While COVID-19’s effects on the lungs and respiratory system are well known, there is growing research suggesting that the virus is also affecting the heart, with potentially lasting effects.
In a presentation at the annual meeting of the Biophysical Society, an international biophysics scientific group, Dr. Andrew Marks, chair of the department of physiology at Columbia University, and his colleagues reported on changes in the heart tissue of COVID-19 patients who had died from the disease, some of whom also had a history of heart conditions. The team conducted autopsy analyses and found a range of abnormalities, particularly in the way heart cells regulate calcium.
All muscles, including those in the heart, rely on calcium to contract. Muscle cells store calcium and open special channels inside of cells to release it when needed. In some conditions such as heart failure, the channel remains open in a desperate attempt to help the heart muscle contract more actively. The leaking of calcium ultimately depletes the calcium stores, weakening the muscle in the end.
“We found evidence, in the hearts of COVID-19 patients, abnormalities in the way calcium is handled,” says Marks. In fact, when it came to their calcium systems, the heart tissue of these 10 people who had died of COVID-19 looked very similar to that of people with heart failure.
Marks plans to further explore the heart changes that SARS-CoV-2 might cause by studying how the infection affects the hearts of mice and hamsters. He intends to measure changes in immune cells as well as any alterations in heart function in the animals both while they are infected and after they have recovered in order to document any lingering effects.
“The data we present show that there are dramatic changes in the heart,” Marks says. “The precise cause and long term consequences of those need to be studied more.”
Previous studies have revealed a link between COVID-19 infections and heart-related problems. A large 2022 analysis of patients in the VA system—some of whom had recovered from COVID-19 and others who had never been diagnosed—showed those who had had COVID-19 had higher rates of a number of heart-related risks, including irregular heartbeats heart attack and stroke. Dr. Susan Cheng, chair of women’s cardiovascular health and population science at Cedars-Sinai, is studying whether there are any associations between rates of heart attacks and surges of COVID-19 infections, in order to better understand how the virus might be affecting the heart.
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There is also early evidence showing that people with hypertension may be at higher risk of heart events when they get COVID-19.
What connects the viral infection to the heart isn’t known yet, but the body’s immune system is likely a major contributor. “It’s been well documented that with SARS-CoV-2, the body responds with an inflammatory response that involves activating the immune system in a very dramatic way,” says Marks. “In the heart, it looks like the same inflammatory process is activating pathways that could be detrimental to heart function.” But more research needs to clarify that process, says Dr. Mariell Jessup, chief science and medical officer at the American Heart Association. “If the assumption is that the infection causes inflammation, and the assumption is that the inflammation is precipitating more cardiovascular events, then how is it doing that?”
It’s also possible that viruses can infect and adversely affect heart cells. “We’re still at the tip of the iceberg with respect to understanding how COVID-19 affects health,” says Cheng.
Marks is hoping to get some of those answers with the animal experiments he plans to conduct. “We hope to optimize the animal model to best reflect what we think is going on in patients,” he says. “We want to study at a very, very detailed level what happens in the heart when the virus infects an animal.”
Ultimately, that knowledge will help to better treat people who might be at higher risk of heart-related problems from COVID-19, which could in turn reduce hospitalizations and deaths from the disease. Marks has already developed a potential drug that can address the leaking calcium if that proves to be a problem with COVID-19; he is ready and eager to test it if his animal studies justify the experiments.
Until more definitive studies clarify how the COVID-19 virus is affecting the heart, Jessup says she would advise her patients to “control the things we know how to control,” such as the risk factors that might put them at higher risk of heart disease to begin with, such as obesity, high blood pressure, and high cholesterol. And with more data emerging, if people are getting repeat COVID-19 infections, it’s also probably worth seeing their doctor to get their heart disease risk factors checked as well.
“We spend a lot of time telling people they should get vaccinated,” she says. “For people who have had COVID-19, we should also be making sure they know their heart numbers and make sure they know blood pressure. “We know how to prevent heart disease, so let’s do the things we know how to do.”
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