Only Half of Those with Heart Disease Get a Flu Shot

Chloe Meck

MAY 06, 2021

Findings Sound the Alarm to Improve Influenza Vaccination Rates, and Carry Important Lessons for COVID-19 Immunization Efforts, Researchers Say

Boston – People with heart disease are more likely to become seriously ill from the flu and other respiratory illnesses, including coronavirus. Yet, new research found that only half of Americans with a history of heart disease or stroke report getting an annual flu shot, despite widespread recommendations to do so. Rates of vaccination were even lower among Blacks and Hispanics, according to a study conducted by physician-researchers at Beth Israel Deaconess Medical Center (BIDMC), data from which will be presented at the American College of Cardiology's 70th Annual Scientific Session.

Researchers say the findings should renew efforts to assure flu vaccination is a routine part of quality cardiovascular care.

"As a nation, the U.S. health care system must do a better job protecting a population that is at very high risk for serious complications and death from the flu," said Varayini Pankayatselvan, MD, an internal medicine resident at BIDMC and the study's lead author. "As physicians, it is our job to help patients take these simple but effective preventative measures as well as to determine what the barriers to vaccination are, so we can help our patients get around them."

The study, which used data from the 2018-2019 Behavioral Risk Factor Surveillance System survey conducted by the Centers for Disease Control and Prevention, provides the first real-world look at national flu vaccination patterns in adults with cardiovascular disease. Pankayatselvan said earlier studies in this area have been limited to inpatient samples from hospitalized patients.

A total of 101,210 respondents with a physician diagnosis of heart attack, coronary heart disease or stroke were included in the analysis. They were asked if they got a flu shot "within the past year." Only 50.4 percent of this population reported being up to date with flu vaccination, which is strikingly low given that the American College of Cardiology and other leading health organizations strongly recommend that anyone with cardiovascular disease get a flu shot every year.

Key findings showed no difference in vaccination rates between women and men. People who attended college were more likely to have received a flu shot within the past year when compared with those who had less education. Black and Hispanic adults were about 20 percent less likely to report getting a flu vaccine compared with whites.

"We haven't made much progress when it comes to closing persistent vaccination gaps among racial and ethnic groups, and preliminary data on COVID-19 vaccination also points to disparities still being an issue, which is concerning," Pankayatselvan said, adding that people with cardiovascular disease are also being urged to get the COVID-19 vaccine. "We need more research to better understand vaccine reluctance, inequities in access to vaccines, as well as the value of seeking out community partnerships to improve vaccinations across the board."

Patients with chronic obstructive pulmonary disease, chronic kidney disease and diabetes were significantly more likely to have gotten a flu shot. Pankayatselvan said this suggests these patients may have more routine access to providers who administer the flu vaccine in their office; earlier studies have shown that compared with pulmonary and endocrinology practices, cardiology offices are much less likely to have the flu vaccine on-site. Additionally, when people think of the flu or COVID-19, they more readily think of lung issues, even though these infections can cause heart troubles too. These infections can place added stress on the body and heart by quickening heart rate, ramping up the body's fight or flight response and triggering inflammation.

"Next time you see a doctor—any doctor—ask about getting your flu shot. Your physician can answer any questions you have and help you make a plan to get it every year," Pankayatselvan said. "It's an easy, fast and safe way to prevent a lot of potential complications including severe illness, pneumonia, heart attacks, heart failure, hospitalization and even death."

There are other benefits too, Pankayatselvan added. "We know that getting the flu shot may be a cardioprotective measure for hospitalized patients with influenza. Previous research has shown that, among hospitalized patients with influenza, the flu vaccine is linked to a lower risk of acute heart failure and acute ischemic heart disease. Additionally, some research indicates the protective effect of getting the flu vaccine may be similar to smoking cessation and some heart medications."

Getting a flu shot also prevents people from transmitting the flu to others, something researchers are hoping will prove true for the COVID-19 vaccine too.

This study is limited in that it relies on people's recollection of getting a flu shot. It also only gives a snapshot of vaccination patterns in 2018-2019; more research needs to be conducted to determine whether the threat of COVID-19 may have prompted more people with heart disease to get vaccinated against the flu.

Pankayatselvan will present the study, "Influenza Vaccination Among Patients with Cardiovascular Disease in the United States," on Monday, May 17, at 12:00 pm ET / 16:00 UTC.

This work was supported in part by the National Institute on Aging (K24AG065525).

The authors declare no competing interests.

Editor's note: This release is adapted from a press release issued by the American College of Cardiology.

About Beth Israel Deaconess Medical Center

Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School and consistently ranks as a national leader among independent hospitals in National Institutes of Health funding. BIDMC is the official hospital of the Boston Red Sox.

Beth Israel Deaconess Medical Center is a part of Beth Israel Lahey Health, a health care system that brings together academic medical centers and teaching hospitals, community and specialty hospitals, more than 4,800 physicians and 36,000 employees in a shared mission to expand access to great care and advance the science and practice of medicine through groundbreaking research and education.