What's up with all these studies that show an improvement in heart attack and
stroke rate but really not much improvement on all-cause mortality?
Oh - again, what's up with that? What good does it do if you get saved
from a heart attack or stroke but you die from something else? We're going to
talk about that in this video. That - it's maybe not as bad as it might seem but
first a couple of quick introductions. The first is myself. My name is Ford
Brewer. I started off as an ER Doc; got very focused on helping people prevent
the things that bring them into the ER; went to Hopkins; got training in it; loved
it; ended up running the program there; and I've spent the past - even after I
left - spent the past 30 years or more helping Docs - over a thousand Docs; and
I don't know how many patients, prevent disease rather than waiting for a
disease to happen and hoping for a cure. You may see some of the faces and names
in the background here and you realize that there's no cure for death and they
cure for a non-fatal heart attack or stroke is not so pretty either. So that's
one point. Let me just bring up one other introductory point and we'll get to the
topic. The other introductory point is - if you haven't been to our forum, John Lorsch-
-eider runs it. You really should take a look. The article for today came up from
the forum. Ben brought up a good point - not really new research, but I thought it -
I would post it anyway. I'm non-medical. I'm not a medical
professional, not a doc, but I look at this issue from time to time. If a - if a
drug doesn't - if a drug helps in something like heart attack and stroke
but it doesn't really change the all cause mortality, sort of like - what good
is it? And, again, great article. And he posted
the - the link. I didn't even have to look up the article for today because, again,
Ben posted it for me. Thank You Ben. Now, you know what I've wondered that many
times as well. I tend to, even though I go on and on and on and talk about - it's not
that simple. I do tend to try to bottom line my own
perceptions for a medicine or for a preventive intervention and it bugs me
when I see so many studies showing a moderate or a good effect but not so
much for all cause mortality. That's exactly what this article is about. It
was published - oh gosh, whoa - where's the in circulation - 2017. So, again, May just
last - just what? A year; year and a half ago but the information in here is - it
doesn't matter if this were ten years old. The information in here is logic,
statistics, and one of the things where - you know - you've heard that old statement
that "Liars used to" - "Statistics may not lie but Liars use statistics" I mean that's
one of those things where if you don't understand the basic statistics on
what's going on, you can really get bamboozled - as my grandma used to say.
So, cardiovascular therapeutics should aim to reduce mortality but it's not
necessary to demonstrate a reduction in all cause mortality when assess - and when
assessing them; and here's the key point - and if it's misguided to attempt to
demonstrate an effect. In other words, most of these articles should not have
tried in the beginning because it's too crude a measure of either benefit or
harm. Results are dominated by causes of death unrelated to intervention. The
signal-to-noise ratio is low. Most effective interventions in public health
and preventive medicine that have together led to substantial improvements
in life expectancy would never have been introduced had policymakers
said "Look, we want to see an impact in the death rate, the all cause mortality."
Now, here's an example; The misinterpretation of the data by the US
Preventive Services Task Force for screening of abdominal aortic aneurysm
- hey, we're going to call it triple A one-time enter - invitation for abdominal
aortic aneurysm screening in men aged 65 or older,
was associated with decreased aneurysm rupture and decreased aneurysm related
mortality rates but had little or no effect on all cause mortality rates. Well,
it ignores the compelling evidence in favor of Triple A screening - the hazard
ratio was 0.6 and there was no evidence for an increase in death from other
cause, so together, these findings are sufficient to make the cause for
screening and I do recommend screening especially for people that have 9p21.
That's an added risk factor for abdominal aneurysm. That's not in there;
and I doubt the author even knows that. Even relying on a meta-analysis of
randomized controlled trials with non-significant result for all cause mortality
- mortality. To argue that an intervention is useless is scientifically wrong and
unethical because your - when you have clear disease specific benefit and
there's no evidence of harm because, again, what we'll talk about in the next
paragraph - it's a - it's a statistics issue from the perspective of trial design of
preventative intervention. The endpoint is neither sensitive nor specific.
Suppose the particular cause is 5% of all deaths in the target,
population over the next 15 years - considering in an intervention that
prevents 75% of deaths - suppose 3% of the target population will
die over the next 15 years. All cause mortality - if it were to reach that
endpoint you de - 90% power to to demonstrate this. You'd
have to have over a million 95 thousand individuals randomized to show that.
When's the last time you saw a randomized clinical trial that had over
a million - that had anywhere near a million participants? So that's the
problem. To get a - an impact on all cause mortality, you'd have to have too large
a study. Now, I will say this - and let me go over here. Heart attack is a much more
common cause than even 5%. It's actually 1 in 3 as you see from our friends
"friends" in quotation mark at the American Heart Association. Now, even at 1
in 3 though, you still need to be careful interpreting all cause mortality and
we'll get back to an exam - another example of this down here. The
cholesterol treatment trials - trials, collaboration of statins illustrates the
insensitivity of all cause prevention. They - they were able to identify a
significant benefit from major vascular events but not with all cause mortality.
Again, it makes you wonder how often and how many times we're going to wait to
see an all cause mortality before we initiate something. A screening item
that's near and dear to my heart is CIMT I'd be very very interested to see
the impact of CIMT because CIMT not only, although it does help people that
know that they're at high risk, it really makes a difference for those of us who
thought we were at low risk. In other words, a smaller section of the
population. Again, as usual, if you've made it this far in the - in this
thing, thank you. Thank you for your attention and if you have more interest
in getting into this level of detail, hit - head over to the forum, take a look. Thank
you very much.