Simply getting a flu shot can cut a heart failure patient’s risk of death by 50 percent during flu season, according to a meta-analysis that will be presented March 11 at the American College of Cardiology’s (ACC) annual scientific session.

In addition, a flu shot can reduce the risk of all-cause mortality by 20 percent over an entire year for people with heart failure and was associated with a 22 percent reduction in hospitalizations for cardiovascular causes.

Influenza-related complications can worsen acute heart failure episodes and lead to secondary infections such as pneumonia, according to the ACC.

"It is well known that influenza infection is associated with increased risk for mortality in heart failure patients," lead study author Hidekatsu Fukuta, MD, said in a press release. "Given the high mortality rate and the relatively low influenza vaccination rates in heart failure patients worldwide, our study supports a wider use of influenza vaccination in heart failure patients."

The researchers drew their conclusions from six studies encompassing more than 78,000 patients from the U.S., Europe and Asia. Five of the studies were observational while the other was a retrospective analysis of a clinical trial.

Vaccination rates varied from 26 to 86 percent in the studies, representing a missed opportunity for many patients. The ACC said the lack of consistent guideline recommendations across all professional societies may contribute to this variability in vaccinations among this patient population.

Fukuta suggested randomized, controlled studies be undertaken to confirm the researchers’ observational findings, which can’t prove causality.