Flu Vaccine Cuts Risk of Heart Attack in Following Year by 34 Per Cent

A new meta-analysis published today in the JAMA Network Open shows a strong association between the seasonal flu vaccine and a reduction in adverse cardiovascular outcomes within a year of follow up, particularly for high-risk patients. This is the strongest evidence to date that influenza vaccines are a key measure in the prevention of cardiovascular events, such as heart attacks.

While we were already aware of this protective association, our previous systemic review and meta-analysis underscored the need for a large scale, adequately powered, and ideally global clinical trial to provide more robust and comprehensive data,” explained Bahar Behrouzi, MD and PhD candidate at the University of Toronto and lead author. “This study looked at randomized controlled trials from 2000-2021 that compared the influenza vaccine with either a placebo or control, in order to assess its impact on fatal and non-fatal cardiovascular events over the course of a year.

The researchers found that 3.6 per cent of the 4,510 clinical trial participants who received a flu vaccine experienced a major cardiovascular event afterwards in the following year, compared with 5.4 per cent of the 4,491 patients who received a placebo or control, which is a significant difference.

Given the pervasive nature of heart disease globally, it is critical that we leverage as many preventative clinical tools and treatments as possible to improve patient outcomes,” said Dr. Jay Udell, cardiologist at Women’s College Hospital and the Peter Munk Cardiac Centre at UHN, scientist at the Women’s College Research Institute, and senior author. “The effect sizes witnessed so far with the flu vaccine are comparable to other common preventative measures such as statins and beta blockers. Our work underscores the value of utilizing influenza vaccines as a mainstay in cardiovascular disease prevention.”

In light of the evidence, the authors advise clinicians to encourage their patients, particularly those with high cardiovascular risk, to get their annual flu shot, an intervention that remains underutilized despite being low cost, well tolerated, and impactful.

Applying our findings more broadly, our study highlights the additional or secondary benefits often associated with vaccinations,” Udell stated. “In the current context of the COVID-19 pandemic and ongoing vaccine hesitancy, we are hopeful that our results highlight the positive ancillary benefits of vaccinations – providing greater motivation and encouragement for those who remain uncertain.”

Source: https://jamanetwork.com/
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