
Acute Myocardial Infarction after Laboratory-Confirmed Influenza Infection - Ice_cream_suit
http://www.nejm.org/doi/full/10.1056/NEJMoa1702090?query=featured_home
======
misnome
I can't get to the full article here, but naively, I'd expect "Illness
increasing stress on the bodily systems increases likelihood of heart attack"
to be the unsurprising result. Is there some other reason that we'd expect
this not to be the case? Are there other infections as agressive that don't
increase the risk in similar ways? Or did we just suspect this and haven't had
the data to back it up before?

i.e. I'm not sure why this is interesting or revelatory? The free summary
doesn't seem to answer this.

~~~
rrmm
The first mechanism I could think of would be via inflammatory response.

Here's an article from 2009 in the Lancet which performs a meta-analysis.

[http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.490...](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.490.1869&rep=rep1&type=pdf)

In their discussion they say:

Influenza might act as an acute inflammatory and procoagulant stimulus
transiently altering endothelial function. 58,59 Recent experimental studies
in mice have explored the links between influenza infection and coronary
artery remodelling. In one study, 60 inoculation of influenza A virus into a
mouse atherosclerosis model of mice deficient in apolipoprotein E resulted in
heavy infiltration of atherosclerotic plaques by inflammatory cells, as well
as platelet aggregation and thrombosis— only the plaques and not normal
sections of coronary arteries were disrupted. Evidence of influenza virus RNA
has been found in human atherosclerotic plaques, although it is not known if
this is clinically important. 61 Another study 62 revealed that infectious
burden (measured by the presence of antibodies to influenza, hepatitis A
virus, Chlamydophila pneumoniae , Helicobacter pylori, and cytomegalovirus in
serum) was independently associated with angiographically-proven
atherosclerosis.

------
nradov
Another good reason to get a flu vaccine every year. Although it isn't
completely effective it improves your odds.

[https://www.cdc.gov/flu/prevent/index.html](https://www.cdc.gov/flu/prevent/index.html)

------
Ice_cream_suit
"CONCLUSIONS We found a significant association between respiratory
infections, especially influenza, and acute myocardial infarction.

RESULTS We identified 364 hospitalizations for acute myocardial infarction
that occurred within 1 year before and 1 year after a positive test result for
influenza. Of these, 20 (20.0 admissions per week) occurred during the risk
interval and 344 (3.3 admissions per week) occurred during the control
interval. The incidence ratio of an admission for acute myocardial infarction
during the risk interval as compared with the control interval was 6.05 (95%
confidence interval [CI], 3.86 to 9.50). No increased incidence was observed
after day 7. Incidence ratios for acute myocardial infarction within 7 days
after detection of influenza B, influenza A, respiratory syncytial virus, and
other viruses were 10.11 (95% CI, 4.37 to 23.38), 5.17 (95% CI, 3.02 to 8.84),
3.51 (95% CI, 1.11 to 11.12), and 2.77 (95% CI, 1.23 to 6.24), respectively."

~~~
JoeAltmaier
Help me understand these 'incidence ratios'. Does this mean the chance of
heart problems in the first week after influenza ranges from 3X to 10X the
nominal rate for heart problems?

------
lawlessone
I presume this was already suspected? The last time i had a virus i was warned
by a doctor not to use gym for a while as it could cause heart problems.

~~~
manmal
I once had the flu so bad that I could barely climb a couple of stairs without
losing my breath. My heart was beating very hard afterwards.. I remember
thinking to myself „Ok this is dangerous, I better lie down“, and I bet it
was.

~~~
lawlessone
I had a viral chest infection once, a good bit of coughing but i was apart
from that feeling fine, so i wanted to go back to them but was told not to.

------
jnordwick
> We identified 364 hospitalizations for acute myocardial infarction that
> occurred within 1 year before and 1 year after a positive test result for
> influenza.

Can somebody explain why they looked at hospitalizations for MI before having
the flu as well as after? if the theory is that the flu causes heart issues
why wouldn't they just look at MIs after hospitalizations?It seems to remove
any explanatory ability.

~~~
nonbel
Look at fig 1. They compared the number of people who had heart attacks from 1
-7 days after getting a positive lab test for influenza, and people who got
heart attacks at any other time +/\- 1 yr of the positive lab test.

They saw that out of these people who had both a positive flu test and heart
attack, there were more heart attacks in the 7 days subsequent to the positive
lab test than at 8+ days after or beforehand.

That abrupt cutoff at 7 days makes it sound like these people were being
advised some kind of treatment that was increasing heart attack risk. This was
in Ontario... they advise:

> _" -stay home and get plenty of rest

-drink lots of fluids

-avoid caffeine

-speak to your doctor or nurse practitioner about over-the-counter medications that can help you feel better (basic pain or fever relievers), but do not give acetylsalicylic acid (ASA or Aspirin®) to children or teenagers under the age of 18

-treat muscle pain using a hot water bottle or heating pad — apply heat for short periods of time

-take a warm bath

-gargle with a glass of warm salt water or suck on hard candy or lozenges

-use spray or saline drops for a stuffy nose

-avoid alcohol and tobacco"_

[https://www.ontario.ca/page/flu-
facts#section-4](https://www.ontario.ca/page/flu-facts#section-4)

My first guess would be ibuprofin:
[https://en.wikipedia.org/wiki/Ibuprofen#Cardiovascular_risk](https://en.wikipedia.org/wiki/Ibuprofen#Cardiovascular_risk)

EDIT:

More on the NSAID possibility (apparently it is not supposed to only be
chronic use):

 _" Taking any dose of NSAIDs for one week, one month, or more than a month
was associated with an increased risk of myocardial infarction."_
[http://www.bmj.com/content/357/bmj.j1909](http://www.bmj.com/content/357/bmj.j1909)

~~~
jnordwick
> Look at fig 1. They compared the number of people who had heart attacks from
> 1 -7 days after getting a positive lab test for influenza, and people who
> got heart attacks at any other time +/\- 1 yr of the positive lab test.

