"Vaccination is safe, cheap, readily available and decreases influenza infection. On top of that, our study suggests that it could also protect against fatal heart attacks and strokes and deaths from other causes," said study first author Daniel Modin from the University of Copenhagen in Denmark.
The study used Danish nationwide healthcare registers to identify 608,452 patients aged 18 to 100 years with hypertension during nine consecutive influenza seasons (2007-2016).
The researchers followed patients over each season and tracked how many died.
In particular, they recorded death from all causes such as cardiovascular, heart attack or stroke.
Finally, they analysed the association between receiving a vaccine before flu season and the risk of death during flu season.
The analysis controlled for patient characteristics that could impact the likelihood of dying such as age, comorbidities, medications, and socioeconomic status.
After adjusting for patient differences, in a given influenza season, vaccination was associated with 18 per cent relative reduction in the risk of dying from all causes, 16 per cent relative reduction in the risk of dying from any cardiovascular cause, and 10 per cent from a heart attack or stroke.
The study shows that influenza vaccination may improve cardiovascular outcomes in patients with hypertension.
Regarding how flu and cardiovascular disease might be connected, the researchers noted that when the influenza virus infects the body, it triggers a strong immune reaction and subsequent inflammation.
These responses fight the infection and clear the virus from the body.
( With inputs from IANS )