DOCTOR’S NOTE: CORONAVIRUS AND HEART DISEASE

Fri 17 April 2020:

Heart disease puts people at higher risk of complications from COVID-19, but the virus can also trigger heart problems.

The link between cardiovascular (heart) disease and the COVID-19 virus is an interesting one because it is a double-edged sword.

A significant proportion of the population has underlying cardiovascular disease or cardiac risk factors which put them at higher risk of developing more severe symptoms if infected with the coronavirus. But we are also finding that infection with the coronavirus can put you at a higher risk of developing cardiovascular disease.

In a study of 191 patients from Wuhan, China, it was found that 8 percent of hospitalised COVID-19 patients had cardiovascular disease.

According to mortality data released by the National Health Commission of China, 35 percent of the patients who died from COVID-19 had a history of high blood pressure and 17 percent had a history of coronary heart disease.

This suggests that underlying cardiovascular disease can increase the severity of symptoms for those who catch the coronavirus, resulting in a higher death rate.

There are three main risk groups these heart patients might fall in to:

1. You are considered to be “high-risk” if you have coronary heart disease. This may mean that you have had a heart attack, a stent or bypass surgery in the past. If you fall into this group, the UK advice is the same as for the rest of the population, which is to stay at home apart from attending to essential needs like grocery shopping, picking up medication from the pharmacy, or doing one hour of daily exercise outdoors.
2. You are considered to be in the “particularly high-risk” group if you are over 70 and have heart disease, or have heart disease at any age but also have lung disease or chronic kidney disease. It also applies to those who have angina that restricts daily life; heart failure; severe heart valve disease; cardiomyopathy; or congenital heart disease. Again, the advice would be no different in that you should stay at home apart from essential outings.
3. However, some heart patients are considered “extremely high-risk” and the UK government suggests that these people be more carefully shielded. This means you should stay at home at all times and minimise contact with people for 12 weeks. You would be considered extremely vulnerable if you have had a heart transplant or if you are pregnant and have significant heart diseases.

It is well documented that COVID-19 can cause pneumonia. However, cardiovascular problems are another complication which can result from contracting the virus.

We have learned from other coronavirus and influenza epidemics that viral infections can trigger heart conditions such as acute coronary syndromes, arrhythmias and heart failure.

This is due to inflammation – caused by the infection and by the body’s immune response to it – developing in the body as a whole and specifically in the blood vessels which can affect plaques (fatty substances which cause the arteries to harden and narrow, restricting the blood flow) in the arteries, leading to cardiac disease.

Studies of COVID-19 patients found that 23 percent of those who were critically ill also suffered from cardiac “injury”. The study did not conclude that the virus caused the cardiac injuries, however, just that they appeared together.

This cardiac injury was defined as an elevated level of a marker called troponin which is a cardiac enzyme that is released when the heart muscle is damaged.

Abnormally high troponin levels are common in patients with COVID-19 and have also been found to be significantly higher in those who died after contracting the virus.

In addition to the raised troponin levels in COVID-19 patients, there have also been reports of ST-segment elevation (STE) being found on electrocardiograms (ECGs).

This is usually a sign that there is obstructive coronary artery disease – an indicator that a heart attack is in the process of happening or has just happened.

However, there have also been documented cases where patients with COVID-19 were found to have STE on their ECG and therefore went on to have invasive coronary angiography to confirm and treat the finding of a heart attack, only to find no sign of the disease.

These false signs of heart attacks may mean that patients undergo procedures that they did not necessarily need.

Rather than having a heart attack as suspected, these patients were actually found to have myocarditis, which results in similar changes to troponin levels and on an ECG.

Myocarditis is the inflammation of the heart muscle, and while it may be reassuring to find that a patient is not having a heart attack, myocarditis can still cause damage to the heart and result in irregular heart rhythms.

The number of patients with COVID-19 developing myocarditis, and the mortality rate for those who do is yet to be determined, but these reports of STE without obstructive coronary disease proves a challenge for diagnosis and management.

It requires hospitals to balance the risks of complicating COVID-19 patients’ situations with unnecessary invasive investigations and treatments versus the potential benefit if the patient truly is experiencing a heart attack.

We are likely to understand more about the pathophysiology of COVID-19 and cardiovascular disease with evolving trials and studies, but until then it remains ever-important to follow the government guidelines if you have any underlying health conditions, including cardiovascular disease.