A Jab in the Arm for Heart Health

Flu vaccine reduced heart attack risk

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

(RxWiki News) Most people get the flu vaccine for the obvious reason: to protect them from the flu. But there may be other benefits to the shot as well.

A recent study found that the risk of having a heart attack was about half as likely among patients who got a flu shot compared to those who didn't.

The study's aim was to see if the flu might increase the risk of a heart attack.

But the researchers' main finding was that the flu shot decreased the risk of a heart attack even if the shot's effectiveness was not high.

"Ask your doctor about the flu shot."

This study, led by C. Raina MacIntyre, PhD, of the School of Public Health and Community Medicine at the University of New South Wales in Australia, looked at whether the flu might contribute to heart attacks.

The researchers compared 559 participants aged 40 or older who had gone to a Sydney, Australia hospital between 2008 and 2010.

Of these participants, 275 had experienced an acute heart attack and 284 were a comparison group who had been outpatients at the hospital but had not had a heart attack.

A total of 34 patients with heart attacks, or 12.4 percent, had influenza confirmed with lab tests.

Meanwhile, 19 patients without heart attacks, or 6.7 percent, had influenza.

Therefore, about twice as many of the patients who experienced heart attacks had been sick with the flu.

About half of the total group had been vaccinated against the flu, and none of these patients were among the patients who had the flu.

After the researchers adjusted their calculations to account for other differences among the patients, having had the flu did not appear to contribute to the risk of having a heart attack.

However, having had the flu vaccine did appear to cut the risk of having a heart attack in half, even with a vaccine effectiveness of about 45 percent.

"Our data should inform vaccination policy and cardiologists should be aware of missed opportunities to vaccinate individuals with ischaemic heart disease against influenza," the authors wrote.

The study was published August 21 in the journal Heart.

The research was funded by a grant from GlaxoSmithKline and two fellowships from the Australian National Health and Medical Research Council.

One author has received grants from GSK, CSL, Sanofi Pasteur, Merck and Pfizer. Another author has received grant funds from GSK and Sanofi Pasteur, and a third received grant funds from GSK, CSL and Sanofi Pasteur. No other conflicts of interest were noted.

Review Date: 
August 23, 2013
Last Updated:
August 24, 2013