HealthDay Reporter
A heart attack is six times more likely in the week after a person is diagnosed with flu than in the year before or after, according to Dutch researchers.
This emphasizes the need for flu patients and those caring for them to be aware of heart attack symptoms. It also underscores the importance of getting a flu shot, the authors said.
The findings are scheduled to be presented April 18 at a meeting of the European Congress of Clinical Microbiology and Infectious Diseases, online and in Copenhagen, Denmark.
“With the potential public health implications of an association between influenza virus infection and acute heart attacks, showing robustness of results in a different study population is important,” said researcher Annemarijn de Boer, of the Julius Center for Life Sciences and Primary Care at UMC Utrecht in the Netherlands.
While the findings don’t make it clear whether those with less severe flu are also at risk, de Boer said they should also be aware of the link.
While the connection between flu and heart attacks was also made in a 2018 Canadian study, it included only hospitalized people and not those who died of heart attacks elsewhere.
In this study, researchers relied on test results from 16 laboratories, covering around 40% of the Dutch population, along with death and hospital records.
More than 26,000 cases of influenza were confirmed by the labs between 2008 and 2019.
The researchers found that 401 individuals had at least one heart attack within a year of their flu diagnosis, with a total of 419 heart attacks.
Of the 419 heart attacks, 25 were in the first seven days after flu diagnosis; 217 in the year before diagnosis; and 177 in the year after flu diagnosis but not including the first seven days.
The researchers calculated that the individuals studied were 6.16 times more likely to have a heart attack in the week following a flu diagnosis than in the year before or after. The Canadian study found they were 6.05 times more likely to have a heart attack in those seven days.
Excluding data from death records, as in the Canadian study, reduced the increase in heart attack risk in the first week to 2.42 times. Dutch researchers said this underscores the impact of incomplete data on study findings.
Researchers also said that differences in testing practices in the two countries may help explain the differences. It’s less common to test for flu outside the hospital in the Netherlands than it is in Canada, according to researchers.
The Dutch researchers said the association is still significant and that they were able to confirm that the increase in risk applies across different populations.
Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.
More information
UCLA Health has more on the connections between heart disease and flu.
SOURCE: European Congress of Clinical Microbiology and Infectious Diseases, news release, March 28, 2023
