The news about flu this season just keeps getting worse. Not only has this been a really bad influenza season by most accounts, but a newly published study now adds a lot more evidence to the notion that flu also raises the risk of heart attacks — a life-threatening connection that was long suspected but never proven.
The study by Canadian researchers, published this week in the New England Journal of Medicine, examined test results from nearly 20,000 adults in Ontario with lab-confirmed flu between 2009 and 2014, and matched them to hospital records.
That allowed them to see which patients with lab-confirmed flu had heart attacks. They found patients were six-times more likely to suffer a heart attack the week after getting the flu.
“Our findings, combined with previous evidence that influenza vaccination reduces cardiovascular events and mortality, support international guidelines that advocate for influenza immunization in those at high risk of a heart attack,” Dr. Jeff Kwong, lead author of the study, said in a written statement.
Dr. Jason Bowling, an infectious disease specialist with UT Health San Antonio and staff epidemiologist at University Health System — who wasn’t involved in the study — said it underscores how serious influenza can be, and why people should take it seriously.
“This is an important study because it reinforces the concern that influenza infection exacerbates underlying medical problems like heart disease, which means it has multiple additional ways of harming people than just the infection alone,” Dr. Bowling said. “In addition to getting the flu vaccine, it is important that people do the important day-to-day recommended care for their medical problems like hypertension and diabetes, which are risk factors for heart disease.”
Flu is the most serious of cold-weather respiratory illnesses. New estimates released last month show that flu kills between 292,000 and 649,000 people around the world each year, more than was previously thought. And even though this year’s flu shot wasn’t a good match to the predominant strain of A-H3N2 circulating, Dr. Bowling and other experts say it’s the best protection available — perhaps lessoning symptoms if not preventing them.
Here’s more good flu advice from the CDC.