If you have heart disease, getting your flu shot (influenza vaccination) may do more than just prevent the flu—it can actually stave off a heart attack, according to a new review published in the October 2009 issue of The Lancet: Infectious Diseases.
Influenza ("the flu") is a viral disease that causes symptoms like fever, chills, cough, sore throat, headache, muscle pain, and general discomfort. Doctors have long known of a link between influenza and heart disease, which both cause inflammation in the arteries. Patients with heart disease are particularly vulnerable to catching the disease, and the stress of the infection on your system can make heart problems worse.
This latest review looked at 39 studies that tested the link between influenza and heart attack. The studies consistently found that the flu acts as a " trigger" for heart attack in people with heart disease. Up to half of unexpected flu deaths turned out to be caused by heart disease. Two trials also tested whether the flu vaccine could prevent a heart attack. Together, they suggest that a flu shot can prevent a heart attack if you already have heart disease (it is not known if it helps people who do not already have heart disease).
None of the studies looked specifically at the H1N1 strain of the flu ("swine flu") that is currently circulating. Although this form is no more dangerous than regular flu for heart patients, it probably shares the same heart attack-triggering effects. However, because the outbreak the flu will likely be more widespread than usual this year, it is especially important for heart patients take steps to protect themselves.
The American Heart Association recommends that all people with heart disease get an influenza vaccination. You should get a regular flu shot and an additional vaccine designed specifically to prevent the H1N1 swine flu virus (check availability here). People who are at high risk for flu complications and therefore benefit most from the vaccine include people with:
- Coronary artery disease or chest pain (angina)
- Heart failure
- A history of heart attack, stroke, or a procedure to treat heart disease
- Peripheral artery disease
- Women who are pregnant
People who are most vulnerable to infection, especially older people, are the least likely to seek out a flu shot and may be putting themselves at risk for heart attack or death. Only 1 in 3 heart patients in the US get regular flu shots.
It is still possible to get the flu even after getting a flu shot. The vaccine takes up to two weeks to take effect, and there are many different strains of the disease - each year's vaccine only protects against the more common types. You should continue to follow common sense measures to protect yourself, including:
- Wash your hands (or use a waterless hand sanitizer) before eating or touching your eyes, mouth, or nose
- Avoid close contact with people who are sick (even grandchildren)
- Get extra sleep, drink plenty of fluids, and eat a healthy diet
- Be physically active and manage stress
If you need another reason to quit smoking, consider that smokers are more likely to contract upper respiratory infections (including the flu), and have more severe symptoms when they do.
Smith SC Jr. et al. AHA/ACC Guidelines for Secondary Prevention for Patients with Coronary and Other Atherosclerotic Vascular Disease: 2006 Update. J Am Coll Cardiol. 2006;47:2130