Alarming Study Findings Shows That SARS-CoV-2 Disrupts Heart Muscle Contraction, Often Leading To Heart Failure
Despite attempts to downplay the seriousness of SARS-CoV-2 coronavirus infections and the issue of Long COVID by Western health officials and experts, more studies are emerging on these areas especially on the myriad of heart issues arising as a result of having had COVID-19.
It has been speculated that a huge amount of excess deaths due to heart issues around the world are in fact been linked to SARS-Cov-2.
Now a new study led by researchers from the University of Washington-Missouri along with scientists from Baylor College of Medicine-Texas, Vanderbilt University-Tennessee, Creighton University-Arizona, University of Texas, Conn Health, the Jackson Laboratory for Genomic Medicine-Connecticut and the University of Heidelberg-Germany has found that the SARS-CoV-2 coronavirus is able to also disrupt the heart muscle contraction which can in turn lead to heart failure
According to the study abstract, “There is ongoing debate as to whether cardiac complications of coronavirus disease 2019 (COVID-19) result from myocardial viral infection or are secondary to systemic inflammation and/or thrombosis. The study team provides evidence that cardiomyocytes are infected in patients with COVID-19 myocarditis and are susceptible to severe acute respiratory syndrome coronavirus 2. The team established an engineered heart tissue model of COVID-19 myocardial pathology, define mechanisms of viral pathogenesis, and demonstrate that cardiomyocyte severe acute respiratory syndrome coronavirus 2 infection results in contractile deficits, cytokine production, sarcomere disassembly, and cell death. These study findings implicate direct infection of cardiomyocytes in the pathogenesis of COVID-19 myocardial pathology and provides a model system to study this emerging disease.”
The study findings were published in the peer reviewed journal: Journal of the American College of Cardiology: Basic to Translational Science. https://www.sciencedirect.com/science/article/pii/S2452302X21000127
Already since early in the pandemic, COVID-19 has been associated with heart problems, including reduced ability to pump blood and abnormal heart rhythms.
However it has been an open question whether these problems are caused by the SARS-CoV-2 virus infecting the heart, or an inflammatory response to viral infection elsewhere in the body. Such details have implications for understanding how best to treat coronavirus infections that affect the heart.
This new study provides evidence that COVID-19 patients' heart damage is caused by the virus invading and replicating inside heart muscle cells, leading to cell death and interfering with heart muscle contraction.
The study team used stem cells to engineer heart tissue that models the human infection and could help in studying the disease and developing possible therapies.
Senior author Dr Kory J. Lavine, MD, Ph.D., an associate professor of medicine from the Cardiovascular Division, Department of Medicine, Washington University School of Medicine-Missouri told Thailand Medical News, "Early on in the pandemic, we had evidence that this coronavirus can cause heart failure or cardiac injury in
generally healthy people, which was alarming to the cardiology community. Even some college athletes who had been cleared to go back to competitive athletics after COVID-19 infection later showed scarring in the heart. There has been debate over whether this is due to direct infection of the heart or due to a systemic inflammatory response that occurs because of the lung infection.”
Dr Lavien added, "Our study is unique because it definitively shows that, in patients with COVID-19 who developed heart failure, the virus infects the heart, specifically heart muscle cells."
Dr Lavine and his colleagues including collaborators Dr Michael S. Diamond, MD, Ph.D., the Herbert S. Gasser Professor of Medicine, and Dr Michael J. Greenberg, PhD, an assistant professor of biochemistry and molecular biophysics also used stem cells to engineer tissue that models how human heart tissue contracts.
By studying these heart tissue models, they determined that viral infection not only kills heart muscle cells but destroys the muscle fiber units responsible for heart muscle contraction.
The study team also showed that this cell death and loss of heart muscle fibers can happen even in the absence of inflammation.
Dr Lavine added, "Inflammation can be a second hit on top of the damage caused by the virus, but the inflammation itself is not the initial cause of the heart injury.”
Numerous other viral infections have also long been associated with heart damage, but Dr Lavine said SARS-CoV-2, the virus that causes COVID-19, is unique in the effect it has on the heart, especially in the immune cells that respond to the infection.
Interestingly in COVID-19, immune cells called macrophages, monocytes and dendritic cells dominate the immune response. For most other viruses that affect the heart, the immune system's T cells and B cells are on the scene.
Dr Lavine further added, "COVID-19 is causing a different immune response in the heart compared with other viruses, and we don't know what that means yet. In general, the immune cells seen responding to other viruses tend to be associated with a relatively short disease that resolves with supportive care. But the immune cells we see in COVID-19 heart patients tend to be associated with a chronic condition that can have long-term consequences. These are associations, so we will need more research to understand what is happening."
Importantly part of the reason these questions of causation in heart damage have been hard to answer is the difficulty in studying heart tissue from COVID-19 patients. The researchers were able to validate their findings by studying tissue from four COVID-19 patients who had heart injury associated with the infection, but more research is needed.
Dr Lavine and Dr Diamond, are also working to develop a mouse model of the heart injury. To emphasize the urgency of the work, Dr Lavine pointed to the insidious nature of the heart damage COVID-19 can cause, “Even young people who had very mild symptoms can develop heart problems later on that limit their exercise capacity. We want to understand what's happening so we can prevent it or treat it. In the meantime, we want everyone to take this virus seriously and do their best to take precautions and stop the spread, so we don't have an even larger epidemic of preventable heart disease in the future.
For more on Heart Failure -SARS-CoV-2
, keep on logging to Thailand Medical news.