Guidance

Myocarditis and pericarditis after COVID-19 vaccination: clinical management guidance for healthcare professionals

Updated 9 January 2023

The UK Health Security Agency (UKHSA), in partnership with the Royal College of General Practitioners (RCGP) and the Royal College of Emergency Medicine (RCEM), has produced this clinical guidance to support the detection and management of clinical cases of myocarditis and pericarditis associated with coronavirus (COVID-19) vaccination. This clinical guidance has been endorsed by the British Congenital Cardiac Association (BCCA).

It is a living document and will be reviewed and updated as further data becomes available. This document has been formulated as practical guidance for use by healthcare professionals in the NHS. Contributions from RCGP and RCEM have ensured that the recommendations made are practical and risk proportionate.

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Background

Background to myocarditis and pericarditis after COVID-19 vaccination and guidelines:

• this is a very rare condition following vaccination (see the Medicines and Healthcare products Regulatory Agency’s (MHRA) monthly summary for the latest data)
• most patients who develop symptoms do so within a week of vaccination
• patients who develop symptoms have usually been vaccinated with a mRNA vaccine (Pfizer/BioNTech or Moderna)
• myocarditis and pericarditis following vaccination is usually mild or stable and patients typically recover fully without medical treatment

• myocarditis – a very small number of those with this condition have been admitted to hospital. In 2 studies from the US ^{[footnote 1] [footnote 2]}, significant left ventricular (LV) fibrosis has been described in a high percentage of those children admitted to hospital, with a small percentage of these having non-sustained ventricular tachycardia (VT)

  • no long-term follow-up data is available yet on hospitalised patients
  • diagnosis of myocarditis and pericarditis should follow published international guidelines ^{[footnote 3] [footnote 4]}
  • the majority of cases appear to be mild and self-limiting; any acutely ill or unstable patients should be referred to hospital directly
  • the long-term consequences of this condition secondary to vaccination are yet unknown, so any screening recommendations need to be balanced against the frequency and severity of the disease with the aim to prevent complications, in particular of myocarditis (arrhythmias, long term myocardial damage or heart failure)

Epidemiology

Myocarditis and pericarditis are both inflammatory conditions of the heart. The incidence of myocarditis is difficult to ascertain as most cases are mild and are often not well investigated. In one study from the UK, it was estimated that between 1998 and 2017, there were 36.5 per 100,000 NHS admissions with myocarditis, with the numbers increasing each year since 2004. In 2017, it was estimated that there were about 2,000 hospital admissions for myocarditis.

Overall, two-thirds of myocarditis cases were in men, and men were significantly younger (median age 33) compared to women. There are many different causes of myocarditis but the most common type of myocarditis is an acute lymphocytic myocarditis, often caused by viral infection.

Pericarditis is often a more benign condition and responds to treatment with anti-inflammatory medical treatment. In most cases, it has no long-term sequelae if treated promptly, but it can reoccur.

Post-COVID-19 vaccination

Reports of myocarditis and pericarditis following vaccination with COVID-19 vaccines have been received by the MHRA.

As of 23 November 2022, there have been 851 reports of myocarditis and 579 reports of pericarditis following the use of the Pfizer/BioNTech vaccine. There have been 251 reports of myocarditis and 149 reports of pericarditis following the use of the Moderna vaccine. Some cases have been reported following the use of the AstraZeneca vaccine but given the extensive use of AstraZeneca in the UK, these are thought to reflect the expected background incidence rate of myocarditis and pericarditis.

As of 23 November 2022, the overall reporting rate across all age groups for myocarditis following vaccination with the monovalent Pfizer/BioNTech vaccine was 10 reports per million doses; for pericarditis, it was 6 reports per million doses. For monovalent Moderna vaccine, the overall reporting rate for myocarditis was 14 reports per million doses; for pericarditis, it was 8 reports per million doses.

In those aged under 18 years, the reported rate for heart inflammation (myocarditis and pericarditis) was 13 per million first doses and 8 per million second doses of the monovalent Pfizer/BioNTech vaccine; these are lower than the reporting rates seen in young adults. There is currently insufficient data to calculate the reporting rate for third/booster doses. The monovalent Pfizer/BioNTech COVID-19 vaccine is recommended for use in this age group for the first and second doses.

It is important to note that Yellow Card data and similar vaccine surveillance data from other countries cannot be used to compare the safety profile of COVID-19 vaccines as many factors can influence reporting.

