Cardiologist Dr. Thais Coutinho, head of prevention and rehabilitation at the Ottawa Heart Institute, said the findings confirm what previous research has suggested about the link between influenza and heart attacks, but this study found "even a greater magnitude of risk".
The Canadian team looked at almost 20,000 cases of laboratory-confirmed flu infection from 2009 to 2014.
Kwong's team started with almost 20,000 Ontario adults who'd come down with a case of the flu that was confirmed through lab testing.
They found the chance of a heart attack was increased six times during the week after flu infection compared to the year before or after.
He notes that the risk may be higher for older adults, for patients with influenza B infection and for those experiencing their first acute MI.More news: Yes, Get Out Deserves Big Oscar Wins Because It's Black
Researchers at the Institute for Clinical Evaluative Sciences (ICES) have found that the chances of a heart attack increase six-fold during the first seven days after contracting the influenza virus.
He and his Canadian team also found that other respiratory diseases can also increase the chance of a heart attack, but not as almost as dramatically. "People at risk of heart disease should take precautions to prevent respiratory infections, and especially influenza, through measures including vaccinations and handwashing". There was no increase in heart attack risk after the first week of flu illness.
"So all of these things are possibilities through which influenza may lead to a heart attack", she said, adding that the study's findings provide a good opportunity to send the message for people to get the flu shot.
Flu can cause swelling or inflammation in the coronary arteries, which can shake loose plaque and cause blockages, cutting off blood flow. So it's not clear, he noted, whether milder cases would carry the same risk.More news: Violence hits India before release of 'Padmaavat'
"Our findings ... support worldwide guidelines that advocate for influenza immunization in those at high risk of a heart attack", Kwong said.
The flu shot is imperfect: It's no guarantee against infection, and it works better during some flu seasons than others.
People who are at risk for heart disease can include those with high blood pressure, high cholesterol levels, diabetes or obesity, as well as those who smoke, have a family history of heart disease or are age 65 or older, according to the American Heart Association (AHA). "Even if the flu shot isn't flawless, it may protect at least somewhat and the flu could be less severe, although this study didn't address that".
The study was published today (Jan. 24) in the New England Journal of Medicine.
Doctors have long known that flu can trigger heart problems.More news: TheStreet Upgrades Boston Scientific (BSX) to "B"
- Curcumin In Turmeric May Help Boost Memory, Lower Risk Of Developing Alzheimer's
- Miitomo Is Shutting Down In May
- Dems agree to end government shutdown
- Vornado Realty Trust (VNO) Stake Lowered by Duff & Phelps Investment Management Co
- DSW Inc. (NYSE:DSW) - Is The Stock Undervalued?
- Sri Lanka, Singapore Premiers discuss stepping up cooperation through trade, investment
- US Govt. Shuts Down As Trump Talks Tough
- Birch Hill Investment Advisors LLC Reduces Position in Costco Wholesale Co. (COST)
- 'SOTY 2' to release on November 23
- New top prosecutor in court for corruption trial of ex-Cuomo aide