Your heart and the flu: Surprise finding about who is most at risk

Influenza can trigger a heart attack. Get vaccinated.

Influenza can trigger a heart attack. Get vaccinated. Photo: Getty

It’s already been a tough winter with the amount of respiratory illness going around.

The flu, COVID, RSV are just the start of it.

Mycoplasma pneumonia is going through people in great numbers. And the antibiotics that can best treat this bug are in critical supply.

The real scale of the problem is unknown, because it’s not a notifiable disease.

Plus, there are a host of viruses that we don’t have names for.

But for people in late middle age and older, winter presents another difficulty, the risks to your heart.

Respiratory infections and the heart

In 2017, University of Sydney researchers found that the risk of having a heart attack is 17 times higher in the seven days following a respiratory infection.

The increased risk peaks in the first seven days and gradually reduces but remains elevated for one month.

This was the first study “to report an association between respiratory infections such as pneumonia, influenza and bronchitis and increased risk of heart attack in patients confirmed by coronary angiography (a special X-Ray to detect heart artery blockages)”.

It’s good to know this because influenza is perceived to be the heart’s main antagonist in winter. For good reason.

It goes two ways

The heart and flu season have a complicated relationship – it’s a two-way trouble-fest.

Heart disease is a known risk factor for developing serious flu complications. On the other hand, the influenza virus can put people at increased risk for heart attack and stroke.

In 2009, it was found that a dose of influenza could trigger acute myocardial infarction (a heart attack) or death from cardiovascular disease.

New research from the University of NSW has confirmed the link between influenza infection and an increased risk of acute myocardial infarction (MI).

But there was a surprise for the researchers. The risk was greatest for patients without a prior hospitalisation for coronary artery disease.

In other words, the greatest risk was in people who haven’t been diagnosed with CAD.

Coronary artery disease is a common type of heart disease, where the arteries that carry blood to the heart become lined with fats, compromising blood flow.

CAD typically takes a long time to develop. And patients often don’t know that they have it until there’s a problem.

If you’re aged 45 years and over, you should arrange a Heart Health Check with your doctor.

In the meantime, if you have CAD, known or unknown, you can protect your heart by getting an influenza vaccine.

Cuts heart attack risk by 45 per cent

According to a 2021 review, published in the Journal of the American Heart Association:

  • Cardiovascular deaths and influenza epidemics spike around the same time
  • Patients are six times more likely to experience a heart attack the week after an influenza infection, more than at any point during the year prior or the year after the infection
  • In one study looking at 336,000 hospital admissions for flu, 11.5 per cent experienced a serious cardiac event. That’s more than one in 10 hospital flu patients
  • Another study looking at 90,000 lab-confirmed influenza infections showed a similar rate of 11.7 per cent experiencing an acute cardiovascular event
  • One in eight patients, or 12.5 per cent, admitted to the hospital with influenza experienced a cardiovascular event, with 31 per cent of those requiring intensive care and 7 per cent dying as a result of the event.

  So why does influenza hurt the heart? What’s the mechanism?  

According to the British Heart Foundation, flu causes stress to your body which can affect your blood pressure, heart rate and heart function. There’s evidence that heart attacks happen more often during or immediately after an acute inflammatory illness. Such as influenza flu.

As we previously reported, research “indicates that infections such as flu might encourage blood to thicken or prompt an inflammatory response in arteries that are already diseased, sparking the development of a blockage”.

How to avoid this? A jab will help.

Stay informed, daily
A FREE subscription to The New Daily arrives every morning and evening.
The New Daily is a trusted source of national news and information and is provided free for all Australians. Read our editorial charter.
Copyright © 2024 The New Daily.
All rights reserved.