Older patients and patients with heart conditions should be encouraged to get their flu vaccination as it may protect against heart attack and stroke, a study has advised.
Patients were markedly more likely to suffer a heart attack or stroke in the days after a respiratory infection, leading researchers to highlight the importance of at-risk patients getting vaccinated.
The study, published in the European Respiratory Journal, looked at just under 2,000 patients from a Scottish inpatient database who had suffered a first heart attack or stroke and had also had a respiratory infection between 2004 and 2014. The patients had an average age of 68.
Researchers found that having an influenza infection made patients almost 10 times as likely to suffer a heart attack and eight times as likely to suffer a stroke in the three days following infection when compared to baseline incidence rates.
They also found that patients were almost six times as likely to have a heart attack or stroke in the three days following an S. pneumoniae infection. The risk for stroke remained high in the month following the infection, with patients four times as likely to suffer an event between 15 and 28 days after exposure.
When the results were adjusted for age, patients aged under 65 were more likely to suffer a cardiovascular event than patients over 65.
The researchers said in the paper: ‘Our findings that both influenza and S. pneumoniae have specific triggering effects on MI and stroke emphasise the need to encourage uptake of influenza and pneumococcal vaccines wherever indicated, especially among populations with existing heart disease in whom influenza vaccine uptake is sub-optimal.’
Lead researcher Dr Charlotte Warren-Gash, associate professor of epidemiology at the London School of Hygiene and Tropical Medicine, said: ‘For most young, healthy people, the risk of heart attacks and strokes occurring after a respiratory infection is low. This research is particularly relevant for those over the age of 65, as well as people with pre-existing heart diseases, as these groups are at higher risk of heart attacks and strokes.
‘These groups are already recommended to have vaccinations against influenza and S. pneumoniae but we know that vaccine uptake is not high among younger people with heart problems. Understanding that there is a link between these bugs and heart attacks and strokes is an added incentive to get those vaccinations.’
Public Health England figures from January showed that flu vaccine uptake in England had increased for most patient groups in the 2017/2018 flu season, compared with the previous year. This came after a PHE spokesman described this year’s flu season as ‘the most significant’ for hospital admissions since 2010/11.
Eur. Respir. J 2018; available online 22 March
