Study: Cardiovascular Complications Following COVID-19 Are Uncommon in Children, Young Adults

A new scientific statement has called for more research into treating and managing cardiovascular complications of COVID-19 in children and young adults, despite being relatively uncommon in these age groups.

According to researchers, some pediatric and adolescent patients with COVID-19 can experience abnormal heart rhythm, inflammation in and around the heart muscle, or multisystem inflammatory syndrome in children (MIS-C), which is a new condition identified during the pandemic. The COVID-19 vaccines have been found to prevent severe COVID-19 disease and decrease the risk of developing MIS-C by 91% among children aged 12 to 18 years, but more research is still necessary, according to investigators.

“Two years into the pandemic and with vast amounts of research conducted in children with COVID-19, this statement summarizes what we know so far related to COVID-19 in children,” said Pei-Ni Jone, MD, FAHA, chair of the statement writing group, in a press release. “We focused on the effects of this virus for those with congenital or other heart disease, as well as the latest data about the potential association of the COVID-19 vaccines with heart complications in children and young adults. While there is a lot we know, this public health emergency needs ongoing research to understand the short- and long-term impacts on children.”

Analysis of the latest research suggests that children generally have mild symptoms from SARS-CoV-2 infection, according to the scientific statement. In the United States, as of February 24, 2022, children have accounted for 17.6% of total COVID-19 cases and approximately 0.1% of deaths from the virus. Furthermore, young adults aged 18 to 29 years have accounted for 21.3% of cases and 0.8% of deaths from COVID-19.

Several factors may help explain why children may be less susceptible to severe COVID-19 infection. For instance, cells in children’s bodies have fewer receptors to attach to the SARS-CoV-2 virus, and children may also have a lower immune response due to a different cytokine response compared to adults and trained immunity from other vaccines and viral infections.

Although children with congenital heart disease have had low infection and mortality rates from SARS-CoV-2, the researchers noted that having an underlying genetic syndrome, such as trisomy 21 (also known as Down syndrome), appears to be associated with an increased risk of severe COVID-19.

The statement also outlines available treatments for children with COVID-19, although there are no specific COVID-19 antiviral therapies at this time. Available treatments include remdesivir and dexamethasone for children in certain age groups.

Remdesivir is the only antiviral currently approved by the FDA for the treatment of individuals aged 12 and older hospitalized with COVID-19 who have risk factors for severe disease and the need for supplemental oxygen. Notably, it is most effective when given as soon as possible after symptoms begin. Dexamethasone has been shown to reduce the risk of death in adults with COVID-19 and is suggested for children with more severe disease who require breathing support.

Heart-related complications in children with COVID-19 are uncommon, but case reports have noted cardiogenic shock, myocarditis, pericarditis, and arrhythmias. Sudden cardiac death and death following intensive medical and life support treatment has occurred in children with severe COVID-19 that affected the heart.

Myocarditis is most commonly caused in children by viral infection, with approximately 1 to 2 out of every 100,000 children diagnosed annually in the United States with myocarditis prior to the COVID-19 pandemic, according to CDC data. Children are also more likely than adults to develop myocarditis as the result of a viral infection, such as COVID-19.

MIS-C was identified at the beginning of the pandemic, with as many as half of global pediatric cases involving inflammation of the heart muscle or heart arteries. During the first year of the pandemic, 1 in every 3164 children with SARS-CoV-2 infection developed MIS-C, according to the statement.

For children who develop MIS-C, intravenous immunoglobulin (IVIG) has been administered alone or as dual therapy with infliximab or other immunomodulatory agents. Most children’s heart recovered well within 1 to 4 weeks of MIS-C diagnosis, but the risk of long-term complications and death from MIS-C is estimated to be between 1.4% and 1.9%.

The majority of MIS-C cases were among children identified in medical records as Black race or Hispanic ethnicity. Additional research is needed to learn why people from diverse racial or ethnic groups may be disproportionately affected and to understand the risk factors for this condition, according to the statement authors.

Researchers have also been specifically investigating the safety of returning to sports and strenuous physical activity for children and adolescents who have had COVID-19. The latest data suggest that those who had mild COVID-19 infection or infection without symptoms are safe to return to activities after full symptom recovery.

For youth with more severe infection or who develop MIS-C, the statement said it is reasonable to consider select cardiovascular screenings, such as echocardiogram, blood tests for heart enzyme levels, and other heart function screening before returning to sports.

The scientific statement concluded that more research is needed to better understand the mechanisms and optimal treatment approaches for SARS-CoV-2 infection, vaccine-associated myocarditis, the long-term outcomes of both COVID-19 and MIS-C, and the impact of these various conditions on the heart in children and young adults. In addition, the researchers said the development of new antiviral therapies need to be tested in clinical trials focused on pediatric patients.

“Although much has been learned about how the virus impacts children’s and young adults’ hearts, how to best treat cardiovascular complications and prevent severe illness and continued clinical research trials are needed to better understand the long-term cardiovascular impacts,” Jone said in the press release. “It is also important to address health disparities that have become more apparent during the pandemic. We must work to ensure all children receive equal access to vaccination and high-quality care.”

REFERENCE

Heart issues after COVID-19 uncommon in children and young adults, more research needed. News release. American Heart Association; April 11, 2022. Accessed April 18, 2022. https://newsroom.heart.org/news/heart-issues-after-covid-19-uncommon-in-children-young-adults-more-research-needed?preview=528c