A Flu Shot for the Heart

Flu vaccine reduced cardiovascular event risk in patients with heart disease

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) The main purpose of the flu vaccine is to protect against influenza. But it may offer other benefits as well.

Because the flu can cause other health problems, the flu shot has been found to indirectly reduce the risk of other conditions and risks.

A recent study found that getting the flu shot reduced the risk of heart attack, stroke and other heart-related events in those patients with increased cardiovascular risk factors.

In fact, for those with one particular heart condition, getting the flu vaccine halved their risk of a serious heart-related event.

Researchers are still trying to learn more about how the flu vaccine may help patients in reducing these and other health risks.

"Ask your doctor about the flu shot."

This study, led by Jacob A. Udell, MD, MPH, of the Women’s College Hospital at the University of Toronto in Canada, aimed to find out whether getting the flu vaccine reduced people's risk of heart attacks and similar events.

The researchers looked through all the studies published in MEDLINE, EMBASE and the Cochrane Library databases to find studies comparing the flu vaccine with a placebo (fake shot) in patients at risk for heart disease.

These researchers identified five published high-quality trials and one unpublished trial that met their criteria. These trials included a total of 6,735 patients.

The patients were 67 years old on average, and just over a third had a history of heart-related conditions. The patients across all the studies had been followed for an average of eight months.

When the researchers compared the results of all the published trials, they found that getting the flu vaccine was linked to a lower risk of a heart-related event such as a heart attack or stroke.

Among the participants who received the flu vaccine, 2.9 percent experienced some kind of cardiovascular event.

Among those who did not receive the vaccine, 4.7 percent experienced a cardiovascular event.

These results did not change much when the researchers added in the data from the unpublished trial.

The researchers calculated that for every 58 individuals who received the vaccine, one person was prevented from having a cardiovascular event.

The participants who were most likely to benefit from the flu vaccine were those who had the highest risk for heart disease, the researchers found.

In fact, getting the flu vaccine cut the risk for cardiovascular events in half for patents with recent acute coronary syndrome.

For every eight patients with recent acute coronary syndrome who received the flu shot, one of them would be prevented from experiencing a cardiovascular event.

This study was published October 22 in the journal JAMA. The research was funded by the Canadian Institutes for Health Research and the Canadian Foundation for Women's Health.

Four of the authors reported having financial ties in some form — through grant funding, speaker's fees, advisory board positions or travel funds — with a variety of pharmaceutical and other industry companies. Among these companies were AstraZeneca, Amarin, Bristol-Myers-Squibb, Medtronic, Eisai, Ethicon, Sanofi-Aventis, FlowCo, PLs Pharma, Takeda, Abbott, Lundbeck, Roche, Sunovion, Eli Lilly, GlaxoSmithKline, Pfizer, Merck, Alnylam, CSL Behring, Lipimediz and Regeneron.

Review Date: 
October 22, 2013
Last Updated:
October 23, 2013