LOS ANGELES — Get a flu shot to ward off a case of influenza, and as an added bonus you'll reduce your risk of a heart attack, stroke or other type of unpleasant "cardiovascular event," a new study finds.
For some time, researchers have suspected that flu shots can protect heart health as well as respiratory health. They have tested this theory in a handful of clinical trials, and the results have been mixed.
Now an international group of researchers has compiled data from a dozen randomized clinical trials to see if they could get a clearer answer to the question. What they found was "a consistent association between influenza vaccination and a lower risk of cardiovascular events," according to their report in today's edition of the Journal of the American Medical Association.
Three of the trials the researchers examined focused on patients with coronary artery disease. Some of those patients had recently experienced acute coronary syndrome, and they benefited the most by getting a flu shot. Patients who got the vaccine were 55 percent less likely to have a serious heart problem than those in the control groups.
Experts aren't sure why the flu increases the risk of serious heart problems, but they have their theories. It may cause a plaque that has built up inside the arteries to rupture, or it may cause the heart muscle to become inflamed, among other possibilities. Knowing what's going on inside the body would help figure out who would get an extra boost from a flu shot, and why.
Even with those uncertainties, the conclusion that a flu shot can protect patients with heart disease is convincing, according to an editorial that accompanies the study in JAMA.