Timely flu shot confers heart benefits too

The study, published in the 'Canadian Medical Association Journal,' found that middle-aged and older adults who got their annual flu shot were less likely to suffer a heart attack in the following year vis-à-vis those who missed out on it.

However, whether a flu shot itself cuts the risk of heart attacks is not known. But researchers believe that it combats the flu infection known to trigger heart attacks in some people.

Details of the study
For the study, British researchers reviewed health records of over 78,000 middle-aged patients, including 16,000 first-time heart attack patients, all hailing from England and Wales.

“The risk of getting a heart attack was reduced by 19 percent for those who had a vaccination in the past year," said A. Niroshan Siriwardena, a professor of primary and pre-hospital health care at the University of Lincoln.

Fifty three percent of the heart attack patients and 51 percent of the non-heart-attack patients (referred to as the control group) had had their annual flu shot.

The health stats of each heart attack patient were matched with four peers from the control group.

Getting a flu vaccination was associated with a 19 percent reduction in the risk of suffering a heart attack in the following year, researchers found.

“The risk of getting a heart attack was reduced by 19 percent for those who had a vaccination in the past year," said A. Niroshan Siriwardena, a professor of primary and pre-hospital health care at the University of Lincoln.

Timing of the shot crucial
Getting a flu shot at fall, from September through mid-November, offers more heart benefits than a shot later in the season, researchers say.

An early vaccine shot offered 21 percent reduction in the odds of suffering a first-time heart attack, as against a 12 percent reduction among those who got their flu shot later in the season.

However, pneumococcal vaccine conferred no such protective benefit, the research team highlighted.

"Our findings reinforce current recommendations for annual influenza vaccination of target groups, with a potential added benefit for prevention of acute myocardial infarction in those without established cardiovascular disease," lead author Siriwardena wrote.

Shortcomings of the study
"This study did not measure risk of heart attack in vaccinated and non-vaccinated people. It measured rates of vaccination among heart attack patients and those without heart attack," said Dr. Kirk Garratt, associate director of the division of cardiac intervention at Lenox Hill Hospital in New York City.

The findings of the study suggest a 19 percent drop in heart attack patients vaccinated in the previous year. This should not be inferred as a “19 percent reduction in heart attacks among the vaccinated”, he stressed.