Hi everyone.
Welcome to Febrile, a cultured podcast about all things infectious disease.
We use consult questions to dive into ID clinical reasoning, diagnostics
and antimicrobial management.
I'm Sara Dong, your host and a Med Peds ID doc.
We are back today with a StAR episode, State of the Art Review.
These focus on recent state of the art reviews that were published in
Clinical Infectious Diseases, or CID.
So I'll start by introducing our guest stars today who are all joining us from
the Division of Public Health, Infectious Diseases, and Occupational Medicine at
Mayo Clinic in Rochester, Minnesota.
Hi.
I am Hassam Tabaja.
I'm really happy to be back on the podcast with you.
I'm really thankful for you having me here again.
Dr. Hassam Tabaja is an Assistant Professor of Medicine.
His clinical research is focused on hardware associated infections, including
both cardiovascular device infection and orthopedic device infection.
Hi, this is Mac Chesdachai.
Really happy to be here and thank you so much for having me.
Dr. Supavit Chesdachai, or Mac, he is also an Assistant Professor of Medicine.
His clinical and research interest include cardiovascular infections and infections
in solid organ transplant recipients.
Hi, I'm Dan De Simone.
Thank you so much for having me back.
I love Febrile StAR.
Thank you so much.
We have Dr. Daniel DeSimone or Dan.
He is a Consultant and now Professor of Medicine at Mayo Clinic.
He also holds a joint appointment in the Department of Cardiovascular Diseases.
He has chaired and vice chaired several American Heart Association
scientific statements in cardiovascular infectious diseases.
His clinical and research interests focus on the prevention, diagnosis and
management of infective endocarditis, cardiac implantable electronic device
infections and vascular graft infections.
All right, let's jump in.
Well, Febrile is everyone's favorite cultured podcast.
I know you guys have shared a little piece of culture before, but I'm gonna
ask you to share something new today.
So what have you guys been interested in recently?
I'll go first.
So what I've been getting into particularly with these, with the past
couple of months where it's about minus 20 out and can't go out on my grill
or do any smoking, uh, on the grill.
Uh, I've gotten into sous vide, um, if is anyone familiar with that?
I, yeah, it's,
Yeah, I have one!
It's pretty cool.
It's, uh, you're essentially cooking steak, or you name it in nice hot water.
Um, and it's, it's cooking it to the perfect temperature you want and then
do whatever you wanna do after that.
But yeah, I've been getting into that a lot.
Now that the weather's starting to turn around, I'm getting the,
breaking the grill out more.
But, uh, but I'll tell you what, that sous vide is, is pretty cool.
Highly recommended for, for anybody who, who, if you, if you can't cook, it's
a good way to, to not mess things up.
And if you can cook, you can, you can tailor things around pretty nice.
So yeah, I've gotten into that.
Um, be careful because once you get into it, you just start to go down
a rabbit hole, but it's, it's fun.
Yeah, it is really fun.
It makes you feel very professional when you use it.
Oh, yeah.
Yeah, absolutely.
I start speaking French.
I, I have to ask for tips from Dan, because I did it in the past and
sometime the plastic bag is just like ballooning and it just flows up.
So
yeah, you gotta get a good sealer sometimes.
Double seal.
Yeah.
I, yeah, that's, there are, there is a learning curve.
There's a small learning curve.
Um, but once you do it, it's, it's, it's worth it.
So for me, I don't have any new activity apart from the pickleball that
we discussed last time with Hassam.
Um, but lately I, I, I was very interesting in how time different travel
and jet lag work, because we just came back from trip to Thailand and then
that's the first time that my 20 month old daughter flew transpacific and then
we were so concerned about like the time difference, 13 hour time difference.
It turned out to be, she was fine in one day, but the problem is that
there, her parents is doing so badly in like five days, not recover at all.
So I'm really surprised that, you know, when you talk about 13 hour
difference jet lag, it doesn't apply to 20 months old daughter.
And I feel like that must have been your daughter that I saw at ID week, right?
Yes you did.
Yeah.
Very cute.
What about you, Hussam?
So I'll go.
Yeah.
I haven't also been engaging in a lot of new activities, but I, I have
been very busy 'cause I'm actually a, a new father now, so I have twins
and, um, I think there's a lot of culture around that to, to be said.
Um, surely a lot of, um, family visits that I was not expecting.
And, uh, a lot of gifts, which I'm very happy with, a lot, a lot of gifts
and a lot of things to learn really.
So I've just been busy trying to figure out how to become a father.
Uh
Oh, congrats!
I'm sure you have your hands full.
Um, well I'm very glad to welcome you guys back.
I'll, um, just plug that you were here on Febrile back for a State
of the Art Review on vascular graft infections, which I'll put a link to, um,
hopefully people have listened to that.
But this is a different article that focused on complexities of cardiac
device infections, and I think all of these questions that we know sound
simple, but actually are quite complex.
Is the device infected?
Should it be taken out?
When it is taken out, when is it safe to put it back in?
Um, and so we will walk through a case today, but I just wanna start more
generally and would love to hear about how you think about the way these infections
should be handled or maybe your experience handling them at your institution.
