A new study, published in the Journal of the American Medical Association, reveals that receiving the influenza vaccination is associated with a lower risk of major adverse cardiovascular events.  This research builds on existing literature that recent flu or flu-like infections are associated with fatal and nonfatal cardiovascular events.  Using a systematic review and meta-analysis of from 1946 to 2013, the study extracted data on the correlation between influenza and heart disease.  Focusing on six randomized clinical trials, they found that the influenza vaccine was significantly associated with a lower risk of composite cardiovascular events.  There was a treatment interaction was detected between patients with and without recent acute coronary syndrome.

In an analysis of the study, WebMD reports that people with recent heart problems who got the flu vaccine were 55 percent less likely to have another event compared to those who didn’t get the vaccine.  Also, the risk of dying from cardiovascular disease was nearly 20 percent lower for those who received the flu vaccine versus those who had not.  Overall, people in the study who got flu shots were one-third less likely to have heart issues, such as heart failure or a heart attack, compared to those who opted against vaccination. The flu shot was associated with an even greater reduction of heart problems if someone had heart disease to start with.

One explanation for the relationship is that the flu triggers an inflammatory response.  That inflammation can cause plaques in the arteries to erupt, resulting in a major adverse cardiovascular event.  Unfortunately, the study was not designed to show a causal link that the vaccine lowers heart disease risk.  However, these findings are one step closer to showing that relationship and follow-up research would need a clinical trial to confirm the causation.

According to the Centers for Disease Control and Prevention (CDC), seasonal influenza is a viral, contagious, respiratory illness.  Certain populations, such as the elderly, young children, and those with compromised immune systems, are more at risk for contracting the virus.  The illness ranges in severity, but certain health conditions can complicate the virus, and there is a small risk of death.  Every year, about 20 percent of Americans get the flu and more than 200,000 are hospitalized.  Anywhere from 3,000 to 49,000 deaths can be attributed to the flu.

The flu vaccine is currently recommended for everyone over 6 months of age in the United States, according to the CDC. The vaccine is highly recommended for certain groups, including people with heart disease.