Baltimore doctor says getting your flu shot can reduce risk of cardiac event or stroke

Now is the ideal time to get your flu shot if you haven’t already, according to medical experts, and doing so can not only keep you from getting sick, but also reduce risk for a cardiac event or stroke.

“Studies and data show that people are six times more likely to have a heart attack during the week after having the flu compared to the year prior and the year after having a flu infection, and there is data showing that death from cardiac events tend to spike around the same time as flu season,” said Dr. Salman Malik, a cardiologist for MedStar Health in Baltimore.

Dr. Salman Malik
Cardiologist, MedStar Health, Baltimore

In some cases, the flu can create an increased inflammatory state, which can increase the risk of a plaque rupture in an artery, causing a clot or the artery to spasm or constrict, walling off blood flow to a part of the heart muscle, causing damage to the heart and ultimately leading to a heart attack, Malik said. Influenza can similarly affect blood vessels in the brain, leading to stroke.

Developing pneumonia or bronchitis from the flu can also put additional strain on the heart, increasing the risk for a heart attack, congestive heart failure, or developing arrhythmias or abnormal heart rhythms, he said.

“There are studies showing that on average, approximately 12% of percent of patients admitted to the hospital — the ones that have had the flu — have a cardiac event, and nearly a third of those patients are admitted to the ICU, with about 7% dying as a result of a cardiac event related to the flu,” Malik said. “So that’s why it’s so important to get the vaccination.”

The beneficial effects of the influenza vaccine are fairly high, Malik notes. Studies show getting vaccinated can reduce the risk of having a cardiac event by approximately 30% and some research shows getting the flu shot after a heart attack reduces the risk of long-term cardiac events.

“There is research and data showing, in regards to the benefits of the flu vaccine, that it’s very comparable or even exceeds the benefits of standard medications we use for high blood pressure and heart disease like ACE inhibitors and statins,” Malik said.

This year’s flu season has potential to be a severe one. Australia often serves as a barometer for influenza in the United States, and the signs are not good, said Dr. Martha Gulati, director of cardiovascular disease prevention in the Smidt Heart Institute at Cedars-Sinai in Los Angeles.

“The Southern Hemisphere had a bad flu season, and it came early,” said Gulati, who co-wrote a 2021 review of research on the flu vaccine in people with cardiovascular disease in the Journal of the American Heart Association. “So we should be concerned that the exact same thing is going to happen here. That’s why I’m specifically encouraging people to get their flu shot as early as possible.”

Perhaps more worrisome is that “vaccine fatigue” will keep some from getting a flu shot. Misinformation and politicization of the COVID-19 vaccines have contributed to that fatigue, but reluctance to get the flu shot pre-dates the pandemic.

In 2018-19, the last flu season unaffected by COVID-19, only about 63% of children and 45% of adults were vaccinated, according to the Centers for Disease Control and Prevention.

“There’s been long-standing vaccine fatigue even prior to COVID, and I think that still exists, typically with more of the younger population than the older population, and there are a number of reasons for that,” Malik said. “It can be due to some degree of misinformation in the media and also due to the lack of education and consistent messaging.”

A flu vaccine’s effectiveness at preventing infection varies from year to year, as the formula changes to keep up with mutations in the virus. But vaccination lowers the odds you’ll get seriously ill. According to the CDC, vaccination is associated with a 26% lower risk of ICU admission and a 31% lower risk of dying from the flu.

The CDC estimates that during the 2019-20 flu season, flu vaccinations prevented 38 million flu cases, 400,000 hospitalizations and 22,000 deaths.

While September and October are typically “prime time” to get the flu vaccine, but there’s no point when it’s too late to get vaccinated, he said.

“The bottom line is, organizations such as the CDC and the American Heart Association do recommend annual flu vaccinations for individuals older than 6 months, other than some rare exceptions,” Malik said. “So I would definitely recommend getting the vaccine for the flu to protect your heart and limit the spread of infection to other individuals.”

Portions of an American Heart Association News article by Michael Merschel were referenced in this post.