That makes total sense. Was there a link to the actual paper? Its really hard
to understand these abstracts or have any meaningful discussion without it,
sadly.

> That abrupt cutoff at 7 days makes it sound like these people were being
> advised some kind of treatment that was increasing heart attack risk.

It would have been nice to a group that had the flu but didn't have any of the
standard treatments to see how they compared to the flu group with treatments
because their test group seems like more than just the flu. Could you have a
group too that did the treatments without the flu? That would seem a little
unethical though ("here do this - we have this theory that you'll have a heart
attack")

All said, for those of you that have actually had influenza as an adult, a
death actually sounds preferable.

~~~
nonbel
> _" Was there a link to the actual paper?"_

The title link goes to the paper. It only shows the abstract by defualt
though. You need to get access to it to read the rest. Perhaps someone else
can help you there.

> _" It would have been nice to a group that had the flu but didn't have any
> of the standard treatments to see how they compared to the flu group with
> treatments because their test group seems like more than just the flu."_

It didn't look like they reported what treatments were involved, but I only
glanced at the paper. It is possible they had this data and missed/ignored it
though.

> "Could you have a group too that did the treatments without the flu?"

I'm sure there are many people on NSAIDs for headaches and such that could be
included. The dosage regimen is probably important though. Eg, suddenly start
taking them for a week then stop, etc.

> _" All said, for those of you that have actually had influenza as an adult,
> a death actually sounds preferable."_

This seems a little strong. I haven't heard before that people consider the
flu to be worse than death...

------
vannevar
I wonder what the AMI risk is for people in respiratory distress in general,
and whether the flu risk is distinguishable.

------
tremendulo
Assuming you've already _caught_ the flu, what are some ways you can reduce
the risk to the heart?

~~~
AstralStorm
As with any infarctions. Take a clotting reducing agent. Non-aspirin anti-
inflammatory should do the trick. (Prostaglandin system is fun.) Aspirin is ok
too if you can live with the tiny risk of Reye's syndrome.

Disclaimer: not an MD.

~~~
nonbel
No, NSAIDs are actually supposed _increase_ the risk of heart attacks. See the
second source in my other post:

"It is generally accepted that oral non-steroidal anti-inflammatory drugs
(NSAIDs) can increase the risk of acute myocardial infarction."
[https://news.ycombinator.com/item?id=16239642](https://news.ycombinator.com/item?id=16239642)

Why would you tell someone that?

~~~
35bge57dtjku
> Why would you tell someone that?

Because there was a huge study that indicated aspirin should be used as a
minor blood thinner and reduced heart attacks, and because most/a lot of
doctors recommend it for such.

~~~
nonbel
I don't follow your point:

>" _aspirin_ should be used as a minor blood thinner and reduced heart
attacks"

>" _Non-aspirin_ anti-inflammatory should do the trick"

~~~
35bge57dtjku
> I don't follow your point

You appeared confused as to why someone would say what they'd said. I pointed
out one of the glaringly obvious reasons why someone could have done that. And
there's also the fact that the study cited is fairly recent and news doesn't
spread instantly...

~~~
nonbel
Can you acknowledge that you realize the parent specifically said "non-
aspirin", and everything you are talking about is regarding aspirin? It isn't
clear to me that you realize this.

Also, the cardiovascular issues in question are not something recent. They
were already widely reported in 2005 to the point the FDA commented:

> _" Back in 2005, the FDA warned that taking nonsteroidal anti-inflammatory
> drugs (NSAIDs) like ibuprofen and naproxen increased the risk of having a
> heart attack or stroke."_ [https://www.health.harvard.edu/blog/fda-
> strengthens-warning-...](https://www.health.harvard.edu/blog/fda-
> strengthens-warning-that-nsaids-increase-heart-attack-and-stroke-
> risk-201507138138)

I asked that question because the advice was so opposite the usual, and the
tone so playful ("Prostaglandin system is fun"), that it almost seemed to be a
troll who had gone too far.

~~~
35bge57dtjku
Are there really no sources that state that things other than aspirin inhibit
platelet aggregation?

~~~
nonbel
1) I've read enough biomedical literature to know there is a source claiming
just about anything you can think of. So regardless of what you mean, my
answer is: "there is at least one such source".

2) Why is your question so loosely connected to the topic? Why say "things"
instead of "non-aspirin NSAIDs", and "inhibit platelet aggregation" instead of
"reduce risk of heart attack"?

3) If you are thinking of a particular paper, why not just say it?

But ok, I am probably being trolled at this point.

~~~
35bge57dtjku
> I've read enough biomedical literature to know there is a source claiming
> just about anything you can think of

Then as I initially said, it _really_ shouldn't be hard for you to imagine why
someone would give the advice that the original person gave. This really isn't
a difficult concept, yet you still act perplexed by it...

> Why is your question so loosely connected to the topic? Why say "things"
> instead of "non-aspirin NSAIDs", and "inhibit platelet aggregation" instead
> of "reduce risk of heart attack"?

Because I was hoping you were capable of following the thread. And because the
specific things arn't all that important to whether or not one should be able
to think of a reason why that piece of advice was given.

> If you are thinking of a particular paper, why not just say it?

Because if you're not just here to whine about being trolled, you can easily
find it with Google.

------
monkmartinez
Age? Hx of cardiac problems? These would be good to know, but I assume they
were controlled for.

