thank you thank you dr. Malak for
putting up weird cases and then we'll be
moving on to one of the more routine and
common causes so nothing too special
there although it's a very important
topic so of course we're talking about a
cult atrial fibrillation I have one
disclosure I'm a Judah cater for cases
for the base trial which is a biomarker
trial somewhat relevant to the topic and
that it's looking at biomarkers to
detect the etiology for cryptogenic
strokes or strokes as they come in so
why do we care so much about occult
atrial fibrillation and stroke
well atrial fibrillation is extremely
common within the United States over 2
million patients in the US have atrial
fibrillation and then we kind of come to
the rule of thirds we're about one third
of all AF patients are yet to be
diagnosed with that condition we also
have about 800,000 strokes in the US per
year with about one-third of those being
of an unknown cause so what that
basically means is that around 250,000
patients a year will be told they have a
stroke but we don't know why that's
somewhat disconcerting from the
patient's standpoint and then we do know
that a EF is very important because it
essentially increases the risk of stroke
by a multiplicative of 5 so it's a very
important cause of stroke so how did we
kind of come around to this well focus
on cryptogenic stroke and the occult AF
well you go back to the wars trial which
is warfarin versus aspirin and one of
the subgroups they looked at various
things and then they looked at the
cryptogenic cohort and within this one
cohort there was about an 8% reduction
in the risk of stroke not statistically
significant because this was not really
powered to to find this difference but
it begged the question what's so special
about the cryptogenic cohort why do they
respond to anticoagulants more than you
than the other conditions so so we want
to start to look at how we can identify
there's no atrial fibrillation so when a
patient comes in a hospital what's one
of the first things you do after you've
potentially treated them with TPA and
other things is you get an EKG and that
admission EKG can diagnose up to 7.7%
new cases of AF just with that admission
EKG in some places or situations where
you may not have the opportunity for
telemetry perhaps this is a stable
patient who's been diagnosed as an
outpatient you can actually do serial
EKGs and capture another 5.5% 5.6
percent of AF cases just by doing EKGs
and with the EKG there's a lot of
information that you can get from that
and this is one of the highest quality
exams that you can do from this category
because you can see multiple channels
you can look at the p-waves you can get
very detailed information from those
things and those things can actually
help you predict whether or not they're
gonna go into atrial fibrillation
the next thing was well they get
admitted and for the most part they're
put on telemetry and basically the
guidelines suggest that all stroke
patients should have at least 24 hours
of cardiac monitoring regardless of what
type of stroke it is and that by itself
will detect another 7% and that during
telemetry one of the things that we
don't often even notice is you know
you're in the room with the patient and
you're looking and yeah it's normal
sinus rhythm but there goes a P AC there
goes a P AC these are relevant we think
of P ACS as kind of precursors for
paroxysmal atrial fibrillation or or
triggers for AF when the PA see perhaps
occurs in the atrial vulnerable period
so you get more cases that way and then
moving forward another option is halter
monitor some places don't have inpatient
telemetry or EKG monitoring so these
patients should get at least 24 to 48
hours of holter monitoring but with
halters you can add another significant
percentage of AF detection halters are
also great because they they can even
calculate for you how many PA sees
they've they've had and the number of PA
sees is very important when you're
trying to decide whether or not somebody
at high risk or not for atrial
fibrillation a couple of studies one
that looked at greater than 70 PA C's
per hour another one looking at greater
than 1500 PA C's and a 24-hour period
was significantly associated with high
rates of AF in the future so you get a
lot of information from that and then
NYX is a event recorders external loop
recorders and things like that and they
got another kind of seven-and-a-half
percent or so some of the the newer ones
that now they can go on for longer
periods of time up to 30 days or so and
then I will talk about a couple of other
more specific ones going forward so the
next one is is M cot or mobile cardiac
outpatient telemetry and this one has
from these these types of monitors had
shown a little bit higher detection
rates up to 25 percent or so when used
for 21 to 30 days I want to talk about
this one a little bit because this is
kind of how I got interested in atrial
fibrillation and cryptogenic stroke but
in 2008 tae-il published 56 patients
with cryptogenic stroke and a detection
rate of 23% for M cot monitoring of 21
days so that's a really good percentage
but that's only 56 patients at a time
that I became interested in they say we
were doing this routinely on patients
and I said why did we do this and it was
well because of this one study a study
