A new study published in Nature Microbiology shows that long COVID may have long-term implications for heart health. Everyone knows chronic inflammation is bad for the heart. But this new study shows that even mild inflammation that lingers after a viral infection like COVID may also harm the heart.
The COVID epidemic might be over, but it is still not rare. The worry is that it causes long COVID in many people. In fact, weakness that drags on is not rare after many viral infections.
Long COVID may last for several months or even years. It causes extreme tiredness, brain fog, mood and sleep changes, body aches, and more. Many people also keep reporting an irregular heartbeat and gut problems after the acute COVID infection clears.
Researchers from the University of Queensland ran this new study. They found raised levels of inflammatory proteins, mainly cytokines (immune signal proteins), even 18 months after the first infection.
These cytokines were only slightly raised. Yet they were enough to cause heart and blood vessel problems. Lab studies found that heart muscle cells were especially sensitive to these proteins. Damage to cardiomyocytes (heart muscle cells) from low levels of cytokines may explain why many people develop heart conditions after they recover.
The researchers enrolled 50 patients who had recovered from COVID. They compared their blood results to people who never had the infection. They followed these patients for 18 months. The patients had symptoms typical of long-COVID.
In long COVID, cytokines are often elevated very little. Such tiny amounts are hard to track with regular lab tests. So the team built a special “immune-storm chip” using nanotechnology. These chips could also track markers of heart tissue damage.
These are very early findings. Other studies must still confirm them. Even so, the work opens doors for more research.
For example, many other infections also cause symptoms like long COVID. Many people keep having chronic fatigue and pain, along with heart and other health problems, long after they recover. So far, science has not explained what drives these lasting problems after certain infections.
So this new tool opens the door for more research. It may help us better understand many chronic health problems. Researchers can use it to study brain, nerve and lung conditions that linger in many people after COVID or other infections.
For now, the study changes little in the clinic. But it gives hope. This tool may help explain many chronic conditions, especially those that cause chronic pain and fatigue. It may give a reliable way to diagnose conditions that today’s lab tests struggle to pick up.
And once we can reliably diagnose these chronic problems, it will be easier to find treatments that work.
Frequently asked questions
What are the symptoms of long COVID?
Long COVID causes extreme tiredness, brain fog, mood and sleep changes and body aches. Many people also keep reporting an irregular heartbeat and gut problems after the acute infection clears. In the University of Queensland study, patients were followed for 18 months. They still had symptoms typical of long COVID. They also had inflammatory proteins that could harm the heart.
How long does long COVID last?
Long COVID can last several months and even years. In the University of Queensland study, researchers still found raised levels of inflammatory proteins called cytokines 18 months after the first infection. That mild, lingering inflammation may explain why symptoms hang on long after the acute illness. That includes heart symptoms.
Does long COVID show up in blood tests?
Not on routine tests. In long COVID, cytokines are usually raised only a little. Those tiny amounts are hard to measure with regular lab methods. For this research, the team built a special “immune-storm chip” using nanotechnology. It could pick up tiny amounts of cytokines and markers of heart tissue damage. The findings are early and still need to be confirmed.
Can long COVID damage your heart?
The study points that way. Cytokine levels were only slightly raised. Yet they were enough to cause heart and blood vessel problems. Lab work showed that heart muscle cells, called cardiomyocytes, are especially sensitive to these proteins. Damage to those cells from low-level inflammation may explain why many people develop heart conditions after they recover from COVID.
Can other infections cause symptoms like long COVID?
Yes. Many other infections leave people with chronic fatigue and pain, along with heart and other health problems, long after they recover. Science has not yet explained what drives these lasting problems. The new chip may help researchers study them. And a reliable way to diagnose them would make good treatments easier to find.
Source:
Sinclair, J. E., Vedelago, C., Ryan, F. J., Carney, M., Redd, M. A., Lynn, M. A., Grubor-Bauk, B., Cao, Y., Henders, A. K., Chew, K. Y., Gilroy, D., Greaves, K., Labzin, L., Ziser, L., Ronacher, K., Wallace, L. M., Zhang, Y., Macauslane, K., Ellis, D. J., … Short, K. R. (2024). Post-acute sequelae of SARS-CoV-2 cardiovascular symptoms are associated with trace-level cytokines that affect cardiomyocyte function. Nature Microbiology, 9(12), 3135–3147. https://doi.org/10.1038/s41564-024-01838-z
Dr. Gurpreet Singh Padda, MD, MBA, MHP
