The Covid-19 pandemic has caused an upheaval in healthcare systems and brought on an unprecedented number of infected cases and deaths worldwide since it was first discovered.

A study1 which looked at the impact of Covid-19 on heart health, has shown that a staggering three quarters of recovered Covid-19 patients suffered from heart inflammation, impairing the ability of the heart to contract, causing scar formation as well as resulting in an enlarged heart. Emerging reports have also suggested that infected patients experience higher risks of blood clot formation and heart disease – but just how much of this is fact? 

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Covid-19 and cardiovascular events

“Internationally, there have been reports that the SARS-COV-2 virus that causes Covid-19 infection can cause increased association with blood clots, heart disease and stroke, with the mechanism postulated as venous or arterial thrombosis either in situ or emboli from the heart,” said Assoc Prof Jack Tan, Deputy Head and Senior Consultant, Department of Cardiology, NHCS.

The silver lining is that among local cases, only about 1 in 1000 experienced cardiovascular events2. However, Assoc Prof Tan warned that the frequency of blood clots is highest in patients requiring intensive care and that can cause complications like heart attack, stroke and pulmonary embolism - clots in the venous system that can travel to the lungs.

He added that older patients, smokers and those with underlying cardiac risk factors, or existing heart and lung issues, tend to be worse off, “If this group of patients becomes critically ill and requires ventilation support, multi-organ failure can ensue. When all these stressors come together, it is not surprising that a heart attack or stroke can be precipitated.”

Can the common flu cause clots and heart attack?

“During each influenza season, we do see critically ill patients presenting with bad pneumonia, whether primarily from the influenza virus or from a superimposed secondary infection. They can be as sick as some of the Covid-19 patients and eventually pass on,” shared Assoc Prof Tan.

Indeed, a study published in the European Respiratory Journal3 showed that several different organisms that cause respiratory infections – including influenza and the bacteria responsible for pneumonia, increase heart attack and stroke risks. Researchers of the study found that the risk of heart attack and stroke occurring after a respiratory infection is generally low in young, healthy individuals. The same cannot be said for those over 65 years and/or with pre-existing heart diseases.

“We advise the at-risk group of individuals to get vaccinated against influenza. Sometimes, the seemingly common flu virus can also directly affect our heart muscles without causing a heart attack,” cautioned Assoc Prof Tan. The condition, known as myocarditis, is an inflammation of the heart muscles, thereby reducing the heart’s ability to pump, causing heart failure and abnormal heart rhythms.


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Practise social distancing

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Maintain an active and healthy lifestyle

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Take your medications as instructed by doctors to control your risk factors, e.g. hypertension drugs

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Seek medical attention if you experience any cardiac symptoms such as chest pain

Regular monitoring for at-risk Covid-19 patients

“We noted that the moment at-risk patients start feeling breathless while exerting minimally, the oxygen levels in their blood can drop drastically and the disease often progresses rather quickly,” Assoc Prof Tan emphasised that elderly and those with underlying heart conditions, are especially susceptible.

Currently, the best standard of care is early diagnosis and monitoring of at-risk patients. Early step up for the level of care for oxygen support, prevention of secondary infection and complications while waiting for the body to recover is still the gold standard of care.

A few medications have been tried and most have proven not to be effective against the SAR-COV-2 virus. The antiviral drug remdesivir and the steroidal drug dexamethasone can have some positive effects in sicker patients but do not cure the infection. The world is still waiting for the first proven vaccine against COVID-19 infections.

Prevention is best

The coronavirus has, in most cases so far, caused a mild respiratory response and a latent infectious asymptomatic period in the majority of patients. For the vulnerable group which tends to fare worse, in particular the elderly, those with chronic conditions like hypertension, coronary artery disease and diabetes. Assoc Prof Tan advised all to adhere to current safe distancing measures and do their part to reduce infections in the community.

1 Outcomes of Cardiovascular Magnetic Resonance Imaging in Patients Recently Recovered From Coronavirus Disease 2019 (COVID-19):
2 Extracted from MOH statement dated 4 June 2020:
3 Laboratory-confirmed respiratory infections as triggers for acute myocardial infarction and stroke: a self-controlled case series analysis of national linked datasets from Scotland:

This article is from Murmurs Issue 37 (May – August 2020). Click here to read the full issue.