Yeah.
Sara, that's great.
Thank you so much for having us.
You know, these, as you mentioned, these are, are not always so
straightforward to make the diagnosis of the device being infected.
And I think that's probably the, the big issue here is or at least the
common goal that we share is we wanna keep devices that are not infected
in the patient's body, and when they are infected, we wanna take them out.
And that's much more easy, easier said than done.
In some cases, it's readily apparent it's infected, and in a lot of other cases
where it becomes very challenging, it's difficult to make that diagnosis, and
hopefully through this podcast, we'll be able to provide our listeners with a
good strategy on how to approach these patients and, and hopefully make it a
little bit easier to achieve that goal.
When a patient gets admitted to our institution with concern
for a device infection, it, this is not a one person show, it's
gonna be multiple teams involved.
They may be admitted to, let's say, our hospital medicine service, so that
involves our hospitalists as the main care team and will often require consultation
with infectious disease, uh, as well as our heart rhythm or electrophysiology
team as well, to be involved.
That's just a couple elements of the team.
Then you have to factor in the possible need for echocardiography, so that brings
in our echocardiographers, uh, possibly PET imaging, NDM scans and so on, uh,
radiology, nuclear radiology as well.
And that's just part of the team and beyond.
So if you do think it's infected.
You may have to get general surgery on board for device removal and involved in
pocket management after device removed, possibly even plastic surgery depending
on the situation and the location as well as cardiovascular or thoracic
surgery to be on, on standby as backup.
As taking the device out is not without risk, risk of significant bleeding,
major bleeding, and possibly death.
So having cardiovascular surgery or thoracic surgery on standby for backup
support following device removal for any complications is, is critical.
So that's kind of start to somewhat finish.
And there's even more to that is okay, a device comes out, does the device need,
does a new device need to go back in?
And that's where our cardiologists and heart rhythm specialists come into play.
So that's kind of the approach.
And again, there's some things that go on in between.
Are they bacteremic or not?
Is there something on the echo, on the heart valve or do the lead itself or both?
And then do they need a new device put back in and when
do you put that back in it?
So with that I'll turn things over to, uh, to Mac and Hussam to
go further into those scenarios.
Excellent.
Alright, well I'm gonna introduce our patient that we're gonna be
taking care of in the hospital.
We meet a 65-year-old woman with morbid obesity, diabetes and a cardiac
device who presented to clinic with three days of pain, redness, and
swelling at the generator pocket.
So we're gonna pause right here this early and ask about how
should we start our assessment?
Yeah.
Uh, as Dan mentioned, CIED infection is a very complex syndrome that
require the whole village of multiple people help taking care of this.
And the definition of the CIED infection itself has changed multiple times since
the first statement came out in 2003, and then the most recent one that Dan is
a lead author came out in 2023 to 2024, um, provide a variety of the definition
of the infection, but in general, um, when we talk about a CIED infection,
we need to think about two main thing.
The first one is that the pocket part, and then the second one is
the infection of the lead or valve.
So when we talk about infection of the lead and valve, we call
that CIED-related endocarditis.
The pocket itself can happen without endocarditis.
So that's the reason why any part of the device is infected, the
whole system become infected.
That's the reason how we, um, define the infection.
So the most challenging thing is how to diagnose the CIED
related infective endocarditis.
Because with the pocket generator side infection, you can get that from the
physical exam in most of the case, which is, if we ask what is the most common
presentation of CIED infection, it is mainly the pocket generator site, which
has happened in two-thirds of the cases, so one third of the cases will have the
device endocarditis as well, but we can talk more of why it's so challenging to
diagnose whether the patient has device related infective endocarditis or not.
So we learned a little bit more.
This patient had their device implanted eight years earlier for a history of
sudden cardiac death with a recent generator revision two months ago.
She also had fatigue, fever, and chills.
And our physical exam shows erythema, tenderness, and fluctuation
at the generator pocket site.
There isn't any purulent drainage, sinus tract formation or device exposure noted.
Um, so what is our best next step?
Yes.
So basically, if, if I summarize this question, you're basically, I'm being
asked to, uh, see a patient who's presenting with pocket site inflammation.
That's, that's called it inflammation.
And so my job here is to figure out whether or not this
inflammation is related to infection or not infectious, right?
Because this soon after a revision only two months out, there are
other non-infectious causes of pocket site inflammation, uh,
such as allergic reaction to the component or maybe a hematoma.
There are certain tools that we could use to help us make that, uh, decision.
And the first tools are history and physical exam, which is just
similar to what we use with any syndrome that we encounter, right?
So there are certain things in history that are important to tease out.
Uh, for example, in order to assess the risk of infection, you have
to look at the age of the patient.
You need to look at the complexity of the device.
Is this a multiple lead?
Is this a pacemaker?
A CRT-D, you need to know whether or not that this is the first device.
Is this a revision?
How many times has it been revised before?
Uh, what are the comorbidities of the other cardiovascular devices?
