People with heart failure who get flu shots may be less likely to die prematurely than their counterparts who don’t get vaccinated, a Danish study suggests.
Researchers followed more than 134,000 patients with heart failure between 2003 and 2015, with half the patients staying in the study for at least 3.7 years. Overall, getting at least one flu shot was associated with an 18 percent lower risk of premature death from all causes and from cardiovascular problems in particular.
“We also found that annual vaccination frequency and vaccination early in the season were associated with greater reductions in the risk of death,” lead study author Daniel Modin of Gentofte University Hospital and the University of Copenhagen.
“We already knew that influenza vaccination benefits the population as a whole, but our study adds support to the importance of influenza vaccination in patients with heart failure, and it also suggests that annual and consistent vaccination is important in this patient group,” Modin said by email.
Infections like the flu increase the body’s demand for energy, requiring the heart to pump harder. Failing hearts may not be able to do this, increasing the risk of serious flu complications like pneumonia.
Previous research also suggests that influenza may play a role in triggering blood clots and heart attacks.
During the study, almost 78,000 people died from all causes, including about 48,000 who died of cardiovascular causes.
Annual flu vaccination rates ranged from a low of 16 percent in 2003 to a high of 54 percent in 2009.