Here, in the United States, the first documented cases of COVID-19 were as early as December 2019. Then came the shutdown of our nation 3 months later in March of 2020. This severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been responsible for countless numbers of deaths and other health complications. One major area of damage in those who have overcome their illness, is heart damage- more specifically, myocarditis. In this article I will break down the research and stats about COVID to find out whether or not it is more likely to contract myocarditis from the COVID vaccine or the COVID virus itself.
Table of Contents
What is Myocarditis?
In simple terms, myocarditis is inflammation of the myocardium (the muscular middle section of your heart wall).
This inflammation can weaken your heart and decrease its ability to pump blood through your body (1).
Causes and Symptoms of Myocarditis
The most common cause of myocarditis is through a viral infection although bacterial and fungal infections can also be a cause (1). It is considered a rare condition however, a diagnosis may include symptoms such as:
- Chest pain
- Fatigue
- Dizziness
- Abnormal heartbeat or palpitations
- Shortness of breath
- Swelling in your extremities (ankles, feet, or hands)
Treatment of Myocarditis
In mild cases, you can recover from myocarditis without medical treatment. Although in more severe cases, including the symptoms above, you may need medical treatment at a hospital.
You may also need several medications to help relax your blood vessels, lower your blood pressure, slow your heart rate, get rid of excess fluid from your body, or control your heart rhythm.
In addition, if excess fluid is causing your extremities to blow up like a balloon, it is best to limit sodium intake to 2,000 mg per day.
>>For some easy-to-understand handouts on how to reduce sodium intake, see my “Sodium: How Much is Too Much?” handout or my “Salt Substitute Guide” handout.
The COVID-Cardiac Link
Okay, let’s get into the nitty gritty on answering the question of whether you are more likely to get myocarditis from a COVID vaccine or the infection. So far, there a few things we KNOW to be true:
- The most common cause of myocarditis is a viral infection.
- COVID-19 is a viral infection.
- COVID-19 causes inflammation within our body.
- Inflammation plays a large role in developing myocarditis.
Research also indicates that those with pre-existing heart disease are more susceptible to COVID-19.
We also know that COVID-19 mainly effects the respiratory system. This includes your airway, lungs, and blood vessels.
Based on this information, it is no surprise that heart complications from a COVID-19 infection can arise. Some of these heart issues include:
- heart attack, cardiac arrest, and myocarditis
- cardiac fibrosis – abnormal thickening of heart valves
- arrhythmias – abnormal heartbeats
- endothelial dysfunction – narrowing of your heart’s blood vessels, restricting blood flow
- dysautonomia – dysfunction of the autonomic nervous system (ANS)
- and cardiac events involving blood clots
Current Statistics
As of May 2023, there have been 1,130,593 total deaths reported that are related to COVID-19.
You can access updated data by visiting the COVID Data Tracker, available through the CDC website. While you are there, you can also view statistics on the total number of hospitalizations, immunizations given, and trends in COVID-related data over time.
Another interesting statistics is that according to the most recent data, only 17% of the current U.S. population have been vaccinated against the COVID-19 virus.
Cases of Myocarditis
Of all the total cases of COVID-19 reported, there is no public database that shows how many of these cases are directly linked to myocarditis.
However, the American Heart Association does have a COVID-19 Cardiovascular Disease Registry. This registry is in place to understand patterns and variations of clinical treatment in hospitalized COVID-19 patients. The data collected will help future research on COVID-19, develop treatment protocols, and identify risk factors related to cardiovascular health.
Unfortunately, only a small fraction of hospitals participate in using the AHA’s registry. Additionally, the registry uses specific inclusion criteria that excludes patients outside of a hospital setting and those under the age of 18 years.
Therefore, there is no way to truly uncover an accurate number of cases of myocarditis that have resulted from COVID-19 infection.
Cases of Myocarditis After COVID-19 Diagnosis
A major report shows that for those diagnosed with myocarditis, ~42% had a history of COVID-19. Of this 42%, the majority of these people (~90%) were diagnosed with COVID-19 and myocarditis during the same month. The remaining ~10% were diagnosed with myocarditis within a few months following their COVID-19 diagnosis.
Populations at Highest Risk
The research does show some clear high risk populations when it comes to those diagnosed with myocarditis and COVID-19.
First let’s talk about who is at higher risk of contracting the COVID-19 virus. Populations that are most susceptible to COVID include:
- Older persons
- Racial and ethnic minorities
- Immunocompromised populations or those with weak immune systems
- Those with chronic conditions (CKD, liver disease, lung diseases, cancer, etc.)
- Individuals with dementia
- Individuals with diabetes or heart conditions
And those with a highest risk of developing myocarditis include:
- Males
- Children <16 years old
- Adults >50 years old and older
- Those with specific underlying medical conditions
In addition, the Myocarditis Foundation mentions that although cardiovascular events often affect the older population, myocarditis can affect anyone.
In fact, it most often affects otherwise healthy, young, athletic types. The age range noted to have the highest risk are those from puberty through the early 30’s, with males being affected twice as often as females.
Therefore, from the information above, we can conclude that the highest risk population of those both with and without COVID-19 are primarily young males.
Should I Be Worried About Getting Myocarditis?
As mentioned earlier, myocarditis is a rare condition. Likewise, developing myocarditis from the COVID virus or myocarditis from a COVID vaccine is also rare. But are you more likely to get myocarditis if you’ve been vaccinated? Let’s talk about this.
