COVID-19 Cardiovascular Complications in Children: AHA Statement

April 12, 2022

Cardiovascular complications are uncommon for children and young adults after COVID-19 disease or SARS-CoV-2 infection, according to a new scientific statement from the American Heart Association.

However, the infection can cause some children and young people to experience arrhythmias, myocarditis, pericarditis, or multisystem inflammatory syndrome (MIS-C), a new condition identified during the pandemic, it notes.

The statement details what has been learned about how to treat, manage, and prevent cardiovascular complications associated with COVID-19 in children and young adults, and calls for more research, including studies following the short- and long-term cardiovascular effects.

It also reports that COVID-19 vaccines have been found to prevent severe COVID-19 disease and decrease the risk of developing MIS-C by 91% among children ages 12-18 years.

On returning to sports, it says data suggest it is safe for young people with mild or asymptomatic COVID-19 to resume exercise after recovery from symptoms. For those with more serious infections, it recommends additional tests including cardiac enzyme levels, electrocardiogram, and echocardiogram, before returning to sports or strenuous physical exercise.

The scientific statement was published online in Circulation on April 11.

"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 chair of the statement writing group Pei-Ni Jone, MD, from the Children's Hospital Colorado, Aurora.

Analysis of the latest research indicates children generally have mild symptoms from SARS-CoV-2 infection. In the US, as of Feb. 24, 2022, children under 18 years of age have accounted for 17.6% of total COVID-19 cases and about 0.1% of deaths from the virus, the report states.  

In addition, young adults, ages 18-29 years, have accounted for 21.3% of cases and 0.8% of deaths from COVID-19.

Like adults, children with underlying medical conditions such as chronic lung disease or obesity and those who are immune compromised are more likely to be hospitalized, to be admitted to an intensive care unit, and to die of COVID-19, the statement notes. There are conflicting reports on the risk of severe COVID-19 in children and young adults with congenital heart disease, with some reports suggesting a slightly increased risk of severe COVID-19.

In terms of cardiovascular complications of COVID-19 in children, arrhythmias have included ventricular tachycardia and atrial tachycardia, as well as first-degree atrioventricular block. Although arrhythmias generally self-resolve without the need for treatment, prophylactic antiarrhythmics have been administered in some cases, and death caused by recurrent ventricular tachycardia in an adolescent with hypertrophic cardiomyopathy has been described.

Elevations of troponin, electrocardiographic abnormalities, including ST-segment changes, and delayed gadolinium enhancement on cardiac magnetic resonance imaging have been seen in those with myocardial involvement. Although death is rare, both sudden cardiac death and death after intensive medical and supportive therapies, have occurred in children with severe myocardial involvement.

In a large retrospective pediatric case series of SARS-CoV-2-associated deaths in individuals under 21 years of age, the median age at death was 17 years, 63% were male, 28% were Black, and 46% were Hispanic. Of those who died, 86% had a comorbid condition, with obesity (42%) and asthma (29%) being the most common.

But the report concludes that: "Although children with comorbidities are at increased risk for symptomatic SARS-CoV-2 infection compared with healthy children, cardiovascular complications, severe illness, and death are uncommon."

MIS-C: Rare but Severe

The authors of the statement explain that children and some young adults may develop MIS-C, a relatively rare but severe inflammatory syndrome generally occurring 2-6 weeks after infection with SARS-CoV-2 that can affect the heart and multiple organ systems.

In the first year of the pandemic, more than 2600 cases of MIS-C were reported to the Centers for Disease Control and Prevention, at an estimated rate of 1 case per 3164 cases of SARS-CoV-2 infection in children, with MIS-C disproportionately affecting Hispanic and Black children.

As many as 50% of children with MIS-C have myocardial involvement including decreased left ventricular function, coronary artery dilation or aneurysms, myocarditis, elevated troponin and BNP or NT-proBNP, or pericardial effusion. Acute-phase reactants, including C-reactive protein, D-dimer, ferritin, and fibrinogen, can be significantly elevated in MIS-C, neutrophil/lymphocyte ratio may be higher, and platelet counts lower than those with non–MIS-C febrile illnesses.

Fortunately, the outcome of MIS-C is generally very good, with resolution of inflammation and cardiovascular abnormalities within 1-4 weeks of diagnosis, the report says.

However, there have been reports of progression of coronary artery aneurysms after discharge, highlighting the potential for long-term complications. Death resulting from MIS-C is rare, with a mortality rate of 1.4%-1.9%.

Compared with children and young adults who died of acute SARS-CoV-2 infection, most of the fatalities from MIS-C were in previously healthy individuals without comorbidities.

The authors recommend structured follow-up of patients with MIS-C because of concern about progression of cardiac complications and an unclear long-term prognosis.

The statement notes that the first-line treatment for MIS-C is typically intravenous immunoglobulin (IVIG) and patients with poor ventricular function may need to have IVIG in divided doses to tolerate the fluid load.  

Supportive treatment for heart failure and vasoplegic shock often requires aggressive management in an ICU for administration of inotropes and vasoactive medications. Antiplatelet therapy with low-dose aspirin is considered in patients with coronary artery involvement, and anticoagulation is added, depending on the degree of coronary artery dilation.

COVID-19 Vaccination

The statement notes that vaccines can prevent patients from getting COVID-19 and decrease the risk of MIS-C by 91% among children 12-18 years of age.

On vaccine-associated myocarditis, it concludes the benefits of getting the vaccines outweigh the risks.  

For example, for every 1 million doses of the mRNA COVID-19 vaccines in males ages 12-29 years (the highest risk group for vaccine-associated myocarditis), it is estimated that 11,000 COVID-19 cases, 560 hospitalizations and six deaths would be prevented, whereas 39-47 cases of myocarditis would be expected.

But it adds that the CDC is continuing to follow myocarditis in children and young adults closely, particularly a possible connection to the mRNA COVID-19 vaccines.

The statement says 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, any new antiviral therapies need to be tested in clinical trials focused on children.

"Although much has been learned about how the virus impacts children's and young adult's 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. "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."

Circulation. Published online April 11. Full text.  


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