So all of this, this helps you define the host and then you'll get an understanding
of what is the, uh, risk of infection.
The next thing is you wanna, uh, look for signs and symptoms that will
give you a definite diagnosis of CIED infection because based on history
and physical exam, there are certain signs that can actually confirm
that you have an infection without having to do any additional testing.
Um, and those are not frequent.
There's not too much of those.
There's maybe three to four signs and some of those, you know, pus
coming out from the pocket, uh, sinus tract, uh, device exposure,
which this patient does not have.
So if this patient had those signs, then just by history and physical
exam, I will be able to tell there is a CIED infection and the next
step will be to do a blood culture.
Because you wanna know whether or not the patient is bacteremic, not to make the
diagnosis, the diagnosis is already made.
The blood cultures help you, uh, because if they're positive, they're gonna
determine your next step in management.
Okay.
But this patient does not fall in this category.
She's presenting with, uh, signs of inflammation, but there is
no signs or symptoms that are definite for CIED infection.
So then the question is, what other tools can we use?
And really this soon after revision in my mind, the only thing that we would do is
a blood culture for this patient because I won't rely on CRP, ESR, white blood
cell count this soon after the revision?
Because they're not gonna be specific for CIED infection.
I also don't rely so much on imaging like ultrasound, CT scans or PET CT this early
after revision because I would expect to see something and it'll still not tell
me whether or not this is an infected abscess, for example, or a hematoma.
So in my mind, uh, for those patients, the only thing that you could rely on is
really, is a blood culture at this point, because if the blood culture is positive.
Then that also will upgrade this patient from an uncertain category to a
confirmed or a definite CIED infection.
Whenever you have a local pocket inflammation and you have a positive
blood culture, that by definition is CIED infection, and so then
we would manage it accordingly.
The more difficult situation is if there is negative blood culture because
then you're stuck again with this challenging question, how do I prove
that this patient has a CIED infection?
And it becomes more challenging if there is no systemic symptoms.
You know, this patient actually has systemic symptoms, so
maybe it's a bit easier.
But if someone comes in with mild inflammation, maybe just minimal
swelling, no systemic symptoms, this could just be a hematoma and inflammatory
reaction from allergic reaction.
It could be even a superficial cellulitis.
So this is where it becomes controversial.
Some physicians in those situations would put patients on oral antibiotics
empirically, uh, considering this may be a superficial cellulitis.
And then they will just follow very closely to see how they respond.
Other physicians would not put antibiotics and they will just follow
them clinically and see how things change because, you know, give it some time
and let it declare itself basically.
But I would say this is, these situations are the less straightforward situations.
I, I think it might be helpful to comment on pocket infection and,
and not aspirating the pocket.
Because I think maybe for residents and earlier trainees that that
might not seem intuitive when we're usually asking for a sample.
Would you be willing to just say a couple sentences on that
so you know there is some physicians that might consider doing an ultrasound
guided aspiration if there's a fluid pocket, send that to for culture,
see if it looks like pus or not.
Um, in, in our center, we really don't like to do that.
We try to avoid that as much as possible.
And the main reason is because if you're not able to confirm the
diagnosis of CIED infection based on blood cultures and physical exam.
We worry that if it's not infected, we're gonna now introduce an
infection, uh, into the pockets.
So we don't really like to do that much.
And I, I, I personally have never seen it being done.
I don't know if Dan or, or Mac has seen that done before.
I have seen it done in other devices.
So we do have a lot of deep brain stimulator devices, for example here,
which they have generator pockets and a lot of times the surgeons here
would do an aspiration of the fluid.
Um, but I have not seen a cardiovascular disease, uh, physician or an infectious
disease physician here in the center in Mayo Clinic that would do an
ultrasound guided aspiration of the pocket, just because we worry that we
might now introduce an infection and it leads to bacteremia and endocarditis.
Yeah, I, I agree with Hassam that I, um, never done.
Um, but Dan can also add onto that too, that, um, I think
there was a study from Israel.
They put a catheter directly into the pocket and try to infuse
antibiotics into the pocket in the setting of pocket infection.
But I don't think that has been widely used.
And that is only in the investigational, um, study rather than clinical practice.
Yeah.
So, so Mac in, in that study where they put a catheter in, they
were instilling antibiotics as a way to, to treat an infection
rather than to make the diagnosis.
But from a diagnostic standpoint, uh, typically why, why we would advise
against doing an aspiration of the pocket would be, what if there is no infection?
You may have potentially introduced infection now.
So every time you go into that pocket, you run the risk of leading
to infection of that device.
So in this patient's history, in our example here, they had
a revision two months ago.
So that's a big red flag that they went back into that pocket and now is
showing up with some pocket findings and systemic symptoms that your suspicion
for infection really has to go up here.
Now I've seen where you can get an ultrasound of the pocket and,
sometimes you could say, Hey, this might look like an abscess.
That might tilt you more towards this being infected, but, uh, but
putting a needle and entering that pocket is very uncommon to do and
typically advise against that.
Thanks guys.
The team has grabbed two sets of blood cultures.