There are currently four vaccines available to protect against the COVID-19 infection:
- Pfizer-BioNTech COVID-19 Vaccine (Comirnaty®)
- Moderna COVID-19 Vaccine (Spikevax®)
- Johnson & Johnson’s Janssen COVID-19 Vaccine
- Novavax COVID-19 Vaccine, Adjuvanted
In 2021, following the implementation of COVID-19 vaccination efforts, the number of people diagnosed with myocarditis and pericarditis in the United States have increased. And researchers have notice a pattern.
There are more cases of myocarditis being reported after RNA COVID-19 vaccinations (Pfizer-BioNTech and Moderna), particularly in adolescents and young adults. These findings were not reported however with the Johnson & Johnson vaccine.
Therefore, the term vaccine-associated myocarditis (VAM) is used to describe this condition. VAM is more common among adolescent and young males between the ages of 12 and 24 years old (2).
The CDC estimates the VAM rate to be 32.4 cases per every million cases for all vaccine doses and 66.7 cases per million after the second dose of mRNA vaccine. The symptoms and course progression of VAM however, are quite mild; requiring a simple treatment of anti-inflammatory drugs (2).
It’s important to note that cases of myocarditis occur more often following the second dose of the mRNA vaccine versus the first dose (3). And onset of symptoms is usually within several days after the mRNA COVID-19 vaccination.
So, you can see that there is, indeed, a risk. Even if only a small risk.
What About Booster Shots?
Just like mRNA vaccines, mRNA boosters are 82% effective against urgent care and emergency department visits and 90% effective against hospitalization. So, although some people may experience side effects or symptoms from vaccines and boosters, the benefits still outweigh the risks.
Updated research continues to assess the safety of booster shots, especially considering the increase in myocarditis risk following the second dose of the vaccine compared to the first.
Additionally, with the different variants of COVID that continue to emerge, the safety and efficacy of future boosters will need to be assessed.
If You are Unvaccinated
Unvaccinated individuals who develop myocarditis are not as lucky. We’ll refer to these cases as COVID-associated myocarditis (CAM).
In these cases, you’re more likely to have complicated and severe symptoms compared to those who are vaccinated. Additionally, unvaccinated individuals are more likely to require ventilator support in critical care units due to more severe symptoms.
As far as the numbers show, myocarditis from COVID is more common than myocarditis from vaccinations, except in the younger male population.
How to Protect Yourself
With the continued decline in the number of COVID-19 cases over time, the Public Health Emergency for COVID-19 expired on May 11, 2023.
And in June 2023, mandatory making requirements have been lifted in every state, with some exceptions. For example, when entering a Federal building, in specific areas within a hospital setting, and anywhere else masks are being mandated.
This doesn’t mean that the COVID-19 virus is no longer out there, or that you won’t get. It is simply more controlled than it was 3 years ago. You can still take the following precautions to avoid contracting COVID and myocarditis as a result of COVID:
- follow recommendations of health experts and scientists
- get fully vaccinated against the COVID-19 virus, including any boosters when available
- continue to wear masks where mandated
- keep a safe distance (at least 6 feet) between you and others where you see it as fitting
- follow proper hand-washing techniques
Healthcare systems are also providing ongoing data to protect the public. Health professionals all over the country continue to report all cases of myocarditis and pericarditis that occur following COVID-19 vaccination. This is by way of the Vaccine Adverse Event Reporting System (VAERS).
Long COVID and Myocarditis
Another complication from the COVID-19 virus is a condition called “long COVID” or post-COVID conditions (PCC). This occurs when an individual still experiences symptoms of COVID for weeks, months, or years beyond their initial diagnosis.
Long COVID can have serious implications on one’s cardiopulmonary health. Long COVID can lead to any of the following heart problems:
- myocardial inflammation
- myocardial infarction
- right ventricular dysfunction
- arrhythmias
Research is still not 100% clear on the pathophysiological mechanisms behind long COVID, however following closely with your healthcare team will make managing your condition and symptoms much easier and less anxiety-provoking.
The Centers for Disease Control and Prevention are still conducting research to better understand all aspects of long COVID. If you are interested in learning more about long COVID, you can visit the CDC website.
Conclusion
Overall, getting a vaccine in order to reduce the number of COVID-19 cases and complications such as myocarditis is still the recommendation. The majority of current research agrees that the risk of myocarditis after vaccination remains less than the risk after a COVID-19 infection.
Even though the risk of getting myocarditis from COVID vaccines and for unvaccinated individuals is very low, unvaccinated individuals are more likely to have more severe symptoms, longer hospital stays, and the possible need for advanced life support.
In contrast, those who develop myocarditis after a COVID vaccine treatment have a generally mild course.
And finally, now that vaccines are available for children and teens, particularly the higher risk male population, I’d say it’s better to be safe than sorry.
Of course, more research is in progress and there are limitations to the studies mentioned. Health organizations will continue to monitor trends, document and analyze data, develop statistics, etc. And hopefully someday, COVID-associated myocarditis and long COVID will no longer be something our future population will experience.
If the thought of COVID has stressed you out, check out this helpful article: Maintaining a Healthful Diet During Times of Stress
And to avoid further cardiac inflammation, consider trying some of my favorite heart-healthy recipes.
Kiran Campbell is a registered dietitian and entrepreneur with 13 years of experience. She has a degree in psychology as well as dietetics. She is also a proud member of the Academy of Nutrition and Dietetics’ and its Cardiovascular Health and Well-being Dietetics Practice Group among others. Kiran proudly presents and promotes the most up-to-date, science-based nutrition information on all things heart-related. She aims to serve not only individuals with heart disease, but also those wanting to protect against it. Learn more about Kiran by visiting her About Page.