of 56 patients that was retrospective
well maybe we should look at that little
bit more during the time we were looking
at it another one came out again
relatively small 62 patients but again a
really high rate of AF detection so this
became a much more important thing in
the detection of a cause for Curt
regenexx stroke patients so this leads
me to the the project that I did during
as a fellow when I came up with the idea
of doing this which was a little bit of
a rehash my supervising staff said I
don't do that it's not worth it you know
there's nothing so like any good fellow
I didn't listen to them and I went ahead
and did it anyways it turned out well
you know it was more than it was a you
know a great study or anything like that
it was just good timing I think people
were saying yes we need more of this and
I got to meet Jose biller who's in
picture right there and that was for the
you know the mobile cardiac update
telemetry we had 156 patients a little
over 17% like seventeen and a half
percent detection rate for AF and it
kind of led me down this path of
interest in this topic so here is what
the mobile cardiac outpatient telemetry
unit looks like so when you tell
patients about what they're gonna have
to wear and things like that you say you
put on this monitor you're gonna look
like this you tell their wife they're
gonna look like this as soon as you put
this monitor on them it's super sorry
additionally so just kind of new
advancement these these monitors are
changing constantly and in this
particular M cup monitor is going
through some other upgrades as well and
there's more of a patch based so it
doesn't have all the leads and the the
thing hanging around his neck is much
smaller so they're they're constantly
evolving and so we keep an eye out for
those evolution and things like that so
based on tie L study my study and bot
study and a bunch of other retrospective
studies looking at a non-invasive
external cardiac monitoring prolonged
cardiac monitoring even though there was
nothing prospective or randomized into
2014 the American Academy of Neurology
followed by the American Heart
Association American Stroke Association
put out guidelines recommending routine
use of prolonged cardiac monitoring up
to say approximately 30 days or so in
cryptogenic stroke patients to look for
occult atrial fibrillation so they
identified the importance of this
condition but again it was basically
expert opinion and on randomized control
trials if they had waited a few months
there was the these two trials the
invade embrace trial and the crystal AF
trial these were the first two
randomized controlled trials looking at
this so what what they considered at the
time comparing it to usual or baseline
monitoring which was only 24-hour halter
monitoring so it wasn't comparing to the
other prolonged external monitors but
comparing to 24-hour halters so the
first one was the embrace trial and the
embrace trial was like a belt
like external event monitor they
detected a little over 16 percent at 30
days versus 3.2 percent with a 24 hour
holder so again very good yield with
this device and then the crystal AF
trial this is the insertable or
implantable cardiac monitor detected
about 9 percent at 6 months this
increased to about 12 and a half percent
at 12 months and then if you were you
know able to wait three years to get the
results you got up to 30 percent so this
was really increasing the yield of
detection now there you see there's a
little bit of a discrepancy with 16
percent at 30 days and then you know
kind of take about a year and a half two
years based on the numbers to get to
that percentage with the implantable
there were some differences between the
studies patients were a little bit older
and the embrace trial things like that
there was another study for the
implantable monitors that kind of risk
stratified and I'll talk about risk
stratification a little bit in a minute
but you know taking people who are
considered at a little bit higher risk
for AF so obviously none not all of
these patients have atrial fibrillation
that you're looking for so there's got
to be some maybe signs or risk factors
that put people at higher risk than
others and and that's really useful
information so in that to study when
they looked at high risk patients they
were able to get you know to that 30
percent mark and within about six months
or so here are some of the other cardiac
monitoring options you know there's a
lot of things like I mentioned for the
EKGs you get a lot of information from
that I'll list some of those other
benefits to the the things that you can
see especially the P wave and the Holter
monitors I mentioned the P AC counts and
things like that atrial runs all of
those things the super ventricular
ectopic beats these are all important in
determining the risk for atrial
fibrillation and whether or not you
proceed with further monitoring then
there's some newer 14-day compact
monitors here's a couple of the examples
ones kind of a patch like the other one
is just kind of a discrete small with a
couple of leads and then there's the
loop recorders and event monitors and
like I mentioned the MCATs and the
insertable cardiac monitors but the keys
to success
is to have a device that's going to give
you quality EKG tracings you know
garbage in garbage out you're not going
