Sections

Services

Information

UK United Kingdom

Flu jab may halve heart attack risk: study

Receiving the flu vaccine may almost halve the chance of a heart attack for middle-aged people with narrow arteries, a new…

Getting the flu vaccine may almost halve the chance of a heart attack for middle-aged people with narrow arteries, the study found. Province of British Columbia

Receiving the flu vaccine may almost halve the chance of a heart attack for middle-aged people with narrow arteries, a new study by Australian researchers has found.

Heart disease kills and disables more Australians than any other disease.

The authors of the research, published in the journal Heart, suggest policy makers should consider this new evidence in any decisions around extending the age cut-off for vaccination.

People aged between 50 and 64 are not always included in routine vaccination programs in Australia and the UK.

Before the risk of cardiovascular illness was considered, the benefits of including younger age groups into flu vaccine programs had been judged not to be worth the cost.

The authors of the study looked at 559 patients over the age of 40 who were referred to a Sydney hospital during the winter months of 2008 to 2010.

Those who were not vaccinated for flu were almost twice as likely as vaccinated subjects to have a heart attack.

The researchers also found that a recent respiratory infection was more common among those patients who had suffered a heart attack.

“The potential population health impact of influenza vaccination, particularly in the age group 50–64 years, who are at risk for acute myocardial infarction (heart attack) but not targeted for vaccination, should be further explored,” the researchers concluded.

“Our data should inform vaccination policy and cardiologists should be aware of missed opportunities to vaccinate individuals with ischaemic heart disease (coronary heart disease) against influenza.”

Professor Raina MacIntyre, a lead author of the study, said almost 10% of people admitted to hospital with heart attack had flu.

“This suggests that it is a precipitant of a heart attack,” she said.

“Inflammation of any kind makes the blood more prone to clotting.”

Minimising risk

Julie Redfern, Senior Research Fellow, Cardiovascular Division at George Institute for Global Health welcomed the finding.

“Prevention of heart attacks and cardiovascular disease is a national health priority. Improving risk factors and implementing other simple measures aimed at preventing heart attacks and reducing the burden of disease are of great importance,” said Dr Redfern, who was not involved in the study.

“The potential of this study, after further research, that found a benefit of the flu vaccination on heart disease risk is important and could be one strategy that help minimise future heart risk.”

Garry Jennings, Director and CEO, Cardiologist at Baker IDI Heart and Diabetes Institute said the researchers had made a very interesting finding.

“It is not possible to say whether the flu vaccination was protective or whether people who have flu injections have other characteristics that lower their risk of heart attack. There is some support for the latter in that flu itself did not seem to increase the risk but people who had flu vaccination had lower risk,” said Dr Jennings, who was also not involved in the study.

“As the authors point out, this is cause for further investigation, particularly as there are some theoretical links related to inflammation that might have a role in the timing of a heart attack.”

Sign in to Favourite

Join the conversation

24 Comments sorted by

  1. Laurie Willberg

    Journalist

    "Of 559 participants, 34/275 (12.4%) cases and 19/284 (6.7%) controls had influenza (OR 1.97, 95% CI 1.09 to 3.54); half were vaccinated. None were recognised as having influenza during their clinical encounter. After adjustment, influenza infection was no longer a significant predictor of recent AMI. However, influenza vaccination was significantly protective (OR 0.55, 95% CI 0.35 to 0.85), with a vaccine effectiveness of 45% (95% CI 15% to 65%)."
    Talk about juggling statistics... There's absolutely no evidence that flu shots prevent heart attacks and certainly none that they prevent flu.

    report
    1. Hugh McColl

      Geographer

      In reply to Laurie Willberg

      Laurie, you talk about juggled statistics but I'm still sorting the English language. I'm sure I read, in the para you quoted there, that 12.4% of cases and 6.7% of controls, HAD influenza..... but that "None was recognised as having influenza during their clinical encounter". Does this mean that influenza wasn't detected at the time but turned up later?
      However, I think you need to explain yourself in regard to your final sentence. They say the vaccine is "significantly protective" and has (by some measure) "vaccine effectiveness", but you suggest there's no evidence flu shots prevent flu. Do you, being a 'journalist', know anything or just about everything about statistics?