Recommendations in paediatric patients in the context of recent COVID-19 vaccination (within 10 days)

Presentation

If the patient is acutely unwell or unstable, has concerning features, or if you have clinical concern, then they should be discussed with the emergency department (ED) or medical team and referred to hospital for further investigation.

Suspected cases should be examined by a doctor or nurse practitioner.

Concerning features that may require further investigation:

• significant chest pain (new onset and unexplained) – it can be difficult for children to localise chest pain
• tachycardia or tachypnoea
• dyspnoea (new onset and unexplained)
• palpitations (new onset and unexplained)
• dizziness or syncope (new onset and unexplained)
• general clinical concern

Where appropriate, the patient should be seen face to face and this assessment should include their vital signs.

Dependent upon the assessment and findings, clinical judgement should be used to determine whether myocarditis or pericarditis remains a potential diagnosis of concern.

Where concern or doubt remains or there are findings that suggest an emergency assessment is required, then a discussion should take place with local paediatric services as to the most appropriate place and time for a further assessment to be made.

Clinicians should ensure they communicate with the young person or their family or carers that the condition is very rare, usually mild, often self-limiting and that long-term consequences are as yet unknown.

If patients have mild symptoms, they do not require a referral to secondary care at this point.

Investigations

Hospital investigations should follow local myocarditis or pericarditis guidelines with the involvement of the regional paediatric cardiology team.

If there is a suspicion of myocarditis or pericarditis, initial investigations should be:

• 12 lead electrocardiogram (ECG)
• inflammatory blood markers (C-reactive protein (CRP), full blood count (FBC) and erythrocyte sedimentation rate (ESR))
• Troponin

If abnormal ECG or Troponin, discuss with the paediatric cardiology team for further management plan, including cardiac imaging (echocardiogram, cardiovascular magnetic resonance imaging (MRI)) and rhythm monitoring (24h Holter, stress ECG).

Further investigations and follow-up should be led by the regional paediatric cardiology team.

Recommendations in adults 18 to 40 years of age in the context of recent COVID-19 vaccination (within 10 days)

Presentation

If the patient is acutely unwell or unstable, has concerning features or if you have clinical concern, then they should be discussed with the ED or medical team, and referred to hospital for further investigation.

Where appropriate the patient should be seen face to face and the assessment should include their vital signs.

Suspected cases should be examined by a doctor or nurse practitioner.

Concerning features that may require a referral for further investigation:

• significant chest pain (new onset and unexplained)
• tachycardia or tachypnoea
• dyspnoea (new onset and unexplained)
• palpitations (new onset and unexplained)
• dizziness or syncope (new onset and unexplained)
• general clinical concern

If patients have mild symptoms, they do not require a referral to secondary care at this point.

Dependent upon the assessment and findings, clinical judgement should be used to determine if myocarditis or pericarditis remains a potential diagnosis of concern.

Investigations in secondary care

If there is a suspicion of myocarditis or pericarditis, the initial investigations should be:

• 12 lead ECG
• inflammatory blood markers (CRP, FBC and ESR)
• Troponin

If ECG or troponin are abnormal, discuss with the cardiology team for further management plan, which might include cardiac imaging (Echocardiogram, cardiovascular MRI) and rhythm monitoring (24h Holter, stress ECG).

Further investigations and follow-up should be led by the regional cardiology team.

Further follow-up (all ages)

Patients that did not require referral to hospital on initial presentation or have normal initial investigations do not require further follow-up.

All patients that did not require referral to hospital in initial presentation should be:

• given the following ‘safety netting’ advice: ‘if symptoms persist or worsen within 5 days, then they should return to their GP for review’
• referred for further investigation if, when seen later, have concerning features including general clinical concern

Patients requiring outpatient follow-up should be referred to cardiology and an assessment undertaken within 4 weeks.

Further vaccination

Patients that have been diagnosed with confirmed myocarditis following COVID-19 infection or vaccination should be treated following published guidelines (for children and for adults).

Cardiology follow-up should include a review 8 weeks after their diagnosis to assess their eligibility for further vaccinations.

If there is no evidence of ongoing myocarditis, vaccination may be considered with the Pfizer/BioNTech (Cominarty) vaccine from 12 weeks after their last dose if further doses are due. Consideration should be given to the current epidemiology of COVID-19 and risk of infection to the individual.

For those that experience myocarditis or pericarditis within 2 weeks of the first dose of an mRNA vaccine, testing for nucleocapsid (N) antibody may indicate prior exposure to COVID-19. These individuals are likely to be well protected and therefore the benefit from a second or subsequent dose is likely to be more limited.

