Dear Mayo Clinic: I had some heart trouble earlier this year and have not yet gotten a flu shot. Is it safe for someone like me, who has heart issues, to get the vaccine?
A: In almost all cases, the answer is yes. Unless you have a specific reason for not getting a flu (influenza) shot _ such as an allergy _ the flu shot is very safe, even if you have heart disease.
In fact, heart disease increases the risk of complications if you get influenza, and, so, in your case, the flu vaccine would be strongly recommended. Influenza, or the flu, is a known risk factor for cardiovascular events such as heart attack and stroke, which sometimes can cause death. The flu also can worsen heart failure or other conditions that can stress the cardiovascular system, such as diabetes or asthma.
It's not entirely clear how the flu triggers cardiovascular problems. It may make artery-clogging plaques more unstable and vulnerable to rupture. It may lower oxygen levels and make the heart work harder. It may directly injure heart cells. Or it may simply put too much stress on a more frail body.
The flu shot reduces the risk of getting the flu. Even if you get the flu after receiving a flu shot, you'll probably have a less severe case of the flu.
A recent review of research suggests that getting the flu vaccine may reduce the risk of a heart attack. The review found that older adults who got the flu vaccine reduced their risk of heart attack over the next eight months by about 36 percent. Among older adults with pre-existing heart disease, getting a flu shot reduced heart attack risk by over half.