These were drawn before vancomycin was administered, and in these
cultures we have gram positive cocci resembling Streptococci
that grew after about 14 hours.
Um, so what would be our approach now?
Yeah, so this gets interesting now.
So given this patient's history, now findings of positive blood
cultures, I think doing the right thing is starting the vancomycin.
You know, this could either be a Streptococcus or an Enterococcus.
So I think starting the antibiotic at this point, would recommend
that and encourage that.
I think the big thing here is the organism is very important when you
approach cardiac device infections.
This is your pretest probability of when you get that echocardiogram with
a, in a patient who has a positive blood culture is gonna be critical.
So in somebody like this with their history with an organism that's growing
either Strep or Enterococcus, now my suspicion is, is very high, uh,
that this device is infected and the recommendation would be to take it out.
There's more discussion there, and we'll likely talk about this
later when it comes time to make that decision to take things out.
But I think your, your next best step here is, does this patient
have valvular or lead endocarditis?
And, and really the focus is on valvular endocarditis as that
has downstream ramifications if the valve has a vegetation.
So if there's valvular endocarditis, your duration of therapy is gonna be longer.
So you're not gonna treat this as just a standard bloodstream
infection or bacteremia with, say, two weeks of antibiotics.
You're likely gonna go down the route of four to six weeks.
Uh, so you can see how that changes your therapy there.
As well as it'll have implications on reimplantation if, if the patient
needs it, on timing of reimplantation.
So instead of 72 hours, you may wait up to two weeks to put a new
device back in if it's needed.
That's the next step in this patient's, uh, route here of
getting an echocardiogram, a TTE and TEE would be recommended.
And again, you're looking for valvular vegetations or
any vegetations on the lead..
That's, that's again, gonna direct us to our next step.
That's perfect.
And, um, you guys in the, for those who have the paper, that figure two roadmap
is about where we're talking about and Hassam started talking earlier about
the importance of knowing if someone has a bloodstream infection or not.
And I think one way we can also reframe this patient is how would
we think about them differently if they had come in and we identified a
blood infection, but there's no signs of generator pocket site infection.
How do you reason through what to do for those patients?
Yeah, and I think this is a very important question because you run
into the situation all the time when the patient got hospitalized
with bacteremia and they have
pacemaker or ICD in place.
Sometime, we don't' know what to do about them.
Should we do echocardiogram?
Should we not?
Should we just monitor?
So it's very, very important question and not a lot of study,
um, looking into this scenario.
So as you mentioned, it's very clear if the patient walk to you and have
the pus come out of the pocket.
We know that device need to come out no matter what, but when the patient come in
with bacteremia, it very difficult to know whether the device is infected or not.
I think the main principle that we would work on is the same as the patient
with vascular graft and other device.
So it's very depend on, um, the pathogen specific.
For example, if the patient has a Staph aureus bacteremia, you would
be very confident that you need to look into the device itself.
However, if the patient has like very localized symptom of, for example, UTI
and have a gram-negative bacteremia.
The chance that the e coli or other gram-negative would,
the device is very low.
So all those situations, you do not need to specifically look at the device
itself, either with TTE or other modality.
We always run into the issue when we encounter the
pathogen that we're uncertain.
For example, Staph aureus, definitely high risk.
Um, coag negative Staph, definitely high risk.
Enterococci.
I would also throw, throw into the high risk category as well.
The same as Strep viridans group.
But from time to time when we run into other gram positives,
other streptococci or high risk gram-negatives, such
as Serratia or Pseudomonas.
From time to time's, very difficult to tell.
So we need to, um, think about other factors as well.
For example, does the patient has prolonged, um, bloodstream
infection, um, are we able to identify the source of infection?
Does the patient have cardiac device or other valvular processes as well.
The more factor that the patient has, um, the more we think that the
device might be infected, for example, prolonged bacteremia, community
onset, and we could not find a source.
So that's the time when we need to look closely into the device.
And one thing that I also wanna mention is that, the prior study also came up with a
multiple scoring system to see, especially with the Staph aureus, um, in the past, in
around 2015, a score called predict SAB.
So we try to, um, plug in the clinical factors that I just mentioned in, um,
how long has the patient been bacteremic, and everything like that into to see
that if the patient has a Staph aureus bacteremia, what is the likelihood
of the underlying device is infected?
And then the most recent one, the study group from Europe also came out with
a score called a CTEPP score, which coming from like community acquisition,
time to positivity, embolization, risk factors for IE, and persistent bacteremia.
So we can use those score to fit into the clinical contact and see how
how high of a risk that the patient who come in with bacteremia has to
have underlying device infection.
For other organisms, we still do not have a good score.
We apply the same score that out there to predict the endocarditis, for example,
like HANDOC for streptococci or DENOVA score for enterococci, but all of those
are not specific to the device itself, but I think it's good enough plus the clinical
judgment to see whether we really need to send the patient to transesophageal
echocardiogram or do additional PET CT.
So I think it's two main thing, depend on the pathogen specific virulence,
and then depend on the nature of the bact itself and the host factor.
