The risk of having a heart attack is 17 times higher in the seven days following a respiratory infection, University of Sydney research has found.

Published today in Internal Medicine Journal, this is 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).

“Our findings confirm what has been suggested in prior studies that a respiratory infection can act as a trigger for a heart attack,” said senior author Professor Geoffrey Tofler, cardiologist from University of Sydney, Royal North Shore Hospital and Heart Research Australia.

“The data showed that the increased risk of a heart attack isn’t necessarily just at the beginning of respiratory symptoms, it peaks in the first 7 days and gradually reduces but remains elevated for one month.”


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The study was an investigation of 578 consecutive patients with heart attack due to a coronary artery blockage, who provided information on recent and usual occurrence of symptoms of respiratory infection.

Seventeen per cent of patients reported symptoms of respiratory infection within 7 days of the heart attack, and 21 per cent within 31 days.

Patients were interviewed about their activities before the onset of their heart attack, including if they experienced a recent “flu-like illness with fever and sore throat”. They were considered affected if they reported sore throat, cough, fever, sinus pain, flu-like symptoms, or if they reported a diagnosis of pneumonia or bronchitis.

Click here to read the full press release.

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