The findings may not only explain the link between COVID and the increased risk of cardiovascular events but mark a starting point for new therapeutic approaches.
“Our study shows there is persistence of viral debris in the artery,” senior investigator Chiara Giannarelli, MD, associate professor of medicine and pathology at NYU Langone Health, New York, said in an interview. “There is an important inflammatory response. We can now look at ways to control this inflammation,” she said.
Dr. Giannarelli says COVID is more than a respiratory virus and that it can affect the whole body. “Our study shows a remarkable ability of the virus to hijack the immune system,” she points out. “Our findings may explain how that happens.”
Dr. Giannarelli says it’s important for doctors and patients to be aware of an increased cardiovascular risk after a SARS-CoV-2 infection and to pay extra attention to traditional risk factors, such as blood pressure and cholesterol.
“This study showing that severe acute respiratory syndrome coronavirus directly infects coronary artery plaques, producing inflammatory substances, really joins the dots and helps our understanding on why we’re seeing so much heart disease in COVID patients,” Peter Hotez, MD, professor of molecular virology and microbiology at Baylor College of Medicine, Houston, said in an interview.
Asked whether this direct infection of vascular plaques was unique to SARS-CoV-2 or whether this may also occur with other viruses, both Dr. Giannarelli and Dr. Hotez said they believe this may be a specific COVID effect.
“I wouldn’t say it is likely that other viruses infect coronary arteries in this way, but I suppose it is possible,” Dr. Giannarelli said.
Dr. Hotez pointed out that other viruses can cause inflammation in the heart, such as myocarditis. “But I can’t think of another virus that stimulates the sequence of events in coronary artery inflammation like we’re seeing here.”
Dr. Giannarelli noted that influenza is also associated with an increased risk of cardiovascular events, but there has been no evidence to date that it directly affects coronary arteries.
Dr. Hotez added that the increased risk of cardiovascular events with influenza has also been reported to be prolonged after the acute infection. “These new findings with SARS-CoV-2 could stimulate a redoubling of efforts to look at this possibility with influenza,” he suggested.
Heart disease after COVID
In a recent article published online in Nature Cardiovascular Research, Dr. Giannarelli and colleagues analyzed human autopsy tissue samples from coronary arterial walls of patients who had died from COVID in the early stages of the pandemic in New York.
They found an accumulation of viral RNA in atherosclerotic plaques in the coronary arteries, which was particularly concentrated in lipid-rich macrophage foam cells present within the plaques.
“Our data conclusively demonstrate that severe acute respiratory syndrome coronavirus is capable of infecting and replicating in macrophages within the coronary vasculature,” the researchers report.
The virus preferentially replicates in foam cells, in comparison with other macrophages, they add, suggesting that these cells might act as a reservoir of viral debris in atherosclerotic plaque.
“We have shown that the virus is targeting lipid-rich macrophages in atherosclerotic lesions. This is the first time this has been shown, and we think this is a very important finding,” Dr. Giannarelli said in an interview.
“We also found that the virus persists in these foam cells that could be responsible for long-term, low-grade inflammation in the vasculature that could contribute to the long-term cardiovascular manifestations in patients who have recovered from COVID,” she said.