So for this patient, uh, they underwent TEE, which demonstrated
a small echo density at the atrial aspect of the CIED lead.
There's no valvular vegetations observed.
Here we can talk about challenges in interpreting TEE findings.
And then I think the other question that we've started alluding to
is, um, when when to use PET CT.
And so I'd love to hear about how you decide on when to reach for that modality.
Okay, perfect.
To best answer this question, really figure three in the article that we have,
uh, actually talks a lot about this.
Um, so if we are looking at the patient.
Our main question, you know, what is the role of the ECHO here?
Um, to me, you know, we've already made the diagnosis of CIED infection for
this specific patient just based on physical exam and positive blood culture.
So the echo here is not really for diagnostic purposes specifically
because we are already labeling this patient as having CIED infection
and we're gonna treat accordingly.
The purpose of the echo here is to tell us what is the duration of treatment.
When is it okay to reimplant a device?
And this will really depend on whether or not the valve has, uh, vegetations
or is there any vegetations only on the lead or is there no vegetation?
So really the echo helps us determine these two questions for this patient.
The more challenging situation is if the patient had come in with bloodstream
infection and no pocket site infection, or no pocket site inflammation.
So in those patients, the echo, uh, is done for diagnostic purposes.
We are trying to get more information to decide whether or not the device
is actually infected and if whether or not we should treat it as such.
So this is where the role of ECHO becomes more critical.
And when we're thinking about echo findings, I can think
of three scenarios really.
The first scenario is you do an echo and you find valve vegetations, so that is
actually the most straightforward scenario because if you do see that, then you're
saying this patient has endocarditis, valvular endocarditis, and that in itself
equates to device infection, and you're going to have to discuss extracting the
device and treating for endocarditis with six weeks of antibiotics.
The other two scenarios are less straightforward, and those include the
second scenario, which is you do an echo and you find a lesion on the lead, but
you're not seeing lesions elsewhere.
So kind of similar to the echo we're seeing here.
The third scenario is you do an echo and you don't see any lesions.
Now, none of these two scenarios are either sensitive or specific for device
infection because you could have a lesion on the lead that is a sterile
thrombus, and it's actually common to have clots on those leads, especially if
those leads have been there for a while.
And there is nothing on the echo that can specifically tell you if
this clot is infected or sterile.
I cannot tell whether or not this lead vegetation or this echo density on
the lead is a, an infected vegetation or it's a thrombus that's sterile.
Even the third scenario where you don't see any lesions, I'm still not able to
confidently rule out, uh, a device lead endocarditis because you could still
miss that on the echo, especially if you can't visualize the entire lead.
And so when it comes to these two scenarios, I think your decision
has to be based on other factors like the type of pathogen, which
Mac has spoken about just now, and also the burden of the bacteremia.
Community acquired bacteremia.
High grade multiple sets, persistent.
No primary focus.
If you have this high burden bacteremia and if you have a high
risk pathogen like staph aureus, then in my mind I would still
consider this device likely infected.
And a lot of experts actually would go ahead and discuss extracting the device
without doing further testing because in their mind, the pretest probability
for device infection is already very high with things like Staph aureus
bacteremia, high burden of bacteremia.
But when you're talking about other bacterias, like maybe gram-negatives,
uh, Clostridium, Cutibacterium, er, other types of bacteria, you cannot make that
assumption because the pretest probability that the device is infected is not
that high, not similar to staph aureus.
And that's when you start wondering, is there any other test that I could
do to help me make that decision?
And that's where PET CT comes in.
And you really, if you look at, there are so many different societies
now that have strengthened their language and statement about using
pet CT for, uh, device infection.
Ever since 2019 up until now, they've been talking about the
use of PET CT for those cases.
And we know that PET CT actually has a very decent sensitivity and
specificity for device infection.
And so a lot of big centers that have PET CTs, they will probably go ahead
and get a PET CT for those cases.
And if it's positive, they call the device infected.
If it's negative, they say the device is probably not infected.
But we have to be very careful and cautious because there is,
there are cons to the PET ct.
The biggest con really is that not every center will have it
accessible or readily accessible.
So some centers can't just get a PET CT and the longer you wait and the
longer that the patient has been on antibiotics, the less reliable that
PET CT becomes because we think the antibiotic can decrease inflammation
and, and so, you know, if you're not able to get PET CT very quickly.
It might not be such a tempting test to get.
The other cons for the PET CT is that while we think, and we know
it's sensitive and specific, it's mostly for pocket site infections.
So it's not that sensitive for lead site infection.
And, and that's why some experts, when they have a high pretest probability
for, uh, device infection, like with Staph aureus high burden bacteremia,
they would not get a PET CT.
They will just discuss extracting the device because they think even
if we do a PET CT and it comes back negative, it still does not rule
out a lead endocarditis because it's not as sensitive for leads as
it's for pocket site infections.
So that's actually one very important thing to keep in mind.
So to summarize things, the role of PET CT seems to be more tempting
when you have an intermediate pretest probability for device infection.
Because in those cases you think that if it's a negative PET ct, then it adds
another reassuring layer that the patient probably does not have a device infection.
