London: People who have had flu or pneumonia may be six times more likely to suffer from a heart attack or stroke in the days after infection, according to a study.
The research, published in the European Respiratory Journal, found that several different organisms that cause respiratory infections also increase heart attack and stroke risk, including S. pneumoniae bacteria and influenza. The findings suggest that getting vaccinated against these two infections could also have a role in preventing heart attack and stroke, along with preventing infection in the first place.
"Heart disease, strokes and lower respiratory infections have been the three leading causes of death globally for over 15 years, and are important public health problems that affect large numbers of people worldwide," said Charlotte Warren-Gash, associate professor at the London School of Hygiene & Tropical Medicine in the UK.
The study found that having flu or pneumonia increases the risk of having a heart attack for up to a week after infection, and the risk of having a stroke is increased for one month. The researchers identified 1,227 adults with a first heart attack and 762 with a first stroke who also had a respiratory virus or bacteria infection at any time between 2004 and 2014.
The team investigated the rate of heart attacks and strokes in the periods of time immediately after a respiratory infection, and then compared this to the rate of cardiovascular events in other periods of time in the same people.
The data showed that having a confirmed respiratory infection made people six times more likely to have a heart attack or stroke for three days after infection.
The S pneumoniae bacteria and the influenza virus were found to have the biggest impact on increasing the risk of having heart attacks and strokes.
The effect of infections on heart attack and stroke risk was greater in people aged less than 65 years compared to those aged 65 and above.
The researchers note that vaccine uptake is higher among those aged 65 and over, and say that being vaccinated could help to protect against heart attacks and strokes after respiratory infection.