in the diagnosis of COVID-19 mRNA vaccine-associated myocarditis.

Myocarditis following COVID-19 vaccination: incidence, mechanisms, and clinical considerations

INTRODUCTION

Vaccines have demonstrated protection against the morbidity and mortality of COVID-19, but concerns regarding the rare side effect of acute myocarditis have stymied immunization efforts. This review aims to describe the incidence and theorized mechanisms of COVID vaccine-associated myocarditis and review relevant principles for management of vaccine-associated myocarditis.

AREAS COVERED

Epidemiologic studies of myocarditis after COVID vaccination are reviewed, which show an incidence of approximately 20-30 per million patients. The vast majority of these cases are seen with mRNA vaccines especially in male patients under 30 years of age. Mechanisms are largely theoretical, but molecular mimicry and dysregulated innate immune reactions have been proposed. While studies suggest that this subtype of myocarditis is mild and self-limited, long-term evidence is lacking. Principles of myocarditis treatment and surveillance are outlined as they apply to COVID vaccine-associated myocarditis.

EXPERT OPINION

COVID vaccine-associated myocarditis is rare but well described in certain at-risk groups. Better understanding of its pathogenesis is key to mitigating this complication and advancing vaccination efforts. Risk-benefit analyses demonstrate that individual- and population-level benefits of vaccination exceed the risks of this rare and mild form of myocarditis.

Development of myocarditis and pericarditis after COVID-19 vaccination in adult population: A systematic review

Objectives

A clear temporal relationship between myocarditis and pericarditis after COVID-19 vaccination has led to the belief that the vaccine may act as a trigger for these cardiologic complications. The aim of this systematic review is to explore the incidence, clinical presentation, management, and association between them.

Methods

We conducted a systematic literature search on Cochrane, MEDLINE, and EMBASE as per guidelines of PRISMA (Preferred Reporting Items for Systematic Reviews). A total of 41 case reports and case series describing 97 patients, and 5 original articles describing 15,585,309 participants were selected as part of this review.

Results

Of the 97 reported cases describing vaccine-associated myocarditis/pericarditis, 67 (69%) patients received Pfizer-BioNTech and 25 (25.7%) received Moderna. The mean onset of symptoms after vaccine administration was 3.8 ± 4.5 days with three-quarters developing symptoms after the second dose. Chest pain (n = 88, 90%) and fever (n = 33, 34%) were the most common presenting complaints. Out of 97, 80 (82.5%) patients recovered while 4 (4.1%) patients expired. The pooled incidence of myocarditis and pericarditis extrapolated from original studies is 0.001% and 0.0004%, respectively. In the original studies, nearly all the cases of myocarditis and pericarditis were mild. Chest pain and fever were the most common presenting symptoms.

Conclusion

Myocarditis and pericarditis after the COVID-19 vaccine have been reported more in young adult males and are most likely to occur after the second dose of mRNA vaccines. The presentation is mild and the majority of the patients recover either completely or partially.

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Myocarditis and pericarditis have been reported after the COVID-19 vaccine.

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It is occurs more commonly in males as compared to females.

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Myocarditis and Pericarditis is more likely to occur after second dose of mRNA vaccine.

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The presentation is mild, and most of the patients recover either completely or partially.

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Autoimmunity (molecular mimicry) is thought to be the major pathological mediator.

First Identified Case of Fatal Fulminant Necrotizing Eosinophilic Myocarditis Following the Initial Dose of the Pfizer-BioNTech mRNA COVID-19 Vaccine (BNT162b2, Comirnaty): an Extremely Rare Idiosyncratic Hypersensitivity Reaction

Rationale

Transient myopericarditis has been recognised as an uncommon and usually mild adverse event predominantly linked to mRNA-based COVID-19 vaccines. These have mostly occurred in young males after the second dose of mRNA COVID-19 vaccines.

Objectives

Fulminant necrotising eosinophilic myocarditis triggered by a variety of drugs or vaccines is an extremely rare hypersensitivity reaction carrying a substantial mortality risk. Early recognition of this medical emergency may facilitate urgent hospital admission for investigation and treatment. Timely intervention can lead to complete cardiac recovery, but the non-specific clinical features and rarity make early diagnosis challenging.

Findings

The clinical and pathological observations from a case of fatal fulminant necrotising myocarditis in a 57-year-old woman, following the first dose of the Pfizer-BioNTech vaccine, are described. Other causes have been discounted with reasonable certainty.

Conclusion

These extremely rare vaccine-related adverse events are much less common than the risk of myocarditis and other lethal complications from COVID-19 infection. The benefits of vaccination far exceed the risks of COVID-19 infection.

Cardiac complications following mRNA COVID-19 vaccines: A systematic review of case reports and case series

There have been several local and systemic adverse events associated with mRNA COVID-19 vaccines. Pericarditis, myocarditis and myocardial infarction are examples of cardiac complications related to these vaccines. In this article, we conducted a systematic review of case reports and case series to identify the clinical profile, investigations, and management of reported cardiac complications post-mRNA COVID-19 vaccines. We systematically searched PubMed, Scopus, Web of Science, and Google Scholar, as well as the medRxiv preprint server, with terms including: 'SARS-CoV-2', 'COVID-19', 'messenger RNA vaccine*', 'mRNA-1273 vaccine', 'BNT162 vaccine', 'myocarditis', 'pericarditis', 'stroke' and 'Myocardial Ischemia' up to 25 September 2021. Studies were excluded if they were not case reports or case series, or reported cases from non-mRNA vaccines. Case reports and case series were included that investigated the potential cardiac complications associated with mRNA COVID-19 vaccines. The JBI checklist was used to assess quality and data synthesis was conducted using a qualitative methodology called narrative synthesis. Sixty-nine studies, including 43 case reports and 26 case series, were included. Myocarditis/myopericarditis and pericarditis were the most common adverse events among the 243 reported cardiac complications, post mRNA COVID-19 vaccination. Males with a median age of 21 years had the highest frequency of myocarditis. Almost three quarters (74.4%) of cases with myocarditis had received the BNT162b2 vaccine and 87.7% had received the second dose of the vaccine. Chest pain (96.1%) and fever (38.2%) were the most common presentations. CK-MB, troponin, and NT-proBNP were elevated in 100%, 99.5% and 78.3% of subjects, respectively. ST-segment abnormality was the most common electrocardiogram feature. Cardiac magnetic resonance imaging, which is the gold-standard approach for diagnosing myocarditis, was abnormal in all patients diagnosed with myocarditis. Non-steroidal anti-inflammatory drugs were the most prescribed medication for the management of myocarditis. Apart from inflammatory conditions, some rare cases of Takotsubo cardiomyopathy, myocardial infarction, myocardial infarction with non-obstructive coronary arteries, and isolated tachycardia were also reported following immunisation with mRNA COVID-19 vaccines. We acknowledge that only reviewing case reports and case series studies is one potential limitation of our study. We found that myocarditis was the most commonly reported adverse cardiac event associated with mRNA COVID-19 vaccines, which presented as chest pain with a rise in cardiac biomarkers. Further large-scale observational studies are recommended.