Now we spoke about the PET CT, what about centers that can't get a PET CT?
What is one other approach that they could consider?
Again, if they think that their pretest probability for, uh, device infection
is not that high, one approach would be to actually treat the bacteremia.
Stop the antibiotics after treatment and do surveillance of blood
cultures about five to seven days after you stop the antibiotics.
If the bacteremia recurs and you still don't have another source, then it's
probably a device infection and then you have to treat it accordingly.
And so that's kind of, you know, talking about the echoes and PET CTs and, and what
to do if you can't do a PET CT as well.
Yeah, I, I just wanna add one point is that apart from the accessibility of the
PET CT, the cost is also, um, another concern, especially when we have a
different reimbursement system, whether it's gonna cover outpatient, gonna cover
inpatient or whether it's a cancer or non-cancer indication, but surprisingly
in Europe, they have no issue with this.
With the reimbursement.
That's the reason why if you look at the European CIED guideline, um, in
2019, and also the update in guideline in 2023, they, they state very clearly
that if the patient has a Staph aureus bacteremia with the device in place,
um, they recommend every single patient to get a PET CT because apart from the
device itself, it can also identify those metastatic foci and everything like that.
But that's also reflects that in Europe, they don't have a lot
of problem in reimbursement that we still seeing here in the us.
One, one other question that I think needs a lot of thought and more
studies to, to answer that question is the mortality and morbidity benefit
of getting those PET CTs right?
Especially like when we're talking about finding out where other sites of seeding.
Uh, you know, like for example, if you have staph aureus bacteremia,
did it seed somewhere else?
Is there a deep abscess?
And the PET CT will help you find that out.
But there are studies showing that it does not really maybe affect
mortality or morbidity that much.
So I think that's a very important question also to look more into in
the, in future studies, if I get a pet CT for those cases, does it
really change the overall outcome in terms of morbidity and mortality?
Yeah.
Thank you guys so much for covering that.
It's a, it's a big topic and obviously a conversation point on many consults.
Well, despite some of her comorbid conditions, the cardiology team
does recommend complete CIED extraction for this patient.
The patient and her family have expressed some reluctance due to
concerns about the complications.
And so how do you structure your discussion when you're
in this type of scenario?
Yeah, it's a great question and that comes up in every case, right?
It's a procedure that carries significant risk and potential bad outcomes.
Granted, it's, it's low for it to happen.
It's quoted anywhere between one to 2%, depending on the center and their
experience and expertise available.
And, and they can be very serious complications that include bleeding
to the superior vena cava, you can get a tear, uh, you can get cardiac
tamponade among other things.
Uh, and, and death is, is a potential risk.
So those are real complications from device removal.
So that's why we wanna be as certain as possible that the
device is infected, taking it out.
Uh, which again, as we, as we've been talking about, it's not always
as straightforward, but you have to balance that with, well, what
if we just keep the device in and put the patient on antibiotics?
How well does that work?
There's been very limited data, uh, out there looking long term
suppression with chronic antibiotic use.
Actually only one study I can think of that looked at that, and the data
from there showed that it's an option.
But it should be one of your final options of suppression.
And every effort should be made to, to remove the device.
And the reason for that is there's risk of relapse with device
retention, uh, especially if there's valvular or CIED related infective
endocarditis, keeping a device in is associated with high mortality, uh,
as well as high rates of relapse.
So, so again, you're in this balancing act of, well, if we keep the device in,
there's risks the infection can come back or potentially we may not be able
to control the infection versus while there's real risk to the procedure, as
I mentioned, uh, ways to approach the patient is, is making them aware of these
potential risks and complications from going for device removal, but also the
risk of not going for device removal.
This is something where you're gonna make a shared decision
approach with the patient.
And, other things that are important to consider is these devices should be
extracted at centers of excellence where they're doing this on, on a regular basis.
The providers that are removing these devices should have significant
experience, uh, with this and have a support system, backing them up.
And what I mean by that is vascular surgery if there is a tear to the
SVC or other, other major vessels.
Cardiothoracic surgery, on standby, ready to go if there is a complication as
these patients may require opening their chest to repair from these complications.
So, um, so again, it's a discussion you gotta have with each and every patient,
and come together what you think is best for that patient at that time.
There's so many variables that come into play and listening to the patient and
their family and what are their concerns.
You know, it may be they're not worried about the one in a hundred chance, they're
more worried about the pain or something else happening, or maybe they, they have
a tough time waking up from sedation and so, so really asking the patient and their
family, what, what are their concerns?
We have our concerns and what we think is concerns, but may not
always match what the patient is concerned about or their family.
Oh, we left this case a little broad.
I was gonna ask now about how you guys set your final antibiotic plan
and the question of when you can reimplant when a device is removed.
Uh, we didn't pinpoint a specific bug.
'cause I think maybe today our goal is to talk more broadly.
But yeah, how would you approach that?
Yeah, so I think that's the question that we all get asked about.
After the device is removed, when is the appropriate time to place this back.
I think it's very depend on what kind of syndrome that the patient has.