      report
    2. Mark Amey

      logged in via Facebook

      In reply to Laurie Willberg

      'However, influenza vaccination was significantly protective (OR 0.55, 95% CI 0.35 to 0.85), with a vaccine effectiveness of 45% (95% CI 15% to 65%).' You do realise that this means that about half of those who received the influnza vaccine suffered MIs...hardly 'juggling statistics!

      report
    3. Laurie Willberg

      Journalist

      In reply to Mark Amey

      It was an observational study (not randomized) involving a small number of participants. The Cochrane Collaboration has repeatedly shown that flu shots are not effective at preventing flu, and could actually cause or exacerbate the inflammation referred to in the study.
      So I'll just use the skeptic's toolbox and state that correlation is not causation.
      Mainstream medicine is light years away from preventive health care -- it's still focussed on sick care and failing miserably.
      This "study" is just another excuse to shill vaccines that are generally useless and being rejected by the public in increasing numbers.

      report
    4. Mark Amey

      logged in via Facebook

      In reply to Laurie Willberg

      'It was an observational study (not randomized) involving a small number of participants. ' Unlike anything from your homeopathy pals. At least this one had an Odds ratio...I thought that was your favourite statistical 'method'.

      'Mainstream medicine is light years away from preventive health care..' Yes, I guess the eradication of polio, tetanus, diphtheria, etc, were just pipe-dreams.

      report
    5. Laurie Willberg

      Journalist

      In reply to Mark Amey

      Kindly prove that vaccines eradicated polio, tetanus and diphtheria. Where are the randomized controlled studies? Where's the evidence besides an industry taking credit? The claim is based on correlation.
      The biggest epidemic of polio in the world right now is in India/Pakistan and the cause was the vaccine.

      report
    6. Mark Amey

      logged in via Facebook

      In reply to Laurie Willberg

      'The biggest epidemic of polio in the world right now is in India/Pakistan and the cause was the vaccine. ' Yes, ten (10) children: http://www.npr.org/blogs/health/2012/12/04/166486379/a-polio-outbreak-in-pakistan-reveals-gaps-in-vaccination, and: http://www.who.int/features/qa/64/en/index.html. This 'epidemic' is from lack of immunisation.

      'Where are the randomized controlled studies? ' Many, like this one: BMJ, 786, SEPT. 23, 1961 are old, and hard to find, but, given time, and a little bit od effort, I'm sure that a Journalist, like you, should be able to find something1

      report
    7. Laurie Willberg

      Journalist

      In reply to Mark Amey

      Wrong. There have been thousands of cases of what's now called Acute Flaccid Paralysis caused by the oral polio vaccine. You can look it up.
      There have been no randomized controlled studies on any vaccines involving vaccinated vs. unvaccinated actually exposed to any disease.

      report
    8. Sue Ieraci

      Public hospital clinician

      In reply to Mark Amey

      Yet again, Laurie Willberg repeats old anti-vaxer lines.

      Firstly, acute flaccid paralysis is a phenomenon that is found in a range of illnesses - of which polio is only one infective cause.

      Secondly, the fact that the only few cases of polio appearing in impoverished communities are the rare cases caused by the oral vaccine speaks volumes: prior to vaccination, polio cases were no news story. When those communities can afford injectable vaccine, polio will essentially vanish.

      report
    9. Laurie Willberg

      Journalist

      In reply to Sue Ieraci

      Yet again Sue Ieraci misrepresents information as a mouthpiece for the vaccine industry. The polio vaccine is currently THE major vector for AFP and the Indian government has had the honesty to admit it.
      It's rather infantile to think that using that childish label "anti-vaxer" does anything to substantiate one's opinions. Labels are the refuge of those who are incapable of engaging in honest consideration of the issues.

      report
    10. Mark Amey

      logged in via Facebook

      In reply to Laurie Willberg

      Laurie Willberg, neither Sue, or I are 'mouthpieces for the vaccine industry', we are both clinicians, who are have cared for patients suffering from vaccine preventable diseases, and are both capable of understanding epidemiology. I would urge you, again, to examine: http://www.who.int/features/qa/64/en/index.html. It has long been observed that very occasional patients ( or relatives) may suffer some mild symptoms, i.e. acute flaccid paralysis, in the case of the polio immunisation, of the disease, where an attenuated virus has been used. No one is denying this, but these people are no where near as ill as those infected by wild-type polio.

