Even mild COVID-19 can increase the risk of heart problems
COVID-19 Heart disease Cytokine Storm

Even mild COVID-19 can increase the risk of heart problems

Santhni Subramaniam
Santhni Subramaniam

In 10 seconds? A large-scale study showed COVID-19 survivors to be at higher risks of experiencing cardiovascular diseases regardless of the severity of the infection.

What’s in the study? Researchers compared data from about 150, 000 individuals who fell ill with COVID-19 to over 5 million contemporary, COVID-free individuals and further 5 million healthy people from before the pandemic (2017, ‘historical cohort’) to study the disease burden a year after infection. After the first 30 days following an infection, COVID-19 survivors were found to be at an increased risk of experiencing a stroke, heart failure, and other heart complications for over a year. For example, out of every 1000 individuals studied, COVID-19 survivors had 4 more people likely to experience stroke and 10 more people to experience irregular heartbeat compared to healthy controls. This was also one of the first studies to look at the disease burden in non-hospitalized patients with mild symptoms from COVID-19 as many other studies focused only on hospitalized patients.

Were heart risks more prevalent for those with pre-existing health conditions? Interestingly, the study suggests higher risks of cardiovascular diseases for COVID-19 survivors regardless of their age, race, sex, and other pre-existing conditions such as obesity or diabetes.  People previously with low risk of cardiovascular diseases were seen to be equally affected by the virus. This does not come as a surprise as about 20-30% of hospitalized COVID-19 patients develop heart problems, a condition that has been referred to as post-COVID-19 cardiac syndrome.

COVID-19 and long term cardiac injury. Source: Unudurthi, Luthra, Bose, 2020
COVID-19 and long term cardiac injury. Source: Unudurthi, Luthra, Bose, 2020

How does the virus affect the heart? As many of us know, the SARS-CoV-2 virus uses ACE2 receptors on the surface of our cells to penetrate them and to start to multiply. ACE2 is abundant in the heart and a high load of the viral genetic material has also been found in the hearts of COVID-19 patients, suggesting damage directly caused by the virus.  A lab-based study showed that heart tissues infected with the virus contributed to irregular heartbeats and released high levels of inflammatory signals, leading to the damaging immune system overreaction, known as the ‘cytokine storm’.

Do we find similar risks in children? Most children with COVID-19 only experience mild symptoms, however, there have been reports on Kawasaki-like disease among children with COVID-19. Kawasaki disease is an inflammation of blood vessels in the heart and affects children younger than five years old. With proper care and treatment, most of the kids are reported to recover from these symptoms.

Any caveats for the research about the increased risk of heart problems? The data for this study was collected from the US Veterans Affairs healthcare database, limiting it to a certain cohort (predominantly white males). This may limit the generalization of these findings. Also, some individuals in the control group may have had COVID-19 but were not tested, so their results might have somewhat biased the findings.

Another virus that affects the heart

Viral infections are the most identified cause of heart inflammation (myocarditis) in developed countries.

One of the viruses, the coxsackievirus (CVB)  —  an enterovirus —  lives in our gut causing mild flu-like symptoms upon infection is a common cause.

Damage to the heart by the virus occurs across several stages, including due to activation of the immune system that destroys cells in the heart.

Unfortunately, many studies conducted so far have been done in animal models and not on humans, limiting the possibility of finding new therapeutics and treatments for this disease.

Santhni has distilled 9 research papers saving you 31.5 hours of reading time with an evidence score of  4.10 out of 5.00

The Science Integrity Check of this 3-min Science Digest was performed by Michael Eze.

Michael Eze

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