COVID-19 and its effects on the cardiovascular system

By Dr. Ananya Mandal, MDMar 29 2020

Researchers collaborating from McGovern Medical School, Department of Medicine, University of Texas Health Science Center at Houston, Houston, Texas Heart Institute, Houston, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts and University of Minnesota, Minneapolis, have reviewed the evidence showing the effects of the SARS-CoV-2 or novel coronavirus infection (COVID-19) on the cardiovascular system. Their study titled, “Potential Effects of Coronaviruses on the Cardiovascular System: A Review,” was published in the latest issue of JAMA Cardiology.

Novel Coronavirus SARS-CoV-2 Colorized scanning electron micrograph of an apoptotic cell (blue) infected with SARS-COV-2 virus particles (red), isolated from a patient sample. Image captured at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland. Credit: NIAID

What was the study about?

The researchers explained that the new viral pandemic of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes COVID-19 has ravaged the world, and people with cardiovascular diseases may have particular implications when infected with the virus. This study was conducted to look at the effects of COVID-19 on the cardiovascular system.

Effects of the coronaviruses in humans

The researchers wrote that coronavirus is named because of the crown-like spikes on its surface these have four structural proteins – “spike (S) protein (which mediates attachment to the host receptor and subsequent fusion of the virus and cell membrane), the nucleocapsid (N) protein, the membrane (M) protein, and the envelope (E) protein”.

They add that severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East Respiratory Syndrome coronavirus (MERS-CoV) and the present SARS-CoV-2 can cause life-threatening respiratory infections in human populations.

Problems of the cardiovascular system associated with SARS

The researchers write that SARS-CoV may result in some complications of the cardiovascular system. However, there are no studies to clearly outline the effects of SARS-CoV on the cardiovascular system except for anecdotal reports that the risk of myocardial infarction or heart attacks and acute coronary syndrome was common after SARS. The researchers speak of a study of 75 patients with SARS and report that for every 5 cases of death, two were due to heart attacks. Thromboembolism and subendocardial infarction have also been reported, they wrote.

What happens in COVID-19?

On the 9^th of January 2020, a novel coronavirus called the SARS-CoV-2 was identified to be the cause of a viral pneumonia. The virus was transmitted from human to human via close contact. In most cases, adults are infected. There are fewer cases among children aged less than 15 years of age. Three significant symptoms include fever, cough, and shortness of breath, and other symptoms include headache, sore throat, fatigue. Both asymptomatic persons with COVID-19, as well as those with active disease, carry equal viral load. This means that asymptomatic individuals can be carriers of the infection in the community. Abnormalities are detected in chest CT scans of 85 percent of patients say reports. Both lung involvement is seen in 75 percent of all patients. The rate of fatality with the infection rises with age.

Other diseases among those with COVID-19

The team of researchers wrote that some of the common conditions seen along with those with COVID-19 include cardiovascular disease in 4.2 percent and high blood pressure in 12.8 percent. They add that the case fatality rate was 6 percent for those COVID-19 patients who had diabetes and 7.3 percent in those who had long term respiratory diseases such as asthma or chronic obstructive pulmonary disease (COPD). Overall case fatality with COVID-19 is 2.3 percent, they wrote. They also added that those that did not survive the disease had a higher likelihood of having heart failure (52 percent compared to 12 percent among survivors) and acute cardiac injury (59 percent compared to 1 percent among survivors). Some of the markers for heart disease such as “troponin, myoglobin, C-reactive protein, serum ferritin, and interleukin-6,” were found to be in higher levels among those who died of COVID-19 and this could indicate systemic inflammation, the researchers wrote.

They explained that SARS-CoV-2 had been known to affect the myocardium and lead to myocarditis. They wrote, “Myocardial injury is likely associated with infection-related myocarditis and/or ischemia and is an important prognostic factor in COVID-19.” A prognostic factor is one that predicts the outcome of a disease. Many patients died of ARDS or acute respiratory distress syndrome, and they found that those patients with cardiac injury were more likely to develop ARDS with COVID-19.

Results and observations

The team summarizes, “A large proportion of patients (with COVID-19) have underlying cardiovascular disease and/or cardiac risk factors. Factors associated with mortality include male sex, advanced age, and presence of comorbidities, including hypertension, diabetes mellitus, cardiovascular diseases, and cerebrovascular diseases.”

They explain that both SARS-CoV and SARS-CoV-2 use the ACE2 receptor to enter into the host cells. ACE2 plays a protective role in the development of lung failure, they wrote. No risks or benefits of using ACE inhibitors and angiotensin receptor blockers (ARBs) or antagonists of the renin-angiotensin system in COVID-19 patients has been noted, they wrote. They added, “A joint statement by the Heart Failure Society of America, American College of Cardiology, and American Heart Association recommends that these medications can be continued in patients with COVID-19 without interruption in compliance with available clinical guidelines.”

Implications and relevance

The authors conclude that COVID-19 has reached pandemic status and is a threat to global health. As of now, it is difficult to predict its course over the next few months or years. What is known is that this viral infection can lead to acute coronary syndromes, arrhythmias, and heart failure. The researchers wrote, “Treatment of cardiovascular complications should be based on optimal and judicious use of guideline-based therapies. As with other triggers for acute CVD events, the use of antiplatelet agents, β-blockers, ACE inhibitors, and statins are recommended per practice guidelines.”

The researchers conclude, “Extensive efforts are underway to find specific vaccines and antivirals against SARS-CoV-2. Meanwhile, cardiovascular risk factors and conditions should be judiciously controlled per evidence-based guidelines.”