Based on reports from China, we know that most COVID-19 patients (about 80%) will develop mild flulike symptoms, including fever, dry cough, and body aches that can be managed at home. 20% will develop more serious symptoms, such as pneumonia requiring hospitalization, with about a quarter of these requiring ICU-level care.

Initial reports focused on the respiratory effects of COVID-19, such as pneumonia and difficulty breathing. But more recent literature has described serious cardiovascular complications occurring in about 10% to 20% of hospitalized patients.

Someone with pre-existing heart disease who becomes ill with COVID-19 may suffer a heart attack or develop congestive heart failure. This rapid worsening of cardiovascular health is likely due to a combination of the severe viral illness and its increased demands on the heart (fever causes rapid heart rate, for example), compounded by low oxygen levels due to pneumonia and increased propensity for blood clot formation. In addition to the increase in these heart problems, a more unusual condition called myocarditis has also been observed in COVID-19 patients.

COVID-19 triggers inflammation of the heart muscle

Some COVID-19 patients who appear to be having a heart attack are instead suffering from marked inflammation of the heart muscle, called myocarditis. The electrocardiograms in these patients show changes suggestive of a major heart attack, and blood tests reveal elevated levels of troponin, a cardiac enzyme that is released when heart muscle is damaged. The heart muscle becomes weak, and dangerous heart rhythms may develop. Severe injury to the heart muscle, as measured by troponin levels, has been strongly associated with increased risk of death in people with COVID-19, according to a review published in JAMA Cardiology.

It is not clear whether myocarditis is due to a direct effect of the virus on the heart muscle, or whether it is due to an overactive immune response to the virus, so doctors do not yet know how best to treat these patients.

Increased risk of severe illness and death in heart patients with COVID-19

About 10% of patients with pre-existing cardiovascular disease (CVD) who contract COVID-19 will die, compared with only 1% of patients who are otherwise healthy. Increased risk has also been seen in people with high blood pressure (hypertension) and coronary artery disease (CAD), though it is not clear why. Some experts have suggested that the missing link may be the use of certain blood pressure medications called angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs).

ACE inhibitors and ARBs — harm or help?

ACE inhibitors and ARBs are among the most commonly prescribed medications for the treatment of high blood pressure. These medications have been proposed as a possible factor in the increased incidence of COVID-19 in people with high blood pressure. That’s because of the observation that the coronavirus attaches to the ACE2 receptor, which is found in lung and heart tissue. People who take ACE inhibitors and ARBs produce increased numbers of these receptors, raising the question of increased susceptibility to infection.

However, ACE2 has been found to protect against viral lung injury in mice. And a study is ongoing to test whether losartan, an ARB, may protect patients infected with COVID-19.

As of today, there is insufficient evidence of either harm or benefit. The American College of Cardiology, American Heart Association, and Heart Failure Society of America therefore recommend that we neither stop the use of ACE inhibitors and ARBs in patients already taking them, nor prescribe them anew.

Do all you can to prevent infection

There are no special protocols for higher-risk cardiac patients to prevent COVID-19 exposure, but these individuals should be especially careful to follow the CDC recommendations, including frequent handwashing and physical distancing.

It is also important to stay up to date on the flu and pneumonia vaccines, because any illness can weaken the body’s ability to fight off COVID-19. Heart patients should avoid close contact with children 18 and under, because although children rarely develop serious illness from COVID-19, they may be asymptomatic carriers who can transmit disease to vulnerable family members.

In addition to these recommendations, it remains vitally important to exercise (outdoors when possible, keeping safe distance from others), get enough sleep, manage stress, and eat a balanced diet. These healthy habits will not only bolster the immune system to help ward off COVID-19, but will help prevent CVD progression in the longer term. After all, once the pandemic has subsided, we will still have heart disease to contend with.

Follow me on Twitter @daraleelewismd.

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