to get a good diagnosis if you can't see
the tracings you want to have the device
should have quality automated AF
detection algorithms so now they've
gotten much better at detecting atrial
fibrillation but there's still
differences between different devices
and you want to make sure that they have
gone through some sort of vetting and
things like that to make sure that they
can actually detect reliably since these
are asymptomatic episodes so and then
you need to know that they're going to
be able to monitor for a long enough
duration so what we've seen is from our
study and the other studies is that
seven days 14 days 21 days 30 days
you're it's kind of a linear line where
you're continuing to get AF episodes
throughout that that time period so you
really need to do at least 21 30 days or
so and then perhaps at that point risk
stratify and decide whether or not
further monitoring is warranted so this
is kind of getting back to the refining
our search and using all the information
that we thus ambient information that we
tend to ignore we don't take all this
stuff into consideration obviously age
is a big factor so as people get older
the risk of AF goes up and up and up the
PA CS I mentioned on the EKG you know if
in our study if somebody had a PA C on
their baseline EKG they had a 60% chance
of having AF detected on monitoring for
21 days
and that's just cuz you know if if
they're having enough PA C is to have
them randomly on your EKG they're
probably having so many that they're
gonna end up having afib because they're
at that higher risk the Holter monitors
are really nice as I mentioned because
you get a lot of information on those
then the P wave morphology so you can
see left a Trull dilatation based off
the P wave there are other things like P
wave inversion in the terminal force in
the v1 lead so if you're good with EKGs
cardiologists other you know internist
or whoever may be good at looking at
these things you can use these and they
will predict whether or not they're at
high risk for afib there's a the P wave
max duration and the P dispersion value
of greater than 40 milliseconds these
are all risk factors for for AF that
most people don't know about or think
about another big one and we're doing
with the residence a review we were able
to utilize the electronic health record
system and pull data from 8,500 patients
looking at their left atrial size from
normal mild moderate and severe and you
see very straight correlations with the
size of the left atrial dilation to the
likelihood that they have AF and those
with severe left atrial dilatation have
about a 50% chance that they've already
been diagnosed with atrial fibrillation
so what about the other 50% so if you
look at patients that have a dilated
left atria of any size a little over a
third of them have been diagnosed with
afib but what about the other two-thirds
we know that they're probably at very
high risk so you know these should be
people that we look at and I have gone
against the guidelines you know looking
for atrial fibrillation and somebody who
has a lacuna infarct that's not what
we're supposed to do but I'm sitting
there I'm seeing PA CS and I see that on
the echo they got a moderately dilated
left atria I know they probably have
done it a few times and sure enough when
we find HF fibrillation so we could even
move start to move away from just
looking at cryptogenic stroke patients
and move this to even primary diagnosis
primary prevention for people who are at
high risk based on echos and EKGs and
things like that and that's one of my
interest is going forward there's other
things that you can find out at EEE this
is things like left atrial appendage
smoke emptying velocity the morphology
all these things that increase the risk
or change that and other things are the
biomarkers like the n-terminal Pro BNP
that's a big biomarker for treatment
aspirin 20% warfarin reduces by 60% it's
a kind of a miracle drug so what is this
miracle drug well it's a pesticide for
rats and mice and Oracle prescribing
practices are bismal and the adherence
is you know even worse so it's kind of a
nightmare drug because of all of its
issues and yes it's rat poison that
comes up repeatedly
and we have patients who say I won't
take that rat poison literally coming
after day I won't take that rat poison
so you have alternatives these dough
acts that we've heard about they're
great they have a lot of options
different doses and things they have
some limitations but they have a lot of
benefits as well and you still get
people that say well no I don't care
about the cumin and I don't care about
the darks no no no no thank you
well how do we convince them well you
take studies the average trial picks a
band versus aspirin and you know this
showed reduce reduction and stroke no
major bleeding increase RI CH and then
she comes back at you and she's still
there looking at you so I but before or
never again so what alternatives do you
have left atrial appendage occlusion 90%
of thrombi occur in the left atrial
appendage you can and our cardiologists
will tell you they basically shove this
thing in there block it off and prevent
strokes and then there's the layer at
procedure which they may mention as well
but just wanted to throw that in there
hold on thank you
[Applause]