In circumstances where a further dose is considered necessary, for example in those at higher risk of the complications of COVID-19 infection, a second or booster dose of Pfizer/BioNTech vaccine should be considered once the patient has fully recovered. Emerging evidence suggests that an interval of at least 12 weeks should be observed from the previous dose.

If there is evidence of ongoing effects of acute or subacute myocarditis, then an individual risk benefit assessment should be undertaken in consultation with the patient or their parents or guardians prior to offering further doses of COVID-19 vaccine.

These recommendations are based on information from Yellow Card reporting data and other published data.

Activity following vaccination

If the individual feels well after receiving their COVID-19 vaccination, then there is no need to pre-emptively restrict physical activity post vaccination and individuals can continue with their pre-existing level of physical activity.

In the unlikely event that they experience chest pain, palpitations, unexpected shortness of breath, or fainting, then they should seek medical attention.

Such individuals should be investigated and managed according to the clinical management guidelines. This advice applies to both adults and children. Strenuous physical activity should be avoided until symptoms improve. If an individual has been diagnosed with myocarditis or pericarditis, advice on exercise should be given by a qualified healthcare professional (for example, cardiologist, sports cardiologist or sports medicine physician) and should follow clinical guidelines on when to resume activity or competitive sports.

Appendix A: membership of the Expert Working Panel

Professor Guido Pieles (Chair) – Consultant Paediatric and Adult Congenital Cardiologist, Congenital Heart Unit, Bristol Heart Institute and University College London.

Professor Amedeo Chiribiri – Cardiovascular Imaging and Consultant Cardiologist, Guy’s and St Thomas’ NHS Foundation Trust.

Dr Paul Clift – Consultant Cardiologist, University Hospitals Birmingham.

Professor Adam Finn – Professor of Paediatrics, University of Bristol and Member of the Joint Committee on Vaccination and Immunisation (JCVI).

Dr Mark Hamilton – Consultant Cardiac Radiologist, Bristol Heart Institute and Bristol Royal Hospital for Children.

Dr Katherine Henderson – Consultant Emergency Medicine, President of the Royal College of Emergency Medicine.

Dr Maria Ilina – Consultant Paediatric Cardiologist, Royal Hospital for Children, Glasgow.

Dr Tevfik Ismail – Consultant Cardiologist, Guy’s and St Thomas’ NHS Foundation Trust.

Dr Jonathan Leach – General Practitioner, the Royal College of General Practitioners and NHS England Medical Director for COVID-19 vaccination.

Dr Conor McCann – Consultant Cardiologist, Belfast Trust.

Dr Rubin Minhas – General Practitioner.

Dr Eva Sammut – Academic Clinical Lecturer and Cardiology Registrar, University Hospitals Bristol and Weston NHS Foundation Trust.

Dr Nicholas Sargant – Consultant Paediatric Emergency Medicine, University Hospitals Bristol and Weston NHS Foundation Trust.

Dr Simon Stockley – General Practitioner and Senior Medical Lead, National COVID-19 Vaccination Programme and Royal College of General Practitioners.

Appendix B: Expert Group for sports exercise guidance

Professor Guido Pieles (Chair) – Consultant Paediatric and Adult Congenital and Sports Cardiologist, Congenital Heart Unit, Bristol Heart Institute and University College London.

Dr Paul Clift – Consultant Cardiologist, University Hospitals Birmingham.

Professor Adam Finn – Professor of Paediatrics, University of Bristol and Member of the Joint Committee on Vaccination and Immunisation (JCVI).

Dr James Hull – Consultant Respiratory Physician, Royal Brompton Hospital.

Professor Mathew Wilson – Head of Sport and Exercise Medicine, Institute of Sport, Exercise and Health.

Dr Charlotte Cowie – Head of Medicine, the Football Association.

1. Association of myocarditis with BNT162b2 messenger RNA COVID-19 vaccine in a case series of children, Journal of the American Medical Association (JAMA) Cardiology, August 2021. ↩

2. COVID-19 vaccination – associated myocarditis in adolescents, American Academy of Pediatrics, November 2021. ↩

3. Current state of knowledge on aetiology, diagnosis, management, and therapy of myocarditis: a position statement of the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases, European Heart Journal, September 2013. ↩

4. Diagnosis and management of myocarditis in children, a scientific statement from the American Heart Association, Circulation, July 2021. ↩