People who get flu shots may be slightly less likely to have heart attacks in the year after the shot. The study doesn’t show that flu shots prevent heart attacks; it is possible that people healthy enough to get flu shots are also healthy enough to avoid heart attacks. But it supports the usual recommendation that older people with heart disease get their shot every year.
British researchers analyzed the medical records of 16,000 people who suffered a heart attack. Each heart attack patient was matched to four healthy individuals. After controlling for blood pressure, smoking, family history, and other risk factors for heart disease, the scientists determined that people who got flu vaccinations were 19 percent less likely to have a heart attack. The investigators hypothesize that a flu infection sets off an inflammatory reaction that might eventually culminate in a heart attack.
[Canadian Medical Association Journal, online Sept.20, 2010]