Getting a Flu Shot Can Help Protect Your Heart, Too

November 06, 2018 1:00 PM

A flu vaccine can shield you, and those you love, from the virus’ potentially life-threatening effects — including heart attack.

Flu season is here again, and health care professionals are making sure the flu vaccine is on their patients’ to-do lists.

Not only can the vaccines help avoid unnecessary flu-related hospitalization and even death — incidents that hit a record high during the 2017-18 flu season — the shots could have a cardiovascular benefit.

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“We have reason to believe that becoming infected with the flu increases the risk of having a heart attack,” says Michigan Medicine interventional cardiologist Nadia Sutton, M.D., MPH.  

Sutton points to a recent study in the New England Journal of Medicine that found the likelihood of hospitalization for a heart attack increases approximately sixfold during the first week after a patient’s flu diagnosis.

The possible reason: “The flu virus can cause an inflammatory reaction throughout the body,” says Sutton, which may increase the risk of heart attack.

She and Michigan Medicine infectious diseases specialist Kevin Gregg, M.D., spoke more about the connection — and offered general tips for staying healthy this flu season.

Flu and heart attack: what to know 

How long is flu season?

Sutton: The flu season typically begins in October and peaks sometime between December and mid-February. However, the season can run into spring and can even go as late as May.

Does the vaccine last all season?

Gregg: The effects of the influenza vaccine do last for the entire flu season and there is no “perfect time” to get the vaccine, but the earlier the better — as that will provide the best chance for protection from the very onset of flu season.

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While the Centers for Disease Control and Prevention recommends everyone age 6 months and older get the flu vaccine by the end of October, this doesn’t mean if you missed this time frame you should skip the vaccine.

Who is at the greatest risk of complications from the flu?

Sutton: Anyone who contracts influenza is susceptible to developing complications of the infection.

In particular, we worry about frail older patients, infants who have not fully developed their immune system and immunocompromised patients. This includes both patients who take immunosuppressing medications (due to cancer, autoimmune disease or having received an organ transplant), as well as patients who are compromised with other medical problems, such as heart failure or COPD.

Receiving the flu vaccine not only protects you, but also protects those you might have come into contact with if you had been infected with the flu.

For example, if you are otherwise healthy, you might be infected with the flu and not realize it initially, go to the grocery store or a clinic appointment, and pass along the infection to someone who might not tolerate the infection as well as you do.

How can a flu virus affect my heart?

Sutton: The inflammation that occurs from the viral infection may increase the risk of heart attack. This may occur due to inflammation causing rupture of a previously existing cholesterol plaque lining the blood vessels of the heart, or it might occur due to the extra demand for blood flow that infection places on the heart.

Viral infections can also lead to myocarditis, or inflammation of the heart muscle, and respiratory failure. While less common, this can occur even in young or otherwise healthy individuals.

"We have reason to believe that becoming infected with the flu increases the risk of having a heart attack."
Nadia Sutton, M.D., MPH

Can the flu vaccine make you sick?

Sutton: This is a common myth. If you do come down with the flu right after getting the vaccine, chances are you were already exposed to a virus prior to the vaccine.

SEE ALSO: 3 Times You Risk Catching the Flu

Some patients have flu-like symptoms after the flu vaccine, as their body is preparing the immune system to fight the virus if exposed, but the vaccine itself does not cause an influenza infection.

Will getting the flu interfere with my other medications?

Sutton: Having the flu could impact the effect of the medication you take for other health problems (such as heart disease, diabetes or lung disease). 

If your appetite diminishes and you are not eating and drinking as usual, or if you’re experiencing nausea, vomiting or diarrhea, it’s important to touch base with your health care provider, particularly if you take medications regularly.

Is the flu nasal spray an option for everyone?

Gregg: The flu nasal spray is a live-attenuated virus, meaning that it has a virus that has been altered so that it should not be able to cause influenza infection.

This vaccine can be given to individuals ages 2 to 49 but is not advised for heart disease patients or individuals with other chronic conditions such as weakened immune systems, lung disease or kidney disease, as its safety and effectiveness have not been established in patients with these conditions. It is also not recommended for pregnant women.

Talk with your doctor to find out if the flu nasal vaccine is appropriate for you.

Are there different vaccine doses for seniors?

Gregg: Patients age 65 and older can get either the quadrivalent influenza vaccine (against four strains of flu) or a high-dose trivalent vaccine (against three strains of flu). Several studies have shown the high-dose vaccine to be more effective at preventing influenza and hospital admission for influenza infection in older individuals.

It is most important to simply get a flu shot, however, so either shot is OK if you are 65 or older.

What if I’ve had a reaction to the flu vaccine in the past?

Gregg: Some reactions are normal, like a sore arm or low-grade fever, and do not mean that you can’t receive the vaccine again. If you have a severe allergy to any ingredient in the vaccine or have had a severe reaction in the past, you should not get a flu shot.

SEE ALSO: Make Sure Your Teen Has Had These 4 Lifesaving Vaccines

It’s important to speak with your doctor about any past flu vaccine reactions to determine if you should not receive the vaccine.

Will anti-viral drugs help if I do get the flu?

Gregg: If you think you might have the flu, it’s important to contact your doctor immediately. He or she may perform a test to confirm if you have the flu and may prescribe you an antiviral medication such as Tamiflu or Xofluza.

Both of these medications are most effective when started within 48 hours of the onset of symptoms, so contact your doctor’s office right away.

To get a flu shot, contact your primary care physician.