The world continues to be affected by the SARS-CoV-2 virus and the resulting epidemic of COVID-19 disease. In contrast to the situation two years ago at the start of the epidemic we have more information about the short- and long-term effects of COVID-19 disease, and in particular its effects on the heart.
Vaccines have proved pivotal in decreasing the morbidity and mortality of the COVID-19 epidemic, but there has been some concern regarding possible cardiac side effects and how this compares to the possible risk of cardiac disease with COVID-19 infection. Early in the COVID-19 epidemic reports from China described the high risk of cardiac complications in patients who were admitted to hospital with COVID-19 infection. It was also clear that patients with pre-existing cardiac disease had a high risk of complications and death with acute COVID-19 infection. In addition to the short-term effects of COVID-19, follow up data in patients who have recovered from infection have made clear that there is an increased risk of several types of cardiac disease over the long term. This risk for heart disease has been noted in patients with all severities of COVID-19 infection and given the large numbers of people who are being infected worldwide has the potential to result in a significant rise in the prevalence of heart disease.
Acute COVID-19 infection and heart disease
Patients who are acutely ill with COVID-19 disease can have a number of types of heart disease. Myocarditis or inflammation of the muscle of the heart has been noted to occur with COVID-19 infection. The exact prevalence of this is difficult to know as it appears to vary with the population of patients that are studied and how sick they are. Data from the Centers for Disease Control and Prevention (CDC) among hospitalised patients found that the incidence of myocarditis was 150 per 100,000 in patients with COVID-19 disease and nine per 100,000 in patients hospitalised without a COVID-19 diagnosis. Thus, the presence of COVID-19 infection increased the risk of heart inflammation over 16-fold, although the absolute numbers of patients was small. The patients at lowest risk were those of age 25 to 39 years, with the highest risk in patients less than 16 and more than 50. It appears that the more severe the COVID-19 infection the higher the chance of finding evidence of myocarditis.
COVID-19 disease has also been documented to increase the risk of heart attack and stroke in the first 14 days after infection. COVID-19 infection has been associated with heart failure although estimates vary as to the prevalence. Data from China in critically ill patients found that 23 per cent of these patients had a syndrome of heart failure. Acute COVID-19 infection has also been associated with abnormalities of heart rhythm including a risk of sudden death.
COVID-19 infection and the long-term risk of heart disease
In contrast to patients with acute COVID infection, data for long-term heart risk in patients who recovered from COVID-19 infection has been sparse. However, a study of over 150,000 patients from the Veterans Administration in the United States was published in Nature Medicine earlier this month. They looked at patients who had been diagnosed with COVID-19 disease and compared them to both contemporary and historical groups of patients who did not have a COVID-19 diagnosis. These patients were followed for almost one year. The patients with a diagnosis of COVID-19 had an increased risk of several types of cardiac and vascular disease including myocardial infarction, stroke, heart failure, inflammation of the muscle and lining of the heart, abnormal heart rhythms and clotting disorders. The risk of getting heart disease in the long term was related to how sick the patient was at the time of the COVID-19 infection, but it is important to note that patients who were not hospitalised and presumably had mild symptoms were also at increased risk when compared to patients who did not have COVID-19 infections.
COVID-19 vaccines and risk of myocarditis
Despite the fact that vaccination for the SARS-CoV-2 virus has been shown to improve the outcome in patients with COVID, in many countries there are significant proportions of the population who are hesitant to take these vaccines. One of the issues that has raised public concern is the risk of myocarditis after vaccination. Data from several countries have found that both mRNA vaccines (Pfizer and Moderna) and the AstraZeneca vaccine are all associated with myocarditis. One of the earliest reports of myocarditis following vaccination described the Israeli experience in April of 2021 where the Pfizer vaccine was found to result in a rate of myocarditis of 12.1 cases per million doses. In the United Kingdom the mRNA vaccines (Pfizer and Moderna) had an incidence of myocarditis of five per million doses. The AstraZeneca vaccine was found to have an incidence of 3.7 per million. The European Medicine Agency reported inflammation of the heart muscle and heart lining of less than two per million doses for both the AstraZeneca and mRNA vaccines. This data is predominantly from vaccines given to the adult population and with the expansion of vaccines to lower age groups it has become clear that younger patients particularly male are at higher risk of heart muscle and heart lining inflammation when compared to older age groups
A report in the J ournal of the American Medical Association earlier this year looked at vaccination in the United States from December 2020 to August 2021 with the Moderna and Pfizer vaccines. They found much higher rates of heart muscle inflammation in the young. The highest risk was for males aged 16-17 years who had a rate of myocarditis of with the Pfizer vaccine of 105 cases per million doses. Of those patients who had myocarditis in this data set 80 per cent were male, and the incidence was increased after the second dose of the vaccine. It did appear that most of the cases were mild with 96 per cent of patients have had resolution of symptoms at the time of discharge.
Relative risks of heart disease with COVID infection versus vaccination
It is clear that both COVID-19 disease and COVID-19 vaccines can result in cardiac disease. Vaccines like all medications and medical treatments are associated with potential side effects. The rate of cardiac side effects with vaccination for COVID-19 disease even in the highest risk group of male adolescents is extremely low. For older patients who acquire COVID-19 disease the risk of heart disease exceeds the cardiac risks of vaccination by an order of magnitude. There also appears to be the potential for long-term cardiac and vascular disease that does not appear to be present with vaccination. Most health authorities worldwide including our own Ministry of Health have concluded that vaccination is a safe and effective way to protect against severe illness and death from the SARS-CoV-2 virus and COVID-19 disease. We encourage our fellow citizens to continue to follow universal contact precautions and to get vaccinated if they have not yet done so.
Dr Ernest Madu, MD, FACC and Dr Paul Edwards, MD, FACC are consultant cardiologists for Heart Institute of the Caribbean (HIC) and HIC Heart Hospital. HIC is the regional centre of excellence for cardiovascular care in the English-speaking Caribbean and has pioneered a transformation in the way cardiovascular care is delivered in the region. HIC Heart Hospital is registered by the Ministry of Health and Wellness and is the only heart hospital in Jamaica. Correspondence to email@example.com or call 876-906-2107