I hope you’ve had your flu shot already, but it’s not too late. You can still protect yourself from getting this year’s strain, and you might get the added benefit of lowering your risk of a heart attack. That’s according to a study reported in the Journal of the American Medical Association.
Researchers from the University of Toronto knew that respiratory tract infections are associated with an increased risk of undesirable cardiovascular events, so they examined whether influenza vaccination could lower this risk. They analyzed all reported randomized clinical studies of flu vaccines that included cardiovascular events as part of their safety profiling. They found 6 studies of adequate quality for inclusion in meta-analysis. All-cause mortality, cardiovascular mortality, and cardiovascular events were recorded. Analyses were done on the whole collective, and on those with and without a recent coronary artery event (acute coronary syndrome, or ACS).
A total of 6735 patients (average age 67, 51% women; 36% with a cardiac history) were included; the average follow-up time was 7.9 months. Influenza vaccination was associated with a lower risk of cardiovascular events: 2.9% vs. 4.7% in vaccinated vs. unvaccinated participants, respectively. In the patients with a recent history of ACS there was an especially lowered risk of major adverse cardiovascular events; such events were seen in 23% of the non-vaccinated subjects, and in only 10% of those who had been vaccinated.
Clearly, having a flu shot was associated with roughly a halving of the risk of having a major coronary artery event (e.g. a heart attack). The greatest effect was seen in high-risk patients with more active coronary disease. But everyone should be aware of this ‘add-on’ benefit of flu shots; and it’s still not too late for this season . . .