So the principle is that, if the patient has the vegetation on the
valve, we would prolong the time of reimplantation as long as possible.
And most of the time we use 14 days.
Because our hypothetical concern is that if we put the new device too soon
and the patient has the vegetation persistently on the valve, we concerned
that vegetation will become a new foci and eventually infect that device,
the new device that was just placed.
If a patient has vegetation on the valve, we would wanna wait as long
as possible, 14 day if possible.
Um, if the patient doesn't have vegetation on the valve, just a lead
vegetation or no vegetation at all.
At all.
And then the device got extracted, we would wait for 48 to 72 hours, um,
after the first negative blood culture.
So as long as the patient has clear from the bacteremia perspective we
should be able to put the new device in.
Some study in Europe also, if the patient doesn't have bacteremia, um, the sooner
that you can place a new device in actually in the same day, so they put a
new device in, in the contralateral side if the patient doesn't have bacteremia.
So I think the key is that as long as the patient is no longer bacteremic, it should
be safe to place a new device unless the patient has a vegetation on the valve.
So I'm going to touch a little bit about interim strategy because that's also an
important topic that we need to discuss.
Um, mainly what device gonna be placed is depend on what was the indication that
the patient has device in the first place.
Maybe the patient no longer need device, which is great.
We don't need to have a time or new device implant.
But let's say if the patient continues to have indication, for example,
ventricular arrhythmia or cardiac pacing that need a new device.
So that's need to be discussed with the electrophysiologist.
Because if, for example, if they do not wanna put the intravascular
device, maybe we have the alternative.
For example, if the patient who need a cardiac pacing without the ICD
function, we can use the leadless pacemaker in that situation.
But if the patient doesn't need a cardiac pacing but need the ICD function,
we can use the subcutaneous or the extravascular ICD, um, in that situation.
But from time to time, if the patient needs both, we may not be
able to find any interim strategy, especially when the patient that
we wanna prolong the implantation.
So that's the reason why I said prolong as much as possible because
when we say 14 day, it's not always possible in the clinical practice.
And regarding the antibiotics after the extraction, if the patient has
a valve vegetation, we would treat the same as infective endocarditis,
which is four to six weeks.
But if the patient doesn't have the vegetation on the valve, we can do
shorter than that which is 2-4 weeks.
Great.
And after some discussion of risk, risks and benefits, the patient and
family declined the device extraction.
At this point, the patient's been on vancomycin, blood cultures have cleared.
So what would be your strategy here and planning for follow-up once
they're in the outpatient setting?
As long as the device remains, unfortunately there is no objective
test that we could do after a treatment.
So let's say we we're gonna treat the syndrome for four
to six weeks with antibiotics.
After we finish this treatment, there is no objective test that
will tell us the infection is completely eradicated from the device.
And so to simplify things, those cases would require to be on
antimicrobial suppression after you finish the treatment phase.
Of course it's not as simple as I'm making it sound because, we're in
the era of antimicrobial resistance.
A lot of times we might not have good or tolerable oral options to suppress
these patients after the treatment.
We don't know how long to suppress them for.
We don't have very good longitudinal studies to tell
us or answer this question.
Dan had talked about one study which had 48 patients where they suppressed.
And you know, in that study, they had about 18% relapse.
So we also don't, I mean, we don't have much studies to tell us about relapse,
how long to keep the patient antibiotic, what happens when we stop the antibiotics,
how much of those patients tolerate the antibiotics and things like that.
So it is really, uh, not an easy thing to, to, to manage, I would say
as long as the device is retained.
You wanna try to keep this patient on antimicrobial
suppression as much as possible.
So, you know, in my mind what I would do is I would finish the
treatment course again, four to six weeks, depending on the syndrome.
See the patient at that point, make sure that the pocket looks good, make
sure that the patient looks good, and then have a discussion with the
patient about getting them on an oral antibiotic that will potentially help
suppress their infection as long as possible, as long as they tolerate it.
Usually it's not an easy discussion, especially when you're trying to
tell the patient that you're likely going to need to be on antibiotics
for the rest of your life.
And so a lot of patients, they might not be very excited about that, so it's
very important to mention this plan, even early on during their treatment,
don't wait until they're done with their treatment and say, hey, we're
gonna put you on oral antibiotics now to suppress you indefinitely.
I think this is something that you have to discuss during the shared
decision making, which Dan talked about, and this should be early during
the hospitalization course itself.
So you guys covered a real, quite a big topic in a pretty short amount of time.
To end, I was just going to ask you separate from this case, what things
you're most excited about in this subset of ID, cardiac device infections.
What things are you most interested in learning about?
Um, maybe studies that are underway that you're looking
forward to hearing results on.
I think we all can share this answer.
For me is that I, I wanna see, um, more accurate diagnosis in this
field because as Hassam mentioned, even though we have TEE, PET-CT.
We still in a lot of, um, conundrum whether this device is infected
or not, whether we should extract it or not, because everything
that we offer to the patient is impact their life substantially.
For example, if we say that, Hey, we are unsure, but we should remove your device.