      If you don't like the term 'anti-vaxers', what would you like to be called 'vaccine deniers'?

      report
    11. Laurie Willberg

      Journalist

      In reply to Mark Amey

      You seem to be in denial that vaccines have adverse effects or that with a good dose of PR they can be swept under the rug. The vast majority of people line up because of what's called "social norming", which is a phenomena that takes place when a particular behaviour becomes commonplace. Most people don't get vaccines because they've studied epidemiology. In fact, the vaccine manufacturers would rather stifle ANY negative information. This is not a "conspiracy theory" as Sue opines, it's a motive that's not difficult to comprehend.
      There is substantial debate about issues surrounding vaccination and your (and Sue's) attitude is that this debate should become a taboo subject. Good luck with that.

      report
    12. Mark Amey

      logged in via Facebook

      In reply to Laurie Willberg

      'There is substantial debate about issues surrounding vaccination and your (and Sue's) attitude is that this debate should become a taboo subject' No, we would like to some some informed debate, unlike most of what you post here.

      report
    13. Laurie Willberg

      Journalist

      In reply to Mark Amey

      So now you think you're going to arbitrate what's "informed" are you?
      There's that "we" again... you seem to be stuck in that labelling mode of "us" versus "them".

      report
    14. Mark Amey

      logged in via Facebook

      In reply to Laurie Willberg

      ' you seem to be stuck in that labelling mode of "us" versus "them".'

      OK, I give up, it's us vs them. the informed vs the ill-informed. You keep harping on about 'no-one's every done a proper RCT on immunisation, then someone gives an example, then you ignore it. It's like talking to a four year old!

      report
    15. Sue Ieraci

      Public hospital clinician

      In reply to Laurie Willberg

      Laurie Willberg may reject the label, but his/her arguments are straight out of the anti-vaxer's handbook.

      Let's take a quick look:

      Page 3:
      ''Claim that all health care professionals who work in public hospitals and care for sick children are part of a world-wide conspiracy.''

      Page 4:
      "Deny that you are a conspiracy theorist"

      Page 13:
      ''Claim that Big Pharma is evil and greedy while supporting Big Tincture to sell little bottles of water or sugar pills at hugely inflated prices.''

      Page 15:
      "Allege that people who understand the benefits of vaccines, and manufacturers of vaccines, are in complete denial of any adverse effects, in spite of the product inserts, research papers and government information sources.''

      Page 23:
      ''No matter what anyone else tells you, block your ears and NEVER EVER give up.''

      report
    16. Laurie Willberg

      Journalist

      In reply to Sue Ieraci

      Still persisting with the labels and a work of fiction to support it. Then again, propaganda is generally quite transparent.

      report
  2. Darron Wolf
    Darron Wolf is a Friend of The Conversation.

    Analyst

    Thank you, all involved, for an interesting and intriguing article. Clearly there is a real argument for further investigation and it will be interesting to see where the evidence & science takes us (as opposed to where the denial of evidence & science would take us).

    report
  3. Ulf Steinvorth

    Doctor

    The study's objective and subsequent design was 'to investigate whether influenza is a significant and unrecognised underlying precipitant of AMI'.

    In this study it was not and even though additional results seem to indicate a statistically relevant correlation (not causation!) between flu vaccination and reduced risk of MI this study was not designed to show whether or not vaccination is protective.

    Retrospective subclass analysis of results when the main issues are not conclusive is questionable at best of times. With the research financed by a company that produces one of the major flu-vaccinations and three of the authors having affiliations with that same company I think some vigilance prior to making recommendations is appropriate.

    report
  4. Darron Wolf
    Darron Wolf is a Friend of The Conversation.

    Analyst

    I have read and reread this string several times but could not bring myself to respond without rancour and disgust to some of the contributions until this morning.

    Medicine (epidemiology), mathematics (statistics) and logic (correlation and causation) are evidence & science based intellectual pursuits.

    On this matter, the effect of Influenza vaccination on heart attacks, it is sensible (to this reader) to apply those disciplines to the question.

    It may be that the evidence for causation…

    Read more