It's not just easy as we say, because that would involve multiple people.
So that's why I'm excited to see whether, is there any new tools,
any new modality that coming out and regarding the treatment perspective.
We don't have a lot of thing in, in the pipeline right now, but I would
like to see if, is there any way that we can treat the device infection
without a chronic suppression or suppression in very limited time.
The thing that I excited for.
Especially with like using biofilm active agents in those treatments,
is there any role for rifampin?
Does quinolone have a different efficacy than other antibiotics?
'cause we know that it has biofilm activity, so, you know, what is
the role of adding those types of agents to the treatment and does it
really help us get the patient off suppression if we retain the device?
So that's one thing I would like, like to look at.
It would be really nice if there is something that could be done about the
device itself to make it more resistant to, to, to infections in the first place.
And I, I know there has been other things that have, that have been looked at in
the past, like this antibiotic envelope.
Dan, you spoke to us multiple times about this in the past, and so, you
know, what are advances that are being, are happening in the field to
somehow make this device resistant to getting those bacteria seeding on it?
Yeah, I think that's definitely the future.
We're seeing some of it already with leadless pacemakers.
I think that's, that's really the, the future for this.
I mean, it's, we're putting leadless pacemakers in patients, uh, you
know, over the last several years.
Uh, the issue is you can't do a leadless in everybody based on, you
know, does it need atrial sensing?
And certain people rely on on that.
It gets beyond, uh, the, the infectious disease doc in me.
It goes more towards the electrophysiologist to comment on
that, but I know they're working on developing those leadless pacemakers to,
to kind of be the go-to for patients.
Uh, it's very easy to take out as compared to a device that has
been in the chest pocket for 10 years, so there's benefits there.
The material itself is different compared to the current, uh,
uh, CIEDs, like pacemaker ICDs.
So the, these organisms, like the staphylococci, like that,
what they have on their surface and what they like to stick to.
It's less likely to be sticky to the leadless pacemakers.
So it doesn't mean leadless pacemakers don't get infected.
They do, um, just much less likely plus the size and surface area.
So if you have like a big bulky CRT with three leads, compare that to something
that's maybe the size of a little bigger than a reasonable size pill of Augmentin.
You know, there's only so much surface area for that organism
to attach compared to multiple leads and a big pocket generator.
And you think of your patients, a lot of these patients are
gonna be elderly, frail.
There's only so much skin soft tissue to, uh, that pocket.
This is endovascular.
Uh, so, so I think that's, that is definitely the future is going leadless.
There's also subcutaneous where you can go outside of the bloodstream, and go subq
and tunnel these leads, and have external leads, rather than be in the bloodstream.
And I think that's a big factor here.
So I know Hussam you mentioned about, uh, deep brain stimulators,
you know, and again, that, and their management is a little bit different
than complete device extraction.
Sometimes it's just taking out the generator and the lead leads
in, or, there's a lot of ways to go about it, but it's different.
And sometimes suppression works really well.
It's, it's these devices that are intravascular, they're in the bloodstream.
Those are tough to suppress compared to say a prosthetic joint, deep
brain stimulator where its not endovascular, in that bloodstream.
So I'm excited for the future in that regard.
And then probably PET imaging, but rather than using FDG, looking at more
like organism specific to where, Hey, I know there's staph aureus in the blood.
Let's do a staph aureus specific biomarker tracer, uh, that
we can, we can search for.
Maybe that'll give us better uptake than just FDG avidity because
those device leads are, are only gonna have so much surface area.
They're only so much uptake and as you get further away from pocket,
that sensitivity of PET goes down.
So I think that's my big thing, our available tools to make the
diagnosis of device infections.
Echo and, and PET scan are not great.
So I said a lot there.
But I'm excited for the future and I think leadless is the way to go.
For this paper, we collaborated with multiple subspecialties, cardiology,
electrophysiology, nuclear medicine expert, and also CV surgery.
So, the co-author who wrote the paper also reflects like the real life that when we
manage a CIED infection, as Dan mentioned earlier, we need the whole village.
We need to talk to patient, we need to talk to family, and we need to talk
to multiple, multiple people in order to make a decision for one patient.
Thank you so much, Hussam Mac and Dan for joining Febrile today.
You can find their article, State of the Art Review, complexities in
Cardiac Implantable Electronic Device Infections, A Contemporary Practical
Approach in Clinical Infectious Diseases.
This is linked on the webpage as well as in the episode information.
You can check out their prior StAR episode on vascular graft
infections, episode number 110.
If you're looking to hear another episode related to cardiac device infection,
diagnosis, and management, you can check out episode number 78 featuring some of
our both ID and cardiology colleagues.
Don't forget to check out the website, Febrile podcast.com to find the consult
notes, which are written supplements to the episodes with links to references,
our library of ID infographics, and a link to our merch store.
Febrile is produced with support from the Infectious Diseases Society of America.
IDSA.
Please reach out if you have any suggestions for future shows or
wanna be more involved with Febrile.
Thanks for listening.
Stay safe and I'll see you next time.